Organic electroluminescent element, organic EL display device, organic EL lighting device, and method for manufacturing organic electroluminescent element

Abstract

The present invention addresses the problem of providing an organic electroluminescent element having a low driving voltage, high luminous efficiency, and a long driving life. The present invention relates to an organic electroluminescent element having a positive electrode, a negative electrode, a light-emitting layer, and a hole injection layer, the light-emitting layer being provided between the positive electrode and the negative electrode, the hole injection layer being provided between the positive electrode and the light-emitting layer, the light-emitting layer containing a specific polycyclic heterocyclic compound and a specific organometallic compound, the polycyclic heterocyclic compound and the organometallic compound satisfy the following relational expression (E-1), and the hole injection layer contains tetraarylborate ions. T1A > = T1B formula (E-1) (In formula (E-1), T1A is the triplet level (eV) of the organometallic compound and T1B is the triplet level (eV) of the polycyclic heterocyclic compound).

Description

Technical Field

[0001] The invention relates to an organic electroluminescent element. Background Art

[0002] In recent years, as a thin-film type electroluminescent element, an organic electroluminescent element using an organic thin film is being developed to replace the electroluminescent element using an inorganic material. An organic electroluminescent element (OLED) generally has a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, etc. between the anode and the cathode, and materials suitable for each layer are being developed continuously. Regarding the luminescent color, red, green, and blue are also being developed separately.

[0003] In addition, as a method for forming an organic layer of an organic electroluminescent element, a vacuum evaporation method and a wet film-forming method (coating method) can be cited. Since the vacuum evaporation method is easy to stack, it has the following advantages: it is easy to improve the charge injection from the anode and / or cathode, and it is easy to seal the exciton in the light-emitting layer. On the other hand, the wet film-forming method has the following advantages: it does not require a vacuum process, it is easy to large-area, and by using a coating liquid mixed with a variety of materials having various functions, it is easy to form a layer containing a variety of materials having various functions. Therefore, in recent years, research and development of organic electroluminescent elements based on film formation using a coating method is being actively carried out.

[0004] For example, Patent Documents 1 to 3 describe an organic electroluminescent device having a hole injection layer containing polystyrene sulfonic acid and a light-emitting layer containing a light-emitting material having a polycyclic heterocyclic compound skeleton containing boron and nitrogen. In addition, research and development are being conducted to utilize the triplet excited state that accounts for 75% of the excitons generated in the organic electroluminescent element. For example, in Non-Patent Document 1, as a method for improving the luminous efficiency of the organic electroluminescent element, it is reported that in the luminescent layer formed by vacuum evaporation, in addition to the luminescent material having a polycyclic heterocyclic compound skeleton, an organic metal compound having iridium as the central metal as a phosphorescent material is contained as a material for auxiliary luminescence. Prior art literature Patent Literature

[0005] Patent Document 1: International Publication No. 2016 / 152418 Patent Document 2: International Publication No. 2019 / 198699 Patent Document 3: International Publication No. 2019 / 235452 Non-patent literature

[0006] Non-patent literature 1: Angewandte Chemie International Edition, 2022, Vol. 61, No. 14, p. e202117181 Summary of the invention Problems to be solved by the invention

[0007] In general, boron-containing polycyclic heterocyclic compounds have empty p orbitals on boron and are easily reacted with various reactive groups. Therefore, in the technologies disclosed in patent documents 1 to 3, the reduction in the driving voltage of the organic electroluminescent element is insufficient, and the driving life cannot be improved. In the technologies disclosed in patent documents 1 to 3, it is believed that the reason is that due to the use of a hole injection layer containing strongly acidic polystyrene sulfonic acid, the moisture and sulfonic acid groups taken in when the hole injection layer is formed react with the boron-containing polycyclic heterocyclic compound during element driving. In addition, in the technology disclosed in non-patent document 1, when a host material is included, it is necessary to keep the evaporation rate ratio of more than three materials constant, and it is difficult to obtain stable performance.

[0008] The present invention is made in view of the above-mentioned existing actual situation, and the problem to be solved is to provide an organic electroluminescent element with low driving voltage, high luminous efficiency and long driving life. Technical solutions to the problem

[0009] The present inventors have conducted intensive research and found that the above-mentioned problems can be solved by using a hole injection layer containing stable tetraarylborate ions that satisfy the octet rule and have no empty p orbitals on boron, and a light-emitting layer containing a boron-containing polycyclic heterocyclic compound and an organic metal compound with iridium as the central metal, and the triplet energy levels of the organic metal compound and the polycyclic heterocyclic compound satisfy a specific relationship, thereby completing the present invention.

[0010] That is, the gist of the present invention is as follows. [1] An organic electroluminescent element comprising an anode, a cathode, a light-emitting layer and a hole injection layer, The light emitting layer is disposed between the anode and the cathode, The hole injection layer is disposed between the anode and the light-emitting layer. The light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1) and an organic metal compound represented by the following formula (201), The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1), T1A≥T1B formula (E-1) (In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) The hole injection layer contains tetraarylborate ions.

[0011] [Chemistry 1]

[0012] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure of formula (1) containing B and Y. At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0013] [Chemistry 2]

[0014] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.] [2] The organic electroluminescent element according to [1], wherein the hole injection layer contains the tetraarylborate ion having a crosslinking group and / or a crosslinked product of the tetraarylborate ion having a crosslinking group. [3] The organic electroluminescent device according to [1], wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the following formula (21).

[0015] [Chemistry 3]

[0016] (In formula (21), Ring a, ring b and ring c are the same as defined in the above formula (1). Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring f and ring g are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, wherein the adjacent carbon atoms are not carbon atoms constituting ring d and ring e containing B and N, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (21) may be substituted by a halogen atom or deuterium. [4] The organic electroluminescent device according to [1], wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the following formula (22).

[0017] [Chemistry 4]

[0018] (In formula (22), Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring a, ring b, ring c, ring f and ring g may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) may be substituted by a halogen atom or deuterium. [5] The organic electroluminescent device according to [1], wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the following formula (71).

[0019] [Chemistry 5]

[0020] (In formula (71), A1 to A7 are each independently a hydrogen atom; a fluorine atom; an alkyl group which may be substituted; an electron accepting heteroaryl group; a nitro group; a cyano group; or an aromatic hydrocarbon group or an aromatic heterocyclic group which has an electron accepting heteroaryl group, a nitro group or a cyano group as a substituent, R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may be substituted, an aromatic hydrocarbon group which may be substituted, an aromatic heterocyclic group which may be substituted, an electron donor substituent, or a combination thereof, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (71) may be substituted by a halogen atom or deuterium, and the dotted line represents a single bond or no bond. [6] According to the organic electroluminescent element described in [5], A1 to A7 of the formula (71) are electron accepting substituents, and each is independently a group represented by the following formula (71-5), a group represented by the following formula (71-6), a group represented by the following formula (71-7) or a group represented by the following formula (71-8).

[0021] [Chemistry 6]

[0022] (In formulas (71-5) to (71-8), R 732 ~R 745 Each is independently a hydrogen atom, an alkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.) [7] The organic electroluminescent device according to [5], wherein R 71 ~R 78 are electron donating substituents and are each independently a group represented by the following formula (71-2), a group represented by the following formula (71-3), or a group represented by the following formula (71-4).

[0023] [Chemistry 7]

[0024] (In formulas (71-2) to (71-4), R 709 ~R 724 , R 727~R 731 Each independently represents an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a hydrogen atom.) [8] The organic electroluminescent device according to [1], wherein the light-emitting layer further contains a host material. [9] The organic electroluminescent device according to [1], wherein the tetraarylborate ion is represented by the following formula (2).

[0025] [Chemistry 8]

[0026] (In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent.

[10] The organic electroluminescent device according to [9], wherein Ar in the formula (2) 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by the following formula (3).

[0027] [Chemistry 9]

[0028] (In formula (3), R 1 Each is independently selected from an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, and an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, a monovalent group formed by connecting multiple structures, an alkyl group substituted with fluorine, a substituent or a crosslinking group, F4 represents the substitution of 4 fluorine atoms, F (5-m) Each independently represents substitution of 5-m fluorine atoms, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0-5. *Indicates bonding position. )

[11] The organic electroluminescent device according to [2], wherein the crosslinking group is represented by any one of the following formulae (X1) to (X18).

[0029] [Chemistry 10]

[0030] In formulae (X1) to (X4), the benzene ring and the naphthalene ring may or may not have a substituent. Furthermore, the substituents may be bonded to each other to form a ring. R in formula (X4), formula (X5), formula (X6) and formula (X10) 110 Each independently represents an alkyl group which may have a substituent. In formulas (X1) to (X18), * represents a bonding position. )

[12] The organic electroluminescent device according to

[11] , wherein the crosslinking group is represented by any one of the formulae (X1) to (X4).

[13] An organic EL display device or organic EL lighting, comprising the organic electroluminescent element according to any one of [1] to

[12] .

[14] A method for manufacturing an organic electroluminescent element, which is a method for manufacturing an organic electroluminescent element having an anode, a hole injection layer, a light-emitting layer and a cathode in this order on a substrate, The method for manufacturing an organic electroluminescent element comprises the steps of: forming the hole injection layer by a wet film-forming method using a composition for forming a hole injection layer, and a step of forming the light-emitting layer by a wet film-forming method using a light-emitting layer-forming composition, The hole injection layer-forming composition contains tetraarylborate ions and an organic solvent. The composition for forming a light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1), an organic metal compound represented by the following formula (201), and an organic solvent. The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1), T1A≥T1B formula (E-1) (In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV).

[0031] [Chemistry 11]

[0032] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure of formula (1) containing B and Y. At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0033] [Chemistry 12]

[0034] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.]

[15] The method for producing an organic electroluminescent device according to

[14] , wherein the tetraarylborate ion has a cross-linking group.

[16] The method for producing an organic electroluminescent device according to

[14] , wherein the tetraarylborate ion is represented by the following formula (2).

[0035] [Chemistry 13]

[0036] (In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent.

[17] The method for producing an organic electroluminescent element according to

[15] , wherein in the step of forming the hole injection layer, the hole injection layer-forming composition is applied and dried and then heated to form a crosslinked product of the tetraarylborate ions. Effects of the Invention

[0037] The organic electroluminescent element of the present invention exhibits excellent element characteristics, particularly low driving voltage, high luminous efficiency and long driving life. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic cross-sectional view showing a structural example of the organic electroluminescent element of the present invention. Description of Reference Numerals 1 substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5. Luminous layer 6 Electron Transport Layer 7 Cathode 8 Organic electroluminescent elements DETAILED DESCRIPTION

[0039] Hereinafter, an organic electroluminescent element as an embodiment of the present invention, an organic EL display device having the organic electroluminescent element, and an organic EL lighting having the organic electroluminescent element are described in detail. The following description is an example (representative example) of an embodiment of the present invention, but the present invention is not limited to these contents as long as it does not exceed the gist of the present invention.

[0040] The organic electroluminescent element of the present invention comprises an anode, a cathode, a light-emitting layer and a hole injection layer, wherein the light-emitting layer is provided between the anode and the cathode. The hole injection layer is disposed between the anode and the light-emitting layer. The light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1) and an organic metal compound represented by the following formula (201), The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1). T1A≥T1B formula (E-1) (In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) The hole injection layer contains tetraarylborate ions.

[0041] [Chemistry 14]

[0042] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, The R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure containing B and Y of formula (1). At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0043] [Chemistry 15]

[0044] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.

[0045] Ring A202 represents an aromatic heterocyclic structure which may have a substituent.

[0046] R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different.

[0047] Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent.

[0048] Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. "*" indicates bonding to Ring A201 or Ring A202.

[0049] B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different.

[0050] i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.]

[0051] The reason why the organic electroluminescent element of the present invention has a low driving voltage and a long driving life is presumably as follows.

[0052] Boron-containing polycyclic heterocyclic compounds have empty p orbitals on boron, and are particularly susceptible to reaction with electron-donating substances. The result of the reaction is the generation of oxides of electron-donating substances, which may further cause degradation reactions during driving. On the other hand, tetraaryl borate ions, which are stable structures that satisfy the octet rule and do not have empty p orbitals on boron, have the effect of stabilizing cations of oxidized electron-donating substances. Therefore, it is speculated that by using tetraaryl borate ions, degradation reactions during driving can be suppressed, durability can be improved, and the driving life of the element can be prolonged. In addition, when the organometallic compound contains heavy atoms such as iridium, the intersystem crossing between the excited triplet state and the excited singlet state is promoted by the heavy atom effect. Since the intersystem crossing is promoted, it is estimated that the energy of the excited triplet state, which accounts for 75% of the excitons generated when a voltage is applied to the organic electroluminescent element, can be effectively used for the emission of the boron-containing polycyclic heterocyclic compound as a fluorescent light-emitting material.

[0053] As described above, it was found that the above-mentioned problems can be solved by using a boron-containing polycyclic heterocyclic compound represented by formula (1) and an organic metal compound represented by formula (201) in a light-emitting layer, and using a hole injection layer containing stable tetraarylborate ions that satisfy the octet rule and have no empty p orbitals on boron, and the triplet energy levels of the organic metal compound and the polycyclic heterocyclic compound satisfy a specific relationship, thereby completing the present invention.

[0054] <Luminous Layer> The light-emitting layer of the present invention contains a polycyclic heterocyclic compound represented by formula (1) and an organic metal compound represented by formula (201), and satisfies the following relational formula (E-1). T1A≥T1B formula (E-1) (T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) By satisfying the above formula (E-1), the organometallic compound efficiently transfers the energy of the excited triplet state generated in the light-emitting layer to the polycyclic heterocyclic compound, so that the polycyclic heterocyclic compound emits light with high efficiency. That is, in the present invention, the polycyclic heterocyclic compound is a light-emitting material.

[0055] In addition, the polycyclic heterocyclic compound in the present invention preferably satisfies the following relational formula (E-2). ΔEST=S1B-T1B≤0.30eVFormula (E-2) (S1B: Singlet energy level of the polycyclic heterocyclic compound (eV)) By satisfying the above formula (E-2), the excited triplet energy of the polycyclic heterocyclic compound is efficiently converted internally to an excited singlet state, so that the polycyclic heterocyclic compound emits light with high efficiency. ΔEST in formula (E-2) is 0.30 eV or less, preferably 0.25 eV or less, and more preferably 0.20 eV or less. The lower limit of ΔEST is not particularly limited, but is usually 0.01 eV or more, and preferably 0.02 eV or more.

[0056] T1A is preferably 1.90 eV or more, more preferably 2.00 eV or more, further preferably 2.10 eV or more, preferably 3.00 eV or less, more preferably 2.80 eV or less, and further preferably 2.70 eV or less. It is believed that by making T1A within this range, since the excited state of the organometallic compound is not too high in energy, the decomposition of the organometallic compound can be suppressed, and the excited state of the organometallic compound is not too low in energy, so that the excited state of the organometallic compound is quickly transferred to the polycyclic heterocyclic compound, so a higher performance element is obtained. For example, as a preferred embodiment, T1A can be 2.10 eV or more and 2.80 eV or less.

[0057] It should be noted that the above-mentioned T1A, T1B and S1B can be obtained by the following method. S1B and T1A and T1B can be obtained from the peak wavelengths of the fluorescence spectrum and phosphorescence spectrum, respectively. The fluorescence spectrum and phosphorescence spectrum can be measured using a spectrophotometer, for example, a spectrofluorophotometer F-7000 manufactured by Hitachi High-Technologies Corporation. During the measurement, the following solution is used as a sample, wherein the compound is diluted to 10 -6 ~10 -5 It is dissolved in an appropriate organic solvent at a concentration of about M. The fluorescence spectrum is measured at room temperature. The phosphorescence is measured by cooling to 77K with liquid nitrogen.

[0058] [Polycyclic heterocyclic compounds] The light-emitting layer contains a polycyclic heterocyclic compound represented by formula (1). The light-emitting layer contains a polycyclic heterocyclic compound represented by formula (1) as a light-emitting material.

[0059] [Chemistry 16]

[0060] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, The R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure of formula (1) containing B and Y. At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0061] (Ring a, Ring b, Ring c, Ring d and Ring e) Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic hetero ring which may have a substituent. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.

[0062] The substituent that the aromatic hydrocarbon ring or aromatic heterocyclic ring of ring a, ring b and ring c may have is preferably a group selected from the following substituent group α.

[0063] (Central fused two-ring structure) In the present invention, for convenience, the condensed bicyclic structure composed of ring d and ring e may be referred to as a "central condensed bicyclic structure". The aromatic hydrocarbon ring or aromatic heterocyclic ring in the ring a, ring b and ring c preferably has a five-membered ring or a six-membered ring covalently bonded to the central fused bicyclic structure of formula (1) composed of B and Y, and more preferably has a six-membered ring covalently bonded to the central fused bicyclic structure of formula (1) composed of B and Y. As the central fused bicyclic structure, a fused bicyclic structure in which ring d is a six-membered ring composed of B, Y, two atoms constituting ring a and two atoms constituting ring b, and ring e is a six-membered ring composed of B, Y, two atoms constituting ring a and two atoms constituting ring c is further preferred.

[0064] In addition, the presence of "a six-membered ring covalently bonded to the central fused bicyclic structure" means, for example, the case where ring a is a benzene ring (six-membered ring). "The aromatic hydrocarbon ring or aromatic heterocyclic ring (as ring a) has a six-membered ring" means that ring a is formed only by the six-membered ring, or that other rings are further fused to the six-membered ring so as to include the six-membered ring to form ring a. The same explanation applies to "ring b", "ring c" and "five-membered ring".

[0065] Examples of the aromatic hydrocarbon ring in ring a, ring b and ring c of formula (1) include aromatic hydrocarbon rings having 6 to 30 carbon atoms, preferably aromatic hydrocarbon rings having 6 to 16 carbon atoms, more preferably aromatic hydrocarbon rings having 6 to 12 carbon atoms, and particularly preferably aromatic hydrocarbon rings having 6 to 10 carbon atoms.

[0066] As specific aromatic hydrocarbon rings, preferred are monocyclic benzene rings; biphenyl rings of bicyclic systems; naphthalene rings of fused bicyclic systems; terphenyl rings (meta-terphenyl, o-terphenyl, p-terphenyl) of tricyclic systems; acenaphthylene rings, fluorene rings, phenalene rings, and phenanthrene rings of fused tricyclic systems; triphenylene rings, pyrene rings, and tetracene rings of fused tetracyclic systems; perylene rings and pentacene rings of fused pentacyclic systems; further preferred are benzene rings, biphenyl rings, naphthalene rings, terphenyl rings, and fluorene rings, and the most preferred is a benzene ring.

[0067] Examples of the aromatic heterocycle in ring a, ring b and ring c of formula (1) include aromatic heterocycles having 2 to 30 carbon atoms, preferably aromatic heterocycles having 2 to 25 carbon atoms, more preferably aromatic heterocycles having 2 to 20 carbon atoms, further preferably aromatic heterocycles having 2 to 15 carbon atoms, and particularly preferably aromatic heterocycles having 2 to 10 carbon atoms. In addition, the "aromatic heterocycle" is preferably a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms.

[0068] Specific aromatic heterocyclic rings are preferably pyrrole ring, oxazole ring, thiazole ring, isothiazole ring, imidazole ring, thiadiazole ring, triazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinazoline ring, quinoxaline ring, naphthyridine ring, carbazole ring, acridine ring, phenoxazine ring, phenothiazine ring, furan ring, benzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, and dibenzothiophene ring.

[0069] (Substituent Group α) Substituent Group α is a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted diheteroarylamino group, a substituted or unsubstituted arylheteroarylamino group (an amino group having an aromatic hydrocarbon group and an aromatic heterocyclic group), a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group or a halogen atom.

[0070] The substituent that the group selected from the substituent group α other than the halogen atom may have is selected from the substituent group β described below.

[0071] As the aromatic hydrocarbon group or aryl structure in the substituent group α, for example, there can be mentioned groups of aromatic hydrocarbon rings in ring a, ring b and ring c. The specific structure and preferred structure of the aromatic hydrocarbon ring are the same as those of the aromatic hydrocarbon rings in ring a, ring b and ring c in formula (1). As the aromatic hydrocarbon group in the substituent group α, a benzene ring is preferred.

[0072] As the aromatic heterocyclic group or heteroaryl structure in the substituent group α, for example, there can be mentioned groups of aromatic heterocyclic rings in ring a, ring b and ring c. The specific structure of the aromatic heterocyclic ring is the same as the aromatic heterocyclic rings in ring a, ring b and ring c of formula (1). As the aromatic heterocyclic group in the substituent group α, a triazine ring, a benzimidazole ring, a benzothiazole ring, a pyrimido[5,4-d]pyrimidine ring or a benzo[1,2-d:4,5-d]biimidazole ring is preferred.

[0073] The alkyl group in the substituent group α may be any of a linear chain and a branched chain, and examples thereof include a linear chain alkyl group having 1 to 24 carbon atoms and a branched chain alkyl group having 3 to 24 carbon atoms. An alkyl group having 1 to 18 carbon atoms (a branched chain alkyl group having 3 to 18 carbon atoms) is preferred, an alkyl group having 1 to 12 carbon atoms (a branched chain alkyl group having 3 to 12 carbon atoms) is more preferred, an alkyl group having 1 to 6 carbon atoms (a branched chain alkyl group having 3 to 6 carbon atoms) is further preferred, and an alkyl group having 1 to 4 carbon atoms (a branched chain alkyl group having 3 to 4 carbon atoms) is particularly preferred.

[0074] Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, and tert-octyl. A part of the hydrogen atoms of the alkyl group in the substituent group α may be substituted with fluorine atoms.

[0075] Examples of the alkoxy group in the substituent group α include a linear alkoxy group having 1 to 24 carbon atoms or a branched alkoxy group having 3 to 24 carbon atoms. An alkoxy group having 1 to 18 carbon atoms (branched alkoxy group having 3 to 18 carbon atoms) is preferred, an alkoxy group having 1 to 12 carbon atoms (branched alkoxy group having 3 to 12 carbon atoms) is more preferred, an alkoxy group having 1 to 6 carbon atoms (branched alkoxy group having 3 to 6 carbon atoms) is further preferred, and an alkoxy group having 1 to 4 carbon atoms (branched alkoxy group having 3 to 4 carbon atoms) is particularly preferred.

[0076] Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group.

[0077] Examples of the halogen atom in the substituent group α include a fluorine atom, a chlorine atom, and a bromine atom, preferably a fluorine atom and a chlorine atom, and more preferably a fluorine atom.

[0078] (Substituent Group β) Substituent group β is an aromatic hydrocarbon group which may be substituted with an aralkyl group, an aromatic heterocyclic group which may be substituted with an aralkyl group, an alkyl group or a halogen atom. As the aromatic hydrocarbon group, aromatic heterocyclic group, alkyl group, aralkyl group and halogen atom in substituent group β, for example, the same substituents as those in substituent group α can be mentioned, and the preferred structure is also the same as that in substituent group α.

[0079] From the viewpoint of improving stability and solubility, the substituent group β is preferably an aromatic hydrocarbon group which may be substituted with an aralkyl group, an aromatic heterocyclic group which may be substituted with an aralkyl group, an alkyl group or an aralkyl group.

[0080] The aralkyl group, the aralkyl group which may substitute the aromatic hydrocarbon group, and the aralkyl group which may substitute the aromatic heterocyclic group in the substituent group β are preferably aralkyl groups having 7 to 30 carbon atoms, and preferably a structure in which a benzene ring and an alkyl group are bonded.

[0081] In the substituent group β, the halogen atom is preferably a fluorine atom.

[0082] (Y) In formula (1), Y is independently O, NR or S.

[0083] (R) R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group. In addition, the two Ys in formula (1) may be the same or different from each other, but are preferably the same. The two Ys are preferably NR.

[0084] When R in formula (1) is an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent, R is the same group as the aromatic hydrocarbon ring group which may have a substituent or the aromatic heterocyclic group which may have a substituent in ring a, ring b and ring c of formula (1). The specific structure and preferred structure are also the same as the aromatic hydrocarbon ring group which may have a substituent or the aromatic heterocyclic group which may have a substituent in ring a, ring b and ring c of formula (1). When R in formula (1) is an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent, the above formula (1) is represented by the following formula (21). The polycyclic heterocyclic compound represented by the above formula (1) is preferably a structure represented by the following formula (21).

[0085] Examples of the alkyl group in R of formula (1) include the alkyl groups in substituent group α. The alkyl group is particularly preferably an alkyl group having 1 to 4 carbon atoms (eg, methyl group, ethyl group, etc.).

[0086] R can be expressed by -O-, -S-, -C(-R a ) 2- Or it is bonded to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b and the ring c by a single bond.

[0087] R a Each is independently a hydrogen atom or an alkyl group. As R a Examples of the alkyl group in the substituent group α include the alkyl groups in the substituent group α. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group and an ethyl group.

[0088] The adjacent carbon atoms are not carbon atoms constituting the central condensed bicyclic structure containing B and Y in the formula (1). In addition, at least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium.

[0089] (Formula (21))

[0090] [Chemistry 17]

[0091] (In formula (21), Ring a, ring b and ring c are the same as defined in the above formula (1). Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring f and ring g are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, wherein the adjacent carbon atoms are not carbon atoms constituting ring d and ring e containing B and N, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (21) may be substituted by a halogen atom or deuterium.

[0092] The aromatic hydrocarbon ring group and the aromatic heterocyclic group in the ring f and the ring g can be selected from the same range as the aromatic hydrocarbon ring group and the aromatic heterocyclic group in the ring a, the ring b and the ring c. The aromatic hydrocarbon ring group and aromatic heterocyclic group in ring f and ring g are particularly preferably an aromatic hydrocarbon ring group having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.) and an aromatic heterocyclic group having 2 to 15 carbon atoms (e.g., carbazolyl, etc.).

[0093] The substituent that Ring f and Ring g, which are aromatic hydrocarbon rings or aromatic hetero rings, may have is the same as that of Ring a, Ring b and Ring c, and is preferably a group selected from the above-mentioned Substituent Group α.

[0094] (Formula (22)) The above formula (21) is preferably a structure represented by the following formula (22). That is, the polycyclic heterocyclic compound represented by the above formula (1) is preferably represented by the following formula (22).

[0095] [Chemistry 18]

[0096] In formula (22), In the above formula (21), ring a, ring b, ring c, ring f and ring g are all benzene ring structures. Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring a, ring b, ring c, ring f and ring g may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) may be substituted with a halogen atom or deuterium.

[0097] The substituents that ring a, ring b, ring c, ring f and ring g may have are the same as the substituents that ring a, ring b, ring c, ring f and ring g in the above formula (21), and the specific structures and preferred structures are also the same.

[0098] The aromatic compound represented by the above formula (22) is preferably a polycyclic heterocyclic compound represented by the formula (71) described later.

[0099] In addition, the aromatic compound represented by the above formula (1) is preferably a polycyclic heterocyclic compound represented by the formula (71) described later.

[0100] (Specific examples of the polycyclic heterocyclic compound represented by formula (1)) The structure of the polycyclic heterocyclic compound represented by formula (1) is not particularly limited, and examples thereof include the following structures.

[0101] [Chemistry 19]

[0102] [Chemistry 20]

[0103] [Chemistry 21]

[0104] [Chemistry 22]

[0105] <Polycyclic heterocyclic compound TD1> The polycyclic heterocyclic compound represented by formula (1) is preferably a polycyclic heterocyclic compound represented by the following formula (71). In the present invention, the polycyclic heterocyclic compound represented by the following formula (71) may be referred to as a polycyclic heterocyclic compound TD1.

[0106] [Chemistry 23]

[0107] (In formula (71), A1 to A7 are each independently a hydrogen atom; a fluorine atom; an alkyl group which may have a substituent; an electron accepting heteroaryl group; a nitro group; a cyano group; or an aromatic hydrocarbon group or an aromatic heterocyclic group which has an electron accepting heteroaryl group, a nitro group or a cyano group as a substituent, R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, an electron donor substituent, or a combination thereof, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (71) may be substituted by a halogen atom or deuterium, and the dotted line represents a single bond or no bond.

[0108] In the polycyclic heterocyclic compound represented by formula (71), the electron cloud of LUMO is localized and concentrated at the position where A1 to A7 are bonded to the phenyl group. Therefore, by making at least one selected from A1 to A7 as an electron acceptor substituent described later, the electron cloud is diffused, the LUMO energy level is stabilized, and the energy difference between HOMO and LUMO is reduced. As a result, by using the polycyclic heterocyclic compound represented by formula (71), a long-wavelength emission spectrum can be obtained.

[0109] In the polycyclic heterocyclic compound represented by formula (71), the electron cloud of HOMO is localized and concentrated on R 71 ~R 78 Therefore, by making the selected 71 ~R 78 At least one of them is an electron donor substituent described later, so that the electron cloud of HOMO is easily diffused outward, the HOMO energy level is unstable, and the energy difference between HOMO and LUMO is reduced. As a result, the polycyclic heterocyclic compound represented by formula (71) can obtain a long-wavelength emission spectrum.

[0110] In the present invention, in order to satisfy the above formula (E-1), it is preferred that the emission wavelength of the polycyclic heterocyclic compound is a long wavelength. Therefore, in the polycyclic heterocyclic compound represented by formula (71), at least one selected from A1 to A7 is an electron acceptor substituent, and R 71 ~R 78 At least one of A1 to A7 is an electron accepting substituent and is selected from R 71 ~R 78 It is preferred that at least one of A1 to A7 is an electron donor substituent because a longer wavelength emission spectrum can be obtained. It is more preferred that at least one of A1 to A7 is an electron acceptor substituent.

[0111] (Substituent) The polycyclic heterocyclic compound of the above formula (71) is described in detail below. In the following description, when the substituent is selected from the substituent group Z, any substituent included in the substituent group Z can be used as the substituent. Among the substituent group Z, an alkyl group, an alkoxy group, an aryloxy group, an aromatic hydrocarbon group or an aralkyl group is preferred.

[0112] (A1~A7) A1 to A7 are each independently a hydrogen atom; a fluorine atom; an alkyl group which may have a substituent; an electron accepting heteroaryl group; a nitro group; a cyano group; or an aromatic hydrocarbon group or an aromatic heterocyclic group which has an electron accepting heteroaryl group, a nitro group or a cyano group as a substituent.

[0113] It is preferred that at least one selected from A1 to A7 is an electron accepting substituent, and A1 to A7 other than the electron accepting substituent are each independently a hydrogen atom, a fluorine atom or an alkyl group which may have a substituent.

[0114] When at least one selected from A1 to A7 is an electron accepting substituent, the emission wavelength can be adjusted by the number and type of A1 to A7, which is preferred.

[0115] (Electron acceptor substituent) In the present invention, the electron accepting substituent refers to a substituent that attracts electrons from an adjacent chemical structure when chemically bonding occurs and is likely to form a chemical structure with excess electrons.

[0116] Examples of the electron accepting substituent include electron accepting heteroaryl groups, nitro groups, cyano groups, and aromatic hydrocarbon groups or aromatic heterocyclic groups having any of these substituents. Among them, electron accepting heteroaryl groups are preferred from the viewpoint of increasing the wavelength.

[0117] The heteroaryl group is an aryl group having at least one atom selected from a nitrogen atom, an oxygen atom and a sulfur atom. Examples of the heteroaryl group include polycyclic aromatic heteroaryl groups having 1 to 4 rings containing carbon atoms, nitrogen atoms, oxygen atoms, sulfur atoms and the like. The electron accepting heteroaryl group refers to a heteroaryl group that easily has too many electrons by attracting electrons from an adjacent chemical structure during chemical bonding, and is preferably a heteroaryl group having an "absolute value α" of 3 eV or more as described below.

[0118] The electron accepting substituent is preferably a group whose absolute value (hereinafter sometimes referred to as "absolute value α") obtained by adding the HOMO level and the LUMO level and dividing by 2 is 3 eV or more. When the absolute value α is 3 eV or more, it is empirically believed that the electron accepting property of the substituent is improved.

[0119] The absolute value α of the electron accepting substituent is preferably 3.1 eV or more, more preferably 3.5 eV or more, and further preferably 4.0 eV or more. The upper limit of the absolute value α of the electron accepting substituent is not particularly set, but is usually 7.0 eV or less.

[0120] The HOMO energy level and LUMO energy level in the electron acceptor substituent are the molecular orbital energy level of HOMO and the molecular orbital energy level of LUMO obtained as follows. That is, the single bond between the electron acceptor substituent and the adjacent phenyl group in formula (1) is cancelled and a hydrogen atom is added. In addition, for the molecular structure of the obtained electron acceptor substituent, a density functional-based structure optimization calculation is performed using molecular orbital calculation software Gaussian16 and using functional: B3LYP and basis function: 6-31G(d).

[0121] In addition, the electron accepting substituents are each independently preferably a group represented by the following formula (71-5), a group represented by the following formula (71-6), a group represented by the following formula (71-7), or a group represented by the following formula (71-8).

[0122] [Chemistry 24]

[0123] In formulas (71-5) to (71-8), R 732 ~R 745 Each is independently a hydrogen atom, an alkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0124] Examples of the alkyl group include linear, branched or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl and dodecyl groups.

[0125] Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having 6 to 60 carbon atoms, and specifically include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monovalent group of a six-membered ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a two- to five-membered condensed ring.

[0126] R 732 ~R 745 The substituent that may be possessed can be selected from the substituent group Z described later.

[0127] Specific examples of the above formulas (71-5) to (71-8) include the following formulas (71-2-1) to (71-2-7).

[0128] [Chemistry 25]

[0129] In the above formulas (71-2-1) to (71-2-7), the absolute value α obtained by calculation is as follows.

[0130] Group represented by formula (71-2-4): 4.35 eV Group represented by formula (71-2-6): 4.18 eV Group represented by formula (71-2-3): 4.17 eV Group represented by formula (71-2-7): 4.12 eV Group represented by formula (71-2-5): 4.10 eV Group represented by formula (71-2-2): 3.73 eV Group represented by formula (71-2-1): 3.13 eV

[0131] That is, when only the same number of groups represented by the above formula (71-2-4), the above formula (71-2-6), the above formula (71-2-3), the above formula (71-2-7), the above formula (71-2-5), the above formula (71-2-2) or the above formula (71-2-1) are introduced at the same position among A1 to A7 in the above formula (1), the effect of lengthening the wavelength of light emission can be obtained in the order of the above formula (71-2-4) > the above formula (71-2-6) > the above formula (71-2-3) > the above formula (71-2-7) > the above formula (71-2-5) > the above formula (71-2-2) > the above formula (71-2-1).

[0132] Among these, the electron accepting substituent is preferably a group represented by the above formula (71-5) from the viewpoint of longer wavelength and ease of production by organic synthesis.

[0133] Since the absolute value α of the group represented by the above formula (71-5) is large and the steric hindrance with the adjacent phenyl group in the above formula (71) is small, the adjacent phenyl group and the π plane of the group represented by the above formula (71-5) are less twisted, and the effect of long wavelength of large emission wavelength can be obtained. In addition, the group represented by the above formula (71-5) can be manufactured relatively easily in organic synthesis, and even when it is desired to improve the solubility in the solvent, it can be relatively easily added to R. 732 , R 733 A long chain (eg, carbon number 4 or more) alkyl group is introduced.

[0134] From the perspective of increasing the absolute value α to easily obtain a longer wavelength of emission, or from the perspective of solubility in a solvent, R 732 , R 733 Preferably, they are alkyl groups which may have a substituent. 732 and R 733 At least one of the groups is a phenyl group having a tert-butyl group.

[0135] In addition, from the viewpoint of solubility in a solvent and narrowing the half-value width of the emission wavelength, R 732 and R 733 One of them is an alkyl group which may have a substituent, and the other is an aromatic hydrocarbon group which may have a substituent. The substituent which the aromatic hydrocarbon group may have may be selected from the substituent group Z.

[0136] Furthermore, A1 to A7 other than the electron accepting substituent are each independently a hydrogen atom, a fluorine atom or an alkyl group which may have a substituent.

[0137] Examples of the alkyl group include linear, branched or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl and dodecyl groups.

[0138] The substituent that A1 to A7 may have can be selected from the substituent group Z described below.

[0139] It should be noted that when A1 to A7 are each independently a fluorine atom or an alkyl group which may have a substituent, based on their electron donating and accepting properties, the emission wavelength will be slightly shorter or longer than when A1 to A7 are hydrogen atoms, so it is preferred to select the substituent according to the target wavelength.

[0140] Furthermore, when a wet film-forming method is used, A1 to A7 are each independently preferably a long-chain alkyl group for the purpose of improving solubility in a solvent.

[0141] The degree of localization of the electron cloud of LUMO varies among A1 to A7, and varies depending on the position. Therefore, among A1 to A7, the positions where the effect of long wavelength is stronger due to the electron accepting substituent are in the order of A4>A1=A7>A3=A5>A2=A6. That is, in A4, the effect of lengthening the wavelength due to the electron accepting substituent is most strongly exhibited.

[0142] Therefore, at least one of A1, A4 and A7 is preferably an electron accepting substituent, and more preferably a group represented by formula (71-5).

[0143] When both A1 and A7 are electron accepting substituents, the effect of lengthening the wavelength can be obtained to a substantially similar degree as when only A4 is the same electron accepting substituent. It is preferred that two or more of A1 to A7 are electron accepting substituents because the wavelength is further increased. It is preferred that two or more of A1 to A7 are electron accepting substituents and at least one of them is A4 because the wavelength is further increased.

[0144] It should be noted that in formula (71), it is preferred that the single bonds connecting A1 to A7 and the adjacent phenyl groups are twisted, and the π plane of the main aromatic hydrocarbon group of the adjacent phenyl groups and the electron acceptor substituent is not twisted. The reason is that this twist makes it difficult for the adjacent phenyl groups and the electron acceptor substituents to exchange charges smoothly, and it is difficult to increase the wavelength of the luminescence of the above formula (71).

[0145] (R71 ~R 78 ) R 71 ~R 78 Each is independently a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, an electron donor substituent or a combination thereof.

[0146] Examples of the alkyl group include linear, branched or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl and dodecyl groups.

[0147] Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having 6 to 60 carbon atoms, and specifically include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monovalent group of a six-membered ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a two- to five-membered condensed ring.

[0148] The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 to 60 carbon atoms, and specifically includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thiophene ... a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, or a monovalent group of a five-membered or six-membered monocyclic ring or a two- to four-membered condensed ring, such as a pyran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, or an azulene ring.

[0149] R 71 ~R 78 The substituent that may be possessed can be selected from the substituent group Z described later.

[0150] In addition, from the perspective of longer wavelength, R 71 ~R 78 At least one of them is preferably an electron donating substituent. (Electron Donating Substituent)

[0151] In the present invention, the electron-donating substituent refers to a substituent that donates electrons to an adjacent chemical structure when chemically bonding and easily becomes an electron-deficient chemical structure.

[0152] In the polycyclic heterocyclic compound represented by formula (71), the electron cloud of HOMO is localized and concentrated on R71 ~R 78 Therefore, by making R 71 ~R 78 At least one of them is an electron donor substituent, the electron cloud of HOMO is easily diffused outward, the HOMO energy level is unstable, and the energy difference between HOMO and LUMO is reduced. As a result, the polycyclic heterocyclic compound represented by formula (71) can obtain a long-wavelength emission spectrum.

[0153] The electron donor substituent is preferably a group having an absolute value α of less than 3 eV. When the absolute value α is less than 3 eV, it is empirically believed that the electron donor property of the substituent is improved.

[0154] From the viewpoint of increasing the wavelength, the absolute value α of the electron donor substituent is more preferably less than 2.97 eV, further preferably less than 2.8 eV, and particularly preferably less than 2.6 eV. The lower limit of the absolute value α of the electron donor substituent is not particularly set, but is usually 1 eV or more.

[0155] The HOMO energy level and LUMO energy level in the electron donor substituent are the molecular orbital energy level of HOMO and the molecular orbital energy level of LUMO obtained as follows. That is, the single bond between the electron donor substituent and the adjacent phenyl group in formula (1) is cancelled and a hydrogen atom is added. In addition, for the molecular structure of the obtained electron donor substituent, a density functional-based structure optimization calculation is performed using molecular orbital calculation software Gaussian16 and using functional: B3LYP and basis function: 6-31G(d).

[0156] In addition, the electron donor substituents are each independently preferably a group represented by the following formula (71-2), a group represented by the following formula (71-3), or a group represented by the following formula (71-4).

[0157] [Chemistry 26]

[0158] In formulas (71-2) to (71-4), R 709 ~R 724 , R 727 ~R 731 Each independently represents an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a hydrogen atom.

[0159] Examples of the alkyl group include linear, branched or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl and dodecyl groups.

[0160] Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having 6 to 60 carbon atoms, and specifically include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monovalent group of a six-membered ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, or a two- to five-membered condensed ring.

[0161] R 709 ~R 724 , R 727 ~R 731 The substituent that may be possessed can be selected from the substituent group Z described later.

[0162] Specific examples of the above formulas (71-2) to (71-4) include the following formulas (71-4-1) to (71-4-3).

[0163] [Chemistry 27]

[0164] In the above formulas (71-4-1) to (71-4-3), the absolute value α obtained by calculation is as follows.

[0165] Group represented by formula (71-4-3): 2.96 eV Group represented by formula (71-4-2): 2.91 eV Group represented by formula (71-4-1): 2.46 eV

[0166] That is, R in the above formula (71) 71 ~R 78 When only the same number of groups represented by the above formula (71-4-3), the above formula (71-4-2) or the above formula (71-4-1) are introduced at the same position, the effect of lengthening the wavelength of light emission can be obtained in the order of the above formula (71-4-1) > the above formula (71-4-2) > the above formula (71-4-3). In addition, R 71 ~R 78 It is preferred that two or more of the substituents are electron donating substituents because the wavelength is further increased.

[0167] Among these, the electron donor substituent is preferably a group represented by the above formula (71-2) from the viewpoint of balancing the wavelength, the ease of production by organic synthesis, and the structural stability.

[0168] The absolute value α of the group represented by the above formula (71-2) is small, and the effect of lengthening the wavelength of luminescence is obtained. In addition, the group represented by the above formula (71-2) can be manufactured relatively easily in organic synthesis, and even if it is desired to improve the solubility in the solvent, it can be relatively easily added to R. 709 ~R 716 Introducing long chain alkyl groups.

[0169] Based on the solubility in solvents and the ease of synthesis, R 709 ~R 716 At least one of them is preferably tert-butyl.

[0170] It should be noted that R 71 ~R 78 When each is independently an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a combination thereof, based on their electron donating and accepting properties, they are compatible with R 71 ~R 78 Since the emission wavelength is slightly shorter or longer than that of a hydrogen atom, it is preferred to select a substituent according to the target wavelength.

[0171] In addition, when a wet film forming method is used, R 71 ~R 78 Each is independently preferably a long-chain alkyl group.

[0172] R 71 ~R 78 In the HOMO, the degree of localization of the electron cloud varies, and can be strong or weak depending on the position. 71 ~R 78 The position where the effect of the electron donor substituent on the wavelength lengthening can be most strongly obtained is R 74 =R 75 >R 71 =R 78 >R 73 =R 76 >R 72 =R 77 That is, R 74 and R 75 Among them, the effect of lengthening the wavelength due to the electron-donating substituent is most strongly manifested.

[0173] (dotted line) In formula (71), the dotted line can be a single bond or no bond. The dotted line is preferably a single bond. When the dotted line is a single bond, the electron cloud diffuses and the emission wavelength becomes slightly longer. In addition, when the dotted line is a single bond, it is easy to introduce electron acceptor substituents and R in A1 to A7. 71 ~R 78 Electron donating substituents in .

[0174] (Symmetry of Polycyclic Heterocyclic Compounds) The polycyclic heterocyclic compound of the above formula (71) is asymmetric and has the effect of narrowing the half-value width of the emission wavelength and is therefore preferred. It is believed that since the asymmetric type reduces the symmetry, the polycyclic heterocyclic compounds are less likely to associate with each other, and the interaction between the polycyclic heterocyclic compounds is reduced, thus narrowing the half-value width of the emission spectrum.

[0175] The polycyclic heterocyclic compound is asymmetric when the line of the bond axis connecting B and A4 in the above formula (71) is used as the rotation axis, and the structure is not the same when rotated 180° relative to the rotation axis, or it is not mirror-symmetric with respect to a plane containing the bond axis and perpendicular to the plane formed by the polycyclic heterocyclic ring of the compound of the above formula (71).

[0176] Specifically, a structure that satisfies at least one of the following (i) or (ii) is preferred. (i) A1 to A7, R 71 ~R 78 This is a structure that does not have the same structure when rotated 180 degrees with respect to its key axis. (ii) A1 is different from A7, A2 is different from A6, A3 is different from A5, R 71 With R 78 Different, R 72 With R 77 Different, R 73 With R 76 Different or R 74 With R 75 Different structures.

[0177] (Specific example of polycyclic heterocyclic compound TD1) The structure of the polycyclic heterocyclic compound TD1 represented by the formula (71) is not particularly limited, and examples thereof include the following structures.

[0178] [Chemistry 28]

[0179] [Chemistry 29]

[0180] [Chemistry 30]

[0181] [Chemistry 31]

[0182] [Chemistry 32]

[0183] [Chemistry 33]

[0184] [Chemistry 34]

[0185] [Chemistry 35]

[0186] [Chemistry 36]

[0187] [Chemistry 37]

[0188] [Chemistry 38]

[0189] <Substituent Group Z> As the substituent group Z, the following structures can be mentioned. The substituent group Z is a group consisting of an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, an aromatic heterocyclic group, an aralkyl group, and a heteroaralkyl group. Preferred structures and specific examples of these substituents are as follows. The alkyl group is a linear, branched or cyclic alkyl group having usually 1 or more, preferably 4 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, dodecyl, cyclohexyl, etc.; The alkenyl group is an alkenyl group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, vinyl group; The alkynyl group is one having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, ethynyl group; The alkoxy group is an alkoxy group having usually 1 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, a methoxy group, an ethoxy group, etc.; The (hetero)aryloxy group is an aryloxy group or a heteroaryloxy group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a phenoxy group, a naphthoxy group, a pyridyloxy group, etc.; The alkoxycarbonyl group is an alkoxycarbonyl group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, methoxycarbonyl, ethoxycarbonyl, etc.; The dialkylamino group is a dialkylamino group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, a dimethylamino group, a diethylamino group, etc.; The diarylamino group is a diarylamino group having usually 10 or more, preferably 12 or more and usually 36 or less, preferably 24 or less carbon atoms; for example, diphenylamino and ditolylamino; The arylalkylamino group is an arylalkylamino group having usually 7 or more and usually 36 or less, preferably 24 or less carbon atoms; for example, phenylmethylamino group; The acyl group is an acyl group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, acetyl, benzoyl, etc.; As the halogen atom, for example, a halogen atom such as a fluorine atom and a chlorine atom; The haloalkyl group is a haloalkyl group having usually 1 or more and usually 12 or less, preferably 6 or less carbon atoms; for example, a trifluoromethyl group; The alkylthio group is an alkylthio group having usually 1 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, methylthio, ethylthio, etc.; The arylthio group is an arylthio group having usually 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less carbon atoms; for example, phenylthio, naphthylthio, pyridylthio, etc.; The silyl group is a silyl group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a trimethylsilyl group, a triphenylsilyl group, etc.; The silyloxy group is a silyloxy group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a trimethylsilyloxy group, a triphenylsilyloxy group, etc.; Cyano; The aromatic hydrocarbon group is an aromatic hydrocarbon group having usually 6 or more and usually 36 or less, preferably 24 or less carbon atoms; for example, phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, triphenylene, naphthylphenyl, etc.; The aromatic heterocyclic group is an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, thienyl, pyridyl, etc.; The aralkyl group includes an aralkyl group having 7 or more, preferably 8 or more and 40 or less, preferably 30 or less, and more preferably 20 or less carbon atoms; for example, 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, 1,1-di(n-hexyl)-1-phenylmethyl, 1,1-di(n-octyl)-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n-hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, 4-phenylcyclohexyl, etc.; The heteroarylalkyl group includes heteroarylalkyl groups having 2 or more, preferably 4 or more and 40 or less, preferably 30 or less, and more preferably 20 or less carbon atoms; 1,1-dimethyl-1-(2-pyridyl)methyl, 1,1-di(n-hexyl)-1-(2-pyridyl)methyl, (2-pyridyl)methyl, (2-pyridyl)ethyl, 3-(2-pyridyl)-1-propyl, 4-(2-pyridyl)-1-n-butyl yl, 1-methyl-1-(2-pyridyl)ethyl, 5-(2-pyridyl)-1-propyl, 6-(2-pyridyl)-1-n-hexyl, 6-(2-pyrimidinyl)-1-n-hexyl, 6-(2,6-diphenyl-1,3,5-triazine-4-yl)-1-n-hexyl, 7-(2-pyridyl)-1-n-heptyl, 8-(2-pyridyl)-1-n-octyl, 4-(2-pyridyl)cyclohexyl, and the like.

[0190] [Organometallic compounds] In the present invention, the organometallic compound contains a metal selected from Groups 7 to 11 of the long-form periodic table (hereinafter, unless otherwise specified, "periodic table" means the long-form periodic table). Preferred metals selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, etc., and iridium or platinum is more preferred. As an organometallic compound, it is preferably a Werner type complex or an organometallic complex. As a ligand of the complex, it is preferably a ligand formed by connecting (hetero)aryl pyridine ligands, (hetero)aryl pyrazole ligands, (hetero)aryl pyridine ligands, (hetero)aryl pyrazole ligands, and pyridine, pyrazole, phenanthroline, etc., and is particularly preferably a phenylpyridine ligand and a phenylpyrazole ligand. Here, (hetero)aryl represents an aryl or a heteroaryl. Through the heavy atom effect of the above-mentioned metal, the organic metal compound containing the above-mentioned metal undergoes intersystem crossing from the excited singlet state to the excited triplet state, and the relaxation time from the excited triplet state to the ground state is shortened to a certain extent. Further, by satisfying the above-mentioned relationship (E-1), it is speculated that the excited state generated by applying a voltage to the organic electroluminescent element can be transferred to the polycyclic heterocyclic compound through electron exchange interaction and dipole-dipole interaction, thereby enabling the polycyclic heterocyclic compound to emit light efficiently. Particularly preferred are organometallic complexes containing iridium. As the organometallic complex containing iridium, a metal compound represented by formula (201) is preferred. The light-emitting layer contains the organic metal compound represented by formula (201).

[0191] [Chemistry 39]

[0192] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.]

[0193] (Ring A201, Ring A202) The aromatic hydrocarbon ring in Ring A201 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, and specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring are preferred.

[0194] The aromatic heterocyclic ring in Ring A201 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any of a nitrogen atom, an oxygen atom or a sulfur atom as a heteroatom, and more preferably a furan ring, a benzofuran ring, a thiophene ring or a benzothiophene ring.

[0195] The ring A201 is more preferably a benzene ring, a naphthalene ring or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, and most preferably a benzene ring.

[0196] The aromatic heterocyclic ring in Ring A202 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms and containing any of a nitrogen atom, an oxygen atom or a sulfur atom as a heteroatom, specifically a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring or a thiazole ring, and most preferably a pyridine ring.

[0197] When m is 2 or 3, the plurality of rings A201 and the plurality of rings A202 may be the same or different.

[0198] The preferred combination of Ring A201 and Ring A202, when expressed as (Ring A201-Ring A202), is (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazole ring), (benzene ring-benzothiazole ring), and the most preferred combination is (benzene ring-pyridine ring).

[0199] The substituent that Ring A201 or Ring A202 may have can be arbitrarily selected, and is preferably one or more substituents selected from the substituent group S described below.

[0200] Substituents bonded to ring A201, substituents bonded to ring A202, or substituents bonded to ring A201 and substituents bonded to ring A202 may be bonded to each other to form a ring.

[0201] (R 201 , R 202 ) R 201 , R 202 Each independently represents a structure represented by the above formula (202), and "*" indicates that it is bonded to ring A201 or ring A202. 201 , R 202 Can be the same or different. 201 , R 202 When there are plural of each, they may be the same or different. 201 When there are multiple, they are the same or different, R 202 When there are plural, they may be the same or different.

[0202] (Ar 201 ,Ar 202 ,Ar 203 ) Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. 201 When there are multiple, they are the same or different, Ar 202 When there are multiple, they are the same or different, Ar 203 When there are plural, they may be the same or different. In Ar 201 ,Ar 202 ,Ar 203 When any one of them is an aromatic hydrocarbon ring structure which may have a substituent, the aromatic hydrocarbon ring structure is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, specifically, preferably a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring, more preferably a benzene ring, a naphthalene ring, or a fluorene ring, and most preferably a benzene ring.

[0203] In Ar 201 ,Ar 202 ,Ar 203 When any one of them is a fluorene ring which may have a substituent, the 9-position and 9'-position of the fluorene ring preferably have a substituent or are bonded to an adjacent structure.

[0204] In Ar 201 ,Ar 202 ,Ar 203 When any one of them is a benzene ring which may have a substituent, it is preferred that at least one benzene ring is bonded to the adjacent structure at the meta position or the para position, and it is more preferred that at least one benzene ring is bonded to the adjacent structure at the meta position.

[0205] In Ar 201 ,Ar 202 ,Ar 203 When any one of the above is an aromatic heterocyclic structure which may have a substituent, the aromatic heterocyclic structure is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms and containing any one of a nitrogen atom, an oxygen atom or a sulfur atom as a heteroatom, and specifically includes a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, a phenanthridine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring, and more preferably a pyridine ring, a pyrimidine ring, a triazine ring, a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring.

[0206] In Ar 201 ,Ar 202 ,Ar 203 When any one of them is a carbazole ring which may have a substituent, the N position of the carbazole ring preferably has a substituent or is bonded to an adjacent structure.

[0207] In Ar 202 In the case of an aliphatic hydrocarbon structure that may have a substituent, the aliphatic hydrocarbon structure is a straight chain, branched chain or cyclic aliphatic hydrocarbon structure, preferably an aliphatic hydrocarbon having 1 to 24 carbon atoms, further preferably an aliphatic hydrocarbon having 1 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon having 1 to 8 carbon atoms.

[0208] (i1, i2, i3, j, k1, k2) i1 and i2 are each independently preferably an integer of 1 to 12, more preferably an integer of 1 to 8, and still more preferably an integer of 1 to 6. Within this range, it is expected that the solubility will be improved and the charge transport property will be improved.

[0209] i3 is preferably an integer of 0 to 5, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0210] j represents an integer of preferably 0 to 2, more preferably 0 or 1.

[0211] k1 and k2 are preferably integers of 0 to 3, more preferably integers of 1 to 3, more preferably 1 or 2, and particularly preferably 1.

[0212] Ar 201 ,Ar 202 ,Ar 203 The substituents that may be possessed may be selected arbitrarily, and are preferably one or more substituents selected from the substituent group S described below, more preferably hydrogen atom, alkyl group, aryl group, particularly preferably hydrogen atom and alkyl group, and most preferably unsubstituted (hydrogen atom).

[0213] Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

[0214] (Substituent Group S) The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, further preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group may be linear or branched. The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and further preferably an alkoxy group having 1 to 6 carbon atoms. The aryloxy group is preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, further preferably an aryloxy group having 6 to 12 carbon atoms, and particularly preferably an aryloxy group having 6 carbon atoms. The heteroaryloxy group is preferably a heteroaryloxy group having 3 to 20 carbon atoms, and more preferably a heteroaryloxy group having 3 to 12 carbon atoms. The alkylamino group is preferably an alkylamino group having 1 to 20 carbon atoms, and more preferably an alkylamino group having 1 to 12 carbon atoms. The arylamino group is preferably an arylamino group having 6 to 36 carbon atoms, and more preferably an arylamino group having 6 to 24 carbon atoms. The aralkyl group is preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and further preferably an aralkyl group having 7 to 12 carbon atoms. The heteroaralkyl group is preferably a heteroaralkyl group having 7 to 40 carbon atoms, and more preferably a heteroaralkyl group having 7 to 18 carbon atoms. The alkenyl group is preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 12 carbon atoms, further preferably an alkenyl group having 2 to 8 carbon atoms, and particularly preferably an alkenyl group having 2 to 6 carbon atoms. - Alkynyl group, preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms. The aryl group is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, further preferably an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 14 carbon atoms. The heteroaryl group is preferably a heteroaryl group having 3 to 30 carbon atoms, more preferably a heteroaryl group having 3 to 24 carbon atoms, further preferably a heteroaryl group having 3 to 18 carbon atoms, and particularly preferably a heteroaryl group having 3 to 14 carbon atoms. The alkylsilyl group is preferably an alkylsilyl group having 1 to 20 carbon atoms, and more preferably an alkylsilyl group having 1 to 12 carbon atoms. The arylsilyl group is preferably an arylsilyl group having 6 to 20 carbon atoms in the aryl group, and more preferably an arylsilyl group having 6 to 14 carbon atoms in the aryl group. - Alkylcarbonyl group, preferably an alkylcarbonyl group having 2 to 20 carbon atoms. The arylcarbonyl group is preferably an arylcarbonyl group having 7 to 20 carbon atoms. · A hydrogen atom, a deuterium atom, a fluorine atom, a cyano group or -SF5.

[0215] One or more hydrogen atoms in the above groups may be replaced by fluorine atoms, or one or more hydrogen atoms may be replaced by deuterium atoms.

[0216] Unless otherwise specified, an aryl group is an aromatic hydrocarbon, and a heteroaryl group is an aromatic heterocycle.

[0217] (Preferred groups in substituent group S) Among these substituent groups S, preferred are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, arylsilyl, groups in which one or more hydrogen atoms of these groups are substituted with fluorine atoms, fluorine atoms, cyano or -SF5; more preferred are alkyl, arylamino, aralkyl, alkenyl, aryl, heteroaryl, groups in which one or more hydrogen atoms of these groups are substituted with fluorine atoms, fluorine atoms, cyano or -SF5; further preferred are alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, alkylsilyl, arylsilyl; particularly preferred are alkyl, arylamino, aralkyl, alkenyl, aryl, heteroaryl; most preferred are alkyl, arylamino, aralkyl, aryl, heteroaryl.

[0218] These substituent groups S may further have a substituent selected from the substituent group S as a substituent. Preferred groups, more preferred groups, further preferred groups, particularly preferred groups, and most preferred groups of the substituents that may be possessed are the same as the preferred groups in the substituent group S.

[0219] (Preferred structure of formula (201)) Among the structures represented by the above formula (202) in the above formula (201), preferred are structures having a group connected to a benzene ring, structures having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded to ring A201 or ring A202, and structures having a dendron bonded to ring A201 or ring A202.

[0220] In the structure having a group connected to a benzene ring, Ar 201 is a benzene ring structure, i1 is 1 to 6, and at least one of the benzene rings is bonded to an adjacent structure at an ortho position or a meta position. With this structure, it is expected that the solubility will be improved and the charge transport property will be improved.

[0221] In the structure having an aromatic hydrocarbon group or an aromatic heterocyclic group in which an alkyl group or an aralkyl group is bonded to the ring A201 or the ring A202, Ar 201 is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar 202 is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, Ar 203 It is a benzene ring structure, and i3 is 0 or 1. In the case of this structure, Ar is preferably 201 The aromatic hydrocarbon structure is more preferably a structure in which 1 to 5 benzene rings are connected, and more preferably a structure in which 1 benzene ring is connected. With this structure, it is expected that the solubility will be improved and the charge transport property will be improved.

[0222] In the structure in which a dendron is bonded to ring A201 or ring A202, Ar 201 ,Ar 202 is a benzene ring structure, Ar 203 It is a biphenyl or terphenyl structure, i1 and i2 are 1 to 6, i3 is 2, and j is 2. With this structure, it is expected that the solubility will be improved and the charge transport property will be improved.

[0223] (By B 201 -L 200 -B 202 Structure of representation) B 201 -L 200 -B 202 When there are plural, they may be the same or different. By B 201 -L 200 -B 202 The structure represented is preferably a structure represented by the following formula (203) or (204).

[0224] [Chemistry 40]

[0225] R 211 , R 212 , R 213 represents a substituent. The substituent is not particularly limited, but is preferably a group selected from the above-mentioned substituent group S.

[0226] [Chemistry 41]

[0227] Ring B3 represents an aromatic heterocyclic structure which may have a substituent and contains a nitrogen atom. Ring B3 is preferably a pyridine ring. The substituent that the ring B3 may have is not particularly limited, but is preferably a group selected from the above-mentioned substituent group S.

[0228] (Molecular weight) The molecular weight of the organometallic compound is not particularly limited, but is preferably 10000 or less, more preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. In addition, the molecular weight of the organometallic compound is 1200 or more, preferably 1300 or more, and more preferably 1700 or more. It is believed that by having a molecular weight within this range, the organometallic compound can be uniformly mixed with the aromatic compound of the present invention and / or other charge transport materials without agglomeration, thereby obtaining a light-emitting layer with high light-emitting efficiency.

[0229] The molecular weight of the organometallic compound is preferably large because the Tg, melting point, decomposition temperature, etc. are high, the heat resistance of the organometallic compound and the formed light-emitting layer is excellent, and the film quality degradation caused by gas generation, recrystallization and molecular migration, and the increase in impurity concentration accompanying thermal decomposition of the material are not likely to occur. On the other hand, the molecular weight of the organometallic compound is preferably small because the organic compound is easy to purify.

[0230] In addition, when the molecular weight of the above-mentioned organic metal compound is set to MwA and the molecular weight of the above-mentioned polycyclic heterocyclic compound is set to MwB, MwA / MwB is preferably 1.0 or more, more preferably 1.5 or more, and further preferably 2.0 or more. It is believed that within the range of MwA / MwB, energy from the organic metal compound to the polycyclic heterocyclic compound can be appropriately generated, and a light-emitting layer with high light-emitting efficiency can be obtained.

[0231] (Specific examples of organometallic compounds) The organometallic compound represented by the formula (201) is not particularly limited, and specific examples thereof include the following structures: Me means a methyl group, and Ph means a phenyl group.

[0232] [Chemistry 42]

[0233] [Chemistry 43]

[0234] [Chemistry 44]

[0235] [Main material] Furthermore, the light-emitting layer preferably contains a host material. The host material is preferably a charge transport material, and materials previously used as materials for organic electroluminescent elements can be used. The charge transport material used as the host material of the light-emitting layer is a material having a skeleton with excellent charge transport properties, preferably selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes. Furthermore, in the present invention, the charge transport material also includes a material for adjusting the charge transport properties. Specific examples of the skeleton having excellent charge transport properties include pyridine, pyrimidine, triazine, carbazole, naphthalene, perylene, pyrene, anthracene, Tetracene, phenanthrene, coronene, fluoranthene, triphenylene, fluorene, acenaphthenefluoranthene, coumarin, p-bis(2-phenylvinyl)benzene and their derivatives, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminophenylvinyl)-4H-pyran) series compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, fused aromatic ring compounds substituted with arylamino groups, styryl derivatives substituted with arylamino groups, etc.

[0236] These may be used alone or in any combination and ratio of two or more.

[0237] Among these, pyridine, pyrimidine, triazine, carbazole, naphthalene, perylene, pyrene, anthracene, Naphthacene, phenanthrene, coronene, fluoranthene, triphenylene, fluorene, acenaphthene, and derivatives thereof, and anthracene derivatives are more preferred.

[0238] Specific examples of skeletons having excellent charge transport properties include aromatic structures, aromatic amine structures, triarylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylbenzene structures, fluorene structures, quinacridone structures, triphenylene structures, carbazole structures, pyrene structures, anthracene structures, phenanthroline structures, quinoline structures, pyridine structures, pyrimidine structures, triazine structures, oxadiazole structures, and imidazole structures.

[0239] As the electron transport material, a compound having a relatively stable pyridine structure, pyrimidine structure or triazine structure having an excellent electron transport skeleton is more preferred, and a compound having a pyrimidine structure or triazine structure is further preferred. As the electron transport material, a compound represented by formula (250) described below is particularly preferred.

[0240] The hole transport material is a compound having a structure with excellent hole transport properties. Among the skeletons with excellent charge transport properties, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure or a pyrene structure is preferred as a structure with excellent hole transport properties, and a carbazole structure, a dibenzofuran structure or a triarylamine structure is further preferred. As the hole transport material, a compound represented by formula (240) described later is particularly preferred.

[0241] As the bipolar material capable of transporting both electrons and holes, a material having both a skeleton having excellent electron-transporting properties and a skeleton having excellent hole-transporting properties is preferable. As a material for adjusting the charge transport property, a compound having a structure formed by connecting multiple benzene rings, i.e., a compound represented by formula (260) described later, is preferred. It is believed that by including this compound as a host material, the excitons generated in the light-emitting layer will efficiently recombine to increase the luminous efficiency. In addition, it is believed that the charge transport property in the light-emitting layer is appropriately adjusted to suppress the degradation of the light-emitting material, thereby extending the driving life.

[0242] The charge transport material used as the main material of the light-emitting layer is preferably a compound having a condensed ring structure of three or more rings, and more preferably a compound having a condensed ring structure of three or more rings or a compound having at least one condensed ring of five or more rings. By using these compounds, it is easy to obtain the effect of increasing the rigidity of the molecule and suppressing the degree of molecular motion in response to heat. Further, from the perspective of charge transportability and material durability, the condensed rings of three or more rings and the condensed rings of five or more rings preferably have aromatic hydrocarbon rings or aromatic heterocyclic rings.

[0243] Specific examples of the fused ring structure having three or more rings include anthracene structure, phenanthrene structure, pyrene structure, structure, tetracene structure, triphenylene structure, fluorene structure, benzofluorene structure, indenofluorene structure, indolefluorene structure, carbazole structure, indenocarbazole structure, indolecarbazole structure, dibenzofuran structure, dibenzothiophene structure, etc.

[0244] Among the condensed ring structures having three or more rings, from the viewpoint of charge transport and solubility, at least one selected from the group consisting of a phenanthrene structure, a fluorene structure, an indenofluorene structure, a carbazole structure, an indenocarbazole structure, an indolecarbazole structure, a dibenzofuran structure and a dibenzothiophene structure is preferred, and from the viewpoint of durability relative to charge, a carbazole structure or an indolecarbazole structure is further preferred.

[0245] [(Group A), (Group B), (Group C)] Here, in this specification, host materials that may be contained in the light-emitting layer are referred to as (A group), (B group), and (C group) as follows for convenience. (Group A) The electron transport material is preferably a compound represented by the following formula (250): (Group B) hole transport material, preferably a compound represented by the following formula (240) (Group C) Materials for adjusting charge transport properties are preferably compounds represented by the following formula (260):

[0246] In the present invention, the host material that may be contained in the light-emitting layer preferably contains at least one compound selected from at least one of the three groups represented by (Group A), (Group B) and (Group C). It is more preferred that the compound contains at least one compound selected from the above (Group A) or the above (Group B), It is further preferred that the compound contains at least two compounds selected from at least two of the three groups represented by (Group A), (Group B) and (Group C). It is more preferred that the compound contains at least two compounds selected from the two groups represented by the above (Group A) and the above (Group B), It is particularly preferred that the compound contains at least three compounds selected from at least one of each of the three groups represented by the above (Group A), the above (Group B), and the above (Group C). It should be noted that the compound selected from each group may be one kind or two or more kinds.

[0247] Since the compound selected from (Group A) is preferably a compound represented by the following formula (250), the compound selected from (Group B) is preferably a compound represented by the following formula (240), and the compound selected from (Group C) is preferably a compound represented by the following formula (260), the main material contained in the light-emitting layer further preferably contains at least two compounds, at least one of which is selected from at least any two of the compounds represented by the following formula (250), the compounds represented by the following formula (240), and the compounds represented by the following formula (260); it is further preferred to contain at least two compounds selected from the compounds represented by the following formula (250) and the compounds represented by the following formula (240); and it is particularly preferred to contain at least three compounds, at least one of which is selected from the compounds represented by the following formula (250), the compounds represented by the following formula (240), and the compounds represented by the following formula (260).

[0248] It is believed that the organic electroluminescent element of the present invention contains a compound having a structure formed by connecting a nitrogen-containing six-membered aromatic heterocyclic ring and a benzene ring in the light-emitting layer, that is, a compound represented by the following formula (250) as a main material, and the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, the luminous efficiency is improved, and the degradation of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material can be suppressed, and the driving life becomes longer. In particular, in the case of a triazine structure in which all W of the following formula (250) are nitrogen atoms, the LUMO is relatively deep, and in addition to the electron transport property, it also has a moderate electron capture (trap) property. By not excessively supplying electrons to the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201), the durability of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material is improved, and as a result, it is believed that the driving life of the organic electroluminescent element becomes longer. In particular, it is believed that electrons entering the empty p orbital of the boron atom of the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material can inhibit the degradation of the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material and the organic metal compound represented by the above formula (201).

[0249] In addition, the compound represented by the following formula (250) has a nitrogen-containing aromatic six-membered ring at the center, so it has high electron transport properties. Therefore, it is believed that when using the compound represented by the following formula (250) as a host material, further using a host material with high hole transport properties as other host materials will further reduce the voltage, improve the luminous efficiency, and increase the driving life.

[0250] It is believed that when the organic electroluminescent element of the present invention contains a compound having two carbazole ring structures, i.e., a compound represented by the following formula (240), as a main material in the light-emitting layer, the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, the luminous efficiency is improved, and the degradation of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material can be suppressed, and the driving life is prolonged. It is believed that when the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material directly accepts holes injected from the layer on the anode side and becomes an oxidized state and thus has the possibility of degradation, the compound represented by the following formula (240) has a hole transport property and is easy to accept holes from the layer on the anode side, so the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material is not easy to be directly oxidized, thereby suppressing degradation. On the contrary, it is believed that when the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material directly accepts electrons injected from the cathode side and becomes reduced and thus easily degraded, holes are quickly transferred from the compound represented by the formula (240) to the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material, and the light-emitting material suppresses degradation by composite light emission.

[0251] The hole transport property of the compound represented by formula (240) is excellent, and the hole transport property of the organic metal compound represented by the above formula (201) is excellent. In addition, it is believed that the compound represented by formula (240) has two highly planar carbazole ring structures, so the hole transport property of the polycyclic heterocyclic compound with high planarity, that is, the polycyclic heterocyclic compound represented by the above formula (1), is improved. At this time, it is believed that the electron supply to the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material is also carried out rapidly, thereby rapidly compounding and emitting light, and the degradation of the light-emitting material is suppressed. Therefore, it is believed that by using the compound represented by the following formula (240) as the first host material, and using a material with high electron transport as the second host material, it is possible to obtain an organic electroluminescent element with low voltage, improved luminous efficiency and long driving life. As a host material with high electron transport, a compound represented by the following formula (250) is preferably used.

[0252] It is believed that the organic electroluminescent element of the present invention contains a compound having a structure formed by connecting multiple benzene rings, that is, a compound represented by the following formula (260) as a main material in the light-emitting layer, and the charge transport property in the light-emitting layer is appropriately adjusted, which can suppress the degradation of the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material or the organic metal compound represented by the above formula (201), and the driving life is prolonged. In particular, the compound represented by the following formula (260) has the effect of suppressing charge transport. In particular, it is believed that in the case where the compound represented by the formula (250) with excellent electron transport is used as a main material, by further adding the compound represented by the formula (260) as a main material, the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material or the organic metal compound represented by the above formula (201) will not be excessively reduced and degraded, and the electron transport property in the light-emitting layer can be suppressed, and the driving life of the element is prolonged.

[0253] <Definition of Substituent> The host material may have a substituent selected from the substituent group Z2. <Substituent Group Z2> The substituent group Z2 is a group consisting of an alkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. These substituents may have any structure of a straight chain, a branched chain, or a ring.

[0254] More specifically, the following structures can be mentioned as the substituent group Z2. For example, a linear, branched or cyclic alkyl group having usually 1 or more, preferably 4 or more and usually 24 or less, preferably 12 or less, more preferably 8 or less, and further preferably 6 or less carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, and a dodecyl group; For example, an alkoxy group such as a methoxy group and an ethoxy group usually has 1 or more carbon atoms and usually has 24 or less carbon atoms, preferably has 12 or less carbon atoms; For example, an aryloxy or heteroaryloxy group having usually 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenoxy group, a naphthoxy group, a pyridyloxy group, etc.; For example, an alkoxycarbonyl group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group; For example, a dialkylamino group having a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less, such as a dimethylamino group and a diethylamino group; For example, a diarylamino group having usually 10 or more, preferably 12 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a diphenylamino group and a ditolylamino group; For example, an arylalkylamino group having usually 7 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenylmethylamino group; For example, an acyl group such as an acetyl group and a benzoyl group usually has 2 or more and usually 24 or less, preferably 12 or less carbon atoms; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a halogenated alkyl group having usually 1 or more and usually 12 or less, preferably 6 or less carbon atoms, such as a trifluoromethyl group; For example, an alkylthio group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methylthio group and an ethylthio group; For example, an arylthio group having usually 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenylthio group, a naphthylthio group, and a pyridylthio group; For example, a silyl group having usually 2 or more, preferably 3 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a trimethylsilyl group and a triphenylsilyl group; For example, a silyloxy group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a trimethylsilyloxy group and a triphenylsilyloxy group; Cyano; For example, an aromatic hydrocarbon group having usually 6 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenyl group and a naphthyl group; For example, an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a thienyl group and a pyridyl group.

[0255] Among the above-mentioned substituent group Z2, an alkyl group, an alkoxy group, a diarylamino group, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferred. From the viewpoint of charge transport, as a substituent, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferred, an aromatic hydrocarbon group is more preferred, and it is further preferred that the substituent has no substituent. From the viewpoint of improving solubility, as a substituent, an alkyl group or an alkoxy group is preferred.

[0256] In addition, each substituent of the above-mentioned substituent group Z2 may further have a substituent. As these substituents, the same groups as the above-mentioned substituents (substituent group Z2) can be cited. Each substituent that the above-mentioned substituent group Z2 may have is preferably an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, and more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group. From the viewpoint of charge transportability, each substituent of the above-mentioned substituent group Z2 preferably has no further substituent.

[0257] <Compound represented by formula (250)>

[0258] [Chemistry 45]

[0259] (In formula (250), W each independently represents CH or N, at least one W is N, XA 1 , Ya 1 and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, XA 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, g11, h11 and j11 each independently represent an integer from 0 to 6, At least one of g11, h11, and j11 is an integer greater than 1, When g11 is 2 or more, the presence of multiple Xa 1 Can be the same or different. When h11 is 2 or more, there are multiple Ya 1 Can be the same or different. When g11 is 2 or more, the presence of multiple Za 1 Can be the same or different. R 31 Represents a hydrogen atom or a substituent, 4 R 31 Can be the same or different. When g11, h11 or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 Not a hydrogen atom.)

[0260] The compound represented by the above formula (250) is preferably a charge transport compound, that is, preferably a charge transport host material.

[0261] <w> W in the above formula (250) represents CH or N, at least one of which is N. From the viewpoint of electron transportability and electron durability, at least two of them are preferably N, and all of them are more preferably N.

[0262] <Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , Za 2 > As Xa in the above formula (250) 1 , Ya 1 , Za 1 When Xa is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent 2 , Ya 2 , Za 2 In the case of an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, the aromatic hydrocarbon ring of the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a six-membered monocyclic ring or a two-membered to five-membered condensed ring. Specifically, the aromatic hydrocarbon ring includes a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, Among them, preferably a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring or a fluorene ring, more preferably a benzene ring, a naphthalene ring, a phenanthrene ring or a fluorene ring, and further preferably a benzene ring, a naphthalene ring or a fluorene ring. In addition, preferably the terminal structural part when g11 is 2 or more, i.e. -Xa 1 -Xa 2 , when h11 is 2 or more, the terminal structural part is -Ya 1 -Ya 2 and j11 is 2 or more, that is, the terminal structural part -Za 1 -Za 2 The compound represented by formula (250) preferably has a terminal structural part when g11 is 2 or more, i.e. -Xa 1 -Xa 2 , when h11 is 2 or more, the terminal structural part is -Ya 1 -Ya 2 and j11 is 2 or more, that is, the terminal structural part -Za 1 -Za 2 At least one of them is a spirofluorene structure.

[0263] As Xa in the above formula (250) 1 , Ya 1 , Za 1 is a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent and Xa 2 , Ya 2 , Za 2 In the case of an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a 5-membered or 6-membered monocyclic ring or a 2- to 5-membered condensed ring. Specific examples include a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, an indolocarbazole ring, an indenocarbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a pyridine ring, a quinazoline ring, and a quinazolinone ring. Among them, preferred are thiophene rings, pyrrole rings, imidazole rings, pyridine rings, pyrimidine rings, triazine rings, quinoline rings, quinazoline rings, carbazole rings, dibenzofuran rings, dibenzothiophene rings, indolecarbazole rings, phenanthroline rings or indenocarbazole rings; more preferred are pyridine rings, pyrimidine rings, triazine rings, quinoline rings, quinazoline rings, carbazole rings, indolecarbazole rings, indenocarbazole rings, dibenzofuran rings or dibenzothiophene rings; further preferred are carbazole rings, indolecarbazole rings, dibenzofuran rings or dibenzothiophene rings.

[0264] In the above formula (250), Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 and Za 2 Among them, particularly preferred aromatic hydrocarbon rings are benzene rings, naphthalene rings or phenanthrene rings, and particularly preferred aromatic heterocyclic rings are carbazole rings, indolocarbazole rings, dibenzofuran rings or dibenzothiophene rings.

[0265] Xa in the above formula (250) 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 and Za 2 The substituent that the aromatic hydrocarbon group having 6 to 30 carbon atoms may have and the substituent that the aromatic heterocyclic group having 3 to 30 carbon atoms may have are preferably each independently selected from the substituent group Z2, and the substituent selected from the substituent group Z2 does not have any further substituent. It is believed that high charge transportability and durability can be maintained by not having any further substituent selected from the substituent group Z2. In addition, among the substituent group Z2, from the viewpoint of charge transportability and durability, an aromatic hydrocarbon group and an aromatic heterocyclic group are preferred, and an aromatic hydrocarbon group is particularly preferred.

[0266] <g11、h11、j11> g11, h11 and j11 each independently represent an integer of 0 to 6, and at least one of g11, h11 and j11 is an integer greater than 1. From the viewpoint of charge transportability and durability, g11 is preferably 2 or greater or at least one of h11 and j11 is preferably 3 or greater.

[0267] In addition, the compound represented by the above formula (250) preferably has 8 to 18 rings in total, including a central ring having three Ws, from the viewpoint of charge transport properties, durability, and solubility in organic solvents.

[0268] <(Xa 1 ) g11 ,(Ya 1 ) h11、 (Za 1 ) j11 > From the viewpoint of solubility and durability of the compound, 1 ) g11 ,(Ya 1 ) h11 and (Za 1 ) j11 At least one group in each of the above preferably independently has a structural part selected from the structural part represented by the following formula (11), the structural part represented by the following formula (12) and the structural part represented by the following formula (13), and when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 It is further preferred that each independently has a structural moiety selected from the group consisting of a structural moiety represented by the following formula (11), a structural moiety represented by the following formula (12), and a structural moiety represented by the following formula (13).

[0269] [Chemistry 46]

[0270] In each of the above formulae (11) to (13), * represents a bond with an adjacent structure or Xa in formula (250) 2 , Ya 2 or Za 2 When it is a hydrogen atom, the hydrogen atom. At least one of the two *s present indicates a bonding position with an adjacent structure. In the following description, unless otherwise specified, the definition of * is the same.

[0271] More preferably, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently has a structural part represented by formula (11) or a structural part represented by formula (12). More preferably, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently has a structural part represented by formula (11) and a structural part represented by formula (12).

[0272] The structural moiety represented by the formula (12) is preferably a structural moiety represented by the following formula (12-2).

[0273] [Chemistry 47]

[0274] As the structural part represented by formula (12), the structural part represented by the following formula (12-3) is more preferable.

[0275] [Chemistry 48]

[0276] From the viewpoint of solubility, as the structural part having the structural part represented by the formula (11) and the structural part represented by the formula (12), it is preferable to select a structural part selected from the structures including a plurality of structures selected from the structural part represented by the formula (11) and the structural part represented by the formula (12), that is, the following formula (14) to the following formula (17). That is, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently preferably has a structural part selected from the group consisting of the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17). In other words, from the viewpoint of solubility, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently preferably has a structural part selected from the group consisting of formula (11) to formula (17).

[0277] [Chemistry 49]

[0278] A structure comprising a plurality of structures selected from the structural parts represented by formula (11) and the structural parts represented by formula (12) refers to, for example, the structural part represented by formula (14), which can be regarded as a structural part having one structural part represented by formula (11) and two structural parts represented by formula (12), as shown in the following formula (14a).

[0279] [Chemistry 50]

[0280] More preferably (Xa 1 ) g11 ,(Ya 1 ) h11 and (Za 1 ) j11 At least one of the above has at least one structural part represented by formula (14) or one structural part represented by formula (15). More preferably, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 It has a structural portion represented by formula (14) or a structural portion represented by formula (15).

[0281] The structural moiety represented by the formula (14) is preferably a structural moiety represented by the following formula (14-2).

[0282] [Chemistry 51]

[0283] As the structural moiety represented by formula (14), a structural moiety represented by the following formula (14-3) is more preferred.

[0284] [Chemistry 52]

[0285] The structural moiety represented by the formula (15) is preferably a structural moiety represented by the following formula (15-2).

[0286] [Chemistry 53]

[0287] As the structural part represented by formula (15), the structural part represented by the following formula (15-3) is more preferable.

[0288] [Chemistry 54]

[0289] The structural moiety represented by the formula (17) is preferably a structural moiety represented by the following formula (17-2).

[0290] [Chemistry 55]

[0291] (Xa 1 ) g11 、(Ya 1 ) h11 and (Za 1 ) j11 At least one of them more preferably has a structural moiety represented by the following formula (19) or a structural moiety represented by the following formula (20) as a structural moiety including the structural moiety represented by the formula (13).

[0292] [Chemistry 56]

[0293] In each of the above formulae (14) to (20), * represents a bond with an adjacent structure or Xa 2 , Ya 2 or Za 2 When it is a hydrogen atom, the hydrogen atom. At least one of the two *s present indicates a bonding position to an adjacent structure.

[0294] Among the structural moieties represented by formulae (14) to (20), the structural moiety represented by formula (14-3) and the structural moiety represented by formula (15-3) are preferred, and the structural moiety represented by formula (14-3) is more preferred.

[0295] -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) each independently preferably has a structural portion represented by formula (11), a structural portion represented by formula (12-3), a structural portion represented by formula (14-3) or a structural portion represented by formula (15-3).

[0296] In addition, -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) preferably has any one of the structural parts or terminal structures represented by the following formula (250-1) to the following formula (250-10).

[0297] [Chemistry 57]

[0298] [In formula (250-1) to formula (250-10), * represents a bonding position. Ar 250 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms. 32 represents a substituent, and the structures represented by Formula (250-1) to Formula (250-10) may further have a substituent.]

[0299] These structures may have substituents similar to R 32 same.

[0300] Ar 250 It is preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms, more preferably a phenyl group or a biphenyl group, and still more preferably a phenyl group.

[0301] In the case of having 2 R 32 In the structure of 32 It can be the same or different. R 32 Preferably, it is an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms, or a heteroaryl group having 3 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms, and more preferably a heteroaryl group having 1 to 2 Preferably, the alkyl group is an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms; more preferably, the alkyl group is an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, or an aryl group having 6 to 14 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms.

[0302] <R 31 > For R as a substituent 31 , preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. From the viewpoint of improving durability and charge transport properties, an aromatic hydrocarbon group which may have a substituent is more preferred. When R is a substituent 31 When there are multiple ones, they can be different.

[0303] The substituent that the aromatic hydrocarbon group having 6 to 30 carbon atoms may have, the substituent that the aromatic heterocyclic group having 3 to 30 carbon atoms may have, and R as a substituent 31 The substituent that may be possessed may be selected from the above-mentioned substituent group Z2.

[0304] From the perspective of charge transport, R 31 Preferred is a hydrogen atom.

[0305] In addition, from the viewpoint of solubility, -(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) are preferably not unsubstituted phenyl at the same time.

[0306] <Molecular weight> The compound represented by the above formula (250) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less. The lower limit of the molecular weight of the compound is usually 400 or more, preferably 500 or more, and more preferably 600 or more.

[0307] <Specific examples of compounds represented by formula (250)> The compound represented by formula (250) is not particularly limited, and examples thereof include the following compounds.

[0308] [Chemistry 58]

[0309] [Chemistry 59]

[0310] [Chemistry 60]

[0311] [Chemistry 61]

[0312] [Chemistry 62]

[0313] [Chemistry 63]

[0314] The light-emitting layer and the light-emitting layer-forming composition of the present invention may contain only one type of compound represented by the above formula (250) or two or more types of compound.

[0315] <Compound represented by formula (240)>

[0316] [Chemistry 64]

[0317] (In formula (240), Ar 611 ,Ar 612 Each independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R 611 , R 612 are each independently a deuterium atom, a halogen atom or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, n 611 、n 612 Each independently represents an integer from 0 to 4.)

[0318] <Ar 611 ,Ar 612 > Ar 611 ,Ar 612 Each independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 50, more preferably 6 to 30, and still more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, A monovalent group of an aromatic hydrocarbon structure having a carbon number of usually 6 or more and usually 30 or less, preferably 18 or less, and more preferably 14 or less, such as a pyrene ring, a benzanthracene ring, or a perylene ring, or a monovalent group of a structure in which a plurality of structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, a structure in which 2 to 8 are linked can be generally cited, and a structure in which 2 to 5 are preferably linked can be cited. When multiple aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0319] Ar 611 ,Ar 612 Preferably, they are independently: Phenyl, A monovalent group formed by multiple benzene rings connected in chains or branches. A monovalent group formed by one or more benzene rings and at least one naphthalene ring connected in a chain or branched manner, A monovalent group formed by one or more benzene rings and at least one phenanthrene ring connected in a chain or branched manner, or A monovalent group formed by one or more benzene rings and at least one tetraphenylene ring connected in a chain or branched manner. More preferably, it is a monovalent group in which a plurality of benzene rings are linked in a plurality of chains or branches. In either case, the linking order is not limited. Ar 611 ,Ar 612 Particularly preferably, each independently of the other, is a monovalent group in which a plurality of benzene rings which may have a substituent are linked in a chain or branched form. Most preferably, each independently of the other, is a monovalent group in which a plurality of benzene rings are linked in a chain or branched form.

[0320] The number of the connected benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is as described above, and is usually 2 to 8, preferably 2 to 5. Among them, a monovalent structure in which 1 to 4 benzene rings are connected, a monovalent structure in which 1 to 4 benzene rings and a naphthalene ring are connected, a monovalent structure in which 1 to 4 benzene rings and a phenanthrene ring are connected, or a monovalent structure in which 1 to 4 benzene rings and a tetraphenylene ring are connected is preferred.

[0321] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0322] From the viewpoint of solubility and durability of the compound, Ar 611 ,Ar 612 At least one of them preferably has a structural part selected from the following formulae (11) to (13) and (21) to (24), Ar 611 and Ar 612 Each independently has a structural part selected from the following formulae (11) to (13) and (21) to (24).

[0323] [Chemistry 65]

[0324] In each of the above formulae (11) to (13) and (21) to (24), * represents a bond to an adjacent structure or a hydrogen atom, and at least one of the two *s present represents a bonding position to an adjacent structure. In the following descriptions, unless otherwise specified, * has the same definition.

[0325] More preferably, Ar 611 ,Ar 612 Each independently has a structural part represented by formula (11) or a structural part represented by formula (12). More preferably, Ar 611 ,Ar 612 Each independently has a structural part represented by formula (11) and a structural part represented by formula (12).

[0326] The structural moiety represented by the formula (12) is preferably a structural moiety represented by the following formula (12-2).

[0327] [Chemistry 66]

[0328] As the structural part represented by formula (12), the structural part represented by the following formula (12-3) is more preferable.

[0329] [Chemistry 67]

[0330] The structural part having the structural part represented by the formula (11) and the structural part represented by the formula (12) is preferably a structural part selected from the following formulas (14) to (17) which include a plurality of structures selected from the structural part represented by the formula (11) and the structural part represented by the formula (12). 611 and Ar 612 Each independently preferably has a structural part selected from the group consisting of the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17).

[0331] [Chemistry 68]

[0332] A structural portion comprising a plurality of structures selected from the structural portion represented by the formula (11) and the structural portion represented by the formula (12) refers to, for example, a structural portion represented by the formula (14), which can be regarded as a structural portion having one structural portion represented by the formula (11) and two structural portions represented by the formula (12), as in the following formula (14a).

[0333] [Chemistry 69]

[0334] More preferably, Ar 611 ,Ar 612 At least one of the above has at least one structural part represented by formula (14) or one structural part represented by formula (15). More preferably, Ar 611 ,Ar 612 It has a structural portion represented by formula (14) or a structural portion represented by formula (15).

[0335] The structural moiety represented by the formula (14) is preferably a structural moiety represented by the following formula (14-2).

[0336] [Chemistry 70]

[0337] As the structural moiety represented by formula (14), a structural moiety represented by the following formula (14-3) is more preferred.

[0338] [Chemistry 71]

[0339] The structural moiety represented by the formula (15) is preferably a structural moiety represented by the following formula (15-2).

[0340] [Chemistry 72]

[0341] As the structural part represented by formula (15), the structural part represented by the following formula (15-3) is more preferable.

[0342] [Chemistry 73]

[0343] The structural moiety represented by the formula (17) is preferably a structural moiety represented by the following formula (17-2).

[0344] [Chemistry 74]

[0345] Ar 611 ,Ar 612 At least one of them more preferably has a structural moiety represented by the following formula (19) or a structural moiety represented by the following formula (20) as a structural moiety including the structural moiety represented by the formula (13).

[0346] [Chemistry 75]

[0347] In each of the above formulae (14) to (20), * represents a bond to an adjacent structure or a hydrogen atom. The presence of at least one of two *s represents a bonding position to an adjacent structure.

[0348] Among the structural moieties represented by formulae (14) to (20), the structural moiety represented by formula (14-3) and the structural moiety represented by formula (15-3) are preferred, and the structural moiety represented by formula (14-3) is more preferred.

[0349] Ar 611 ,Ar 612 Each independently preferably has a structural moiety represented by formula (11), a structural moiety represented by formula (12-3), a structural moiety represented by formula (14-3), or a structural moiety represented by formula (15-3).

[0350] <R 611 , R 612 > R 611 , R 612 Each is independently a deuterium atom, a halogen atom such as a fluorine atom, or a monovalent aromatic hydrocarbon having 6 to 50 carbon atoms which may have a substituent. It is preferably a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent. Examples of the aromatic hydrocarbon group include monovalent groups having an aromatic hydrocarbon structure having more preferably 6 to 30 carbon atoms, further preferably 6 to 18 carbon atoms, and particularly preferably 6 to 10 carbon atoms. As the monovalent aromatic hydrocarbon group, specifically, 611 The same applies to the above-mentioned groups, and the preferred aromatic hydrocarbon groups are also the same, with a phenyl group being particularly preferred. These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0351] <n 611 、n 612 > n 611 、n 612 Each independently represents an integer of 0 to 4. Preferably it is 0 to 2, and more preferably 0 or 1. Ar 611 When it is unsubstituted phenyl, n 611 is an integer from 1 to 4, Ar 612 When it is unsubstituted phenyl, n 612 It is an integer of 1 to 4, and is preferably from the viewpoint of having high solubility in an organic solvent.

[0352] <Substituent> Ar 611 ,Ar 612 , R 611 , R 612 In the case of a monovalent aromatic hydrocarbon group, the substituent that may be possessed is preferably a substituent selected from the above-mentioned substituent group Z2.

[0353] <g> G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

[0354] The number of carbon atoms of the aromatic hydrocarbon group of G is preferably 6 to 50, more preferably 6 to 30, and even more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, A divalent group of an aromatic hydrocarbon structure having a carbon number of usually 6 or more and usually 30 or less, preferably 18 or less, and more preferably 14 or less, such as a pyrene ring, a benzanthracene ring, or a perylene ring, or a divalent group of a structure in which a plurality of structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, a structure in which 2 to 8 are linked can be generally cited, and a structure in which 2 to 5 are preferably linked can be cited. When multiple aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0355] G is preferably a single bond, a phenylene group, a divalent group formed by combining a plurality of benzene rings in a plurality of chains or branches, a divalent group formed by combining one or more benzene rings and at least one naphthalene ring in a chain or branch, a divalent group formed by combining one or more benzene rings and at least one phenanthrene ring in a chain or branch, or a divalent group formed by combining one or more benzene rings and at least one tetraphenylene ring in a chain or branch, and is further preferably a divalent group formed by combining a plurality of benzene rings in a plurality of chains or branches. In any case, the connection order is not limited.

[0356] The number of connected benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is as described above, and is usually 2 to 8, preferably 2 to 5. Among them, a divalent structure in which 1 to 4 benzene rings are connected, a divalent structure in which 1 to 4 benzene rings and a naphthalene ring are connected, a divalent structure in which 1 to 4 benzene rings and a phenanthrene ring are connected, or a divalent structure in which 1 to 4 benzene rings and a tetraphenylene ring are connected is more preferred.

[0357] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0358] <Molecular weight> The compound represented by the above formula (240) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, further preferably 2,000 or less, particularly preferably 1,500 or less, and is usually 400 or more, preferably 500 or more, and more preferably 600 or more.

[0359] <Specific example of compound IV represented by the above formula (240)> Preferred specific examples of the compound IV represented by the above formula (240) are shown below, but the present invention is not limited to these.

[0360] [Chemistry 76]

[0361] [Chemistry 77]

[0362] The light-emitting layer and the light-emitting layer-forming composition of the present invention may contain only one type of compound represented by the above formula (240) or two or more types of compound.

[0363] <Compound represented by formula (260)>

[0364] [Chemistry 78]

[0365] (In formula (260), Ar 1 ~Ar 5 are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, L 1 ~L 5 are each independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, R each independently represents a substituent, m1 to m5 each independently represent an integer of 0 to 5, n represents an integer from 0 to 10, a1 to a3 each independently represent an integer of 0 to 3, Among them, Ar 1 ,Ar 2 ,Ar 3 ,Ar 4 and n is 1 or more when at least one Ar 5 At least one of them is not a hydrogen atom.)

[0366] (Ar 1 ,Ar 2 ,Ar 5 ) Ar in formula (260) 1 ,Ar 2 and Ar 5 Each independently represents a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

[0367] From the viewpoint of solubility and durability of the compound, Ar in formula (260) 1 ,Ar 2 and Ar 5 It is preferably a hydrogen atom, a monovalent group on a benzene ring, a monovalent group on a naphthalene ring, or a structure represented by formula (4) or (5); more preferably a hydrogen atom, a monovalent group on a benzene ring, or a structure represented by formula (4) or (5); further preferably a hydrogen atom, a monovalent group on a benzene ring, or a structure represented by formula (5); and particularly preferably a structure represented by formula (5). From the viewpoint of durability and charge transport, Ar 1 ,Ar 2 and at least one Ar 5 In the formula (4) or (5), one or more and three or less are preferably the following: Ar 1 ,Ar 2 and at least one and Ar 5 Among them, one or more and three or less are more preferably the following formula (5). From the viewpoint of charge transport and solubility, Ar 1 ,Ar 2 and at least one Ar 5 Among them, one is preferably represented by the following formula (5). From the perspective of durability, Ar 1 ,Ar 2 and at least one Ar 5 Among them, two or more are preferably represented by the following formula (5), and three are more preferably represented by the following formula (5).

[0368] (Formula (4), Formula (5))

[0369] [Chemistry 79]

[0370] (In formula (4) or formula (5), The asterisk (*) indicates the bonding position to formula (260), R 1 ~R 26 Each independently represents a hydrogen atom or a substituent. )

[0371] Ar 1 In the case of formula (4) or formula (5), m1 is preferably 0 or 1, and more preferably 0. 2 In the case of formula (4) or formula (5), m2 is preferably 0 or 1, and more preferably 0. 5 In the case of formula (4) or formula (5), m5 is preferably 0 or 1, and more preferably 0.

[0372] (Ar 3 ,Ar 4 ) Ar in formula (260) 3 and Ar 4 Each independently represents a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms.

[0373] Examples of the aromatic hydrocarbon group having a monovalent carbon number of 6 or more and 60 or less include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a tetraphenylene ring, A monovalent group of a 1,2-diphenylene ring, ...

[0374] From the viewpoint of solubility and durability of the compound, Ar in formula (260) 3 ,Ar 4 Each independently is preferably a hydrogen atom, a monovalent group of a benzene ring, or a monovalent group of a naphthalene ring, and more preferably a hydrogen atom or a monovalent group of a benzene ring.

[0375] (L 1 ~L 5 ) L in formula (260) 1 ~L 5 Each independently represents a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

[0376] Examples of the aromatic hydrocarbon group having 6 to 60 divalent carbon atoms include a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, A divalent group of a chrysene ring, a pyrene ring, a benzanthracene ring or a perylene ring. L 1 ~L 5 Each independently preferably is a phenylene group which may have a substituent or a divalent group in which two or more, for example, 2 to 5, phenylene groups are directly bonded. From the viewpoint of solubility, 1,3-phenylene group which may have a substituent is more preferred.

[0377] (R) R in formula (260) each independently represents a substituent. As a substituent, a substituent selected from the above-mentioned substituent group Z can be used. Among these, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a silyloxy group, an aralkyl group or an aromatic hydrocarbon group is preferred. From the viewpoint of heat resistance and durability, an alkyl group, an alkenyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a silyloxy group, an aralkyl group or an aromatic hydrocarbon group is preferred, and an alkyl group, an alkoxy group, an aralkyl group or an aromatic hydrocarbon group is further preferred, and an alkyl group having less than 10 carbon atoms, an aralkyl group having less than 30 carbon atoms, or an aromatic hydrocarbon group having less than 30 carbon atoms is more preferred, and a benzene ring or a group formed by connecting 2 to 5 benzene rings is particularly preferred.

[0378] (m1~m5) In formula (260), m1, m2 and m5 each independently represent an integer from 0 to 5, m3 and m4 each independently represent an integer of 1-5.

[0379] From the viewpoint of solubility and durability of the compound, m1, m2 and m5 in formula (260) are preferably 4 or less, more preferably 3 or less, further preferably 2 or less, particularly preferably 1 or less, and most preferably 0. In addition, Ar 1 When m1 and Ar are in formula (4) or (5), 2 When m2 and Ar are in formula (4) or (5), 5 In the case of formula (4) or formula (5), m5 is preferably 0.

[0380] From the viewpoint of solubility and durability of the compound, m3 and m4 in formula (260) are preferably 1 or more, preferably 4 or less, more preferably 3 or less, and particularly preferably 2 or less.

[0381] When m1 in formula (260) is 2 or more, multiple L 1 When m2 in formula (260) is 2 or more, multiple L 2 When m3 in formula (260) is 2 or more, multiple L 3 When m4 in formula (260) is 2 or more, multiple L 4 When m5 in formula (260) is 2 or more, multiple L 5 Can be the same or different.

[0382] ((L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 ,(L 5 ) m5 ) From the viewpoint of solubility and durability of the compound, (L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 In the embodiment, at least one preferably has a structural part selected from the structural part represented by the following formula (11), the structural part represented by the following formula (12) and the structural part represented by the following formula (13), and when m1 is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When n is 1 or more and m5 is 1 or more (L 5 ) m5 , and when m3 is 1 or more (L 3 ) m3 When m4 is greater than 1 (L 4 ) m4 It is further preferred that the compound has a structural portion selected from the group consisting of the structural portion represented by the following formula (11), the structural portion represented by the following formula (12), and the structural portion represented by the following formula (13). As a preferred embodiment, for example, when m1 in formula (260) is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each independently may have a structural moiety selected from the structural moieties represented by the following formulae (11) to (17).

[0383] [Chemistry 80]

[0384] In each of the above formulae (11) to (13), * represents a bond with an adjacent structure or Ar 1 ,Ar 2 ,Ar 3 ,Ar 4 or Ar 5 When the hydrogen atom is a hydrogen atom, at least one of the two *s present indicates a bonding position to an adjacent structure. In the following description, the definition of * is the same unless otherwise specified.

[0385] More preferably, (L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 Among them, at least one has a structural portion represented by formula (11) or a structural portion represented by formula (12). It is further preferred that in formula (260), when m1 is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each of them has a structural part represented by formula (11) or a structural part represented by formula (12). In the formula (260), it is particularly preferred that (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 They respectively have a structural portion represented by formula (11) and a structural portion represented by formula (12).

[0386] In formula (260), as formula (12), the following formula (12-2) is preferred.

[0387] [Chemistry 81]

[0388] In formula (260), as formula (12), the following formula (12-3) is more preferred.

[0389] [Chemistry 82]

[0390] In addition, from the viewpoint of solubility and durability of the compound, (L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 In the formula (1), at least one of the structural moieties preferably has a structural moiety represented by the formula (11) and a structural moiety represented by the formula (12).

[0391] In formula (260), as the structural part having the structural part represented by formula (11) and the structural part represented by formula (12), it is preferred to select a structural part from the structural parts including a plurality of structures selected from the structural parts represented by formula (11) and the structural parts represented by formula (12), that is, the structural parts selected from the following formulas (14) to (17). That is, when m1 is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each independently preferably has a structural part selected from the group consisting of the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17).

[0392] [Chemistry 83]

[0393] In formula (260), a structural portion comprising multiple structures selected from the structural portion represented by formula (11) and the structural portion represented by formula (12) refers to, for example, formula (14), which can be regarded as a structural portion having one structural portion represented by formula (11) and two structural portions represented by formula (12), as shown in the following formula (14a).

[0394] [Chemistry 84]

[0395] In addition, it is further preferred that (L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 In the formula (14), at least one of the above has a structural part represented by formula (14) or a structural part represented by formula (15). More preferably, when m1 is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 It has a structural portion represented by formula (14) or a structural portion represented by formula (15).

[0396] In formula (260), as formula (14), the following formula (14-2) is preferred.

[0397] [Chemistry 85]

[0398] In formula (260), as formula (14), the following formula (14-3) is more preferred.

[0399] [Chemistry 86]

[0400] In formula (260), as formula (15), the following formula (15-2) is preferred.

[0401] [Chemistry 87]

[0402] In formula (260), as formula (15), the following formula (15-3) is more preferred.

[0403] [Chemistry 88]

[0404] In formula (260), as formula (17), the following formula (17-2) is preferred.

[0405] [Chemistry 89]

[0406] In addition, (L in formula (260) 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 At least one of them more preferably has a structural moiety represented by the following formula (19) or a structural moiety represented by the following formula (20) as a structural moiety including the structural moiety represented by the formula (13).

[0407] [Chemistry 90]

[0408] In each of the above formulae (14) to (20), * represents a bond to an adjacent structure or a hydrogen atom, and at least one of the two *s present represents a bonding position to an adjacent structure.

[0409] In formula (260), among formulas (14) to (20), formula (14-3) and formula (15-3) are preferred, and formula (14-3) is more preferred.

[0410] (L 1 ~L 5 Preferred structural part) In formula (260), L 1 ~L 5 It preferably has a structural portion represented by formula (11), a structural portion represented by formula (12-3), a structural portion represented by formula (14-3), or a structural portion represented by formula (15-3).

[0411] (n) In formula (260), n represents an integer from 0 to 10. From the viewpoint of solubility and durability of the compound, n in formula (260) is preferably 1 or more, more preferably 2 or more, preferably 6 or less, more preferably 5 or less, and particularly preferably 4 or less.

[0412] (a1~a3) a1 to a3 each independently represent an integer of 0 to 3. From the viewpoint of solubility and durability of the compound, a1 to a3 are each independently preferably 0 or 1, and most preferably a1=a2=a3=0.

[0413] (R 1 ~R 26 ) In formula (260), R 1 ~R 26 Each independently represents a hydrogen atom or a substituent. As a substituent, a substituent selected from the above-mentioned substituent group Z can be used. Among these, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a silyloxy group, an aralkyl group or an aromatic hydrocarbon group is preferred. From the viewpoint of durability, an alkyl group, an alkenyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a silyloxy group, an aralkyl group or an aromatic hydrocarbon group is preferred, a hydrogen atom and an aromatic hydrocarbon group are more preferred, and a hydrogen atom is particularly preferred.

[0414] (Substituent) In formula (260), Ar 1 ~Ar 5 The monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms and L 1 ~L 5 The substituents that the aromatic hydrocarbon group having 6 or more and 60 or less divalent carbon atoms in may have may be independently selected from the above-mentioned substituent group Z. Among them, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a silyloxy group, an aralkyl group, or an aromatic hydrocarbon group is preferred, and an alkyl group, an alkenyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a silyloxy group, an aralkyl group, or an aromatic hydrocarbon group is more preferred.

[0415] (Molecular weight) The molecular weight of the compound represented by formula (260) is preferably 3,000 or less, more preferably 2,500 or less, further preferably 2,000 or less, particularly preferably 1,500 or less, and is usually 400 or more, preferably 500 or more, and more preferably 600 or more.

[0416] (specific example) Specific examples of the compound represented by formula (260) are shown below, but the compound is not limited to these.

[0417] [Chemistry 91]

[0418] [Chemistry 92]

[0419] [Chemistry 93]

[0420] The light-emitting layer and the light-emitting layer-forming composition of the present invention may contain only one type of compound represented by the above formula (260) or two or more types of compound.

[0421] [Luminescent layer forming composition] The light-emitting layer may be formed by vacuum deposition or wet film formation, and is preferably formed by wet film formation. In the wet film formation, the light-emitting layer is formed by applying a light-emitting layer-forming composition containing an organic solvent and drying the composition.

[0422] The composition for forming a luminescent layer contains a polycyclic heterocyclic compound represented by the above formula (1), an organic metal compound represented by the above formula (201) and an organic solvent, and the polycyclic heterocyclic compound and the organic metal compound satisfy the above relationship (E-1). The composition for forming a luminescent layer further preferably contains the host material. The composition for forming a luminescent layer is a composition in which the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) are dissolved or dispersed in an organic solvent. The composition for forming a luminescent layer can be a composition in which the polycyclic heterocyclic compound represented by the above formula (1), the organic metal compound represented by the above formula (201) and the host material are dissolved or dispersed in an organic solvent.

[0423] (Organic Solvent) The organic solvent that may be contained in the light-emitting layer-forming composition is a volatile liquid component used for forming a layer containing a polycyclic heterocyclic compound by wet film formation.

[0424] The organic solvent is not particularly limited as long as it is an organic solvent that can well dissolve the polycyclic heterocyclic compound and the charge transporting compound as solutes.

[0425] Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin, and methylnaphthalene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2, Aromatic ethers such as 4-dimethylanisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; alicyclic ketones such as cyclohexanone, cyclooctanone, and fenchone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; aliphatic alcohols such as butanol and hexanol; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), etc.

[0426] Among these, from the viewpoint of viscosity and boiling point, alkanes, aromatic hydrocarbons, and aromatic esters are preferred, and aromatic hydrocarbons and aromatic esters are particularly preferred.

[0427] These organic solvents may be used alone or in any combination and ratio.

[0428] The boiling point of the organic solvent used is usually 80°C or more, preferably 100°C or more, more preferably 120°C or more, and usually 350°C or less, preferably 330°C or less, more preferably 300°C or less. When the boiling point of the organic solvent is lower than this range, the film formation stability may be reduced due to the evaporation of the solvent from the light-emitting layer-forming composition during wet film formation. When the boiling point of the organic solvent is higher than this range, the film formation stability may be reduced due to the residual solvent after film formation during wet film formation.

[0429] In particular, it is considered that a combination of two or more organic solvents having a boiling point of 150° C. or higher among the above-mentioned organic solvents is preferred because a more uniform coating film can be easily formed.

[0430] (content) The content of the polycyclic heterocyclic compound represented by the formula (1) in the composition for forming a light-emitting layer is usually 0.001 mass % or more, preferably 0.01 mass % or more and usually 30.0 mass % or less, preferably 20.0 mass % or less. The content of the organometallic compound represented by the formula (201) in the composition for forming a light-emitting layer is usually 0.001 mass % or more, preferably 0.01 mass % or more and usually 30.0 mass % or less, preferably 20.0 mass % or less. By making the content be the range, it is possible to efficiently inject holes or electrons from adjacent layers (for example, hole transport layer, hole blocking layer) to the light-emitting layer, thereby reducing the driving voltage. It should be noted that the polycyclic heterocyclic compound represented by the formula (1) and the organometallic compound represented by the formula (201) may contain only one in the composition for forming a light-emitting layer, or may contain two or more in combination. The content of the organic metal compound represented by formula (2) contained in the composition for forming a light-emitting layer is usually 100 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, and is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, relative to 1 part by mass of the polycyclic heterocyclic compound represented by formula (1).

[0431] When the light-emitting layer-forming composition contains a host material, the content of the host material is usually 0.01 mass % or more, preferably 0.1 mass % or more, and usually 30.0 mass % or less, preferably 20.0 mass % or less.

[0432] The content of the main material contained in the composition for forming a light-emitting layer is usually 1000 parts by mass or less, preferably 100 parts by mass or less, and more preferably 50 parts by mass or less, relative to 1 part by mass of the organic metal compound represented by formula (201), and is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and more preferably 1 part by mass or more.

[0433] The content of the organic solvent contained in the composition for forming the luminescent layer is usually 10% by mass or more, preferably 50% by mass or more, particularly preferably 80% by mass or more, and usually 99.95% by mass or less, preferably 99.9% by mass or less, particularly preferably 99.8% by mass or less. If the content of the organic solvent is above the lower limit, it has a moderate viscosity and improves the coating property, and if it is below the upper limit, it is easy to obtain a uniform film and make the film-forming property good.

[0434] (Other ingredients) The light-emitting layer-forming composition may contain other compounds in addition to the above-mentioned compounds as necessary. Preferred examples of other compounds include phenols known as antioxidants such as dibutylhydroxytoluene and dibutylphenol.

[0435] (Film Forming Method) The method for forming the luminescent layer is preferably a wet film-forming method. The wet film-forming method refers to a method of applying a composition to form a liquid film, drying and removing an organic solvent to form a luminescent layer film. As a coating method, for example, a method of forming a film by a wet method such as spin coating, dip coating, die coating, rod coating, blade coating, roller coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, gravure printing, flexographic printing, etc. is adopted, and the coated film is dried to form a film. Among these coating methods, spin coating, spray coating, inkjet, nozzle printing, etc. are preferably used. When manufacturing an organic EL display device having an organic electroluminescent element, an inkjet method or a nozzle printing method is preferably used, and an inkjet method is particularly preferably used.

[0436] The drying method is not particularly limited, and natural drying, reduced pressure drying, heating drying, or heating and reduced pressure drying can be used as appropriate. Heating drying can also be performed after natural drying or reduced pressure drying in order to further remove the residual organic solvent.

[0437] The reduced pressure in the reduced pressure drying is preferably reduced to a pressure not higher than the vapor pressure of the organic solvent contained in the light-emitting layer-forming composition.

[0438] In the case of heating, the heating method is not particularly limited, and heating using a hot plate, heating in an oven, infrared heating, etc. can be used. The heating time is usually 80° C. or more, preferably 100° C. or more, more preferably 110° C. or more, and preferably 200° C. or less, more preferably 150° C. or less.

[0439] The heating time is usually 1 minute or longer, preferably 2 minutes or longer, and usually 60 minutes or shorter, preferably 30 minutes or shorter, and more preferably 20 minutes or shorter.

[0440] [Hole injection layer] The hole injection layer needs to have a function of transporting holes and therefore contains a hole transport material. The organic electroluminescent device of the present invention contains tetraarylborate ions in the hole injection layer.

[0441] In order to improve the hole injectability from the anode to the hole injection layer, improve the hole transportability in the hole injection layer, the hole transport material contained in the hole injection layer preferably contains a cation radical part. In order to make the hole transport material cation radical, an electron accepting compound is used when forming the hole injection layer. As the parent skeleton of the electron accepting compound, the ionic compound composed of the tetraaryl borate ion and the counter cation as the anion with an ionic valence of 1 described later is preferred because of having high stability.

[0442] The cation radicalization of the hole transport material is carried out as follows. When a compound having a triarylamine structure is used as the hole transport material, for example, and a tetraarylborate having a diaryliodonium as a counter cation is used as the electron accepting compound, when the hole injection layer is formed, the counter cation can be changed from diaryliodonium to triarylammonium as shown in the following formula.

[0443] [Chemistry 94]

[0444] (e.g., Ar, Ar 1 ~Ar 4 Each is independently a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an aromatic hydrocarbon ring group which may have a substituent and an aromatic heterocyclic group which may have a substituent.)

[0445] Since the triarylammonium generated in the above reaction has a half occupied orbital (SOMO) that can accept electrons, the tetraarylborate having the triarylammonium as a counter cation is an electron accepting compound.

[0446] In the present invention, a compound composed of a cation of the hole transport material and a tetraarylborate ion as an anion is referred to as a charge transport ion compound. The details are described later.

[0447] [Electron-accepting compound having a cross-linking group] As mentioned above, the electron accepting compound includes a compound having an ionic compound composed of a tetraarylborate ion and a counter cation as a parent skeleton, or a compound having an ionic compound composed of a tetraarylborate ion and a counter cation as a parent skeleton and having the following crosslinking group.

[0448] (Cross-linking group) The crosslinking group of the electron accepting compound of the crosslinked product of the electron accepting compound having a crosslinking group that may be included in the hole injection layer of the organic electroluminescent element of the present invention refers to a group that reacts with other groups located near the crosslinking group by irradiation with heat and / or active energy lines to generate a new chemical bond. In this case, the reactive group may be the same group as the crosslinking group or a different group.

[0449] It is believed that when the electron accepting compound includes a crosslinking group, a crosslinking reaction can be performed when the hole injection layer is formed, and the electron accepting compound is fixed to the hole injection layer, and when the layer on the hole injection layer is formed by a wet film forming method, the electron accepting compound will not diffuse to the layer on the hole injection layer. Therefore, it is inferred that when using an electron accepting compound with a crosslinking group, the degradation reaction in the drive can be suppressed.

[0450] In addition, the boron-containing polycyclic heterocyclic compound has an empty p orbital on boron and is particularly susceptible to reaction with an electron donating substance.

[0451] The following method is usually used: by using an electron accepting compound in the hole injection layer, the hole injection from the metal anode is promoted to reduce the driving voltage. However, it is believed that in the previous technology, when the layer on the hole injection layer is formed by a wet film forming method, the electron accepting compound of the hole injection layer will diffuse and reach the light-emitting layer, and the electron accepting compound reacts with the boron-containing polycyclic heterocyclic compound in the device drive, resulting in an increase in driving voltage and a reduction in driving life.

[0452] On the other hand, it is believed that by containing a crosslinking group in the electron accepting compound, a crosslinking reaction is carried out when forming a hole injection layer, thus when the electron accepting compound is fixed to the hole injection layer, when the layer on the hole injection layer is formed by a wet film forming method, the electron accepting compound will not diffuse. Therefore, it is inferred that by using an electron accepting compound with a crosslinking group, the degradation reaction in the drive can be suppressed. In addition, when the organometallic compound contains heavy atoms such as iridium, the intersystem crossing between the excited triplet state and the excited singlet state is promoted by the heavy atom effect. Since the intersystem crossing is promoted, it is estimated that the excited triplet energy, which accounts for 75% of the excitons generated by applying voltage to the organic electroluminescent element, can be effectively used for the emission of the boron-containing polycyclic heterocyclic compound as a fluorescent light-emitting material.

[0453] The crosslinking group is preferably a crosslinking group represented by any one of the following formulae (X1) to (X18).

[0454] [Chemistry 95]

[0455] In formulae (X1) to (X4), the benzene ring and the naphthalene ring may have a substituent. Furthermore, the substituents may be bonded to each other to form a ring. R in formula (X4), formula (X5), formula (X6) and formula (X10) 110 Each independently represents an alkyl group which may have a substituent. In formulas (X1) to (X18), * represents a bonding position. )

[0456] By R 110 The alkyl group represented by is a linear, branched or cyclic structure, and has 1 or more carbon atoms, preferably 24 or less, more preferably 12 or less, and further preferably 8 or less.

[0457] The benzene ring and naphthalene ring of formulae (X1) to (X4), R of formulae (X4) to (X6) and (X10) 110 The substituent that may be possessed is preferably an alkyl group, an aromatic hydrocarbon group, an alkoxy group, or an aralkyl group.

[0458] The alkyl group as a substituent has a linear, branched or cyclic structure and has preferably 24 or less carbon atoms, more preferably 12 or less carbon atoms, further preferably 8 or less carbon atoms, and preferably 1 or more carbon atoms.

[0459] The number of carbon atoms of the aromatic hydrocarbon group as a substituent is preferably 24 or less, more preferably 18 or less, further preferably 12 or less, and preferably 6 or more. The aromatic hydrocarbon group may further have the above-mentioned alkyl group as a substituent.

[0460] The number of carbon atoms of the alkoxy group as a substituent is preferably 24 or less, more preferably 12 or less, further preferably 8 or less, and preferably 1 or more.

[0461] The carbon number of the aralkyl group as a substituent is preferably 30 or less, more preferably 24 or less, further preferably 14 or less, and preferably 7 or more. The alkylene group contained in the aralkyl group is preferably a linear or branched structure. The aryl group contained in the aralkyl group may further have the above-mentioned alkyl group as a substituent.

[0462] As a cross-linking group, a cross-linking group represented by any one of formulae (X1) to (X4) is preferred because of its small polarity and small effect on charge transport. Furthermore, since the cross-linking reaction is carried out only by heat, a cross-linking group represented by any one of formulae (X1) to (X3) is more preferred.

[0463] The crosslinking group represented by the formula (X1) is as shown below. The cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0464] [Chemistry 96]

[0465] The crosslinking group represented by the formula (X2) is as shown below: the cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0466] [Chemistry 97]

[0467] The crosslinking group represented by the formula (X3) is as shown below: the cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0468] [Chemistry 98]

[0469] Regarding the crosslinking group represented by any one of formulae (X1) to (X3), the cyclobutene ring is opened by heat, and when there is a double bond nearby, the ring-opened group reacts with the double bond to form a crosslinking structure. The following is an example of a crosslinking structure formed by the ring-opened group represented by formula (X1) and the crosslinking group represented by formula (X4) having a double bond site. (Wherein, R of formula (X4) 110 Not shown.)

[0470] [Chemistry 99]

[0471] As a group containing a double bond that can react with a crosslinking group represented by any one of formulas (X1) to (X3), in addition to the crosslinking group represented by formula (X4), a crosslinking group represented by any one of formulas (X5), (X6), (X12), (X15), (X16), (X17), and (X18) can also be mentioned. When these groups containing double bonds are used as crosslinking groups in electron-accepting compounds, it is preferred to include a crosslinking group represented by any one of formulas (X1) to (X3) in other components forming a hole injection layer such as a hole transporting compound, because this increases the possibility of forming a crosslinked structure.

[0472] As the crosslinking group, a crosslinking group represented by any of the radical polymerizable formulae (X4), (X5), and (X6) is preferred because it has a small polarity and is unlikely to hinder charge transport.

[0473] As the crosslinking group, a crosslinking group represented by formula (X7) is preferred from the viewpoint of improving electron accepting property. When a crosslinking group represented by formula (X7) is used, the following crosslinking reaction proceeds.

[0474] [Chemical 100]

[0475] From the viewpoint of high reactivity, the crosslinking group represented by any one of formula (X8) and (X9) is preferred. It should be noted that when the crosslinking group represented by formula (X8) and the crosslinking group represented by formula (X9) are used, the following crosslinking reaction is performed.

[0476] [Chemistry 101]

[0477] As the crosslinking group, a cationically polymerizable crosslinking group represented by any one of formulae (X10), (X11), and (X12) is preferred because of its high reactivity.

[0478] (Cross-linked product of electron accepting compound) As described later, the hole injection layer of the organic electroluminescent element of the present invention is preferably obtained by wet film formation of a composition for hole injection layer formation, and the composition for hole injection layer formation is more preferably a composition obtained by dissolving or dispersing the first ionic compound having a tetraaryl borate ion structure described later and the hole transport material described later in an organic solvent. Moreover, in the hole transport layer of the organic electroluminescent element of the present invention, it is preferred to contain a charge transporting ionic compound having a tetraaryl borate ion structure in the present invention as an anion and a cation of the hole transport material as a counter cation.

[0479] Therefore, as the electron accepting compound in the electron accepting compound having a crosslinking group, the electron accepting compound as an ionic compound is preferably an ionic compound with a tetraaryl borate ion structure as an anion. In the case where the electron accepting compound is an ionic compound with a tetraaryl borate ion structure as an anion, the tetraaryl borate ion preferably has a crosslinking group. The tetraaryl borate ion structure is described later.

[0480] When an electron accepting compound having a crosslinking group is used, a crosslinked product of the electron accepting compound having a crosslinking group is formed. The crosslinked product of the electron accepting compound having a crosslinking group includes the following crosslinked products. A compound in which electron-accepting compounds are cross-linked. A compound formed by cross-linking an electron-accepting compound and a hole-transporting material. A compound formed by cross-linking an electron accepting compound with the tetraarylborate ion in the present invention. The compound of the present invention is a compound in which tetraarylborate ions are cross-linked. The compound of the present invention is a cross-linked compound of a tetraarylborate ion and a hole transport material.

[0481] Here, the “tetraarylborate ion in the present invention” includes the case where it exists as an electron-accepting compound of an ionic compound formed of a tetraarylborate ion described below and a counter cation, and the case where it exists as a charge-transporting ionic compound formed of a tetraarylborate ion described below and a cation of a hole transport material. The cross-linked product of the tetraarylborate ion having a cross-linking group in the present invention may be the following cross-linked product. A compound formed by cross-linking an electron accepting compound with the tetraarylborate ion in the present invention. The compound of the present invention is a compound in which tetraarylborate ions are cross-linked. The compound of the present invention is a cross-linked compound of a tetraarylborate ion and a hole transport material.

[0482] The two crosslinking groups in the crosslinking reaction may be the same crosslinking group or different crosslinking groups as long as the crosslinking reaction can proceed.

[0483] [Tetraarylborate ion] The tetraarylborate ion is an anion having an ion valence of 1, in which four aromatic hydrocarbon rings or aromatic hetero rings which may have a substituent and / or a crosslinking group are substituted on a boron atom.

[0484] The tetraarylborate ion contained in the organic electroluminescent device of the present invention preferably has a fluorine atom or an alkyl group substituted with fluorine as a substituent of the aryl group from the viewpoint of further improving stability.

[0485] [Chemistry 102]

[0486] (In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent.

[0487] Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them preferably has a cross-linking group.

[0488] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The aromatic hydrocarbon ring group used in the present invention is preferably a monocyclic ring or a two-membered to six-membered condensed ring. Specifically, the aromatic hydrocarbon ring group may be a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring, biphenyl structure, terphenyl structure or quadrophenyl structure.

[0489] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The aromatic heterocyclic group used in is preferably a monocyclic ring or a two-membered to six-membered condensed ring. Specifically, it can include: a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring or an azulene ring.

[0490] Among them, a monovalent group derived from a benzene ring, a naphthalene ring, a fluorene ring, a pyridine ring or a carbazole ring or a biphenyl group is more preferred due to excellent stability and heat resistance. A monovalent group derived from a benzene ring, that is, a phenyl group or a biphenyl group is particularly preferred.

[0491] The total number of monocyclic or dicyclic to hexacyclic condensed aromatic hydrocarbon ring groups and monocyclic or dicyclic to hexacyclic condensed aromatic heterocyclic groups contained in the monovalent group formed by connecting multiple structures selected from aromatic hydrocarbon ring groups that may have substituents and / or cross-linking groups and aromatic heterocyclic groups that may have substituents and / or cross-linking groups is 2 or more, preferably 8 or less, more preferably 4 or less, and more preferably 3 or less.

[0492] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The substituents which may be possessed include the groups described in the substituent group W described later.

[0493] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The substituent of Ar is preferably a fluorine atom or an alkyl group substituted with fluorine from the viewpoint of increasing the stability of the anion and improving the effect of stabilizing the cation. 1 ,Ar 2 ,Ar 3 and Ar 4 2 or more of the substituted moieties are substituted, more preferably 3 or more of the substituted moieties are substituted, and most preferably 4 of the substituted moieties are substituted.

[0494] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The fluorine-substituted alkyl group of the substituent is preferably a linear or branched alkyl group having 1 to 12 carbon atoms and substituted with a fluorine atom, more preferably a perfluoroalkyl group, further preferably a linear or branched perfluoroalkyl group having 1 to 5 carbon atoms, particularly preferably a linear or branched perfluoroalkyl group having 1 to 3 carbon atoms, and most preferably a perfluoromethyl group. The reason is that the hole injection layer containing the crosslinked product of the electron accepting compound having a tetraarylborate ion or a crosslinking group, or the coating film stacked thereon becomes stable.

[0495] Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The crosslinking groups that may be present are as shown in the above-mentioned crosslinking groups.

[0496] From the perspective of further increasing the stability of the anion and further improving the effect of stabilizing the cation, the tetraarylborate ion contained in the organic electroluminescent device of the present invention is preferably Ar in the above formula (2): 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by formula (3), more preferably Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least two of them are independently a group represented by formula (3), and Ar is more preferably 1 ,Ar 2 ,Ar 3 and Ar 4 At least three of them are independently a group represented by formula (3), and Ar is most preferred 1 ,Ar 2 ,Ar 3 and Ar 4 All of them are independently a group represented by formula (3).

[0497] [Chemistry 103]

[0498] (In formula (3), R 1 Each is independently selected from an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, and an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, a monovalent group formed by connecting multiple structures, an alkyl group substituted with fluorine, a substituent or a crosslinking group, F4 represents the substitution of 4 fluorine atoms, F (5-m) Each independently represents substitution of 5-m fluorine atoms, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0-5. *Indicates bonding position. )

[0499] From the viewpoint of further improving the stability of anions, k is preferably 1 or more, and more preferably 2 or more. From the viewpoint of facilitating uniform dispersion, k is preferably 0 or 1, and preferably 0.

[0500] From the perspective of better durability, m is preferably 0, from the perspective of being able to introduce various functions into the tetraarylborate ion, it is preferably 1 or more and preferably 3 or less, and from the perspective of achieving durability, it is more preferably 1 or 2. From the viewpoint of improving anion stability and excellent durability, k+m≥1 is preferred.

[0501] As R 1 The aromatic hydrocarbon ring group or aromatic heterocyclic group, the preferred structure and the substituents that may be possessed by Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The structure and possible substituents are the same.

[0502] As R 1 The substituents and R 1 When it is a substituent, the substituent includes the groups described in the substituent group W described later.

[0503] In formula (3), from the perspective of further increasing the anion stability and further improving the effect of stabilizing the cation, at least one R 1 It is preferably the alkyl group substituted with fluorine, preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0504] As R 1 The cross-linking groups and R 1 When it is a cross-linking group, the cross-linking group is as described above for the cross-linking group.

[0505] In one embodiment of the present invention, from the perspective of achieving both crosslinking properties and electron accepting properties, it is preferred that at least one R in formula (3) 1 Contains the above cross-linking group. In this case, as R 1 , preferably a structure in which the cross-linking group or one or more cross-linking groups are bonded to an aromatic hydrocarbon group.

[0506] In another embodiment of the present invention, from the perspective of further increasing the anion stability and further improving the effect of stabilizing the cation, at least one R in formula (3) 1 It is preferably the alkyl group substituted with fluorine, preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0507] As R 1 The cross-linking groups and R 1 When it is a cross-linking group, the cross-linking group is as described above for the cross-linking group.

[0508] From the perspective of achieving both crosslinking properties and electron accepting properties, Ar in the above formula (2) is preferably 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is at least one R 1 The structure represented by the above formula (3) is a cross-linking group. 1 , preferably a structure in which the cross-linking group or one or more cross-linking groups are bonded to an aromatic hydrocarbon group.

[0509] Further, R 1 A group including a group represented by the following formula (4) or a group represented by the following formula (5) is also preferred.

[0510] [Chemistry 104]

[0511] The groups represented by the formula (4) and the groups represented by the formula (5) may have a substituent. Examples of the substituents are: 1 The substituents that may be possessed are the same.

[0512] As R 1 , preferably a group represented by formula (4) or a group represented by formula (5), or a structure in which one or more groups represented by formula (4) or groups represented by formula (5) are bonded to an aromatic hydrocarbon group.

[0513] As R 1 In the case where one or more of the crosslinking groups are bonded to an aromatic hydrocarbon group, the aromatic hydrocarbon group is preferably a benzene ring, a naphthalene ring, or a structure in which two or more selected from a benzene ring and a naphthalene ring are connected, and the number of connections is preferably 4 or less. In this case, more preferably R 1 The structure in which the crosslinking group is bonded to a benzene ring or a naphthalene ring is more preferably a structure in which the crosslinking group is bonded to a benzene ring, and a structure in which one or two crosslinking groups are bonded is particularly preferred.

[0514] In R 1 When it is a group including a group represented by the formula (4) or a group represented by the following formula (5), it is further preferred that R 1 It is a structure in which a group represented by formula (4) or a group represented by formula (5) is bonded to a benzene ring or a naphthalene ring. It is further preferably a structure in which a group represented by formula (4) or a group represented by formula (5) is bonded to a benzene ring. It is particularly preferably a structure in which one or two groups represented by formula (4) or groups represented by formula (5) are bonded.

[0515] The group represented by the formula (4) and the group represented by the formula (5) are crosslinkable and are considered to be preferred because the tetraarylborate ions and the counter cations do not diffuse into other layers.

[0516] (Substituent Group W) The substituent group W is a hydrogen atom, a halogen atom, a cyano group, an aromatic hydrocarbon ring group composed of 1 to 5 aromatic hydrocarbon rings, an aliphatic hydrocarbon ring group, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkyl ketone group or an aryl ketone group.

[0517] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In view of the stability of the compound, a fluorine atom is preferred.

[0518] Examples of the aromatic hydrocarbon ring group consisting of 1 to 5 aromatic hydrocarbon rings include phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, triphenylene, naphthylphenyl, etc., and phenyl, naphthyl, biphenyl, terphenyl or quaterphenyl is preferred in view of the stability of the compound.

[0519] Examples of the aliphatic hydrocarbon ring group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0520] The alkyl group has a carbon number of usually 1 or more, preferably 4 or more and usually 24 or less, preferably 12 or less, more preferably 8 or less, and more preferably 6 or less. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, octyl, 2-ethylhexyl, and dodecyl.

[0521] The alkenyl group has a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less. Specific examples thereof include ethenyl, propenyl, and butenyl.

[0522] The alkynyl group has usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms. Specific examples thereof include ethynyl, propynyl, and butynyl.

[0523] Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenylhexyl group.

[0524] The alkoxy group has a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, and more preferably 6 or less. Specific examples thereof include a methoxy group, an ethoxy group, a butoxy group, a hexyloxy group, and an octyloxy group.

[0525] The aryloxy group has a carbon number of usually 4 or more, preferably 5 or more, more preferably 6 or more and usually 36 or less, preferably 24 or less, more preferably 12 or less. Specific examples thereof include a phenoxy group and a naphthoxy group.

[0526] The alkylthio group has a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less. Specific examples thereof include a methylthio group, an ethylthio group, a butylthio group, and a hexylthio group.

[0527] The arylthio group has usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less carbon atoms. Specific examples thereof include a phenylthio group and a naphthylthio group.

[0528] The alkyl ketone group has a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, and more preferably 6 or less. Specific examples thereof include acetyl, ethylcarbonyl, butylcarbonyl, and octylcarbonyl.

[0529] The aryl keto group has a carbon number of usually 5 or more, preferably 7 or more, and usually 25 or less, preferably 13 or less. Specific examples thereof include a benzoyl group and a naphthylcarbonyl group.

[0530] Furthermore, adjacent substituents may be bonded to each other to form a ring. Examples of the ring formation include a cyclobutene ring and a cyclopentene ring.

[0531] Furthermore, these substituents may be further substituted with a substituent, and examples of the substituent include a halogen atom, an alkyl group, an aryl group, or the crosslinking group.

[0532] Among these substituents, a halogen atom or an aryl group is preferred from the viewpoint of the stability of the compound, a halogen atom is most preferred, and a fluorine atom is preferred among the halogen atoms.

[0533] [Specific examples of tetraarylborate ions] Specific examples of the tetraarylborate ion used in the organic electroluminescent device of the present invention are given below, but the present invention is not limited to these.

[0534] [Chemistry 105]

[0535] [Chemistry 106]

[0536] [Chemistry 107]

[0537] [Chemistry 108]

[0538] [Chemistry 109]

[0539] [Chemistry 110]

[0540] [Chemistry 111]

[0541] [Chemistry 112]

[0542] [Chemistry 113]

[0543] [Chemistry 114]

[0544] Among the above specific examples, compounds (A-1) and (A-2) are preferred from the viewpoints of electron accepting property, heat resistance and solubility. Furthermore, compounds (A-18), (A-19), (A-20), (A-21), (A-25), (A-26) and (A-28) are more preferred from the viewpoint of high stability as a charge transport film composition, and compounds (A-19), (A-21), (A-25), (A-26) and (A-28) are particularly preferred from the viewpoint of stability of an organic electroluminescent element.

[0545] It should be noted that the tetraarylborate ions of (A-18), (A-19), (A-20), (A-21), (A-25), (A-26), (A-28), and (A-29) can form "crosslinked products of electron-accepting compounds" because they have crosslinking groups.

[0546] [Electron-accepting ionic compounds containing tetraarylborate ions] Tetraaryl borate ions are also preferably used as electron accepting ionic compounds containing tetraaryl borate ions. The electron accepting ionic compound containing tetraaryl borate ions is referred to as a first ionic compound. The first ionic compound is composed of the tetraaryl borate ions as anions and counter cations. The first ionic compound is used as an electron accepting compound.

[0547] The counter cation is preferably an iodonium cation, a sulfonium cation, a carbonium ion, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation or a ferrocenium cation having a transition metal, more preferably an iodonium cation, a sulfonium cation, a carbonium ion or an ammonium cation, and particularly preferably an iodonium cation.

[0548] As the iodonium cation, a structure represented by the general formula (6) described below is preferred, and the more preferred structure is the same.

[0549] Specifically, the iodonium cation is preferably a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, a 4-tert-butyloxyphenylphenyliodonium cation, a 4-methoxyphenylphenyliodonium cation, a 4-isopropylphenyl-4-methylphenyliodonium cation, or the like.

[0550] Specific examples of the sulfonium cation include triphenylsulfonium cation, 4-hydroxyphenyldiphenylsulfonium cation, 4-cyclohexylphenyldiphenylsulfonium cation, 4-methanesulfonylphenyldiphenylsulfonium cation, (4-tert-butoxyphenyl)diphenylsulfonium cation, bis(4-tert-butoxyphenyl)phenylsulfonium cation, and 4-cyclohexylsulfonylphenyldiphenylsulfonium cation.

[0551] Specifically, preferred examples of the carbocation include trisubstituted carbocations such as triphenylcarbocation, tri(methylphenyl)carbocation, and tri(dimethylphenyl)carbocation.

[0552] As the ammonium cation, specifically, preferred are trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, and tri(n-butyl)ammonium cation; N,N-dialkylanilinium cations such as N,N-diethylanilinium cation and N,N-2,4,6-pentamethylanilinium cation; and dialkylammonium cations such as di(isopropyl)ammonium cation and dicyclohexylammonium cation.

[0553] Specifically, the phosphonium cation is preferably a tetraarylphosphonium cation such as a tetraphenylphosphonium cation, a tetra(methylphenyl)phosphonium cation, and a tetra(dimethylphenyl)phosphonium cation; or a tetraalkylphosphonium cation such as a tetrabutylphosphonium cation and a tetrapropylphosphonium cation.

[0554] Among these, from the viewpoint of the film stability of the compound, an iodonium cation, a carbenium ion, and a sulfonium cation are preferred, and an iodonium cation is more preferred.

[0555] The iodonium cation as the counter cation of the first ionic compound preferably has a structure represented by the following formula (6).

[0556] [Chemistry 115]

[0557] In formula (6), Ar 5 ,Ar 6 Each is independently an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. 5 ,Ar 6 The aromatic hydrocarbon ring group or aromatic heterocyclic group can be selected from Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure, the preferred structure can also be selected from Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure.

[0558] In addition, the counter cation represented by the above formula (6) is preferably a structure represented by the following formula (7).

[0559] [Chemistry 116]

[0560] In the above formula (7), Ar 7 and Ar 8 and Ar in the above formula (6) 5 and Ar 6 The substituents that may be possessed are the same.

[0561] The molecular weight of the first ionic compound used in the present invention is usually 900 or more, preferably 1000 or more, more preferably 1200 or more, and is usually 10000 or less, preferably 5000 or less, more preferably 3000 or less. When the molecular weight is too small, the delocalization of positive and negative charges is insufficient, so the electron accepting ability may be reduced, and when the molecular weight is too large, it may hinder the charge transport.

[0562] [Specific example] Hereinafter, specific examples of ionic compounds with iodonium cations will be given as the first ionic compound in the present invention, but the first ionic compound is not limited to these.

[0563] [Chemistry 117]

[0564] [Chemistry 118]

[0565] [Chemistry 119]

[0566] [Chemistry 120]

[0567] [Chemistry 121]

[0568] [Chemistry 122]

[0569] [Chemistry 123]

[0570] [Chemistry 124]

[0571] [Chemistry 125]

[0572] [Chemistry 126]

[0573] [Chemistry 127]

[0574] [Chemistry 128]

[0575] [Chemistry 129]

[0576] Among the above specific examples, compounds (B-1) and (B-2) are preferred from the perspective of electron acceptance, heat resistance, and solubility. Furthermore, compounds (B-18), (B-19), (B-20), (B-21), (B-25), (B-26), (B-28), and (B-29) are more preferred from the perspective of high stability as a charge transport film composition, and compounds (B-19), (B-21), (B-25), (B-26), (B-28), and (B-29) are particularly preferred from the perspective of stability of an organic electroluminescent element.

[0577] [Hole transport materials] The hole injection layer preferably contains a hole transport material, and is preferably formed using a hole transport material. As a hole transport material, based on the hole transport ability, a compound having an ionization potential of 4.5 eV to 5.5 eV is preferred. As examples, aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, etc. can be cited. Among them, aromatic amine compounds are preferred from the perspective of amorphousness, solubility in solvents, and visible light transmittance.

[0578] Among the aromatic amine compounds, aromatic tertiary amine compounds are particularly preferred in the present invention. It should be noted that the aromatic tertiary amine compounds referred to in the present invention refer to compounds having an aromatic tertiary amine structure, and also include compounds having a group derived from an aromatic tertiary amine.

[0579] The type of aromatic tertiary amine compound is not particularly limited, and aromatic tertiary amine polymer compounds are preferred as polymer compounds. Regarding the molecular weight of the polymer compound, from the perspective of surface smoothing effect, the weight average molecular weight is preferably 5000 or more, more preferably 7000 or more, particularly preferably 10000 or more, preferably 1000000 or less, more preferably 200000 or less, and particularly preferably 100000 or less. From the viewpoint of hole transport, among aromatic tertiary amine polymer compounds, polymer compounds having a triphenylamine structure in the main chain are further preferred.

[0580] [Aromatic tertiary amine polymer compounds] Preferred examples of the aromatic tertiary amine polymer compound include polymer compounds having a repeating unit represented by the following formula (11).

[0581] [Chemistry 130]

[0582] In the above formula (11), j 10 , k 10 , l 10 、m 10 、n 10 、p 10 Each independently represents an integer greater than 0. 10 +m 10 ≥1.

[0583] In the above formula (11), Ar 11 ,Ar 12 ,Ar 14 Each independently represents a divalent aromatic ring group which may have a substituent. 13 represents a divalent aromatic ring group which may have a substituent or a divalent group represented by the following formula (12), Q 11 , Q 12 Each independently represents an oxygen atom, a sulfur atom, or a hydrocarbon chain having 6 or less carbon atoms which may have a substituent, S 1 ~S 4 Each is independently represented by a group represented by the following formula (13).

[0584] Ar 11 ,Ar 12 ,Ar 14 The aromatic ring group is a divalent group formed by connecting at least two groups selected from a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent. 11 ,Ar 12 ,Ar 14 The aromatic ring group preferably has 60 or less carbon atoms.

[0585] The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms, and specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monocyclic six-membered ring or a divalent group of a two- to five-membered condensed ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring or a fluorene ring.

[0586] The aromatic heterocyclic group preferably has 3 to 30 carbon atoms, and specifically includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring or an azulene ring.

[0587] Among them, from the perspective of excellent charge transport properties, as well as excellent durability and heat resistance, divalent groups or divalent biphenyl groups derived from benzene rings, naphthalene rings, fluorene rings, pyridine rings or carbazole rings are preferred, and divalent groups or divalent biphenyl groups derived from benzene rings, fluorene rings or carbazole rings are more preferred.

[0588] Therefore, as Ar 11 ,Ar 12 ,Ar 14 , preferably a group selected from a divalent benzene ring which may have a substituent, a divalent fluorene ring which may have a substituent, or a divalent carbazole ring which may have a substituent, or a divalent group formed by connecting two or more rings selected from these structures, Ar 11 ,Ar 12 ,Ar 14 The aromatic ring group preferably has 60 or less carbon atoms.

[0589] These aromatic ring groups may have a substituent, and the substituent may be selected from the above-mentioned substituent group Z.

[0590] Ar 13 When it is an aromatic ring group, 11 ,Ar 12 ,Ar 14 The same situation. In addition, Ar 13 Preferred is a divalent group represented by the following formula (12).

[0591] [Chemistry 131]

[0592] In the above formula (12), R 11 R represents an alkyl group, an aromatic ring group, or a trivalent group consisting of an alkyl group having 40 or less carbon atoms and an aromatic ring group, and these groups may have a substituent. 12 Ar represents an alkyl group, an aromatic ring group, or a divalent group consisting of an alkyl group having 40 or less carbon atoms and an aromatic ring group, and these groups may have a substituent. 31 represents a monovalent aromatic ring group or a monovalent crosslinking group, and these groups may have a substituent. The asterisk (*) represents a bonding site to the nitrogen atom of the formula (11).

[0593] As R 11 Specific examples of the aromatic ring group include a trivalent group derived from a benzene ring, a naphthalene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a connected ring having 30 or less carbon atoms formed by connecting these rings.

[0594] As R 11 Specific examples of the alkyl group include trivalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0595] As R 12 Specific examples of the aromatic ring group include a divalent group derived from a benzene ring, a naphthalene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a connected ring having 30 or less carbon atoms formed by connecting these rings.

[0596] As R 12 Specific examples of the alkyl group include divalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0597] As Ar 31 Specific examples of the aromatic ring group include a monovalent group derived from a benzene ring, a naphthalene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a connected ring having 30 or less carbon atoms formed by connecting these rings.

[0598] As Ar 31 The crosslinking group is not particularly limited and is the same as the crosslinking group of the electron accepting compound having the crosslinking group contained in the hole injection layer of the organic electroluminescent element of the present invention, and is preferably a crosslinking group represented by any one of the above formulae (X1) to (X18). Among them, preferably, there can be mentioned: a group derived from a benzocyclobutene ring, a naphthalenecyclobutene ring or an oxetane ring, a vinyl group, and an acryloyl group. For the stability of the compound, a group derived from a benzocyclobutene ring or a naphthalenecyclobutene ring is more preferred.

[0599] S 1 ~S 4 Each is independently a group represented by the following formula (13).

[0600] [Chemistry 132]

[0601] In the above formula (13), q and r each independently represent an integer of 0 to 6. q and r are each independently preferably 0 to 4, more preferably 0 or 1.

[0602] Ar 21 ,Ar 23 Each independently represents a divalent aromatic ring group, and these groups may have a substituent. 22 represents a monovalent aromatic ring group which may have a substituent, R 13 represents an alkyl group, an aromatic ring group, or a divalent group consisting of an alkyl group and an aromatic ring group, and these groups may have a substituent. 32 represents a monovalent aromatic ring group or a monovalent crosslinking group, and these groups may have a substituent. The asterisk (*) represents a bonding site to the nitrogen atom of the general formula (11).

[0603] As Ar 21 ,Ar 23 Examples of aromatic ring groups, with Ar 11 ,Ar 12 ,Ar 14 The same situation.

[0604] Ar 22 ,Ar 32 The aromatic ring group is a monovalent group formed by connecting at least two groups selected from a monovalent aromatic hydrocarbon group which may have a substituent, a monovalent aromatic heterocyclic group which may have a substituent, or a monovalent aromatic hydrocarbon group which may have a substituent and a monovalent aromatic heterocyclic group which may have a substituent. 22 ,Ar 32 The aromatic ring group preferably has 60 or less carbon atoms.

[0605] The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms, and specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monovalent group of a six-membered ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring or a condensed two- to five-membered ring.

[0606] The aromatic heterocyclic group preferably has 3 to 30 carbon atoms, and specifically includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring or azulene ring.

[0607] Among them, a monovalent group derived from a benzene ring, a naphthalene ring, a fluorene ring, a pyridine ring or a carbazole ring, or a biphenyl group is preferred from the viewpoint of excellent charge transport properties, and excellent durability and heat resistance.

[0608] These aromatic ring groups may have a substituent, and the substituent may be selected from the above-mentioned substituent group Z.

[0609] As R 13 Examples of alkyl groups or aromatic ring groups, with R 12 same.

[0610] Ar 32 The cross-linking group is not particularly limited, and Ar 31 Examples of the cross-linking group are the same as those of the above, and preferred examples are also the same.

[0611] The above Ar 11 ~Ar 14 , R 11 , R 12 ,Ar 21 ~Ar 23 ,Ar 31 ~Ar 32 , Q 11 , Q 12 Unless it violates the gist of the present invention, it may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. The type of the substituent is not particularly limited, and as an example, one or more substituents selected from the above-mentioned substituent group Z can be cited.

[0612] In particular, among the polymer compounds having a repeating unit represented by the formula (11), the polymer compounds having a repeating unit represented by the following formula (14) are preferred because they have extremely high hole injection / transport properties.

[0613] [Chemistry 133]

[0614] In the above formula (14), R 21 ~R 25 Each independently represents an arbitrary substituent. 21 ~R 25 Specific examples of the substituent are the same as the substituents described in the above-mentioned substituent group Z.

[0615] Y' represents a divalent aromatic ring group having 30 or less carbon atoms which may have a substituent. Examples of the aromatic ring group of Y' are the same as those of Ar 11 ,Ar 12 and Ar 14 The case is the same as that of , and the substituents which may be possessed are also the same.

[0616] s and t each independently represent an integer of 0 or more and 5 or less. u, v, and w each independently represent an integer of 0 or more and 4 or less.

[0617] Preferred examples of the aromatic tertiary amine polymer compound include polymer compounds containing repeating units represented by the following formula (15) and / or formula (16).

[0618] [Chemistry 134]

[0619] In the above formula (15) and formula (16), Ar 45 ,Ar 47 and Ar 48 Each independently represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent aromatic heterocyclic group which may have a substituent. 44 and Ar 46 Each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. 41 ~R 43 Each independently represents a hydrogen atom or an arbitrary substituent. r is an integer of 0-2.

[0620] Ar 45 ,Ar 47 and Ar 48 Specific examples, preferred examples, examples of substituents that may be possessed, and preferred examples of substituents are each independently the same as Ar 22 and Ar 32 The same situation.

[0621] Ar 44 and Ar 46 Specific examples, preferred examples, examples of substituents that may be possessed, and preferred examples of substituents are each independently the same as Ar 11 and Ar 14 The same situation.

[0622] As R 41 ~R 43 , preferably a hydrogen atom or a substituent described in the above-mentioned substituent group Z, among which a hydrogen atom, an alkyl group, an alkoxy group, an amino group, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferred.

[0623] r is preferably 0 or 1, and more preferably 0.

[0624] Preferred specific examples of the repeating units represented by formula (15) and formula (16) that can be used in the present invention are listed below, but the present invention is not limited to these.

[0625] [Chemistry 135]

[0626] In addition, as aromatic amine compounds that can be used as hole transport materials, there can be mentioned compounds that are previously known to be used as hole injection / transport layer forming materials in organic electroluminescent elements. For example, there can be mentioned: aromatic diamine compounds connected with tertiary aromatic amine units such as 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane (Japanese Patent Publication No. 59-194393); aromatic amines containing two or more tertiary amines and two or more condensed aromatic rings substituted with nitrogen atoms, represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (Japanese Patent Publication No. 5-234681); aromatic triamines that are derivatives of triphenylbenzene and have a starburst structure (U.S. Patent No. 4,923,774); N,N'-diphenyl-N,N '-bis(3-methylphenyl)biphenyl-4,4'-diamine and other aromatic diamines (U.S. Patent No. 4,764,625); α,α,α',α'-tetramethyl-α,α'-bis(4-di-p-tolylaminophenyl)-p-xylene (Japanese Patent Publication No. 3-269084); triphenylamine derivatives with stereoasymmetric molecules as a whole (Japanese Patent Publication No. 4-129271); compounds with multiple aromatic diamino groups substituted on the pyrene group (Japanese Patent Publication No. 4-175395); aromatic diamines with tertiary aromatic amine units connected by ethylene groups (Japanese Patent Publication No. 4-264 189th Publication); aromatic diamines having a styrene structure (Japanese Patent Publication No. 4-290851); compounds having aromatic tertiary amine units connected via a thienyl group (Japanese Patent Publication No. 4-304466); star-shaped aromatic triamines (Japanese Patent Publication No. 4-308688); benzylphenyl compounds (Japanese Patent Publication No. 4-364153); compounds having tertiary amines connected via a fluorene group (Japanese Patent Publication No. 5-25473); triamine compounds (Japanese Patent Publication No. 5-239455); bipyridylaminobiphenyl (Japanese Patent Publication No. 5-320634); ); N,N,N-triphenylamine derivatives (Japanese Patent Publication No. 6-1972); aromatic diamines having a phenoxazine structure (Japanese Patent Publication No. 7-138562); diaminophenylphenanthridine derivatives (Japanese Patent Publication No. 7-252474); hydrazone compounds (Japanese Patent Publication No. 2-311591); silazane compounds (US Patent No. 4,950,950); silaneamine derivatives (Japanese Patent Publication No. 6-49079); phosphamine derivatives (Japanese Patent Publication No. 6-25659); quinacridone compounds, etc. These aromatic amine compounds can be used in combination of two or more as needed.

[0627] In addition, as another specific example of an aromatic amine compound that can be used as a hole transport material, a metal complex of an 8-hydroxyquinoline derivative having a diarylamino group can be cited. The central metal of the above-mentioned metal complex is selected from any one of alkali metals, alkaline earth metals, Sc, Y, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Al, Ga, In, Si, Ge, Sn, Sm, Eu, and Tb, and the 8-hydroxyquinoline as a ligand has a diarylamino group as a substituent, but may have an arbitrary substituent in addition to the diarylamino group.

[0628] In addition, preferred specific examples of phthalocyanine derivatives or porphyrin derivatives that can be used as hole transport materials include porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphyrin cobalt (II), 5,10,15,20-tetraphenyl-21H,23H-porphyrin copper (II), 5,10,15,20-tetraphenyl-21H,23H-porphyrin, 3H-porphyrin zinc (II), 5,10,15,20-tetraphenyl-21H,23H-porphyrin vanadium (IV) oxide, 5,10,15,20-tetrakis (4-pyridyl)-21H,23H-porphyrin, 29H,31H-phthalocyanine copper (II), phthalocyanine zinc (II), phthalocyanine titanium, phthalocyanine magnesium oxide, phthalocyanine lead, phthalocyanine copper (II), 4,4',4",4"'-tetraaza-29H,31H-phthalocyanine, etc.

[0629] In addition, specific preferred examples of oligothiophene derivatives that can be used as hole transport materials include α-sexithiophene and the like.

[0630] It should be noted that the molecular weight of these hole transport materials, except for the polymer compound having the above-mentioned specific repeating unit, is usually 5000 or less, preferably 3000 or less, more preferably 2000 or less, further preferably 1700 or less, particularly preferably 1400 or less, and usually 200 or more, preferably 400 or more, more preferably 600 or more. When the molecular weight of the hole transport material is too large, it is difficult to synthesize and purify and is not preferred. On the other hand, when the molecular weight is too small, the heat resistance may be reduced and is still not preferred.

[0631] The hole injection layer of the organic electroluminescent element of the present invention may contain any one of the above-mentioned hole transport materials alone, or may contain two or more. In the case where the hole injection layer contains two or more hole transport materials, the combination is arbitrary, preferably using one or two or more aromatic tertiary amine polymer compounds and one or two or more other hole transport materials. As the type of hole transport material used in combination with the aforementioned polymer compound, an aromatic amine compound is preferred.

[0632] The content of the hole transport material in the hole injection layer of the organic electroluminescent element of the present invention is within a range satisfying the ratio with the electron accepting compound. When two or more charge transport film compositions are used in combination, the total content of these is within the above range.

[0633] [Charge transport ionic compounds] The hole injection layer of the organic electroluminescent element of the present invention preferably contains a charge transport ionic compound formed by ion bonding of the above-mentioned tetraaryl borate ions and the cation free radicals of the hole transport material or a crosslinked product of an electron accepting compound having a crosslinking group. As the electron accepting compound, it is preferably a charge transport ionic compound formed by ion bonding of the above-mentioned tetraaryl borate ions and the cation free radicals of the hole transport material. For example, the hole injection layer of the organic electroluminescent element of the present invention may contain the tetraaryl borate ions having a crosslinking group and / or a crosslinked product of the tetraaryl borate ions having a crosslinking group.

[0634] The hole injection layer of the organic electroluminescent device of the present invention particularly preferably contains a charge transporting ionic compound in which the tetraarylborate ion is ionically bonded to a cation radical of the aromatic tertiary amine polymer compound as a hole transporting material.

[0635] The charge-transporting ionic compound can be obtained by any of the following methods. i) The first ionic compound and the hole transport material are dissolved or dispersed in an organic solvent and mixed. ii) The first ionic compound and the hole transport material are dissolved or dispersed in an organic solvent, mixed, and further heated. iii) The composition obtained in the above i) or ii) is subjected to wet film formation, and the film is heated.

[0636] Since the first ionic compound is an electron accepting compound, the hole transport material is oxidized by the first ionic compound to convert it into a cation radical in any of the above methods. As a result, a charge transporting ionic compound is generated, which has the tetraarylborate ion as a counter anion and the cation radical of the hole transport material as a counter cation.

[0637] The hole injection layer of the organic electroluminescent element of the present invention preferably comprises a first ionic compound containing the above-mentioned tetraarylborate ion as a counter anion and a hole transport material. From the viewpoint of charge transportability, it is further preferred to comprise a charge transporting ionic compound containing the above-mentioned tetraarylborate ion as a counter anion and a cation radical of the hole transport material as a counter cation.

[0638] [Hole Injection Layer Forming Composition] The hole injection layer of the organic electroluminescent element of the present invention is preferably obtained by wet film formation of a composition for forming a hole injection layer.

[0639] The hole injection layer forming composition is preferably a composition obtained by dissolving or dispersing the first ionic compound having the tetraaryl borate ion structure and the hole transport material in an organic solvent. Alternatively, the hole injection layer forming composition preferably contains an electron accepting compound having a crosslinking group and an organic solvent, and more preferably a composition obtained by dissolving or dispersing the first ionic compound having the tetraaryl borate ion structure and the hole transport material in an organic solvent.

[0640] From the viewpoint of obtaining a uniform hole injection layer film, the hole injection layer-forming composition is preferably a solution in which the first ionic compound and the hole transport material are dissolved in an organic solvent.

[0641] Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the above method i), the charge-transporting ionic compound can be obtained by the above method ii) or the above method iii). Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the above method ii), the charge-transporting ionic compound can be obtained by the above method iii).

[0642] Regarding the ratio of the above-mentioned first ionic compound and the above-mentioned hole transport material for obtaining a hole injection layer forming composition, relative to 100 parts by mass of the hole transport material, the amount of the first ionic compound is usually 0.1 parts by mass or more, preferably 1 part by mass or more, and usually 100 parts by mass or less, preferably 40 parts by mass or less. If the content of the first ionic compound is above the above lower limit, free carriers (cation radicals of hole transport materials) can be fully generated, and hole transport properties are improved, so it is preferred. If it is below the above upper limit, it is possible to fully ensure charge transport capacity, so it is preferred. In the case of using two or more of the first ionic compounds, the total content of these is included in the above range. The same is true for the hole transport material.

[0643] (Organic Solvent) The concentration of the organic solvent in the hole injection layer forming composition is usually 10 mass % or more, preferably 30 mass % or more, more preferably 50 mass % or more, further preferably 70 mass % or more, and usually 99.999 mass % or less, preferably 99.99 mass % or less, further preferably 99.9 mass % or less. It should be noted that when two or more organic solvents are mixed, the total of these organic solvents is made to meet this range.

[0644] As preferred organic solvents, for example, ether solvents and ester solvents can be mentioned. Specifically, as ether solvents, for example, fatty ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA) can be mentioned; aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole can be mentioned. As ester solvents, for example, fatty esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate can be mentioned; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate can be mentioned. These can be used alone or in any combination and ratio.

[0645] As solvents that can be used except the above-mentioned ether solvents and ester solvents, for example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, etc. can be cited. These can be used alone or in any combination and ratio. In addition, one or more of these solvents can be used in combination with one or more of the above-mentioned ether solvents and ester solvents. In particular, aromatic hydrocarbon solvents such as benzene, toluene, xylene are preferably used in combination with ether solvents and ester solvents because they have low ability to dissolve electron accepting compounds and free carriers (cation radicals).

[0646] Among these organic solvents, a solvent having an aromatic hydrocarbon structure is more preferred.

[0647] (Film Forming Method) The hole injection layer can be formed by wet film formation using a composition for forming a hole injection layer. As a wet film formation method, the same as the method of forming a film of a composition for forming a light-emitting layer by wet film formation, it is preferred to apply and dry and then heat. The heating temperature is preferably 120°C or more, more preferably 150°C or more, more preferably 180°C or more, and preferably 300°C or less, more preferably 260°C or less.

[0648] The hole injection layer can be crosslinked by heating the film after coating and drying. In this case, the crosslinking reaction can be caused by the following combination.

[0649] The cross-linking groups of the hole transport material are mutually · Crosslinking groups of hole transport materials and crosslinking groups of electron accepting compounds · The cross-linking groups of the electron accepting compound The cross-linking groups of the hole transport material and the cross-linking groups of the tetraarylborate ions in the present invention The crosslinking groups of the tetraarylborate ions in the present invention are mutually The crosslinking group of the electron accepting compound and the crosslinking group of the tetraarylborate ion in the present invention Through this step, a cross-linked product of the electron accepting compound is formed in the hole injection layer.

[0650] In addition, it is preferred that the formation of the charge-transporting ionic compound, which is an ionic compound of a tetraarylborate ion as a counter anion of the first ionic compound and a cation radical of the hole transporting material, is promoted by heating.

[0651] <Structure of Organic Electroluminescent Element> As an example of the structure of the organic electroluminescent element of the present invention, Figure 1 Schematic diagram (cross section) of a structural example of the organic electroluminescent element 8 is shown in FIG. Figure 1 , 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light emitting layer, 6 represents an electron transport layer, and 7 represents a cathode.

[0652] [Substrate] Substrate 1 is the support of organic electroluminescent element, and quartz or glass plate, metal plate or metal foil, plastic film or sheet etc. are usually used. Among these, preferably glass plate or transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, polysulfone etc. are used. Because it is not easy to cause the deterioration of organic electroluminescent element caused by external gas, substrate preferably adopts material with high gas barrier property. Therefore, particularly when using synthetic resin substrate etc. such material with low gas barrier property, preferably dense silicon oxide film etc. are set on at least one side of substrate to improve gas barrier property.

[0653] [anode] The anode 2 has a function of injecting holes into the layer on the light-emitting layer 5 side.

[0654] The anode 2 is usually composed of metals such as aluminum, gold, silver, nickel, palladium, platinum, etc.; metal oxides such as indium and / or tin oxides; halogenated metals such as copper iodide; carbon black and conductive polymers such as poly(3-methylthiophene), polypyrrole, polyaniline, etc.

[0655] The formation of the anode 2 is usually performed by a dry method such as a sputtering method or a vacuum evaporation method. In addition, when anodes are formed using metal particles such as silver, particles such as copper iodide, carbon black, conductive metal oxide particles, conductive polymer powders, etc., they can also be dispersed in a suitable binder resin solution and coated on a substrate. In addition, in the case of conductive polymers, a thin film can be directly formed on a substrate by electrolytic polymerization, or a conductive polymer can be coated on a substrate to form an anode (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0656] The anode 2 is usually a single-layer structure, but may be a laminated structure as appropriate. When the anode 2 is a laminated structure, a different conductive material may be laminated on the anode of the first layer.

[0657] The thickness of the anode 2 can be determined according to the required transparency and material, etc. In particular, when high transparency is required, the thickness is preferably 60% or more of the transmittance of visible light, and more preferably 80% or more of the transmittance of visible light. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode 2 can be arbitrarily set according to the required strength, etc. In this case, the anode 2 can be the same thickness as the substrate.

[0658] When forming other layers on the surface of the anode 2, it is preferred to perform ultraviolet / ozone, oxygen plasma, argon plasma or other treatment before film formation to remove impurities on the anode 2 and adjust its ionization potential to improve hole injection properties.

[0659] [Hole injection layer] The hole injection layer in the organic electroluminescent device of the present invention is as described above. Regarding the film formation method of the hole injection layer, the wet film formation method is as described above, and a vacuum deposition method may also be used.

[0660] [Formation of hole injection layer by vacuum deposition] In the case of forming the hole injection layer of the organic electroluminescent element of the present invention by vacuum evaporation, the above-mentioned first ionic compound can be used as a material containing tetraarylborate ions, and a low-molecular hole transport material that can be evaporated can be used as a hole transport material. As a low-molecular hole transport material that can be evaporated, a hole transport material with a molecular weight of less than 1500 is preferably used, and a hole transport material with a molecular weight of less than 1000 is more preferably used, and a hole transport material with a molecular weight of more than 400 is preferably used, and a hole transport material with a molecular weight of more than 600 is more preferably used. As a low-molecular hole transport material, an aromatic amine compound is preferably used, and an aromatic tertiary amine compound is more preferably used.

[0661] When the hole injection layer 3 is formed by vacuum deposition, one or more of the constituent materials of the hole injection layer 3 are usually placed in a crucible provided in a vacuum container (when two or more materials are used, they are usually placed in different crucibles), and the vacuum container is evacuated to 100°C by a vacuum pump. -4 Pa. Then, the crucible is heated (when two or more materials are used, each crucible is usually heated), and the evaporation amount of the material in the crucible is controlled while evaporating (when two or more materials are used, each is usually independently controlled while evaporating), and a hole injection layer is formed on the anode on the substrate placed facing the crucible. It should be noted that when two or more materials are used, their mixture can also be placed in a crucible and heated to evaporate to form a hole injection layer.

[0662] The vacuum degree during vapor deposition is not limited unless the effect of the present invention is significantly impaired, but is usually 0.1×10 - 6 Torr(0.13×10 -4 Pa) or above, 9.0×10 -6 Torr(12.0×10 -4 Pa) or less. As long as the effect of the present invention is not significantly impaired, the evaporation rate is not limited, and is usually above, The film forming temperature during vapor deposition is not limited unless the effects of the present invention are significantly impaired, but is preferably 10° C. or higher and 50° C. or lower.

[0663] [Hole Transport Layer] The hole transport layer 4 is a layer that has the function of transporting holes from the anode 2 side to the light-emitting layer 5 side. The hole transport layer 4 is not an essential layer in the organic electroluminescent element of the present invention, but it is preferably formed from the perspective of strengthening the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, usually, the hole transport layer 4 is formed between the anode 2 and the light-emitting layer 5. In addition, when the hole injection layer 3 is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0664] The film thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

[0665] The hole transport layer 4 may be formed by vacuum deposition or wet film formation. The wet film formation is preferred because of its excellent film-forming properties.

[0666] The hole transport layer 4 generally contains a hole transport compound.

[0667] As hole transporting compounds, preferred compounds include: aromatic diamines containing two or more tertiary amines and two or more condensed aromatic rings substituted with nitrogen atoms, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (Japanese Patent Publication No. 5-234681), aromatic amine compounds having a star-shaped structure such as 4,4',4"-tri(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), aromatic amine compounds composed of tetramers of triphenylamine (Chem. Chem. Ommun., p. 2175, 1996), spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), carbazole derivatives such as 4,4'-N,N'-dicarbazole biphenyl, etc. In addition, for example, polyvinyl carbazole, polyethylene triphenylamine (Japanese Patent Publication No. 7-53953), polyarylethersulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996), etc. may also be included.

[0668] [Formation of hole transport layer by wet film formation] When the hole transport layer is formed by a wet film forming method, it can be formed using a hole transport layer forming composition instead of a hole injection layer forming composition, as in the case of forming the hole injection layer by the wet film forming method.

[0669] When the hole transport layer is formed by a wet film forming method, the hole transport layer forming composition generally further contains a solvent. The solvent used in the hole transport layer forming composition can be the same solvent as that used in the hole injection layer forming composition described above.

[0670] The concentration of the hole transporting compound in the hole transport layer forming composition may be in the same range as the concentration of the hole transporting compound in the hole injection layer forming composition.

[0671] [Formation of hole transport layer by vacuum deposition] When the hole transport layer is formed by vacuum deposition, it can be formed by using a hole transport layer forming composition instead of a hole injection layer forming composition, as in the case of forming the hole injection layer by vacuum deposition. The film forming conditions such as the vacuum degree, deposition rate and temperature during deposition can be the same as those during vacuum deposition of the hole injection layer.

[0672] [Luminous layer] The light-emitting layer 5 is a layer that performs the following functions: when an electric field is applied between a pair of electrodes, the holes injected from the anode 2 are excited to recombine with the electrons injected from the cathode 7, thereby emitting light. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7. When a hole injection layer is present on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. When a hole transport layer is present on the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0673] As described above, the light-emitting layer of the organic electroluminescent device in the present invention preferably contains the polycyclic heterocyclic compound represented by formula (1) and the organic metal compound represented by formula (201), and more preferably contains a host material.

[0674] As long as the effect of the present invention is not significantly impaired, the film thickness of the light-emitting layer 5 is arbitrary, but based on the perspective of not being easy to produce defects in the film, the film thickness is preferably thicker, and on the other hand, based on the perspective of easily forming a low driving voltage, the film thickness is preferably thinner. Therefore, it is preferably more than 3nm, more preferably more than 5nm, and on the other hand, it is usually preferably less than 200nm, and more preferably less than 100nm.

[0675] The light-emitting layer 5 preferably contains one or more host materials while containing at least a material having a light-emitting property (light-emitting material).

[0676] [Hole blocking layer] A hole blocking layer may be provided between the light emitting layer 5 and the electron injection layer described later. The hole blocking layer is a layer stacked on the light emitting layer 5 so as to be in contact with the interface of the light emitting layer 5 on the cathode 7 side.

[0677] The hole blocking layer has the function of preventing holes migrated from the anode 2 from reaching the cathode 7 and the function of efficiently transporting electrons injected from the cathode 7 toward the light-emitting layer 5. The physical properties required of the material constituting the hole blocking layer include: high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet energy level (T1).

[0678] As materials for the hole blocking layer that meet such conditions, there can be mentioned, for example, mixed ligand complexes such as bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(triphenylalkanolate)aluminum, metal complexes such as bis(2-methyl-8-quinoline)aluminum-μ-oxy-bis(2-methyl-8-hydroxyquinoline) binuclear aluminum metal complex, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Publication No. 7-41759), and phenanthroline derivatives such as bathocuproin (Japanese Patent Publication No. 10-79297). As the material for the hole blocking layer, a compound having at least one pyridine ring substituted at the 2-, 4-, or 6-position as described in International Publication No. 2005 / 022962 is further preferred.

[0679] There is no limitation on the method for forming the hole blocking layer, and therefore, the hole blocking layer may be formed by a wet film forming method, an evaporation method, or other methods.

[0680] The thickness of the hole blocking layer is arbitrary unless the effects of the present invention are significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0681] [Electron transport layer] The electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 for the purpose of further improving the current efficiency (cd / A) of the element.

[0682] The electron transport layer 6 is formed of a compound that can efficiently transport electrons injected from the cathode 7 between electrodes to which an electric field is applied toward the light-emitting layer 5. The electron transport compound used in the electron transport layer 6 needs to be a compound that has high electron injection efficiency from the cathode 7, high electron mobility, and can efficiently transport injected electrons.

[0683] Specific examples of the electron transport compound used in the electron transport layer include: metal complexes such as aluminum complex of 8-hydroxyquinoline (Japanese Patent Publication No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, tribenzimidazolylbenzene (U.S. Patent No. 5,645,948), quinoxaline compounds (Japanese Patent Publication No. 6-207169), phenanthroline derivatives (Japanese Patent Publication No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimide, N-type hydrogenated amorphous silicon carbide, N-type zinc sulfide, N-type zinc selenide, etc.

[0684] The film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0685] The electron transport layer 6 is formed by laminating on the hole blocking layer by a wet film forming method or a vacuum deposition method in the same manner as described above. Usually, the vacuum deposition method is used.

[0686] [Electron injection layer] In order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5 , an electron injection layer may be provided.

[0687] In order to efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. As an example, alkali metals such as sodium or cesium, alkaline earth metals such as barium or calcium, etc. are used. The film thickness is usually preferably not less than 0.1 nm and not more than 5 nm.

[0688] Furthermore, in organic electron transport materials represented by nitrogen-containing heterocyclic compounds such as bathophenanthroline or metal complexes such as aluminum complexes of 8-hydroxyquinoline, doping with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (recorded in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) can also improve electron injection / transport properties and have excellent film quality, so it is preferred.

[0689] The film thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[0690] The electron injection layer is formed by a wet film forming method or a vacuum deposition method by stacking on the light emitting layer 5 or the hole blocking layer or the electron transporting layer 6 thereon. The details of the wet film formation method are the same as those of the above-mentioned light-emitting layer.

[0691] There is also a case where the hole blocking layer, the electron transport layer, and the electron injection layer are formed into one layer by co-doping the electron transport material with the lithium complex.

[0692] [cathode] The cathode 7 functions as a layer (electron injection layer or light emitting layer, etc.) that injects electrons into the light emitting layer 5 .

[0693] As the material of the cathode 7, the material that can be used in the above-mentioned anode 2 can be used, but based on efficient electron injection, it is preferred to use a metal with a low work function, for example, tin, magnesium, indium, calcium, aluminum, silver and other metals or their alloys. As specific examples, for example, alloy electrodes with low work functions such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys can be cited.

[0694] From the perspective of the stability of the organic electroluminescent element, it is preferred to stack a metal layer with a high work function and stable to the atmosphere on the cathode to protect the cathode composed of a metal with a low work function. Examples of the stacked metal include aluminum, silver, copper, nickel, chromium, gold, platinum and the like.

[0695] The cathode film thickness is usually the same as the anode film thickness.

[0696] [Other layers] The organic electroluminescent device of the present invention may further include other layers unless the effects of the present invention are significantly impaired. That is, the organic electroluminescent device may include any other layer described above between the anode and the cathode.

[0697] [Other components] The organic electroluminescent element of the present invention may also have a structure opposite to that described above, that is, for example, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode are stacked in this order on a substrate.

[0698] When the organic electroluminescent element of the present invention is applied to an organic electroluminescent device, it can be used as a single organic electroluminescent element, or it can be made into a structure in which a plurality of organic electroluminescent elements are arranged in an array, or it can be made into a structure in which the anode and cathode are arranged in an XY matrix.

[0699] <Method for producing organic electroluminescent element> The method for producing the organic electroluminescent device of the present invention is not particularly limited. As one mode of the method for manufacturing an organic electroluminescent element of the present invention, it is preferably as described above, and has the following steps: using a hole injection layer forming composition and utilizing a wet film forming method to form a hole injection layer, and using a luminescent layer forming composition and utilizing a wet film forming method to form a luminescent layer. The hole injection layer forming composition preferably contains tetraaryl borate ions and an organic solvent. The luminescent layer forming composition preferably contains a polycyclic heterocyclic compound represented by formula (1), an organometallic compound represented by formula (201) and an organic solvent, and the polycyclic heterocyclic compound and the organometallic compound satisfy the above-mentioned relationship (E-1). Preferably, these compositions are used to manufacture an organic electroluminescent element having an anode, a hole injection layer, a luminescent layer and a cathode in sequence on a substrate.

[0700] The hole injection layer-forming composition is preferably a composition obtained through a step of dissolving or dispersing an electron-accepting ion compound having a tetraarylborate ion structure and a hole transport material in an organic solvent.

[0701] The preferred embodiments of the tetraarylborate ion and the organic solvent contained in the hole injection layer forming composition are as described above. Similarly, the preferred embodiments of the polycyclic heterocyclic compound represented by formula (1), the organic metal compound represented by formula (201) and the organic solvent contained in the light-emitting layer forming composition are as described above.

[0702] As another embodiment of the method for manufacturing an organic electroluminescent element of the present invention, for example, it includes the following steps: a step of using a hole injection layer forming composition containing an electron accepting compound having a cross-linking group and an organic solvent to form a hole injection layer by a wet film-forming method, and a step of using a light-emitting layer forming composition containing a polycyclic heterocyclic compound represented by formula (1), an organic metal compound represented by formula (201) and an organic solvent, and the polycyclic heterocyclic compound and the organic metal compound satisfy the above-mentioned relationship (E-1) and forming a light-emitting layer by a wet film-forming method, thereby manufacturing an organic electroluminescent element having an anode, a hole injection layer, a light-emitting layer and a cathode in sequence on a substrate.

[0703] In the method for producing an organic electroluminescent element of the present invention, in the step of forming the hole injection layer, it is preferred that a crosslinked product of an electron accepting compound, for example, a crosslinked product of tetraarylborate ions, is formed by applying a hole injection layer-forming composition, drying it, and then heating it.

[0704] The preferred embodiments of the polycyclic heterocyclic compound represented by formula (1), the organic metal compound represented by formula (201), the crosslinked product of the electron-accepting compound having a crosslinking group, the electron-accepting compound having a crosslinking group and the organic solvent in the above-mentioned method for manufacturing the organic electroluminescent element are as described above.

[0705] The hole injection layer-forming composition is preferably a composition obtained through a step of dissolving or dispersing an electron-accepting ionic compound having a crosslinking group and a hole transport material in an organic solvent. Preferred embodiments of the electron-accepting ionic compound having a crosslinking group and the organic solvent contained in the hole injection layer-forming composition are as described above.

[0706] <Organic EL Display Device> The organic EL display device (organic electroluminescent element display device) of the present invention comprises the organic electroluminescent element of the present invention. There is no particular limitation on the type or structure of the organic EL display device of the present invention, and the organic electroluminescent element of the present invention can be used and assembled according to conventional methods.

[0707] For example, the organic EL display device of the present invention can be formed by the method described in “Organic EL Display” (Ohmsha Co., Ltd., published on August 20, 2004, written by Shizuo Tokito, Chibashi Adachi, and Hideyuki Murata).

[0708] <Organic EL Lighting> The organic EL lighting (organic electroluminescent element lighting) of the present invention comprises the organic electroluminescent element of the present invention. There is no particular limitation on the type or structure of the organic EL lighting of the present invention, and the organic electroluminescent element of the present invention can be used and assembled according to conventional methods.

[0709] As described above, the present specification discloses the following contents. <1> An organic electroluminescent element comprises an anode, a cathode, a light-emitting layer and a hole injection layer. The light emitting layer is disposed between the anode and the cathode, The hole injection layer is disposed between the anode and the light-emitting layer. The light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1) and an organic metal compound represented by the following formula (201), The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1), T1A≥T1B formula (E-1) (In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) The hole injection layer contains tetraarylborate ions.

[0710] [Chemistry 136]

[0711] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure of formula (1) containing B and Y. At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0712] [Chemistry 137]

[0713] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.] <2> according to <1> In the organic electroluminescent element, the hole injection layer comprises the tetraaryl borate ions having a cross-linking group and / or a cross-linked product of the tetraaryl borate ions having a cross-linking group. <3> according to <1> or <2> In the organic electroluminescent element, the polycyclic heterocyclic compound represented by the above formula (1) is represented by the following formula (21).

[0714] [Chemistry 138]

[0715] (In formula (21), Ring a, ring b and ring c are the same as defined in the above formula (1). Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring f and ring g are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, wherein the adjacent carbon atoms are not carbon atoms constituting ring d and ring e containing B and N, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (21) may be substituted by a halogen atom or deuterium. <4> according to <1> or <2> In the organic electroluminescent element, the polycyclic heterocyclic compound represented by the above formula (1) is represented by the following formula (22).

[0716] [Chemistry 139]

[0717] (In formula (22), Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring a, ring b, ring c, ring f and ring g may have a substituent, Ring f can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b, Ring g can be formed by -O-, -S-, -C(-R a ) 2- or is single-bonded to a carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) may be substituted by a halogen atom or deuterium. <5> according to <1> or <2> In the organic electroluminescent element, the polycyclic heterocyclic compound represented by the above formula (1) is represented by the following formula (71).

[0718] [Chemistry 140]

[0719] (In formula (71), A1 to A7 are each independently a hydrogen atom; a fluorine atom; an alkyl group which may have a substituent; an electron accepting heteroaryl group; a nitro group; a cyano group; or an aromatic hydrocarbon group or an aromatic heterocyclic group which has an electron accepting heteroaryl group, a nitro group or a cyano group as a substituent, R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, an electron donor substituent, or a combination thereof, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (71) may be substituted by a halogen atom or deuterium, and the dotted line represents a single bond or no bond. <6> according to <5> In the organic electroluminescent element, A1 to A7 in the above formula (71) are electron accepting substituents, and each is independently a group represented by the following formula (71-5), a group represented by the following formula (71-6), a group represented by the following formula (71-7) or a group represented by the following formula (71-8).

[0720] [Chemistry 141]

[0721] (In formulas (71-5) to (71-8), R 732 ~R 745 Each is independently a hydrogen atom, an alkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.) <7> according to <5> The organic electroluminescent element, R 71 ~R 78 are electron donating substituents and are each independently a group represented by the following formula (71-2), a group represented by the following formula (71-3), or a group represented by the following formula (71-4).

[0722] [Chemistry 142]

[0723] (In formulas (71-2) to (71-4), R 709 ~R 724 , R 727 ~R 731 Each is independently an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a hydrogen atom.) <8> according to <1> ~ <7> In the organic electroluminescent device described above, the light-emitting layer further comprises a host material. <9> according to <1> ~ <8> In the organic electroluminescent device described above, the tetraarylborate ion is represented by the following formula (2).

[0724] [Chemistry 143]

[0725] (In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent. <10> according to <9> The organic electroluminescent element, Ar in the above formula (2) 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by the following formula (3).

[0726] [Chemistry 144]

[0727] (In formula (3), R 1 Each is independently selected from an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, and an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, a monovalent group formed by connecting multiple structures, an alkyl group substituted with fluorine, a substituent or a crosslinking group, F4 represents the substitution of 4 fluorine atoms, F (5-m) Each independently represents substitution of 5-m fluorine atoms, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0-5. *Indicates bonding position. ) <11> according to <2> In the organic electroluminescent element, the crosslinking group is represented by any one of the following formulae (X1) to (X18).

[0728] [Chemistry 145]

[0729] In formulae (X1) to (X4), the benzene ring and the naphthalene ring may have a substituent. Furthermore, the substituents may be bonded to each other to form a ring. R in formula (X4), formula (X5), formula (X6) and formula (X10) 110 Each independently represents an alkyl group which may have a substituent. In formulas (X1) to (X18), * represents a bonding position. ) <12> according to <11> In the organic electroluminescent element, the cross-linking group is represented by any one of the above formulae (X1) to (X4). <13> An organic EL display device or organic EL lighting, comprising <1> ~ <12> The organic electroluminescent element described above. <14> A method for manufacturing an organic electroluminescent element, which is a method for manufacturing an organic electroluminescent element having an anode, a hole injection layer, a light-emitting layer and a cathode in sequence on a substrate. The method for manufacturing an organic electroluminescent element comprises the steps of: forming the hole injection layer by a wet film-forming method using a composition for forming a hole injection layer, and a step of forming the light-emitting layer by a wet film-forming method using a light-emitting layer-forming composition, The hole injection layer-forming composition contains tetraarylborate ions and an organic solvent. The composition for forming a light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1), an organic metal compound represented by the following formula (201), and an organic solvent. The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1), T1A≥T1B formula (E-1) (In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV).

[0730] [Chemistry 146]

[0731] (In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, The R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R can be -O-, -S-, -C(-R a ) 2- or is bonded by a single bond to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms that constitute the central fused bicyclic structure containing B and Y of formula (1). At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c.)

[0732] [Chemistry 147]

[0733] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Represents an anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may be atoms constituting a ring. In this case, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are plural, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number of is an integer greater than 0 which is the upper limit. j can replace Ar 201 The number of is an integer greater than 0 which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit. m is an integer from 1 to 3.] <15> according to <14> In the method for manufacturing an organic electroluminescent element, the tetraarylborate ion has a cross-linking group. <16> according to <14> or <15> In the method for manufacturing an organic electroluminescent element, the tetraarylborate ion is represented by the following formula (2).

[0734] [Chemistry 148]

[0735] (In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent. <17> according to <15> In the method for manufacturing an organic electroluminescent element, in the step of forming the hole injection layer, the hole injection layer forming composition is applied and dried and then heated to form a crosslinked product of the tetraarylborate ions. Example

[0736] [Example I-1] An organic electroluminescent element was produced by the following method. A plate (manufactured by Gioma Technology, a sputtered film product) in which an indium tin oxide (ITO) transparent conductive film was deposited to a thickness of 50 nm on a glass substrate was patterned into stripes of 2 mm width using conventional photolithography and hydrochloric acid etching to form an anode. The substrate on which the ITO pattern was formed was cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, dried with compressed air, and finally cleaned with ultraviolet ozone. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0 wt % of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6 wt % of an electron accepting compound (HI-1) in ethyl benzoate.

[0737] [Chemistry 149]

[0738] [Chemistry 150]

[0739] The solution was spin-coated on the substrate in the air, and dried at 240° C. for 30 minutes using a hot plate in the air to form a uniform thin film with a thickness of 40 nm to form a hole injection layer. Next, a charge transporting polymer compound having the following structural formula (HT-1) was dissolved in 1,3,5-trimethylbenzene to prepare a 2.0 wt % solution. The solution was spin-coated on the substrate coated with the hole injection layer in a nitrogen glove box, and dried at 230° C. for 30 minutes using a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm to prepare a hole transport layer.

[0740] [Chemistry 151]

[0741] Next, as light-emitting layer materials, a compound (H-1) having the following structure at a concentration of 1.17 wt %, a compound (H-2) at a concentration of 1.17 wt %, a compound (H-3) at a concentration of 0.78 wt %, an organometallic compound (A-1) at a concentration of 0.93 wt %, and a polycyclic heterocyclic compound (D-1) at a concentration of 0.16 wt % were dissolved in cyclohexylbenzene to prepare a light-emitting layer-forming composition.

[0742] [Chemistry 152]

[0743] The solution was spin-coated on the substrate coated with the hole transport layer in a nitrogen glove box, and dried at 120° C. for 20 minutes using a hot plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm to form a light-emitting layer. The substrate on which the light-emitting layer was formed was placed in a vacuum deposition device, and the inside of the device was evacuated to 2×10 -4 Below Pa. Next, the following structural formula (ET-1) and 8-hydroxyquinoline lithium were co-deposited on the light-emitting layer at a film thickness ratio of 2:3 by vacuum deposition to form an electron transport layer with a film thickness of 30 nm.

[0744] [Chemistry 153]

[0745] Next, as a cathode evaporation mask, a 2 mm wide stripe-shaped shadow mask was placed in close contact with the substrate in a manner perpendicular to the ITO stripes of the anode, and the aluminum was heated by a molybdenum boat to form an aluminum layer with a thickness of 80 nm, thereby forming a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm×2 mm was obtained.

[0746] [Example I-2] An organic electroluminescent device was prepared in the same manner as in Example I-1 except that a compound represented by the following structural formula (HI-2) was used instead of (HI-1) as the electron accepting compound of the hole injection layer forming composition.

[0747] [Chemistry 154]

[0748] [Comparative Example I-1] As a composition for forming a hole injection layer, a composition obtained by dissolving 1.5 wt % of a hole-transporting polymer compound (P-1) and 0.3 wt % of an electron-accepting compound (CHI-1) having the following structure in anisole was prepared and used. Except for this, an organic electroluminescent element was prepared in the same manner as in Example I-1.

[0749] [Chemistry 155]

[0750] [Evaluation of components] Measured at 1,000cd / m 2 The voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) when the organic electroluminescent elements obtained in Examples I-1, I-2, and Comparative Example I-1 were made to emit light. In addition, as the driving life, the voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) were measured at 15 mA / cm 2 The time (LT95) (hr) for the brightness to decrease to 95% of the initial brightness when the element is continuously energized with a current density of 1000 Hz is shown in Table 1. As the values ​​in Table 1, for voltage, the voltage difference (V) based on Comparative Example I-1 is expressed as a relative voltage (V), and for current efficiency, EQE, and driving life, the relative values ​​when Comparative Example I-1 is set to 1.00 are expressed as relative current efficiency, relative EQE, and relative life, respectively. From the results in Table 1, it can be seen that the performance of the organic electroluminescent element of the present invention is improved.

[0751] [Table 1] Relative voltage(V) Relative current efficiency Relative EQE Relative lifespan Example I-1 -5.42 1.08 1.08 3.48 Example I-2 -5.43 1.05 1.04 3.16 Comparative Example I-1 0.00 1.00 1.00 1.00

[0752] It should be noted that, regarding Examples I-1 to I-2 and Comparative Example I-1, when T1A, T1B and S1B were determined by the method described in the specification, the relationship between Formula (E-1) and Formula (E-2) was satisfied.

[0753] [Example II-1] An organic electroluminescent device was prepared in the same manner as in Example I-1 except that a compound having the following structural formula (HT-2) was used instead of (HT-1) as the charge-transporting polymer compound used in the hole-transporting layer.

[0754] [Chemistry 156]

[0755] [Example II-2] An organic electroluminescent device was prepared in the same manner as in Example II-1 except that (HI-2) was used instead of (HI-1) as the electron-accepting compound of the hole injection layer-forming composition.

[0756] [Comparative Example II-1] An organic electroluminescent element was produced in the same manner as in Example II-1 except that a composition prepared by dissolving 1.5 wt % of a hole-transporting polymer compound (P-1) and 0.3 wt % of an electron-accepting compound (CHI-1) in anisole was prepared and used as a composition for forming a hole injection layer.

[0757] [Evaluation of components] Measured at 1,000cd / m 2 The voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) when the organic electroluminescent elements obtained in Examples II-1, II-2, and Comparative Example II-1 were made to emit light. In addition, as the driving life, the voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) were measured at 15 mA / cm 2 The time (LT95) (hr) for the brightness to decrease to 95% of the initial brightness when the element is continuously energized with a current density of 1.50 is shown in Table 2. As the values ​​in Table 2, for voltage, the voltage difference (V) based on Comparative Example II-1 is expressed as a relative voltage (V), and for current efficiency, EQE and driving life, the relative values ​​when Comparative Example II-1 is set to 1.00 are expressed as relative current efficiency, relative EQE, and relative life, respectively. From the results in Table 2, it can be seen that the performance is improved in the organic electroluminescent element using the present invention.

[0758] [Table 2] Relative voltage(V) Relative current efficiency Relative EQE Relative lifespan Example II-1 -5.21 1.09 1.08 1.97 Example II-2 -5.30 1.05 1.04 1.28 Comparative Example II-1 0.00 1.00 1.00 1.00

[0759] It should be noted that, regarding Examples II-1 to II-2 and Comparative Example II-1, when T1A, T1B and S1B were determ...

Claims

1. An organic electroluminescent element comprising an anode, a cathode, a light-emitting layer and a hole injection layer, The light-emitting layer is disposed between the anode and the cathode, The hole injection layer is disposed between the anode and the light-emitting layer. The light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1) and an organic metal compound represented by the following formula (201), The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1): T1A≥T1B formula (E-1) In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) The hole injection layer contains tetraarylborate ions, [Chemistry 1] In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is represented by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms constituting the central fused bicyclic structure of formula (1) containing B and Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) is substituted by a halogen atom or deuterium or is unsubstituted, Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c, [Chemistry 2] Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent, Ring A202 represents an aromatic heterocyclic structure which may have a substituent, R 201 , R 202 Each is independently a structure represented by the above formula (202), R 201 , R 202 When there are multiple of each, they are the same or different, Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent, Ar 202 represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent, Ar 201 ,Ar 202 and Ar 203 When there are multiple of each, they are the same or different, * indicates bonding to ring A201 or ring A202, B 201 -L 200 -B 202 represents anionic bidentate ligand; B 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and when these atoms are atoms constituting a ring, B 201 and / or B 202 Represents a ring structure; L 200 Represents a single bond or with B 201 and B 202 The atomic groups that together form the bidentate ligand, B 201 -L 200 -B 202 When there are multiple, they are the same or different, i1 and i2 each independently represent an integer greater than or equal to 0 and less than or equal to 12, i3 can replace Ar 202 The number of is an integer greater than 0, which is the upper limit, j can replace Ar 201 The number of is an integer greater than 0, which is the upper limit, k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit, m is an integer of 1-3. 2 . The organic electroluminescent element according to claim 1 , wherein the hole injection layer comprises the tetraarylborate ion having a crosslinking group and / or a crosslinked product of the tetraarylborate ion having a crosslinking group.

3. The organic electroluminescent element according to claim 1, wherein the polycyclic heterocyclic compound represented by formula (1) is represented by the following formula (21): [Chemistry 3] In formula (21), Ring a, ring b and ring c are the same as defined in the formula (1), Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring f and ring g are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Ring f is formed by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to an atom bonded to N in at least one of ring a and ring b, Ring g is formed by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to an atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, in, The adjacent carbon atoms are not carbon atoms constituting the ring d and ring e containing B and N, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (21) is substituted with a halogen atom or deuterium or is unsubstituted.

4. The organic electroluminescent element according to claim 1, wherein the polycyclic heterocyclic compound represented by formula (1) is represented by the following formula (22): [Chemistry 4] In formula (22), Ring d is a ring composed of B, N, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, N, and a part of the atoms constituting ring a and ring c, Ring a, ring b, ring c, ring f and ring g may have a substituent, Ring f is formed by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to an atom bonded to N in at least one of ring a and ring b, Ring g is formed by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to an atom bonded to N in at least one of ring a and ring c, The R a are each independently a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) is substituted with a halogen atom or deuterium or is unsubstituted.

5. The organic electroluminescent element according to claim 1, wherein the polycyclic heterocyclic compound represented by formula (1) is represented by the following formula (71): [Chemistry 5] In formula (71), A1 to A7 are each independently a hydrogen atom; a fluorine atom; an alkyl group which may be substituted; an electron accepting heteroaryl group; a nitro group; a cyano group; or an aromatic hydrocarbon group or an aromatic heterocyclic group which has an electron accepting heteroaryl group, a nitro group or a cyano group as a substituent, R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may be substituted, an aromatic hydrocarbon group which may be substituted, an aromatic heterocyclic group which may be substituted, an electron donor substituent, or a combination thereof, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (71) is substituted by a halogen atom or deuterium or is unsubstituted, Dashed lines represent single bonds or no bonds.

6. The organic electroluminescent element according to claim 5, wherein A1 to A7 of the formula (71) are electron acceptor substituents, and each is independently a group represented by the following formula (71-5), a group represented by the following formula (71-6), a group represented by the following formula (71-7), or a group represented by the following formula (71-8), [Chemistry 6] In formulas (71-5) to (71-8), R 732 ~R 745 Each is independently a hydrogen atom, an alkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

7. The organic electroluminescent element according to claim 5, wherein R 71 ~R 78 are electron donor substituents, and are each independently a group represented by the following formula (71-2), a group represented by the following formula (71-3), or a group represented by the following formula (71-4), [Chemistry 7] In formulas (71-2) to (71-4), R 709 ~R 724 , R 727 ~R 731 Each independently represents an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a hydrogen atom. The organic electroluminescent device according to claim 1 , wherein the light-emitting layer further comprises a host material.

9. The organic electroluminescent element according to claim 1, wherein the tetraarylborate ion is represented by the following formula (2): [Chemistry 8] In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them has a fluorine atom or an alkyl group substituted with fluorine as a substituent.

10. The organic electroluminescent element according to claim 9, wherein Ar in the formula (2) 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by the following formula (3), [Chemistry 9] In formula (3), R 1 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, and an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, an alkyl group substituted with fluorine, a substituent or a crosslinking group, F4 represents the substitution of 4 fluorine atoms, F (5-m) Each independently represents substitution of 5-m fluorine atoms, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0 to 5, *Indicates bonding position.

11. The organic electroluminescent device according to claim 2, wherein the crosslinking group is represented by any one of the following formulae (X1) to (X18): [Chemistry 10] In formulae (X1) to (X4), the benzene ring and the naphthalene ring may or may not have a substituent; further, the substituents may or may not be bonded to each other to form a ring, R in formula (X4), formula (X5), formula (X6) and formula (X10) 110 each independently represents an alkyl group which may have a substituent, In formulae (X1) to (X18), * represents a bonding position. 12 . The organic electroluminescent device according to claim 11 , wherein the crosslinking group is represented by any one of the formulae (X1) to (X4). 13 . An organic EL display device or an organic EL lighting device comprising the organic electroluminescent element according to claim 1 .

14. A method for manufacturing an organic electroluminescent element, which comprises a substrate having an anode, a hole injection layer, a light-emitting layer and a cathode in sequence, The method for manufacturing an organic electroluminescent element comprises the steps of: forming the hole injection layer by a wet film-forming method using a composition for forming a hole injection layer, and a step of forming the light-emitting layer by a wet film-forming method using a light-emitting layer-forming composition, in, The hole injection layer forming composition contains tetraarylborate ions and an organic solvent. The composition for forming a light-emitting layer contains a polycyclic heterocyclic compound represented by the following formula (1), an organic metal compound represented by the following formula (201), and an organic solvent. The polycyclic heterocyclic compound and the organometallic compound satisfy the following relationship (E-1): T1A≥T1B formula (E-1) In formula (E-1), T1A: triplet energy level of the organometallic compound (eV) T1B: triplet energy level of the polycyclic heterocyclic compound (eV) [Chemistry 11] In formula (1), Ring a, ring b and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocyclic ring which may have a substituent, Y is each independently O, NR or S, R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is represented by -O-, -S-, -C(-R a ) 2- or is bonded to or not bonded to a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of the ring a, the ring b, and the ring c, The R a are each independently a hydrogen atom or an alkyl group, The adjacent carbon atoms are not carbon atoms constituting the central fused bicyclic structure of formula (1) containing B and Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) is substituted by a halogen atom or deuterium or is unsubstituted, Ring d is a ring composed of B, Y, and a part of the atoms constituting ring a and ring b, and ring e is a ring composed of B, Y, and a part of the atoms constituting ring a and ring c, [Chemistry 12] Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent, Ring A202 represents an aromatic heterocyclic structure which may have a substituent, R 201 , R 202 Each is independently a structure represented by the above formula (202), R 201 , R 202 When there are multiple of each, they are the same or different, Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent, Ar 202 represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent, Ar 201 ,Ar 202 and Ar 203 When there are multiple of each, they are the same or different, * indicates bonding to ring A201 or ring A202, B 201 -L 200 -B 202 represents anionic bidentate ligand; B 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and when these atoms are atoms constituting a ring, B 201 and / or B 202 Represents a ring structure; L 200 Represents a single bond or with B 201 and B 202 The atomic groups that together form the bidentate ligand, B 201 -L 200 -B 202 When there are multiple, they are the same or different, i1 and i2 each independently represent an integer greater than or equal to 0 and less than or equal to 12, i3 can replace Ar 202 The number of is an integer greater than 0, which is the upper limit, j can replace Ar 201 The number of is an integer greater than 0, which is the upper limit, k1 and k2 are each independently an integer greater than or equal to 0, with the number of substitutable rings A201 and A202 being the upper limit, m is an integer of 1-3. 15 . The method for producing an organic electroluminescent device according to claim 14 , wherein the tetraarylborate ion has a crosslinking group.

16. The method for producing an organic electroluminescent element according to claim 14, wherein the tetraarylborate ion is represented by the following formula (2): [Chemistry 13] In formula (2), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group, an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them has a fluorine atom or an alkyl group substituted with fluorine as a substituent. 17 . The method for producing an organic electroluminescent element according to claim 15 , wherein in the step of forming the hole injection layer, the crosslinked product of the tetraarylborate ions is formed by applying the hole injection layer-forming composition, drying it, and then heating it.

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