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

Abstract

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, and the hole injection layer being provided between the positive electrode and the light-emitting layer. The light-emitting layer contains a polycyclic heterocyclic compound represented by formula (1) 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: represents the triplet level (eV) of the organometallic compound; and T1B represents the triplet level (eV) of the polycyclic heterocyclic compound. ) (In formula (1), each structural group is as defined in the description. > # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an organic electroluminescent element, an organic EL display device, an organic EL lighting and a method for manufacturing the 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 an 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 an anode and a cathode, and materials suitable for each layer are being developed. Regarding the luminescent color, red, green, and blue are also being developed.

[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 solution formed by mixing a variety of materials with various functions, it is easy to form a layer containing a variety of materials with various functions. Therefore, in recent years, research and development of organic electroluminescent elements based on film formation by 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 document 1] Advanced Materials, 2022, p. 2201442 Summary of the invention Problems to be solved by the invention

[0007] Generally, polycyclic heterocyclic compounds containing boron have empty p orbitals on boron and are prone to react 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 is not improved. The technologies disclosed in Patent Documents 1 to 3 believe 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 polycyclic heterocyclic compounds containing boron during the 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 studies and have found that the above-mentioned problems can be solved by using a hole injection layer and a light-emitting layer containing a polycyclic heterocyclic compound and an organic metal compound with iridium as the central metal, wherein the hole injection layer contains a stable tetraarylborate ion that satisfies the octet rule and has no empty p orbital 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. In addition, the present inventors conducted intensive research and found that by using a hole injection layer and a light-emitting layer containing a polycyclic heterocyclic compound and an organic metal compound with iridium as the central metal, the hole injection layer contains a cross-linked product of an electron-accepting compound having a cross-linked group, particularly preferably a cross-linked product of a tetraarylborate ion having a cross-linked group, 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.

[0011] Aspect 1 of the present invention is an organic electroluminescent element, It is an organic electroluminescent element having 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: represents the triplet energy level of the organometallic compound (eV) T1B: represents the triplet energy level (eV) of the polycyclic heterocyclic compound. The hole injection layer contains tetraarylborate ions,

[0012]

Chemical formula 1

[0013] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring, Cyclo 1 , Cy 2 , Cy 3 Cy 4 It may further have a condensed ring. R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they may be the same or different. When R is a substituent, it can be connected with adjacent R or adjacent to R Cy 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0014]

Chemical formula 2

[0015] [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 a plurality of each is present, 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 a plurality of each is present, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Indicates 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, L 200 Indicates a single bond or, with B 201 and B 202 Atom groups that together form a bidentate ligand. B 201 -L 200 -B 202 When there are multiple, they may be 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 is an integer greater than 0, j is a substituted 201 The number is an integer greater than 0, k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for ring A201 and ring A202 being the upper limit, m is an integer from 1 to 3.]

[0016] Mode 2 of the present invention is: The organic electroluminescent element according to Embodiment 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.

[0017] Mode 3 of the present invention is: The organic electroluminescent device according to Embodiment 1 or 2, wherein the polycyclic heterocyclic compound represented by Formula (1) is represented by Formula (2-1) or Formula (2-2).

[0018]

Chemical formula 3

[0019] [In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring.]

[0020] Mode 4 of the present invention is: The organic electroluminescent device according to Embodiment 1 or 2, wherein the polycyclic heterocyclic compound represented by Formula (1) is represented by Formula (2-3).

[0021]

Chemical formula 4

[0022] [In formula (2-3), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring. R' represents a hydrogen atom or a substituent. When there are multiple R', they are independent of each other and may be the same or different.]

[0023] Mode 5 of the present invention is: The organic electroluminescent element according to any one of aspects 1 to 4, wherein the light-emitting layer further contains a host material.

[0024] Mode 6 of the present invention is: The organic electroluminescent device according to any one of Embodiments 1 to 5, wherein the tetraarylborate ion is represented by the following formula (112).

[0025]

Chemical formula 5

[0026] (In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents 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 a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups 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 a fluorine-substituted alkyl group as a substituent. )

[0027] Mode 7 of the present invention is: The organic electroluminescent element according to Embodiment 6, wherein Ar in the formula (112) 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by the following formula (113).

[0028]

Chemical formula 6

[0029] (In formula (113), R A Each independently represents 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, a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups which may have a substituent and / or a cross-linking group, a fluorine-substituted alkyl group, a substituent or a cross-linking group, F4 represents 4 fluorine atoms substituted, F (5-m) Each independently represents 5-m fluorine atom substitution, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0-5. *Indicates bonding position. )

[0030] Mode 8 of the present invention is: The organic electroluminescent device according to any one of aspects 2 to 7, wherein the crosslinking group is represented by any one of the following formulae (X1) to (X18).

[0031]

Chemical formula 7

[0032] In formulae (X1) to (X4), the benzene ring and the naphthalene ring may have a substituent. In addition, the substituents may be bonded to each other to form a ring. R in formula (X4), formula (X5), formula (X6) and formula (X10) X Each independently represents an alkyl group which may have a substituent. In formulas (X1) to (X18), * represents a bonding position. )

[0033] Mode 9 of the present invention is: The organic electroluminescent element according to Embodiment 8, wherein the crosslinking group is represented by any one of the formulae (X1) to (X4).

[0034] Mode 10 of the present invention is: An organic EL display device or organic EL lighting, comprising the organic electroluminescent element according to any one of aspects 1 to 9.

[0035] Mode 11 of the present invention is: A method for manufacturing an organic electroluminescent element, The invention relates to 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 producing 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 comprises tetraarylborate ions and an organic solvent. The composition for forming a light-emitting layer comprises 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: represents the triplet energy level of the organometallic compound (eV) T1B: represents the triplet energy level (eV) of the polycyclic heterocyclic compound.

[0036]

Chemical formula 8

[0037] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring. Cyclo 1 , Cy 2 , Cy 3 Cy 4 It may further have a condensed ring. R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they may be the same or different. When R is a substituent, it may be coupled to adjacent R groups or to adjacent ring Cy groups. 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0038]

Chemical formula 9

[0039] [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 a plurality of each is present, 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 a plurality of each is present, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Indicates 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, L 200 Indicates a single bond or, with B 201 and B 202 Atom groups that together form a bidentate ligand. B 201 -L 200 -B 202 When there are multiple, they may be 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 is an integer greater than 0, j is a substituted 201 The number is an integer greater than 0, k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for ring A201 and ring A202 being the upper limit, m is an integer from 1 to 3.]

[0040] Mode 12 of the present invention is: The method for producing an organic electroluminescent element according to Embodiment 11, wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the formula (2-1) or the formula (2-2).

[0041]

Chemical formula 10

[0042] [In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring.]

[0043] Mode 13 of the present invention is: The method for producing an organic electroluminescent element according to Embodiment 11, wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the formula (2-3).

[0044]

Chemical formula 11

[0045] [In formula (2-3), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring. R' represents a hydrogen atom or a substituent. When there are multiple R', they are independent of each other and may be the same or different.]

[0046] A fourteenth aspect of the present invention is: The method for producing an organic electroluminescent element according to any one of aspects 11 to 13, wherein the tetraarylborate ion has a crosslinking group.

[0047] Mode 15 of the present invention is: The method for producing an organic electroluminescent element according to any one of Embodiments 11 to 14, wherein the tetraarylborate ion is represented by the following formula (112).

[0048]

Chemical formula 12

[0049] (In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents 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 a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups 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 a fluorine-substituted alkyl group as a substituent. )

[0050] Mode 16 of the present invention is: The method for producing an organic electroluminescent element according to any one of aspects 14 to 17, wherein the hole injection layer-forming composition is 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.

[0051] A seventeenth aspect of the present invention is: The method for producing an organic electroluminescent element according to any one of aspects 14 to 16, 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. Effects of the Invention

[0052] 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

[0053]

Figure 1

[0054] The following is a detailed description of 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. 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 its main purpose.

[0055] The organic electroluminescent element of the present invention is an organic electroluminescent element having 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), The hole injection layer contains tetraarylborate ions. T1A≥T1B formula (E-1) (In formula (E-1), T1A: represents the triplet energy level of the organometallic compound (eV) T1B: represents the triplet energy level (eV) of the polycyclic heterocyclic compound.

[0056]

Chemical formula 13

[0057] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring. Cyclo 1 , Cy 2 , Cy 3 Cy 4 It may further have a condensed ring. R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they may be the same or different. When R is a substituent, it can be connected with adjacent R or adjacent to R Cy 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0058]

Chemical formula 14

[0059] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent.

[0060] Ring A202 represents an aromatic heterocyclic structure which may have a substituent.

[0061] R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When a plurality of each is present, they may be the same or different.

[0062] 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.

[0063] 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 a plurality of each is present, they may be the same or different. "*" indicates bonding to Ring A201 or Ring A202.

[0064] B 201 -L 200 -B 202 Indicates 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, L 200 Indicates a single bond or, with B 201 and B 202 Atom groups that together form a bidentate ligand. B 201 -L 200 -B 202 When there are multiple, they may be the same or different.

[0065] i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 can replace Ar 202 The number is an integer greater than 0 which is the upper limit. j is a substituted 201 The number is an integer greater than or equal to 0, which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for Ring A201 and Ring A202 being the upper limit. m is an integer from 1 to 3.]

[0066] <Reasons for achieving the effect> The reason why the organic electroluminescent element of the present invention has a low driving voltage and a long driving life is presumed to be as follows.

[0067] The polycyclic heterocyclic compound containing boron has an empty p orbital on boron, and in particular, it is easy to react with an electron donating substance. The result of the reaction is to generate an oxide of an electron donating substance, which is likely to further cause a degradation reaction during driving. On the other hand, the tetraaryl borate ion, which is a stable structure satisfying the octet rule and does not have an empty p orbital on boron, has the effect of stabilizing the oxidized cation of the electron donating substance. Therefore, it is presumed that by using tetraaryl borate ions, the degradation reaction during driving can be suppressed.

[0068] In addition, a method is generally used to promote hole injection from a metal anode and reduce the driving voltage by using an electron accepting compound in a hole injection layer. However, it is believed in the prior art that when a layer above the hole injection layer is formed by a wet film forming method, the electron accepting compound of the hole injection layer diffuses and reaches the light-emitting layer, and the electron accepting compound reacts with a polycyclic heterocyclic compound containing boron during device driving, thereby causing an increase in driving voltage and a reduction in driving life.

[0069] On the other hand, it is believed that: by containing a crosslinking group in the electron accepting compound, when forming the hole injection layer, by performing a crosslinking reaction, 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 driving can be suppressed.

[0070] 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 due to 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 by applying voltage to the organic electroluminescent element, can be effectively utilized for the emission of the polycyclic heterocyclic compound containing boron as a fluorescent light-emitting material.

[0071] As described above, it was found that: by using a polycyclic heterocyclic compound containing boron represented by formula (1) and an organic metal compound represented by formula (201) for a light-emitting layer, and using a hole injection layer containing a stable tetraarylborate ion satisfying the octet rule and having no empty p orbital on boron, the triplet energy levels of the organic metal compound and the polycyclic heterocyclic compound satisfy a specific relationship, the above-mentioned problems were solved and the present invention was completed.

[0072] <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: represents the triplet energy level of the organometallic compound (eV) T1B: represents the triplet energy level (eV) of the polycyclic heterocyclic compound. By satisfying the above formula (E-1), the organometallic compound can efficiently transfer the energy of the excited triplet state generated in the light-emitting layer to the polycyclic heterocyclic compound, and the polycyclic heterocyclic compound emits light efficiently. That is, in the present invention, the polycyclic heterocyclic compound is a light-emitting material.

[0073] 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 internally converted to the excited singlet state, and the polycyclic heterocyclic compound emits light efficiently. 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.

[0074] 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. By making T1A within this range, since the energy of the excited state of the organometallic compound is not too high, the decomposition of the organometallic compound is suppressed, and since the energy is not too low, the excited state of the organometallic compound can be quickly delivered to the polycyclic heterocyclic compound, so that a higher performance element can be obtained. For example, as a preferred embodiment, T1A can be 2.10 eV or more and 2.80 eV or less.

[0075] Note that the above-mentioned T1A, T1B and S1B can be obtained by the following method. S1B, 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-Tech Science. When measuring, the compound is dissolved in an appropriate organic solvent at 10 -6 ~10 -5 The sample was a solution dissolved at a concentration of about 1.5 M. The fluorescence spectrum was measured at room temperature. The phosphorescence spectrum was measured at 77 K using liquid nitrogen.

[0076] Furthermore, the polycyclic heterocyclic compound in the present invention preferably satisfies the following relational formula (E-3). PkA<PkB formula (E-3) (In formula (E-3), PkA: represents the maximum emission wavelength of the organometallic compound (nm) PkB: represents the maximum emission wavelength (nm) of the polycyclic heterocyclic compound.

[0077] In the present invention, by satisfying the above formula (E-3), the organic metal compound efficiently transfers the excitation energy generated in the light-emitting layer to the polycyclic heterocyclic compound, and the polycyclic heterocyclic compound efficiently emits light.

[0078] PkA is preferably above 550nm and below 650nm, and the lower limit is further preferably above 560nm, more preferably above 570nm, and the upper limit is further preferably below 630nm, more preferably below 610nm. PkB only needs to satisfy the above formula (E-3), but the difference between PkB and PkA is preferably usually below 80nm, preferably below 50nm, more preferably below 40nm, more preferably below 30nm, and particularly preferably below 25nm. By making PkA and PkB within this range, since the excitation energy of the organometallic compound is efficiently transferred to the polycyclic heterocyclic compound, a higher performance element is obtained. In addition, it is believed that by making the molecular weight of the organometallic compound above 1,200, the polycyclic heterocyclic compound of the present invention in the relationship of formula (E-3) emits light efficiently at long wavelengths, especially in the red light-emitting region, to obtain a higher performance element.

[0079] (Maximum emission wavelength) PkA and PkB were measured by the following method. At room temperature, the organometallic compound or polycyclic heterocyclic compound of the present invention is prepared at a concentration of 1×10 - 4The solution formed by dissolving 1 mol / L or less in an organic solvent is measured by a spectrophotometer (organic EL quantum yield measuring device C9920-02 manufactured by Hamamatsu Photonics Co., Ltd.) to obtain a luminescent spectrum of the solution. The wavelength showing the maximum value of the obtained luminescent spectrum intensity is taken as the maximum luminescent wavelength in the present invention. As an organic solvent for dissolving an organometallic compound or a polycyclic heterocyclic compound, toluene, 2-methyltetrahydrofuran, etc. are preferably used, and toluene is generally preferred.

[0080] [Polycyclic heterocyclic compounds] The light-emitting layer contains the polycyclic heterocyclic compound represented by formula (1) as a light-emitting compound.

[0081]

Chemical formula 15

[0082] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring. Cyclo 1 , Cy 2 , Cy 3 Cy 4 It may further have a condensed ring. R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they may be the same or different. When R is a substituent, it can be connected with adjacent R or adjacent to R Cy 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0083] <Preferred polycyclic heterocyclic compounds> The polycyclic heterocyclic compound represented by the formula (1) is preferably a compound represented by the formula (2-1) or the formula (2-2).

[0084]

Chemical formula 16

[0085] [In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring.]

[0086] The polycyclic heterocyclic compound represented by the formula (1) is more preferably a compound represented by the formula (2-3).

[0087]

Chemical formula 17

[0088] [In formula (2-3), Q 31 and Q 32 Indicates O or S, R is the same as in the above formula (1). When there are multiple Rs, they are independent of each other and may be the same or different. When R is a substituent, it may bond with adjacent R to form a ring. R' represents a hydrogen atom or a substituent. When there are multiple R', they are independent of each other and may be the same or different.]

[0089] In the polycyclic heterocyclic compound represented by the formula (1), the formula (2-1), the formula (2-2) and the formula (2-3), it is further preferred that R is a hydrogen atom or a substituent selected from the following [Substituent Group W1]. In the polycyclic heterocyclic compound represented by the formula (2-3), it is further preferred that R' is selected from the following [R'].

[0090] [R] R is a hydrogen atom or a substituent. When R is a substituent, it is an arbitrary substituent, but is preferably a substituent selected from the following [Substituent Group W1]. [Substituent group W1] D, F, Cl, Br, I, -N(R')2, -CN, -NO2, -OH, -COOR', -C(=O)R', -C(=O)NR', ​​-P(=O)(R')2, -S(=O)R', -S(=O)2R', -OS(=O)2R', a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 30 carbon atoms, a linear, branched or cyclic alkylthio group having 1 to 30 carbon atoms, a linear, branched or cyclic alkylthio group having 2 to 30 carbon atoms The present invention further comprises an alkenyl group having 2 to 30 carbon atoms, a linear, branched or cyclic alkynyl group having 2 to 30 carbon atoms, an aromatic hydrocarbon group having 5 to 60 carbon atoms, a heteroaryl group having 5 to 60 carbon atoms, an aryloxy group having 5 to 40 carbon atoms, an arylthio group having 5 to 40 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, a heteroaralkyl group having 5 to 60 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an arylheteroarylamino group having 10 to 40 carbon atoms, or a diheteroarylamino group having 10 to 40 carbon atoms. Two or more adjacent R's may be bonded to each other to form a single or condensed aliphatic, aromatic, or heteroaromatic ring. The alkyl group, the alkoxy group, the alkylthio group, the alkenyl group and the alkynyl group may be further substituted with one or more R' groups, and one -CH2- group or two or more non-adjacent -CH2- groups in these groups may be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2-, -C(=O)-, -NR'-, -O-, -S-, -CONR'- or a divalent aromatic hydrocarbon group. In addition, one or more hydrogen atoms in these groups may be substituted with D, F, Cl, Br, I or -CN. The aromatic hydrocarbon group, the heteroaryl group, the aryloxy group, the arylthio group, the arylalkyl group, the heteroarylalkyl group, the diarylamino group, the arylheteroarylamino group and the diheteroarylamino group may each independently be further substituted by one or more R′.

[0091] [R'] R' is independently selected from a hydrogen atom, D, F, Cl, Br, I, -N(R")2, -CN, -NO2, -Si(R")3, -B(OR")2, -C(=O)R", -P(=O)(R")2, -S(=O)2R", -OSO2R", a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 30 carbon atoms, a linear, branched or cyclic alkylthio group having 1 to 30 carbon atoms, a linear, branched or cyclic alkene group having 2 to 30 carbon atoms The present invention may be any of the following: a cyclopentyl group having 2 to 30 carbon atoms, a linear, branched or cyclic alkynyl group having 2 to 30 carbon atoms, an aromatic hydrocarbon group having 5 to 60 carbon atoms, a heteroaryl group having 5 to 60 carbon atoms, an aryloxy group having 5 to 40 carbon atoms, an arylthio group having 5 to 40 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, a heteroaralkyl group having 5 to 60 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an arylheteroarylamino group having 10 to 40 carbon atoms, or a diheteroarylamino group having 10 to 40 carbon atoms. Two or more adjacent R's may be bonded to each other to form a single or condensed aliphatic, aromatic, or heteroaromatic ring. The alkyl group, the alkoxy group, the alkylthio group, the alkenyl group and the alkynyl group may be further substituted with one or more R", and one -CH2- group or two or more non-adjacent -CH2- groups in these groups may be substituted with -C(-R")=C(-R")-, -C≡C-, -Si(-R")2-, -C(=O)-, -NR"-, -O-, -S-, -CONR"- or a divalent aromatic hydrocarbon group. In addition, one or more hydrogen atoms in these groups may be substituted with D, F, Cl, Br, I or -CN. The aromatic hydrocarbon group, the heteroaryl group, the aryloxy group, the arylthio group, the arylalkyl group, the heteroarylalkyl group, the diarylamino group, the arylheteroarylamino group and the diheteroarylamino group may be further substituted by one or more R″.

[0092] [R”] R" is each independently selected from a hydrogen atom, D, F, -CN, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 1 to 20 carbon atoms, or a heteroaryl group having 1 to 20 carbon atoms. Two or more adjacent R" may be bonded to each other to form an aliphatic, aromatic hydrocarbon or heteroaromatic monocyclic or condensed ring.

[0093] (Specific examples of polycyclic heterocyclic compounds) The polycyclic heterocyclic compound represented by the formula (1) is not particularly limited, and specific examples thereof include the following structures.

[0094]

Chemical formula 18

[0095] [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 aforementioned relationship (E-1), it is presumed 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 or dipole-dipole interaction, thereby enabling the polycyclic heterocyclic compound to emit light efficiently. In particular, an organometallic complex containing iridium is preferred. 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).

[0096]

Chemical formula 19

[0097] [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 a plurality of each is present, they may be the same or different. Ar 201 ,Ar 203Each 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 a plurality of each is present, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Indicates 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 Atom groups 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 is an integer greater than or equal to 0, which is the upper limit. j is a substituted 201 The number is an integer greater than or equal to 0, which is the upper limit. k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for Ring A201 and Ring A202 being the upper limit. m is an integer from 1 to 3.]

[0098] (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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] When m is 2 or 3, the plurality of rings A201 and the plurality of rings A202 may be the same or different.

[0103] Preferred combinations of Ring A201 and Ring A202, when expressed as (Ring A201-Ring A202), are (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazole ring), and (benzene ring-benzothiazole ring), and the most preferred combination is (benzene ring-pyridine ring).

[0104] The substituent that Ring A201 or Ring A202 may have can be arbitrarily selected, but is preferably one or more substituents selected from the substituent group S described below.

[0105] 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.

[0106] (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 may be the same or different, R 202 When there are plural of them, they may be the same or different.

[0107] (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 202It 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 may be the same or different. 202 When there are multiple, they may be the same or different. 203 When there are plural of them, 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] In Ar 201 ,Ar 202 ,Ar 203When 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.

[0112] In Ar 202 When it is 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, more preferably an aliphatic hydrocarbon having 1 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon having 1 to 8 carbon atoms.

[0113] (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.

[0114] i3 is preferably an integer of 0 to 5, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0115] j represents an integer of preferably 0 to 2, more preferably 0 or 1.

[0116] 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.

[0117] Ar 201 ,Ar 202 ,Ar 203 The substituents that may be possessed may be arbitrarily selected, but 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).

[0118] Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

[0119] (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.

[0120] 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.

[0121] Unless otherwise specified, an aryl group is an aromatic hydrocarbon, and a heteroaryl group is an aromatic heterocycle.

[0122] (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.

[0123] 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.

[0124] (Preferred structure of formula (201)) Among the structures represented by the formula (202) in the 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] (B 201 -L 200 -B 202 The structure represented) B 201 -L 200 -B 202 When there are plural, they may be the same or different. B 201 -L 200 -B 202 The structure represented is preferably a structure represented by the following formula (203) or (204).

[0129]

Chemical formula 20

[0130] 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.

[0131]

Chemical formula 21

[0132] 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 ring B3 may have is not particularly limited, but is preferably a group selected from the above-mentioned substituent group S.

[0133] (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 being within this molecular weight 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.

[0134] The molecular weight of the organometallic compound is preferably large because of the high Tg, melting point, decomposition temperature, etc., excellent heat resistance of the organometallic compound and the formed light-emitting layer, and the difficulty in causing film quality degradation due to gas generation, recrystallization, and molecular migration, and the increase in impurity concentration accompanying thermal decomposition of the material. On the other hand, the molecular weight of the organometallic compound is preferably small because the purification of the organic compound is easy.

[0135] 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 light-emitting 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 light-emitting compound can be appropriately generated, thereby obtaining a light-emitting layer with high light-emitting efficiency.

[0136] (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. In addition, Me means methyl group, and Ph means phenyl group.

[0137]

Chemical formula 22

[0138]

Chemical formula 23

[0139]

Chemical formula 24

[0140] [Main material] 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 so-called charge transport material is set to also include 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.

[0141] These may be used alone or in any combination and ratio of two or more.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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 a plurality of 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 and the degradation of the light-emitting material is suppressed, thereby extending the driving life.

[0147] The charge transport material used as the main material of the light-emitting layer is preferably a compound having a condensed ring structure of more than three rings, and more preferably a compound having a condensed ring structure of more than two three rings or a compound having at least one condensed ring of more than five 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. Furthermore, from the perspective of charge transportability and material durability, the condensed rings of more than three rings and the condensed rings of more than five rings preferably have aromatic hydrocarbon rings or aromatic heterocyclic rings.

[0148] 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.

[0149] 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.

[0150] [(Group A), (Group B), (Group C)] Here, in this specification, for the sake of convenience, host materials that may be contained in the light-emitting layer are referred to as (A group), (B group), and (C group) as follows. (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):

[0151] 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 group consisting of (Group A) or (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 at least three compounds are contained, at least one compound selected from each of the three groups represented by the above (Group A), the above (Group B), and the above (Group C). In addition, the number of compounds selected from each group may be one or two or more.

[0152] 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), Therefore, the host material contained in the light-emitting layer preferably contains at least two compounds selected from at least one of at least 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 that the compound contains at least two compounds selected from the group consisting of a compound represented by the following formula (250) and a compound represented by the following formula (240), It is particularly preferred that the compound contains at least three compounds selected from at least one compound represented by the following formula (250), at least one compound represented by the following formula (240), and at least one compound represented by the following formula (260).

[0153] It is believed that: when the compound having a structure in which a nitrogen-containing 6-membered heteroaromatic ring is connected to a benzene ring, i.e., the compound represented by the formula (250), is contained as a main material in the light-emitting layer of the organic electroluminescent element of the present invention, the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, the luminous efficiency is improved, the degradation of the polycyclic heterocyclic compound represented by the formula (1) and the organic metal compound represented by the formula (201) as the light-emitting material can be suppressed, and the driving life becomes longer. In particular, when the triazine structure in which all W of the formula (250) is a nitrogen atom, it is believed that: 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 formula (1) and the organic metal compound represented by the formula (201), the durability of the polycyclic heterocyclic compound represented by the formula (1) and the organic metal compound represented by the formula (201) as the light-emitting material is improved, and as a result, the driving life of the organic electroluminescent element becomes longer. In particular, it is believed that electrons enter the empty p orbital of the boron atom of the polycyclic heterocyclic compound represented by the formula (1) as a light-emitting material, which may inhibit the degradation of the polycyclic heterocyclic compound represented by the formula (1) as a light-emitting material and the organic metal compound represented by the formula (201).

[0154] In addition, the compound represented by the formula (250) has a high electron transport property because it has an aromatic six-membered ring containing a nitrogen atom at the center. Therefore, it is believed that when the compound represented by the formula (250) is used as a host material, by further using a host material with high hole transport properties as another host material, the voltage can be further reduced, the luminous efficiency can be improved, and the driving life can be increased.

[0155] It is believed that when the light-emitting layer of the organic electroluminescent element of the present invention contains a compound having two carbazole ring structures, i.e., a compound represented by the formula (240), as a main material, the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, the light-emitting efficiency is improved, the degradation of the polycyclic heterocyclic compound represented by the formula (1) and the organic metal compound represented by the 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 formula (1) or the organic metal compound represented by the formula (201) as the light-emitting material directly accepts holes injected from the layer on the anode side and becomes an oxidized state and there is a possibility of degradation, since the compound represented by the formula (240) has a hole transport property and easily accepts holes from the layer on the anode side, the polycyclic heterocyclic compound represented by the formula (1) or the organic metal compound represented by the formula (201) as the light-emitting material is difficult to be directly oxidized, and the degradation is suppressed. On the contrary, it is believed that when the polycyclic heterocyclic compound represented by the formula (1) or the organic metal compound represented by the formula (201) as a light-emitting material directly accepts electrons injected from the cathode side and becomes reduced and easily degraded, holes are quickly transferred from the compound represented by the formula (240) to the polycyclic heterocyclic compound represented by the formula (1) or the organic metal compound represented by the formula (201) as a light-emitting material, and the light-emitting material recombines to emit light, thereby suppressing degradation.

[0156] The compound represented by formula (240) has excellent hole transport properties, and has excellent hole transport properties to the organic metal compound represented by the formula (201). In addition, it is believed that: since the compound represented by formula (240) has two highly planar carbazole structures, the hole transport properties of the polycyclic heterocyclic compound represented by the formula (1) as a polycyclic heterocyclic compound with high planarity are improved. At this time, it is believed that: since the electron supply to the polycyclic heterocyclic compound represented by the formula (1) as a light-emitting material is also carried out rapidly, the light emission is rapidly compounded, and the degradation of the light-emitting material is suppressed. Therefore, it is believed that: by using the compound represented by the formula (240) as the first host material, a material with high electron transport properties is used as the second host material, so that an organic electroluminescent element with low voltage, improved luminous efficiency and long driving life can be obtained. As a host material with high electron transport properties, the compound represented by the formula (250) is preferably used.

[0157] It is believed that: when a compound having a structure connecting multiple benzene rings, i.e., a compound represented by the formula (260), is included as a main material in the light-emitting layer of the organic electroluminescent element of the present invention, the charge transportability in the light-emitting layer is appropriately adjusted, and the degradation of the polycyclic heterocyclic compound represented by the formula (1) or the organic metal compound represented by the formula (201) as the light-emitting material can be suppressed, and the driving life is prolonged. In particular, the compound represented by the formula (260) has the effect of suppressing charge transportability. In particular, it is believed that: when a compound represented by the formula (250) having excellent electron transportability is used as a main material, by further adding a compound represented by the formula (260) as a main material, the electron transportability in the light-emitting layer is suppressed, so that the polycyclic heterocyclic compound represented by the formula (1) as the light-emitting material or the organic metal compound represented by the formula (201) will not be excessively reduced and degraded, and the driving life of the element is prolonged.

[0158] <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.

[0159] 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, usually 24 or less, preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl; For example, an alkoxy group such as a methoxy group and an ethoxy group usually has 1 or more carbon atoms, usually 24 or less, and preferably 12 or less; 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 phenoxy, naphthoxy, pyridyloxy, etc.; For example, an alkoxycarbonyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less, such as a methoxycarbonyl group and an ethoxycarbonyl group; For example, a dialkylamino group having usually 2 or more, usually 24 or less, and preferably 12 or less carbon atoms, 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, usually 36 or less, and 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 carbon atoms, usually 24 or less, and preferably 12 or less; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a halogenated alkyl group having usually 1 or more, usually 12 or less, and preferably 6 or less carbon atoms, such as a trifluoromethyl group; For example, an alkylthio group having usually 1 or more carbon atoms, usually 24 or less, and preferably 12 or less carbon atoms, 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 phenylthio, naphthylthio and pyridylthio; 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 carbon atoms, usually 36 or less, and preferably 24 or less carbon atoms, such as phenyl and naphthyl; For example, it 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, such as thienyl and pyridyl.

[0160] 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.

[0161] 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.

[0162] <Compound represented by formula (250)>

[0163]

Chemical formula 25

[0164] (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 or equal to 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.

[0165] The compound represented by the above formula (250) is preferably a charge transport compound, that is, preferably a charge transport host material.

[0166] <W> W in the 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.

[0167] <Xa 1 , Ya1 , Za 1 , Xa 2 , Ya 2 , Za 2 > As Xa in the formula (250) 1 , Ya 1 , Za 1 is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, and Xa 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.

[0168] Xa in the 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 2In 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.

[0169] Xa in the formula (250) 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.

[0170] Xa in the formula (250) 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 and Za 2 The substituents that the aromatic hydrocarbon group having 6 to 30 carbon atoms may have and the substituents that the aromatic heterocyclic group having 3 to 30 carbon atoms may have are preferably each independently selected from the substituent group Z2, and more preferably the substituents selected from the substituent group Z2 do not have any further substituents. It is considered that the substituents selected from the substituent group Z2 do not have any further substituents, thereby maintaining high charge transport properties and durability, which is preferred. 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.

[0171] <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.

[0172] In addition, from the viewpoints of charge transport properties, durability, and solubility in organic solvents, the compound represented by the formula (250) preferably has a total of 8 to 18 such rings including the central ring having three Ws.

[0173] <(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).

[0174]

Chemical formula 26

[0175] In each of the above formulae (11) to (13), * represents a bonding position 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 to an adjacent structure. In the following description, unless otherwise specified, the definition of * is the same.

[0176] 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).

[0177] The structural moiety represented by the formula (12) is preferably a structural moiety represented by the following formula (12-2).

[0178]

Chemical formula 27

[0179] As the structural part represented by formula (12), the structural part represented by the following formula (12-3) is more preferable.

[0180]

Chemical formula 28

[0181] 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 preferred to select a structural part selected from the following formulas (14) to (17) containing 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, 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 (Za1 ) j11 Each independently preferably has a structural part selected from the group consisting of formula (11) to formula (17).

[0182]

Chemical formula 29

[0183] A structure comprising multiple 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 having one structural part represented by formula (11) and two structural parts represented by formula (12) as shown in the following formula (14a).

[0184]

Chemical formula 30

[0185] It is further preferred that (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).

[0186] The structural moiety represented by the formula (14) is preferably a structural moiety represented by the following formula (14-2).

[0187]

Chemical formula 31

[0188] As the structural moiety represented by formula (14), a structural moiety represented by the following formula (14-3) is more preferred.

[0189]

Chemical formula 32

[0190] The structural moiety represented by the formula (15) is preferably a structural moiety represented by the following formula (15-2).

[0191]

Chemical formula 33

[0192] As the structural moiety represented by formula (15), a structural moiety represented by the following formula (15-3) is more preferred.

[0193]

Chemical formula 34

[0194] The structural moiety represented by the formula (17) is preferably a structural moiety represented by the following formula (17-2).

[0195]

Chemical formula 35

[0196] (Xa 1 ) g11 ,(Ya 1 ) h11 and (Za 1 ) j11 At least one of the above-mentioned compounds preferably has a structural portion represented by the following formula (19) or a structural portion represented by the following formula (20) as a structural portion including the structural portion represented by the formula (13).

[0197]

Chemical formula 36

[0198] In each of the above formulae (14) to (20), * represents a bonding position to 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.

[0199] 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.

[0200] -(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).

[0201] 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).

[0202]

Chemical formula 37

[0203] [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.]

[0204] These structures may have substituents similar to R 32 same.

[0205] 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.

[0206] In the case of having 2 R 32 In the structure of 32 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.

[0207] <R 31 > Regarding 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.

[0208] 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 present may be selected from the above-mentioned substituent group Z2.

[0209] From the perspective of charge transport, R 31 Preferred is a hydrogen atom.

[0210] 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.

[0211] <Molecular weight> The compound represented by 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.

[0212] <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.

[0213]

Chemical formula 38

[0214]

Chemical formula 39

[0215]

Chemical formula 40

[0216]

Chemical formula 41

[0217]

Chemical formula 42

[0218]

Chemical formula 43

[0219] The light-emitting layer and the material for an organic electroluminescent device of the present invention may contain only one type of the compound represented by the formula (250) or two or more types of the compound.

[0220] <Compound represented by formula (240)>

[0221]

Chemical formula 44

[0222] (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.)

[0223] <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, 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 a plurality of 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 a plurality of aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0224] Ar 611,Ar 612 Preferably, they are independently: Phenyl, A monovalent group formed by multiple benzene rings bonded in multiple chains or branches, A monovalent group formed by one or more benzene rings and at least one naphthalene ring bonded in a chain or branched manner, A monovalent group formed by one or more benzene rings and at least one phenanthrene ring bonded in a chain or branched manner, or A monovalent group formed by one or more benzene rings and at least one tetraphenylene ring bonded in a chain or branched manner. More preferably, it is a monovalent group in which a plurality of benzene rings are bonded in a plurality of chains or branches. In any case, the bonding 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 bonded 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 bonded in a chain or branched form.

[0225] The number of bonded 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, preferred are monovalent structures in which 1 to 4 benzene rings are connected, monovalent structures in which 1 to 4 benzene rings and a naphthalene ring are connected, monovalent structures in which 1 to 4 benzene rings and a phenanthrene ring are connected, or monovalent structures in which 1 to 4 benzene rings and a tetraphenylene ring are connected.

[0226] 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 substituent group Z2. Preferred substituents are the preferred substituents of the substituent group Z2.

[0227] 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).

[0228]

Chemical formula 45

[0229] In each of the above formulae (11) to (13) and (21) to (24), * represents a bonding position 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, the definition of * is the same.

[0230] 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).

[0231] The structural moiety represented by the formula (12) is preferably a structural moiety represented by the following formula (12-2).

[0232]

Chemical formula 46

[0233] As the structural part represented by formula (12), the structural part represented by the following formula (12-3) is more preferable.

[0234]

Chemical formula 47

[0235] 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-mentioned formula (11) to the above-mentioned formula (13) and the following formula (14) to the following formula (17).

[0236]

Chemical formula 48

[0237] The structural portion comprising multiple structures selected from the structural portion represented by the formula (11) and the structural portion represented by the formula (12) refers to, for example, the structural portion represented by the formula (14). For example, the following formula (14a) is a structural portion that can be regarded as having one structural portion represented by the formula (11) and two structural portions represented by the formula (12).

[0238]

Chemical formula 49

[0239] More preferably, Ar 611 ,Ar 612At 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).

[0240] As the structural moiety represented by formula (14), a structural moiety represented by the following formula (14-2) is more preferred.

[0241]

Chemical formula 50

[0242] As the structural moiety represented by formula (14), a structural moiety represented by the following formula (14-3) is more preferred.

[0243]

Chemical formula 51

[0244] The structural moiety represented by the formula (15) is preferably a structural moiety represented by the following formula (15-2).

[0245]

Chemical formula 52

[0246] As the structural moiety represented by formula (15), a structural moiety represented by the following formula (15-3) is more preferred.

[0247]

Chemical formula 53

[0248] The structural moiety represented by the formula (17) is preferably a structural moiety represented by the following formula (17-2).

[0249]

Chemical formula 54

[0250] 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).

[0251]

Chemical formula 55

[0252] In each of the above formulae (14) to (20), * represents a bonding position to an adjacent structure or a hydrogen atom. At least one of the two *s present represents a bonding position to an adjacent structure.

[0253] 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.

[0254] 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).

[0255] <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 of aromatic hydrocarbon structures 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 substituent group Z2. Preferred substituents are the preferred substituents of the substituent group Z2.

[0256] <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. From the viewpoint of high solubility in organic solvents, 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 from 1 to 4.

[0257] <Substituent> Ar 611 ,Ar 612 , R 611 , R 612In the case of a monovalent aromatic hydrocarbon group, the substituent that may be present is preferably a substituent selected from the substituent group Z2.

[0258] <G> G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

[0259] 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, 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 a plurality of 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 a plurality of aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0260] G is preferably a single bond, a phenylene group, a divalent group in which a plurality of benzene rings are bonded in a plurality of chains or branches, a divalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a chain or branch, a divalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a chain or branch, or a divalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a chain or branch, and is further preferably a divalent group in which a plurality of benzene rings are bonded in a plurality of chains or branches. In any case, the bonding order is not limited.

[0261] The number of bonded 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.

[0262] 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 substituent group Z2. Preferred substituents are the preferred substituents of the substituent group Z2.

[0263] <Molecular weight> The compound represented by the 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.

[0264] <Specific examples of compound IV represented by the formula (240)> Preferred specific examples of the compound IV represented by the formula (240) are shown below, but the present invention is not limited to these.

[0265]

Chemical formula 56

[0266]

Chemical formula 57

[0267] The light-emitting layer and the material for an organic electroluminescent device of the present invention may contain only one type of the compound represented by the formula (240) or two or more types of the compound.

[0268] <Compound represented by formula (260)>

[0269]

Chemical formula 58

[0270] (In formula (260), Ar 61 ~Ar 65 are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent, L 1 ~L 5 are each independently a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent, R 60 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 61 ,Ar 62 ,Ar 63 ,Ar 64 and at least one Ar when n is 1 or more 65 At least one group is not a hydrogen atom.)

[0271] (Ar 61 ,Ar 62 ,Ar 65 ) Ar in formula (260) 61 ,Ar 62 and Ar 65Each is independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

[0272] From the viewpoint of solubility and durability of the compound, Ar in formula (260) 61 ,Ar 62 and Ar 65 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 (261) or (262); it is more preferably a hydrogen atom, a monovalent group on a benzene ring, or a structure represented by formula (261) or (262); it is further preferably a hydrogen atom, a monovalent group on a benzene ring, or a structure represented by formula (262); and it is particularly preferably a structure represented by formula (262). From the viewpoint of durability and charge transport, Ar 61 ,Ar 62 and at least one Ar 65 Among them, preferably one or more and three or less groups are of the following formula (261) or the following formula (262), Ar 61 ,Ar 62 and at least one Ar 65 Among them, it is more preferred that one or more and three or less groups are the following formula (262). From the viewpoint of charge transport and solubility, Ar 61 ,Ar 62 and at least one Ar 65 Among them, preferably one group is represented by the following formula (262). From the perspective of durability, Ar 61 ,Ar 62 and at least one Ar 65 Among them, preferably, two or more groups are represented by the following formula (262), and more preferably, three groups are represented by the following formula (262).

[0273] (Formula (261), Formula (262))

[0274]

Chemical formula 59

[0275] (In formula (261) or formula (262), The asterisk (*) indicates the bonding position to formula (260), R 101 ~R 126 Each independently represents a hydrogen atom or a substituent. )

[0276] When Ar 61When it is Formula (261) or Formula (262), m1 is preferably 0 or 1, more preferably 0. 62 When it is Formula (261) or Formula (262), m2 is preferably 0 or 1, more preferably 0. 65 In the case of formula (261) or formula (262), m5 is preferably 0 or 1, and more preferably 0.

[0277] (Ar 63 ,Ar 64 ) Ar in formula (260) 63 and Ar 64 Each independently represents a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

[0278] Examples of the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms 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, ...

[0279] From the viewpoint of solubility and durability of the compound, Ar in formula (260) 63 ,Ar 64 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.

[0280] (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.

[0281] Examples of the divalent aromatic hydrocarbon group having 6 or more and 60 or less 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.

[0282] (R 60 ) R in formula (260) 60Each independently represents a substituent. As a substituent, a substituent selected from the substituent group Z2 can be used. Among these, preferably 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. From the viewpoint of heat resistance and durability, preferably 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, an aromatic hydrocarbon group, more preferably an alkyl group having less than 10 carbon atoms, an aralkyl group having less than 30 carbon atoms, an aromatic hydrocarbon group having less than 30 carbon atoms, and particularly preferably a group formed by a benzene ring or 2 to 5 benzene rings connected.

[0283] (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.

[0284] 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 61 When m1 and Ar are the formula (261) or (262), 62 When m2 is the formula (261) or (262), and Ar 65 When it is formula (261) or formula (262), m5 is preferably 0.

[0285] 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.

[0286] 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.

[0287] ((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 Among them, at least one group 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 more preferably (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When n is greater than 1 and m5 is greater than 1, (L 5 ) m5 When m3 is greater than 1 (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 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). 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 greater than 1 and m5 is greater than 1, (L 5 ) m5 Each independently may have a structural moiety selected from the structural moieties represented by the following formulae (11) to (17).

[0288]

Chemical formula 60

[0289] In each of the above formulae (11) to (13), * represents a bonding position to an adjacent structure, or Ar61 ,Ar 62 ,Ar 63 ,Ar 64 or Ar 65 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, unless otherwise specified, the definition of * is the same.

[0290] More preferably, (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 group has a structural portion represented by the formula (11) or a structural portion represented by the 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).

[0291] In formula (260), as formula (12), the following formula (12-2) is preferred.

[0292]

Chemical formula 61

[0293] In formula (260), as formula (12), the following formula (12-3) is more preferred.

[0294]

Chemical formula 62

[0295] 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 above, the preferred structural moiety possessed by at least one group is a structural moiety having a structural moiety represented by the formula (11) and a structural moiety represented by the formula (12).

[0296] 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-mentioned formula (11) to the above-mentioned formula (13) and the following formula (14) to the following formula (17).

[0297]

Chemical formula 63

[0298] 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) is a structural portion that can be regarded as having one structural portion represented by formula (11) and two structural portions represented by formula (12) as shown in the following formula (14a).

[0299]

Chemical formula 64

[0300] 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 group has 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).

[0301] In formula (260), as formula (14), the following formula (14-2) is preferred.

[0302]

Chemical formula 65

[0303] In formula (260), as formula (14), the following formula (14-3) is more preferred.

[0304]

Chemical formula 66

[0305] In formula (260), as formula (15), the following formula (15-2) is preferred.

[0306]

Chemical formula 67

[0307] In formula (260), as formula (15), the following formula (15-3) is more preferred.

[0308]

Chemical formula 68

[0309] In formula (260), as formula (17), the following formula (17-2) is preferred.

[0310]

Chemical formula 69

[0311] In addition, (L in formula (260) 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 Among at least one of the above, it is more preferable to have a structural moiety represented by the following formula (19) or a structural moiety represented by the following formula (20) as the structural moiety including the structural moiety represented by the formula (13).

[0312]

Chemical formula 70

[0313] In each of the above formulae (14) to (20), * represents a bonding position 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.

[0314] In formula (260), among formulas (14) to (20), formula (14-3) and formula (15-3) are preferred, and formula (14-3) is more preferred.

[0315] (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).

[0316] (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.

[0317] (a1~a3) a1 to a3 each independently represent an integer of 0 to 3. Regarding a1 to a3, from the viewpoint of solubility and durability of the compounds, a1 to a3 are each independently preferably 0 or 1, Most preferably, a1=a2=a3=0.

[0318] (R 101 ~R 126 ) R in formula (260) 101 ~R 126 Each independently represents a hydrogen atom or a substituent. As a substituent, a substituent selected from the substituent group Z2 can be used. Among these, preferably 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. From the viewpoint of durability, preferably 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, more preferably a hydrogen atom, an aromatic hydrocarbon group, and particularly preferably a hydrogen atom.

[0319] (Substituent) In formula (260), Ar 61 ~Ar 65 a monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms and L 1 ~L 5 The substituents that the divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms may have may be independently selected from the above substituent group Z2. Among them, alkyl, alkenyl, alkynyl, alkoxy, aryloxy, alkoxycarbonyl, acyl, halogen atom, halogenated alkyl, alkylthio, arylthio, silyl, silyloxy, aralkyl or aromatic hydrocarbon group is preferred, and alkyl, alkenyl, alkoxy, aryloxy, alkoxycarbonyl, acyl, halogen atom, halogenated alkyl, silyl, silyloxy, aralkyl or aromatic hydrocarbon group is more preferred.

[0320] (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.

[0321] (specific example) Specific examples of the compound represented by formula (260) are shown below, but the compound is not limited to these.

[0322]

Chemical formula 71

[0323]

Chemical formula 72

[0324]

Chemical formula 73

[0325] The light-emitting layer and the light-emitting layer-forming composition of the present invention may contain only one type of the compound represented by the formula (260) or two or more types of the compound.

[0326] [Luminescent layer forming composition] The light-emitting layer may be formed by vacuum deposition or wet film formation, preferably 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.

[0327] The composition for forming a luminescent layer comprises a polycyclic heterocyclic compound represented by the formula (1), an organic metal compound represented by the formula (201) and an organic solvent, and the polycyclic heterocyclic compound and the organic metal compound preferably satisfy the above-mentioned relationship (E-1). The composition for forming a luminescent layer preferably further comprises the host material. The composition for forming a luminescent layer is a composition in which the polycyclic heterocyclic compound represented by the formula (1) and the organic metal compound represented by the formula (201) are dissolved or dispersed in an organic solvent. The composition for forming a luminescent layer may also be a composition in which the polycyclic heterocyclic compound represented by the formula (1), the organic metal compound represented by the formula (201) and the host material are dissolved or dispersed in an organic solvent.

[0328] (Organic Solvent) The organic solvent contained in the composition for forming a light-emitting layer is a volatile liquid component used for forming a layer containing a polycyclic heterocyclic compound by wet film formation.

[0329] The organic solvent is not particularly limited as long as it is an organic solvent in which the polycyclic heterocyclic compound and the charge transporting compound as solutes are well dissolved.

[0330] 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.

[0331] 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.

[0332] These organic solvents may be used alone or in any combination and ratio.

[0333] 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 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.

[0334] 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.

[0335] (content) The content of the polycyclic heterocyclic compound represented by formula (1) in the composition for forming a light-emitting layer is usually more than 0.001 mass %, preferably more than 0.01 mass %, usually less than 30.0 mass %, preferably less than 20.0 mass %. The content of the organometallic compound represented by formula (201) in the composition for forming a light-emitting layer is usually more than 0.001 mass %, preferably more than 0.01 mass %, usually less than 30.0 mass %, preferably less than 20.0 mass %. By making the content in this range, it is possible to efficiently inject holes or electrons from adjacent layers (such as hole transport layers, hole blocking layers) to the light-emitting layer, thereby reducing the driving voltage. Furthermore, the polycyclic heterocyclic compound represented by formula (1) and the organometallic compound represented by formula (201) can contain only one in the composition for forming a light-emitting layer, or can 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, relative to 1 part by mass of the polycyclic heterocyclic compound represented by formula (1), 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.

[0336] 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.

[0337] The content of the main material contained in the composition for forming the light-emitting layer is usually less than 1000 parts by mass, preferably less than 100 parts by mass, and more preferably less than 50 parts by mass, relative to 1 part by mass of the organic metal compound represented by formula (201), and is usually more than 0.01 parts by mass, preferably more than 0.1 parts by mass, and more preferably more than 1 part by mass.

[0338] The content of the organic solvent contained in the composition for forming the light-emitting 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.

[0339] (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.

[0340] (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 the 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, it is preferably an inkjet method or a nozzle printing method, and the inkjet method is particularly preferably used.

[0341] 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.

[0342] 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.

[0343] In the case of heating, the heating method is not particularly limited, and heating by 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.

[0344] 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.

[0345] [Hole injection layer] The organic electroluminescent device of the present invention preferably has a hole injection layer on the anode. The hole injection layer is usually formed in contact with the anode. The hole injection layer needs to have a function of transporting holes and therefore contains a hole transport material. The organic electroluminescent element of the present invention contains tetraaryl borate ions in the hole injection layer, or contains a crosslinked product of an electron accepting compound having a crosslinking group in the hole injection layer. For example, the hole injection layer of the organic electroluminescent element of the present invention contains tetraaryl borate ions having a crosslinking group and / or a crosslinked product of tetraaryl borate ions having a crosslinking group.

[0346] In order to improve the hole injectability from anode to hole injection layer, improve the hole transportability in hole injection layer, the hole transport material contained in hole injection layer preferably contains cation free radical site. In order to make hole transport material cation free radical, electron accepting compound is used when forming hole injection layer. As the parent skeleton of electron accepting compound, the ionic compound composed of tetraaryl borate ion and counter cation as anion with ionic valence of 1 described later is preferred because of having high stability.

[0347] 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, a tetraarylborate having a diaryliodonium as a counter cation is used as an electron accepting compound, when forming a hole injection layer, the counter cation can be changed from diaryliodonium to triarylamine as shown in the following formula.

[0348]

Chemical formula 74

[0349] (e.g., Ar, Ar 1 ~Ar 4 Each is independently an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group formed by connecting a plurality of structures selected from an aromatic hydrocarbon ring group which may have a substituent and an aromatic heterocyclic group which may have a substituent.)

[0350] Since the triarylaminium generated in the above reaction has a half occupied orbital (SOMO) that can accept electrons, the tetraarylborate having the triarylaminium as a counter cation is an electron accepting compound.

[0351] 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.

[0352] [Electron-accepting compound having a cross-linking group] Examples of the electron accepting compound include compounds having an ionic compound composed of a tetraarylborate ion and a counter cation as a parent skeleton as described above, or compounds having an ionic compound composed of a tetraarylborate ion and a counter cation as a parent skeleton and having the following crosslinking groups.

[0353] (Crosslinking 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 to generate a new chemical bond by irradiation with heat and / or active energy lines. In this case, the reactive group may be the same group as the crosslinking group or a different group.

[0354] It is believed that: when the electron accepting compound includes a crosslinking group, a crosslinking reaction is performed when the hole injection layer is formed, so that the electron accepting compound can be 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 an electron accepting compound with a crosslinking group is used, the degradation reaction in driving can be suppressed.

[0355] In addition, the polycyclic heterocyclic compound containing boron has an empty p orbital on boron and is particularly prone to react with an electron donating substance.

[0356] A method of promoting hole injection from a metal anode and reducing a driving voltage by using an electron-accepting compound in a hole injection layer is generally used. However, it is believed that in the prior art, when a layer above a hole injection layer is formed by a wet film-forming method, the electron-accepting compound of the hole injection layer diffuses and reaches the light-emitting layer, and the electron-accepting compound reacts with a polycyclic heterocyclic compound containing boron during element driving, resulting in an increase in driving voltage and a reduction in driving life.

[0357] On the other hand, it is believed that: by containing a crosslinking group in the electron accepting compound, when forming a hole injection layer, by performing a crosslinking reaction, 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 presumed that by using an electron accepting compound with a crosslinking group, the degradation reaction in driving 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 due to the heavy atom effect. Due to the promotion of intersystem crossing, it is estimated that the energy of the excited triplet state, which accounts for 75% of the excitons generated by applying voltage to the organic electroluminescent element, can be effectively utilized for the emission of the boron-containing polycyclic heterocyclic compound as a fluorescent light-emitting material.

[0358] The crosslinking group is preferably a crosslinking group represented by any one of the following formulae (X1) to (X18).

[0359]

Chemical formula 75

[0360] 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) X Each independently represents an alkyl group which may have a substituent. ) In formulas (X1) to (X18), * represents a bonding position. )

[0361] R X The alkyl group represented 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.

[0362] The benzene ring and naphthalene ring of formulae (X1) to (X4), R of formulae (X4) to (X6) and (X10) X The substituent that may be possessed is preferably an alkyl group, an aromatic hydrocarbon group, an alkoxy group, or an aralkyl group.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] As a cross-linking group, a cross-linking group represented by any one of formulae (X1) to (X4) is preferred from the perspective of having small polarity and having little influence 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.

[0368] The crosslinking group represented by the formula (X1) forms a crosslinking structure by thermally opening the cyclobutene ring as shown in the following formula, and the groups after the ring opening are bonded to each other.

[0369]

Chemical formula 76

[0370] The crosslinking group represented by the formula (X2) forms a crosslinking structure by thermally opening the cyclobutene ring as shown in the following formula, and the groups after the ring opening are bonded to each other.

[0371]

Chemical formula 77

[0372] The crosslinking group represented by the formula (X3) forms a crosslinking structure by thermally opening the cyclobutene ring as shown in the following formula, and the groups after the ring opening are bonded to each other.

[0373]

Chemical formula 78

[0374] The crosslinking group represented by any one of formulae (X1) to (X3) is opened by thermal cyclobutene ring, and when there is a double bond nearby, the group after ring opening reacts with the double bond to form a crosslinking structure. The following is an example of a crosslinking structure formed by the group after ring opening of the crosslinking group represented by formula (X1) and the crosslinking group represented by formula (X4) having a double bond site. (Wherein, R of formula (X4) X Not shown.)

[0375]

Chemical formula 79

[0376] 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 the crosslinking group in the electron accepting compound, it is preferred to contain a crosslinking group represented by any one of formulas (X1) to (X3) in other components forming the hole injection layer such as a hole transporting compound because the possibility of forming a crosslinked structure is increased.

[0377] 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.

[0378] As the crosslinking group, a crosslinking group represented by formula (X7) is preferred from the viewpoint of improving electron accepting property. When the crosslinking group represented by formula (X7) is used, the following crosslinking reaction proceeds.

[0379]

Chemical formula 80

[0380] From the viewpoint of high reactivity, a crosslinking group represented by any one of formulae (X8) and (X9) is preferred. When a crosslinking group represented by formula (X8) and a crosslinking group represented by formula (X9) are used, the following crosslinking reaction proceeds.

[0381]

Chemical formula 81

[0382] 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.

[0383] (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 hole injection layer forming composition, and the hole injection layer forming composition is preferably a composition obtained by a process of 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.

[0384] 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.

[0385] 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.

[0386] Here, the “tetraarylborate ion in the present invention” includes the case where it exists as an electron-accepting compound of an ionic compound formed by a tetraarylborate ion described later and a counter cation, and the case where it exists as a charge-transporting ionic compound formed by a tetraarylborate ion described later and a cation of a hole transport material. The crosslinked product of the tetraarylborate ion having a crosslinking group in the present invention may be the following crosslinked products. 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.

[0387] The two crosslinking groups in the crosslinking reaction may be the same crosslinking group or different crosslinking groups as long as they can undergo the crosslinking reaction.

[0388] [Tetraarylborate ion] The tetraarylborate ion is an anion having an ion valence of 1, in which a boron atom is substituted with four aromatic hydrocarbon rings which may have a substituent and / or a crosslinking group, or an aromatic heterocyclic ring which may have a substituent and / or a crosslinking group.

[0389] From the viewpoint of further improving stability, the tetraarylborate ion that may be included in the organic electroluminescent element of the present invention preferably has a fluorine atom or an alkyl group substituted with fluorine as a substituent of the aryl group. That is, the tetraarylborate ion is preferably represented by the following formula (112).

[0390]

Chemical formula 82

[0391] (In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents 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 a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups 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 a fluorine-substituted alkyl group as a substituent. )

[0392] Ar1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them preferably has a cross-linking group.

[0393] 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.

[0394] 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.

[0395] 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.

[0396] 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.

[0397] 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.

[0398] As Ar 1 ,Ar2 ,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.

[0399] 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.

[0400] Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The crosslinking group that may be present is as shown in the above-mentioned crosslinking group.

[0401] From the perspective of further increasing the stability of the anion and further improving the effect of stabilizing the cation, the tetraarylborate ion that may be contained in the organic electroluminescent element of the present invention is preferably Ar in the formula (112): 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them is a group represented by formula (113), more preferably Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least two of them are independently a group represented by formula (113), 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 (113), and Ar is most preferred 1 ,Ar 2 ,Ar 3 and Ar 4All of them are independently a group represented by the formula (113).

[0402]

Chemical formula 83

[0403] (In formula (113), R A Each independently represents 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, a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups which may have a substituent and / or a cross-linking group, an alkyl group substituted with fluorine, a substituent or a cross-linking group, F4 represents 4 fluorine atoms substituted, F (5-m) Each independently represents 5-m fluorine atom substitution, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0 to 5, *Indicates bonding position. )

[0404] From the viewpoint of further improving the stability of the anion, 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.

[0405] 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 combining durability, it is more preferably 1 or 2. From the viewpoint of improving the stability of anions and also being excellent in durability, k+m≥1 is preferred.

[0406] 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.

[0407] As R A 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.

[0408] As R A The substituents and RA When it is a substituent, the substituent includes the groups described in the substituent group W described later.

[0409] In formula (113), from the perspective of further increasing the stability of anions and further improving the effect of stabilizing cations, at least one R A It is preferably the alkyl group substituted with fluorine, preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0410] As R A The cross-linking group and R A When it is a crosslinking group, the crosslinking group is as described above for the crosslinking group.

[0411] In formula (113), from the perspective of balancing crosslinking and electron accepting properties, it is preferred that at least one R A In this case, as R A , preferably a structure in which the crosslinking group or one or more crosslinking groups are bonded to an aromatic hydrocarbon group.

[0412] In another embodiment of the present invention, in formula (113), from the perspective of further increasing the stability of the anion and further improving the effect of stabilizing the cation, at least one R A It is preferably the alkyl group substituted with fluorine, preferably a perfluoroalkyl group, and more preferably a trifluoromethyl group.

[0413] As R A The cross-linking group and R A When it is a crosslinking group, the crosslinking group is as described above for the crosslinking group.

[0414] In order to balance the crosslinking property and the electron accepting property, Ar of the formula (112) 1 ,Ar 2 ,Ar 3 and Ar 4 In the embodiment, at least one group is preferably at least one R A The structure represented by the above formula (113) is a crosslinking group. A , preferably a structure in which the crosslinking group or one or more crosslinking groups are bonded to an aromatic hydrocarbon group.

[0415] Furthermore, R A A group including a group represented by the following formula (114) or a group represented by the following formula (115) is also preferred.

[0416]

Chemical formula 84

[0417] The groups represented by the formula (114) and the groups represented by the formula (115) may have a substituent. Examples of the substituents are: A The substituents that may be possessed are the same.

[0418] As R A , preferably a group represented by formula (114) or a group represented by formula (115), or a structure in which one or more groups represented by formula (114) or groups represented by formula (115) are bonded to an aromatic hydrocarbon group.

[0419] As R A 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, a further preferred R 1 The structure in which the crosslinking group is bonded to a monocyclic benzene ring or a monocyclic naphthalene ring is preferred, the structure in which the crosslinking group is bonded to a benzene ring is further preferred, and the structure in which one or two crosslinking groups are bonded is particularly preferred.

[0420] In R A When it is a group including a group represented by the formula (114) or a group represented by the following formula (115), further preferred R 1 It is a structure in which a group represented by formula (114) or a group represented by formula (115) is bonded to a monocyclic benzene ring or a monocyclic naphthalene ring. It is further preferably a structure in which a group represented by formula (114) or a group represented by formula (115) is bonded to a benzene ring. It is particularly preferably a structure in which one or two groups represented by formula (114) or groups represented by formula (115) are bonded.

[0421] The group represented by the formula (114) and the group represented by the formula (115) are crosslinkable and are considered to be preferred because the tetraarylborate ions and the counter cations will not diffuse into other layers.

[0422] (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.

[0423] 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.

[0424] 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.

[0425] Examples of the aliphatic hydrocarbon ring group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0426] The alkyl group has a carbon number of usually 1 or more, preferably 4 or more, 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.

[0427] 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.

[0428] 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.

[0429] Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenylhexyl group.

[0430] 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.

[0431] 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 phenoxy and naphthoxy.

[0432] 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.

[0433] 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.

[0434] 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.

[0435] 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.

[0436] 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.

[0437] 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.

[0438] 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.

[0439] [Specific examples of tetraarylborate ions] Specific examples of the tetraarylborate ion used in the organic electroluminescent device of the present invention are listed below, but the present invention is not limited to these.

[0440]

Chemical formula 85

[0441]

Chemical formula 86

[0442]

Chemical formula 87

[0443]

Chemical formula 88

[0444]

Chemical formula 89

[0445]

Chemical formula 90

[0446]

Chemical formula 91

[0447]

Chemical formula 92

[0448]

Chemical formula 93

[0449]

Chemical formula 94

[0450] 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.

[0451] Furthermore, 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.

[0452] [Electron-accepting ionic compounds containing tetraarylborate ions] Tetraarylborate ions are also preferably used as electron-accepting ionic compounds containing tetraarylborate ions. The electron-accepting ionic compound containing tetraarylborate ions is referred to as a first ionic compound. The first ionic compound is composed of the tetraarylborate ions as anions and counter cations. The first ionic compound is used as an electron-accepting compound.

[0453] 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.

[0454] As the iodonium cation, a structure represented by the general formula (6) described below is preferred, and the more preferred structure is the same.

[0455] Specifically, the iodonium cation is preferably a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, a 4-tert-butoxyphenylphenyliodonium cation, a 4-methoxyphenylphenyliodonium cation, a 4-isopropylphenyl-4-methylphenyliodonium cation, or the like.

[0456] As the sulfonium cation, specifically, a triphenylsulfonium cation, a 4-hydroxyphenyldiphenylsulfonium cation, a 4-cyclohexylphenyldiphenylsulfonium cation, a 4-methanesulfonylphenyldiphenylsulfonium cation, a (4-tert-butoxyphenyl)diphenylsulfonium cation, a bis(4-tert-butoxyphenyl)phenylsulfonium cation, a 4-cyclohexylsulfonylphenyldiphenylsulfonium cation and the like are preferred.

[0457] Specifically, preferred examples of the carbocation include trisubstituted carbocations such as triphenylcarbocation, tri(methylphenyl)carbocation, and tri(dimethylphenyl)carbocation.

[0458] 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.

[0459] 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.

[0460] 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.

[0461] The iodonium cation as the counter cation of the first ionic compound is preferably a structure represented by the following formula (116).

[0462]

Chemical formula 95

[0463] In formula (116), 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 obtained from 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure as in the case of Ar can be selected, and the preferred structure can also be selected from 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure is selected in the case.

[0464] In addition, the counter cation represented by the formula (116) is preferably a structure represented by the following formula (117).

[0465]

Chemical formula 96

[0466] In the above formula (117), Ar7 and Ar 8 and Ar in the above formula (116) 5 and Ar 6 The substituents that may be possessed are the same.

[0467] 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, charge transport may be hindered.

[0468] [Specific example] Specific examples of ionic compounds with iodonium cations are given below as the first ionic compound in the present invention, but the first ionic compound is not limited to these.

[0469]

Chemical formula 97

[0470]

Chemical formula 98

[0471]

Chemical formula 99

[0472]

Chemical Formula 100

[0473]

Chemical Formula 101

[0474]

Chemical Formula 102

[0475]

Chemical Formula 103

[0476]

Chemical Formula 104

[0477]

Chemical Formula 105

[0478]

Chemical formula 106

[0479]

Chemical formula 107

[0480]

Chemical formula 108

[0481]

Chemical formula 109

[0482] 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.

[0483] [Hole transport material] 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 transmittance of visible light.

[0484] Among the aromatic amine compounds, aromatic tertiary amine compounds are particularly preferred in the present invention. In addition, the aromatic tertiary amine compound referred to in the present invention refers to a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from an aromatic tertiary amine.

[0485] 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.

[0486] [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 (101).

[0487]

Chemical Formula 110

[0488] In the above formula (101), j 10 , k 10 , l 10 、m 10 、n 10 、p 10 Each independently represents an integer greater than 0. 10 +m 10 ≥1.

[0489] In the above formula (101), 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 (102), 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 (103).

[0490] Ar 11 ,Ar 12 ,Ar 14 The aromatic ring group represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group formed by connecting at least two groups selected from 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.

[0491] The aromatic hydrocarbon group preferably has 6 or more and 30 or less 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.

[0492] The aromatic heterocyclic group preferably has 3 or more and 30 or less 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.

[0493] Among them, from the perspective of excellent charge transport properties, 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.

[0494] 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.

[0495] These aromatic ring groups may have a substituent, and the substituent that these aromatic ring groups may have may be selected from the substituent group Z2 that the host material may have.

[0496] 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 (102).

[0497]

Chemical Formula 111

[0498] In the above formula (102), 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. 12Ar 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 position to the nitrogen atom of the formula (101).

[0499] 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.

[0500] As R 11 Specific examples of the alkyl group include trivalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0501] 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.

[0502] As R 12 Specific examples of the alkyl group include divalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0503] 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.

[0504] 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 formulas (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.

[0505] S 1 ~S 4 Each is independently a group represented by the following formula (103).

[0506]

Chemical Formula 112

[0507] In the above formula (103), q1 and r1 each independently represent an integer of 0 to 6. ql and rl are each independently preferably 0 to 4, more preferably 0 or 1.

[0508] 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 position to the nitrogen atom in the general formula (101).

[0509] As Ar 21 ,Ar 23 Examples of aromatic ring groups, with Ar 11 ,Ar 12 ,Ar 14 The same situation.

[0510] Ar 22 ,Ar 32 The aromatic ring group represents a monovalent aromatic hydrocarbon group which may have a substituent, a monovalent aromatic heterocyclic group which may have a substituent, or a monovalent group formed by connecting at least two groups selected from 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.

[0511] 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.

[0512] The aromatic heterocyclic group preferably has 3 or more and 30 or less 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.

[0513] Among them, from the viewpoint of excellent charge transport properties, excellent durability and heat resistance, 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.

[0514] These aromatic ring groups may have a substituent, and the substituent may be selected from the substituent group Z2.

[0515] As R 13 Examples of alkyl groups or aromatic ring groups, with R 12 same.

[0516] Ar 32 The crosslinking group is not particularly limited, and Ar 31 Examples of the cross-linking group are the same as those of the embodiment, and preferred examples are also the same.

[0517] As long as it does not violate the gist of the present invention, the above Ar 11 ~Ar 14 , R 11 , R 12 ,Ar 21 ~Ar 23 ,Ar 31 ~Ar 32 , Q 11 , Q 12 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 substituent group Z2 can be cited.

[0518] In particular, among the polymer compounds having a repeating unit represented by the formula (11), a polymer compound having a repeating unit represented by the following formula (14) is preferred because it has extremely high hole injection / transport properties.

[0519]

Chemical formula 113

[0520] 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 substituent group Z2.

[0521] Y' represents a divalent aromatic ring group having 30 or less carbon atoms which may have a substituent. 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.

[0522] 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.

[0523] Preferred examples of the aromatic tertiary amine polymer compound include polymer compounds containing repeating units represented by the following formula (105) and / or formula (106).

[0524]

Chemical formula 114

[0525] In the above formula (105) and formula (106), 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.

[0526] 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.

[0527] 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.

[0528] As R 41 ~R 43 , preferably a hydrogen atom or a substituent described in the substituent group Z2, 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.

[0529] r is preferably 0 or 1, and more preferably 0.

[0530] Preferred specific examples of the repeating units represented by formula (105) and formula (106) that can be used in the present invention are listed below, but the present invention is not limited to these.

[0531]

Chemical Formula 115

[0532] 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.

[0533] 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 an alkali metal, an alkaline earth metal, 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.

[0534] 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.

[0535] Preferred specific examples of oligothiophene derivatives that can be used as hole transport materials include α-sexithiophene and the like.

[0536] Furthermore, 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, which is not preferred. On the other hand, when the molecular weight is too small, the heat resistance may be reduced, which is still not preferred.

[0537] 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. When the hole injection layer contains two or more hole transport materials, the combination is arbitrary, but preferably one or two or more aromatic tertiary amine polymer compounds and one or two or more other hole transport materials are used in combination. As the type of hole transport material used in combination with the aforementioned polymer compound, an aromatic amine compound is preferably used.

[0538] 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.

[0539] [Charge transport ionic compounds] The hole injection layer of the organic electroluminescent element of the present invention preferably contains a charge transporting ionic compound in which the tetraarylborate ion is ionically bonded to a cation radical of a hole transporting material. Furthermore, the hole injection layer of the organic electroluminescent element of the present invention preferably contains a crosslinked product of an electron accepting compound having a crosslinking group, and the electron accepting compound includes a charge transporting ionic compound in which the tetraarylborate ion is ionically bonded to a cation radical of a hole transporting material. For example, the hole injection layer of the organic electroluminescent device of the present invention may contain the tetraarylborate ion having a crosslinking group and / or a crosslinked product of the tetraarylborate ion having a crosslinking group.

[0540] 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 the cation radical of the aromatic tertiary amine polymer compound as the hole transporting material.

[0541] The charge-transporting ionic compound can be obtained by any of the following methods. i) dissolving or dispersing the first ionic compound and the hole transport material in an organic solvent to mix them. ii) The first ion compound and the hole transport material are dissolved or dispersed in an organic solvent to mix, and further heated. iii) forming a film from the composition obtained in i) or ii) by a wet process, and heating the film.

[0542] Since the first ionic compound is an electron accepting compound, the hole transport material is oxidized by the first ionic compound by any of the above methods to convert it into a cation radical. As a result, an ionic compound having the tetraarylborate ion as a counter anion and the cation radical of the hole transport material as a counter cation, i.e., a charge transporting ionic compound, is generated.

[0543] The hole injection layer of the organic electroluminescent element of the present invention preferably comprises a first ionic compound containing the tetraarylborate ion as a counter anion and a hole transport material. From the viewpoint of charge transport properties, it is further preferred to comprise a charge transport ionic compound containing the tetraarylborate ion as a counter anion and a cation radical of the hole transport material as a counter cation.

[0544] [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.

[0545] The hole injection layer-forming composition is preferably a composition obtained through a step of dissolving or dispersing the first ionic compound having the tetraarylborate 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 is a composition obtained by a step of dissolving or dispersing the first ionic compound having the tetraarylborate ion structure and the hole transport material in an organic solvent.

[0546] 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.

[0547] Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the method i), the charge-transporting ionic compound can be obtained by the method ii) or the method iii). Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the method ii), the charge-transporting ionic compound can be obtained by the method iii).

[0548] Regarding the ratio of the first ionic compound and the 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 generally 0.1 parts by mass or more, preferably 1 part by mass or more, and generally 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.

[0549] (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. Furthermore, when two or more organic solvents are mixed, the total of these organic solvents is made to meet this range.

[0550] As preferred organic solvents, for example, ether solvents and ester solvents can be mentioned. Specifically, as ether solvents, for example, aliphatic 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, aliphatic 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. Any one of these can be used alone, or two or more can be used in any combination and ratio.

[0551] 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. Any one of these can be used alone, or two or more can be used 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).

[0552] Among these organic solvents, solvents having an aromatic hydrocarbon structure are more preferred.

[0553] (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 method as the method of forming a film of a composition for forming a light-emitting layer by wet film formation is used, but it is preferably heated after coating and drying. 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.

[0554] 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.

[0555] ·The cross-linking groups of hole transport materials are mutually · Crosslinking groups of hole transport materials and electron accepting compounds · The cross-linking groups of the electron accepting compound The crosslinking group of the hole transport material and the crosslinking group of the tetraarylborate ion 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.

[0556] 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.

[0557] <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.

[0558] [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, glass plate or transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone etc. are preferred. Because it is difficult to cause the deterioration of organic electroluminescent element caused by external gas, substrate is preferably set to the material with high gas barrier property. Therefore, particularly when using the material with low gas barrier property such as synthetic resin substrate, it is preferred to set a dense silicon oxide film etc. on at least one side of substrate to improve gas barrier property.

[0559] [anode] The anode 2 has a function of injecting holes into the layer on the light-emitting layer 5 side.

[0560] 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.

[0561] The formation of the anode 2 is usually carried out by a dry method such as a sputtering method or a vacuum evaporation method. In addition, when using metal particles such as silver, particles such as copper iodide, carbon black, conductive metal oxide particles, conductive polymer powders, etc. to form the anode, it can also be formed by dispersing them in a suitable binder resin solution and coating them on a substrate. In addition, in the case of conductive polymers, a thin film can be directly formed on the substrate by electrolytic polymerization, or a conductive polymer can be coated on the substrate to form the anode (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0562] 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.

[0563] 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 of the anode 2 is preferably 60% or more, and more preferably 80% or more. 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.

[0564] When forming other layers on the surface of the anode 2, it is preferred to remove impurities on the anode 2 by ultraviolet / ozone, oxygen plasma, argon plasma or the like before film formation, and adjust its ionization potential to improve hole injection properties.

[0565] [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.

[0566] [Formation of Hole Injection Layer by Vacuum Deposition] When the hole injection layer of the organic electroluminescent element of the present invention is formed by vacuum evaporation, the first ionic compound can be used as a material containing tetraaryl borate 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.

[0567] When the hole injection layer 3 is formed by vacuum evaporation, one or more of the constituent materials of the hole injection layer 3 are usually placed in a crucible set 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 10 -4 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. Furthermore, 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.

[0568] The vacuum degree during the 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. The evaporation rate is not limited unless the effect of the present invention is significantly impaired, but is generally 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.

[0569] [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.

[0570] 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.

[0571] 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.

[0572] The hole transport layer 4 generally contains a hole transport compound.

[0573] 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.

[0574] [Formation of hole transport layer by wet film formation method] When the hole transport layer is formed by a wet film forming method, it is usually formed in the same manner as when the hole injection layer is formed by the wet film forming method, except that the hole transport layer forming composition is used instead of the hole injection layer forming composition.

[0575] When the hole transport layer is formed by a wet film forming method, the hole transport layer forming composition generally further contains an organic 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.

[0576] The concentration of the hole transporting compound in the hole transport layer forming composition can be set to the same range as the concentration of the hole transporting compound in the hole injection layer forming composition.

[0577] [Formation of hole transport layer by vacuum deposition method] When the hole transport layer is formed by vacuum deposition, it can usually be formed in the same manner as the case of forming the hole injection layer by vacuum deposition, using a hole transport layer forming composition instead of a hole injection layer forming composition. The film forming conditions such as the degree of vacuum during deposition, deposition rate, and temperature can be the same as those during vacuum deposition of the hole injection layer.

[0578] [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 there is a hole injection layer on the anode, the light-emitting layer is formed between the hole injection layer and the cathode, and when there is a hole transport layer on the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0579] The light-emitting layer of the organic electroluminescent device in the present invention contains the polycyclic heterocyclic compound represented by formula (1) and the organic metal compound represented by formula (201) as described above, and preferably further contains the host material.

[0580] 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 being difficult 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.

[0581] 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).

[0582] [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.

[0583] 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).

[0584] 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.

[0585] 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.

[0586] 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.

[0587] [Electron transport layer] For the purpose of further improving the current efficiency (cd / A) of the element, the electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 .

[0588] 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.

[0589] 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.

[0590] 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.

[0591] 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.

[0592] [Electron injection layer] An electron injection layer may be provided in order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5 .

[0593] In order to efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. As examples, alkali metals such as sodium or cesium, and alkaline earth metals such as barium or calcium are used. The film thickness is usually preferably not less than 0.1 nm and not more than 5 nm.

[0594] Furthermore, doping organic electron transport materials represented by nitrogen-containing heterocyclic compounds such as bathophenanthroline or metal complexes such as aluminum complexes of 8-hydroxyquinoline 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.

[0595] 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.

[0596] The electron injection layer is formed by laminating on the light emitting layer 5 or the hole blocking layer or the electron transport layer 6 thereon by a wet film forming method or a vacuum evaporation method. The details of the wet film formation method are the same as those of the above-mentioned light-emitting layer.

[0597] 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.

[0598] [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 .

[0599] 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.

[0600] 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.

[0601] The cathode film thickness is usually the same as the anode film thickness.

[0602] [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.

[0603] [Other component configuration] 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.

[0604] 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 a plurality of organic electroluminescent elements can be arranged in an array, or anodes and cathodes can be arranged in an XY matrix.

[0605] <Method for producing organic electroluminescent element> The method for producing the organic electroluminescent device of the present invention is not particularly limited. As a method for manufacturing an organic electroluminescent element of the present invention, it is preferred that as described above, there is a process of forming a hole injection layer by a wet film-forming method using a hole injection layer forming composition, and a process of forming a light-emitting layer by a wet film-forming method using a light-emitting layer forming composition. The hole injection layer forming composition preferably includes tetraaryl borate ions and an organic solvent. The light-emitting layer forming composition preferably includes 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). It is preferred to use these compositions to manufacture an organic electroluminescent element having an anode, a hole injection layer, a light-emitting layer and a cathode in sequence on a substrate.

[0606] 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.

[0607] 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 luminescent layer forming composition are as described above.

[0608] As another method for manufacturing the organic electroluminescent element of the present invention, for example, it is possible to manufacture an organic electroluminescent element having an anode, a hole injection layer, a light-emitting layer and a cathode in sequence on a substrate by a wet film-forming method using a hole injection layer-forming composition comprising an electron-accepting compound having a cross-linking group and an organic solvent, and a light-emitting layer by a wet film-forming method using a light-emitting layer-forming composition comprising 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 satisfying the above-mentioned relationship (E-1).

[0609] In the method for producing an organic electroluminescent device of the present invention, it is preferred that the hole injection layer forming step comprises applying and drying the hole injection layer forming composition and then heating to form a crosslinked product of the electron accepting compound, for example, a crosslinked product of tetraarylborate ions.

[0610] In the above-mentioned method for manufacturing an organic electroluminescent element, 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 are as described above.

[0611] 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.

[0612] <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.

[0613] 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, Chihaya Adachi, and Hideyuki Murata).

[0614] <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.

[0615] <Example of embodiment> [Production Example of Organic Electroluminescent Device] The organic electroluminescent element can be produced by the following method. The glass substrate on which ITO was patterned was cleaned. The hole injection layer is formed by wet-forming the composition for forming a hole injection layer on a substrate and then drying it by heating. Thus, a hole injection layer is formed. The hole transport layer is formed by wet-forming a composition for forming a hole transport layer on the hole injection layer and then heating and drying the composition to form a hole transport layer. The composition for forming a light-emitting layer is wet-formed on the hole transport layer and then heated and dried to form a light-emitting layer.

[0616] [Example 1 of implementation method] Although not particularly limited, the organic electroluminescent element can be produced by, for example, 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 on a glass substrate to a thickness of 50 nm was patterned into stripes of 2 mm width using conventional photolithography and hydrochloric acid etching to form an anode. The substrate after the ITO pattern was cleaned in this manner 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.

[0617]

Chemical formula 116

[0618]

Chemical formula 117

[0619] The solution is spin-coated on the substrate in the air, and dried and cross-linked by heating at 240° C. for 30 minutes on a hot plate in the air to form a uniform thin film with a thickness of, for example, 40 nm, thereby forming a hole injection layer. Next, a charge transporting polymer compound having the following structural formula (HT-a1) 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.

[0620]

Chemical formula 118

[0621] Next, as materials for the light-emitting layer, a main material (H-a1) having the following structure at a concentration of 1.17 wt%, a main material (H-a2) at a concentration of 1.17 wt%, a main material (H-2) at a concentration of 0.78 wt%, an organic metal compound (A-1) at a concentration of 0.93 wt%, and (D-1), (D-2) or (D-3) as a polycyclic heterocyclic compound at a concentration of 0.16 wt% were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

[0622]

Chemical formula 119

[0623]

Chemical Formula 120

[0624]

Chemical Formula 121

[0625] The solution is spin-coated on a substrate coated with the hole transport layer in a nitrogen glove box, and dried at 120° C. for 20 minutes using a heating plate in the nitrogen glove box to form a uniform thin film with a thickness of 40 nm, for example, to form a light-emitting layer. Furthermore, the molecular weight of the organic metal compound represented by formula (A-1) is 1592, and the maximum emission wavelength is 555 nm. The maximum emission wavelengths of the polycyclic heterocyclic compounds represented by formula (D-1), formula (D-2), and formula (D-3) are 613 nm, 628 nm, and 619 nm, respectively, satisfying formula (E-3). The substrate on which the light-emitting layer was formed was placed in a vacuum deposition apparatus, and the inside of the apparatus was evacuated to a pressure of 2×10 -4 Below Pa. Next, the compound (ET-1) represented by the following structural formula and 8-hydroxyquinoline lithium are co-deposited on the light-emitting layer by vacuum deposition at a film thickness ratio of 2:3 to form an electron transport layer with a film thickness of, for example, 30 nm.

[0626]

Chemical formula 122

[0627] Next, as a cathode evaporation mask, a 2 mm wide stripe-shaped shadow mask is placed in close contact with the substrate in a manner perpendicular to the ITO stripes of the anode, and the aluminum is heated by a molybdenum boat to form, for example, an aluminum layer with a film thickness of 80 nm to form a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm×2 mm can be obtained.

[0628] [Example 2 of implementation method] As the electron-accepting compound of the composition for forming a hole injection layer, a compound represented by the following structural formula (HI-2) or a compound represented by the following structural formula (HI-3) can be used instead of (HI-1). Except for this, an organic electroluminescent element is prepared in the same manner as in Example 1 of the embodiment.

[0629]

Chemical Formula 123

[0630]

Chemical formula 124

[0631] Furthermore, in Example 1 of the embodiment, when T1A, T1B, and S1B are calculated according to the method described in the specification, the relationships of Formula (E-1) and Formula (E-2) are satisfied.

[0632] [Example 3 of implementation method] An organic electroluminescent element was produced in the same manner as in Example 1 of the embodiment except that a compound having the following structural formula (HT-1) was used instead of (HT-a1) as the charge transporting polymer compound used in the hole transporting layer.

[0633]

Chemical formula 125

[0634] [Example 4 of implementation method] An organic electroluminescent element was produced in the same manner as in Example 3 of the embodiment except that (HI-2) or (HI-3) was used instead of (HI-1) as the electron accepting compound in the hole injection layer-forming composition. [Example]

[0635] [Example 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 on a glass substrate to a thickness of 50 nm was patterned into stripes of 2 mm width using conventional photolithography and hydrochloric acid etching to form an anode. The substrate after the ITO pattern was cleaned in this manner 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.

[0636]

Chemical formula 126

[0637]

Chemical formula 127

[0638] The solution was spin-coated on the substrate in the air, and dried on a hot plate at 240° C. for 30 minutes 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.

[0639]

Chemical formula 128

[0640] Next, as materials for the light-emitting layer, a main material (H-1) having the following structure at a concentration of 2.4 wt%, a main material (H-2) at a concentration of 0.8 wt%, an organic metal compound (A-1) at a concentration of 0.96 wt%, and a polycyclic heterocyclic compound (D-1) at a concentration of 0.064 wt% were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

[0641]

Chemical formula 129

[0642]

Chemical Formula 130

[0643]

Chemical Formula 131

[0644]

Chemical formula 132

[0645] 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 apparatus, and the inside of the apparatus was evacuated to a pressure of 2×10 -4 Below Pa. Next, the compound (ET-1) represented by the following structural formula 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.

[0646]

Chemical formula 133

[0647] 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 to form a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm × 2 mm was obtained.

[0648] [Example 2] An organic electroluminescent device was prepared in the same manner as in Example 1 except that a compound represented by the following structural formula (HI-2) was used instead of compound (HI-1) as the organic metal complex in the light-emitting layer.

[0649]

Chemical formula 134

[0650] [Comparative Example 1] An organic electroluminescent element was manufactured in the same manner as in Example 1 except that a composition was prepared and used as a composition for forming a hole injection layer, wherein 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 were dissolved in anisole.

[0651]

Chemical formula 135

[0652] [Triplet energy levels of organometallic compounds and polycyclic heterocyclic compounds] The triplet energy level (T1) of the organometallic compound (A-1) is obtained by the peak wavelength of the phosphorescence spectrum of the solution at room temperature. In addition, similarly, the singlet energy level (S1) of the polycyclic heterocyclic compound is calculated by the peak wavelength of the fluorescence spectrum at room temperature. The energy difference (ΔEST) between the singlet energy level and the triplet energy level of the polycyclic heterocyclic compound is calculated by the peak wavelength of the fluorescence spectrum and the phosphorescence spectrum at 77K. Using these, the triplet energy level (T1) of the polycyclic heterocyclic compound at room temperature is calculated. The above results are summarized in Table 1. It is obvious from Table 1 that the organometallic compound (A-1) and the polycyclic heterocyclic compound (D-1) satisfy formula (E-1).

[0653]

Table 1

[0654] [Evaluation of components] The organic electroluminescent elements obtained in Examples 1, 2 and Comparative Example 1 were measured at 1,000 cd / m 2 The voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) during light emission were measured at 60 mA / cm2 The time (LT95) for the brightness to decrease to 95% of the initial brightness when the element is continuously energized with a current density of 1. The measurement results are shown in Table 2. For the values ​​in Table 2, the difference with respect to Comparative Example 1 is expressed as "voltage difference", and the relative values ​​with respect to current efficiency, external quantum efficiency and LT95 with Comparative Example 1 as 1.00 are expressed as "relative current efficiency", "relative EQE" and "relative life", respectively. It can be seen from the results in Table 2 that the performance of the organic electroluminescent element of the present invention is improved.

[0655]

Table 2

[0656] [Example 3] As materials for the light-emitting layer, 2.5 wt% of the main material (H-1), 2.5 wt% of the main material (H-2) having the following structure, 1.5 wt% of the organic metal compound (A-1), and 0.1 wt% of the polycyclic heterocyclic compound (D-1) were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer and use it to form a light-emitting layer with a film thickness of 60 nm. Except for this, an organic electroluminescent element was prepared in the same manner as in Example 1.

[0657]

Chemical formula 136

[0658] [Example 4] An organic electroluminescent device was produced in the same manner as in Example 3 except that the compound (HI-2) was used instead of the compound (HI-1) as the electron-accepting compound in the hole injection layer-forming composition.

[0659] [Example 5] An organic electroluminescent device was prepared in the same manner as in Example 3 except that a compound represented by the following structural formula (HI-3) was used instead of compound (HI-1) as the electron accepting compound of the hole injection layer forming composition.

[0660]

Chemical formula 137

[0661] [Comparative Example 2] An organic electroluminescent element was prepared in the same manner as in Example 3 except that a composition was prepared by dissolving 1.5 wt % of a hole-transporting polymer compound (P-1) and 0.3 wt % of the electron-accepting compound (CHI-1) in anisole as a composition for forming a hole injection layer.

[0662] [Evaluation of components] The organic electroluminescent elements obtained in Examples 3 to 4 and Comparative Example 2 were measured at 1,000 cd / m 2 The voltage (V), current efficiency (cd / A), and external quantum efficiency (EQE) (%) during light emission are shown in Table 3. For the values ​​in Table 3, the difference between the voltage and the comparative example 2 is expressed as "voltage difference", and the relative values ​​of the current efficiency and external quantum efficiency when the comparative example 2 is 1.00 are expressed as "relative current efficiency" and "relative EQE", respectively. From the results in Table 3, it can be seen that the performance of the organic electroluminescent element of the present invention is improved.

[0663]

Table 3

[0664] [Example 6] An organic electroluminescent element was produced by the following method. An indium tin oxide (ITO) transparent conductive film was deposited on a glass substrate to a thickness of 50 nm (manufactured by Gioma Technology, a sputtered film product), and patterned into 2 mm wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate after the ITO pattern 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 prepared by dissolving 3.0 wt % of the hole transporting polymer compound (P-1) and 0.6 wt % of the electron accepting compound (HI-2) in ethyl benzoate was prepared. The solution was spin-coated on the substrate in the air, and dried on a hot plate at 240° C. for 30 minutes 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-2) 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.

[0665]

Chemical formula 138

[0666] Next, as materials for the light-emitting layer, a main material (H-1) at a concentration of 2.4 wt%, a main material (H-2) at a concentration of 0.8 wt%, an organic metal compound (A-1) having a structure shown below at a concentration of 0.96 wt%, and a polycyclic heterocyclic compound (D-1) at a concentration of 0.064 wt% were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer. 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 apparatus, and the inside of the apparatus was evacuated to a pressure of 2×10 -4 Below Pa.

[0667] Next, the compound (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. 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 to form a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm × 2 mm was obtained.

[0668] [Example 7] An organic electroluminescent device was produced in the same manner as in Example 6, except that the compound (HI-1) was used instead of the compound (HI-2) as the electron-accepting compound in the hole injection layer-forming composition.

[0669] [Comparative Example 3] An organic electroluminescent element was prepared in the same manner as in Example 6 except that a composition for forming a hole injection layer was 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.

[0670] [Comparative Example 4] An organic electroluminescent device was produced in the same manner as in Example 6 except that the light-emitting layer was formed without using the organometallic compound (A-1) as a component of the light-emitting layer.

[0671] [Comparative Example 5] An organic electroluminescent device was produced in the same manner as in Example 7 except that the light-emitting layer was formed without using the organometallic compound (A-1) as a component of the light-emitting layer.

[0672] [Comparative Example 6] An organic electroluminescent device was produced in the same manner as in Comparative Example 3 except that the light-emitting layer was formed without using the organometallic compound (A-1) as a component of the light-emitting layer.

[0673] [Evaluation of components] The organic electroluminescent devices obtained in Examples 6 and 7 and Comparative Examples 3 to 6 were measured at 1,000 cd / m 2 The voltage (V), current efficiency (cd / A) and wavelength (nm) of the peak emission during luminescence were measured. 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 1.5 %. The measurement results are shown in Table 4. For the values ​​in Table 4, the difference with Comparative Example 4 as the reference is expressed as "voltage difference", and the relative values ​​with Comparative Example 4 as 1.0 are expressed as relative current efficiency and relative life respectively for current efficiency and LT95. As is clear from Table 4, it was found that the organic electroluminescent element of the present invention provided an element having good emission wavelength, voltage, efficiency and life.

[0674]

Table 4

[0675] Various embodiments have been described above, but the present invention is certainly not limited to the examples. If it is a person skilled in the art, then it is obvious that various variations or modifications can be thought of within the scope of the claims, and it can be understood that these also belong to the technical scope of the present invention. In addition, within the scope of not departing from the gist of the invention, the various constituent elements in the above-mentioned embodiments can also be arbitrarily combined.

[0676] Furthermore, the present application is based on Japanese patent application (Japanese Patent Application No. 2022-138448) filed on August 31, 2022 and Japanese patent application (Japanese Patent Application No. 2022-162632) filed on October 7, 2022, the contents of which are incorporated herein by reference. Industrial Applicability

[0677] The organic electroluminescent element of the present invention exhibits excellent element characteristics, particularly low driving voltage, high luminous efficiency and long driving life.

Claims

1. An organic electroluminescent element, which is an organic electroluminescent element having 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, T1B: triplet energy level of the polycyclic heterocyclic compound, The unit of triplet energy level is eV, The hole injection layer contains tetraarylborate ions, In formula (1), the ring Cy 1 , Cy 2 , Cy 3 and Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring, Cyclo 1 , Cy 2 , Cy 3 Cy 4 further having or not having a fused ring, R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they are the same or different. When R is a substituent, it may be bonded to an adjacent R to form a ring or not, or R and its adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 Bonding to form a ring or not, 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 formula (202), R 201 , R 202 When there are plural 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 plural of each, they are the same or different, * indicates bonding to ring A201 or ring A202, B 201 -L 200 -B 202 Indicates anionic bidentate ligand, B 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may or may not constitute a ring. When B is an atom constituting a ring, 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 is an integer greater than 0, j is a substituted 201 The number is an integer greater than 0, k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for ring A201 and ring 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 includes 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 the formula (1) is as shown in the formula (2-1) or the formula (2-2), In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in the formula (1); when there are multiple R, they are independent of each other and may be the same or different. When R is a substituent, it may be bonded to adjacent R to form a ring or may not form a ring.

4. The organic electroluminescent element according to claim 1, wherein The polycyclic heterocyclic compound represented by the formula (1) is as shown in the formula (2-3), In formula (2-3), Q 31 and Q 32 Indicates O or S, R is the same as in the formula (1); when there are multiple R, they are independent of each other and may be the same or different. When R is a substituent, it may be bonded to adjacent R to form a ring or not. R' represents a hydrogen atom or a substituent. When there are multiple R's, they are independent of each other and may be the same or different.

5. The organic electroluminescent element according to claim 1, wherein The light-emitting layer further comprises a host material.

6. The organic electroluminescent element according to claim 1, wherein The tetraarylborate ion is represented by the following formula (112): In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents 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 a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups 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 a fluorine-substituted alkyl group as a substituent.

7. The organic electroluminescent element according to claim 6, wherein: Ar in the formula (112) 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the following is a group represented by the formula (113), In formula (113), R A Each independently represents 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, a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups which may have a substituent and / or a cross-linking group, a fluorine-substituted alkyl group, a substituent or a cross-linking group, F4 represents 4 fluorine atoms substituted, F (5-m) Each independently represents 5-m fluorine atom substitution, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0 to 5, *Indicates bonding position.

8. The organic electroluminescent element according to claim 2, wherein: The crosslinking group is represented by any one of the following formulas (X1) to (X18), In formulae (X1) to (X4), the benzene ring and the naphthalene ring may or may not have substituents, and 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) X each independently represents an alkyl group which may have a substituent, In formulae (X1) to (X18), * represents a bonding position.

9. The organic electroluminescent element according to claim 8, wherein The crosslinking group is represented by any one of the formulae (X1) to (X4).

10. An organic EL display device or an organic EL lighting, wherein: A device comprising the organic electroluminescent element according to any one of claims 1 to 9.

11. 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 producing 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 comprises tetraarylborate ions and an organic solvent. The composition for forming a light-emitting layer comprises 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, T1B: triplet energy level of the polycyclic heterocyclic compound, The unit of triplet energy level is eV, In formula (1), the ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring, Cyclo 1 , Cy 2 , Cy 3 Cy 4 further having or not having a fused ring, R represents a hydrogen atom or a substituent, x, y, z, and w represent R and can be bonded to the ring Cy. 1 , Cy 2 , Cy 3 , Cy 4 The maximum number of Q 11 , Q 12 , Q 21 and Q 22 indicates NR, O or S, When there are multiple Rs, they are the same or different. When R is a substituent, it may be bonded to an adjacent R to form a ring or not, or R and its adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 Bonding to form a ring or not, 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 formula (202), R 201 , R 202 When there are plural 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 plural of each, they are the same or different, * indicates bonding to ring A201 or ring A202, B 201 -L 200 -B 202 Indicates anionic bidentate ligand, B 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may or may not constitute a ring. When B is an atom constituting a ring, 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 is an integer greater than 0, j is a substituted 201 The number is an integer greater than 0, k1 and k2 are each independently an integer greater than or equal to 0, with the number of rings that can be substituted for ring A201 and ring A202 being the upper limit, m is an integer of 1-3.

12. The method for manufacturing an organic electroluminescent element according to claim 11, wherein: The polycyclic heterocyclic compound represented by the formula (1) is as shown in the formula (2-1) or the formula (2-2), In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in the formula (1); when there are multiple R, they are independent of each other and may be the same or different. When R is a substituent, it may be bonded to adjacent R to form a ring or may not form a ring.

13. The method for manufacturing an organic electroluminescent element according to claim 11, wherein: The polycyclic heterocyclic compound represented by the formula (1) is as shown in the formula (2-3), Q in formula (2-3) 31 and Q 32 Indicates O or S, R is the same as in the formula (1); when there are multiple R, they are independent of each other and may be the same or different. When R is a substituent, it may be bonded to adjacent R to form a ring or not. R' represents a hydrogen atom or a substituent. When there are multiple R's, they are independent of each other and may be the same or different.

14. The method for manufacturing an organic electroluminescent element according to claim 11, wherein: The tetraarylborate ion has a cross-linking group.

15. The method for manufacturing an organic electroluminescent element according to claim 11, wherein: The tetraarylborate ion is represented by the following formula (112): In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents 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 a monovalent group formed by connecting a plurality of structures selected from aromatic hydrocarbon ring groups which may have a substituent and / or a cross-linking group and aromatic heterocyclic groups 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 a fluorine-substituted alkyl group as a substituent.

16. The method for manufacturing an organic electroluminescent element according to claim 11, wherein: The hole injection layer-forming composition is 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.

17. The method for manufacturing an organic electroluminescent element according to claim 14, wherein: In the step of forming the hole injection layer, the hole injection layer-forming composition is applied, dried, and then heated to form a crosslinked product of the tetraarylborate ions.

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