Material for light-emitting layer, organic EL element, organic EL display device, organic EL lighting device, composition, and method for producing organic EL element

Abstract

The present invention addresses the problem of providing an organic electroluminescent element having a long driving life. The present invention relates to a material for a light-emitting layer of an organic electroluminescent element containing a light-emitting compound and an organometallic compound, the organometallic compound having a molecular weight of 1,200 or more, and the light-emitting compound being a specific compound and satisfying the following relational expression (E-1). 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 light-emitting compound. ).

Description

Technical Field

[0001] The present invention relates to a material for a light-emitting layer, an organic electroluminescent element, an organic EL display device, an organic EL lighting, a composition and a method for producing 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 the electroluminescent element using an inorganic material. An organic electroluminescent element (OLED) generally has a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, etc. between an anode and a cathode, and materials suitable for each layer are being developed continuously. 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 liquid mixed with a variety of materials having various functions, it is easy to form a layer containing a variety of materials having various functions. Therefore, in recent years, research and development of organic electroluminescent elements based on film formation using a coating method is being actively carried out.

[0004] For example, Patent Documents 1 to 3 describe an organic electroluminescent device having a hole injection layer containing polystyrene sulfonic acid and a light-emitting layer containing a light-emitting material having a polycyclic heterocyclic compound skeleton containing boron and nitrogen. In addition, research and development is 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 documents 1 and 2, as a method for improving the luminous efficiency of the organic electroluminescent element, it is reported that in the luminescent layer formed by the vacuum evaporation method, in addition to the luminescent material having a polycyclic heterocyclic compound skeleton, an organic metal compound having iridium as the central metal, 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 Non-patent document 2: Angewandte Chemie International Edition, 2022, Vol. 61, No. 14, p. e202117181 Summary of the invention Problems to be solved by the invention

[0007] In general, polycyclic heterocyclic compounds containing boron have empty p orbitals on boron and are easily reacted with various reactive groups. Therefore, in the technologies disclosed in patent documents 1 to 3, the reduction in the driving voltage of the organic electroluminescent element is insufficient, and the driving life cannot be improved. In the technologies disclosed in patent documents 1 to 3, it is believed that the reason is that due to the use of a hole injection layer containing strongly acidic polystyrene sulfonic acid, the moisture and sulfonic acid groups taken in when the hole injection layer is formed react with the 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 has been made in view of the above-mentioned existing actual situation, and an object of the present invention is to provide an organic electroluminescent element having a long driving life. Technical solutions to the problem

[0009] The inventors conducted intensive research and found that the above-mentioned problems can be solved by using a light-emitting layer, thereby completing the present invention. The light-emitting layer contains a light-emitting compound and an organic metal compound, wherein the molecular weight of the organic metal compound is within a specific range, the triplet energy level of the organic metal compound is higher than the triplet energy level of the light-emitting compound, and the singlet energy level and triplet energy level of the light-emitting compound are in a specific relationship.

[0010] That is, the gist of the present invention is as follows.

[0011] A first aspect of the present invention is a light-emitting layer material, which is a light-emitting layer material for an organic electroluminescent element containing a light-emitting compound and an organic metal compound, wherein: The molecular weight of the organometallic compound is 1,200 or more, The luminescent compound is a compound represented by the following formula (1): The following relational expression (E-1) is satisfied. 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 of the light-emitting compound (eV).

[0012] [Chemistry 1]

[0013] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a five-membered or six-membered aromatic hydrocarbon ring or a five-membered or six-membered aromatic heterocyclic ring. Cyclo 1 , Cy 2 , Cy 3 Cy 4 It may or may not further have a condensed ring. R represents a hydrogen atom or a substituent, x, y, z, and w each represent a group of molecules that 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 plural Rs, they may be the same or different. When R is a substituent, adjacent R may be bonded to each other to form a ring or may not form a ring, or R may be bonded to an adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 The bonds may form a ring or not.]

[0014] A second aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of the first aspect, The organic metal compound is represented by the following formula (201).

[0015] [Chemistry 2]

[0016] [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 the structure represented by the above formula 202. R 201 , R 202 When there are plural of each, they may be the same or different. Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Indicates anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. When they are atoms constituting a ring, B 201 and / or B 202 Represents a ring structure. L 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are multiple ones, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 is capable of 202 The number of substitutions in is an integer greater than or equal to 0, which is the upper limit. j is to be able to 201 The number of substitutions in 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 substitutable atoms in ring A201 and ring A202 being the upper limit. m is an integer from 1 to 3.]

[0017] A third aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of the first or second aspect, The T1A is greater than or equal to 2.10 eV and less than or equal to 2.80 eV.

[0018] A fourth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 1 to 3, The light-emitting compound represented by the formula (1) is represented by the formula (2-1) or the formula (2-2).

[0019] [Chemistry 3]

[0020] [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, adjacent Rs may be bonded to each other to form a ring.]

[0021] A fifth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 1 to 4, The light-emitting compound represented by the formula (1) is represented by the formula (2-3).

[0022] [Chemistry 4]

[0023] [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, adjacent Rs may be bonded to form a ring. 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.]

[0024] A sixth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 1 to 5, When the molecular weight of the organometallic compound is MwA and the molecular weight of the light-emitting compound is MwB, MwA / MwB is 2.0 or more.

[0025] A seventh aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 1 to 6, It also contains a host material.

[0026] Embodiment 8 of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of embodiment 7, The host material includes at least one selected from the group consisting of a compound represented by the following formula (250), a compound represented by the following formula (240), and a compound represented by the following formula (260).

[0027] [Chemistry 5]

[0028] (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, multiple Xa 1 Can be the same or different. When h11 is 2 or more, multiple Ya 1 Can be the same or different. When g11 is 2 or more, 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.)

[0029] [Chemistry 6]

[0030] (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.)

[0031] [Chemistry 7]

[0032] (In formula (260), Ar 61 ~Ar 65 are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, L 1 ~L 5 are each independently a divalent aromatic hydrocarbon group having 6 to 60 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 n is 1 or more when at least one Ar 65 At least one group is not a hydrogen atom.)

[0033] A ninth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of the eighth aspect, The host material contains at least the compound represented by the formula (250).

[0034] A tenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of the eighth or ninth aspect, in the formula (250), -(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) are not unsubstituted phenyl at the same time.

[0035] Aspect 11 of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 10, In the formula (250), 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 selected from the following substituent group Z2, and the substituents selected from the following substituent group Z2 have no further substituents.

[0036] <Substituent Group Z2> Alkyl, alkoxy, aryloxy, heteroaryloxy, alkoxycarbonyl, dialkylamino, diarylamino, arylalkylamino, acyl, halogen atom, haloalkyl, alkylthio, arylthio, silyl, silyloxy, cyano, aromatic hydrocarbon and aromatic heterocyclic groups

[0037] A twelfth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 11, At least two of W in the formula (250) are N.

[0038] A thirteenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 12, When g11 in the formula (250) 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 , Ar in the formula (240) 611 and Ar 612 , and when m1 in the formula (260) is 1 or more (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each independently has a partial structure selected from the partial structures represented by the following formula (11) to the following formula (17).

[0039] [Chemistry 8]

[0040] [Chemistry 9]

[0041] (In each of formulae (11) to (17), * indicates the bonding position with the adjacent structure, or for formula (250), Xa 2 , Ya 2 or Za 2 When the hydrogen atom is a hydrogen atom, the hydrogen atom in formula (260) is Ar 61 ,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 with an adjacent structure.

[0042] A fourteenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 13, In the formula (250), -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) has any one of the partial structures or terminal structures represented by the following formula (250-1) to the following formula (250-10).

[0043] [Chemistry 10]

[0044] [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 or may not have a substituent.]

[0045] A fifteenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 14, The host material contains at least the compound represented by the formula (240).

[0046] A 16th aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 15, The Ar in the compound represented by the formula (240) 611 and the Ar 612 Each independently has a partial structure selected from the following formulae (11) to (17) and (21) to (24).

[0047] [Chemistry 11]

[0048] [Chemistry 12]

[0049] (* represents a bonding position with an adjacent structure or a hydrogen atom, and at least one of the two *s present represents a bonding position with an adjacent structure)

[0050] A seventeenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 16, The host material contains at least the compound represented by the formula (260).

[0051] An eighteenth aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 17, Ar in the formula (260) 61 ,Ar 62 and at least one Ar 65 Among them, one or more and three or less groups are of the following formula (261) or the following formula (262).

[0052] [Chemistry 13]

[0053] (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. )

[0054] A 19th aspect of the present invention is a light-emitting layer material, wherein in the light-emitting layer material of any one of aspects 8 to 18, When the compound represented by the formula (250) is set to (Group A), the compound represented by the formula (240) is set to (Group B), and the compound represented by the formula (260) is set to (Group C), the main material contains at least two compounds of at least one each selected from at least any two of the three groups represented by the (Group A), the (Group B), and the (Group C).

[0055] Aspect 20 of the present invention is an organic electroluminescent element comprising an anode, a cathode, and a light-emitting layer, wherein: The light-emitting layer is disposed between the anode and the cathode, The light-emitting layer comprises the material for a light-emitting layer according to any one of Embodiments 1 to 19.

[0056] A 21st aspect of the present invention is an organic EL display device or an organic EL lighting device, which includes the organic electroluminescent element of the 20th aspect.

[0057] Aspect 22 of the present invention is a composition comprising the material for a light-emitting layer according to any one of aspects 1 to 19 and an organic solvent.

[0058] A 23rd aspect of the present invention is a method for producing an organic electroluminescent element, which is a method for producing an organic electroluminescent element having an anode, a light-emitting layer, and a cathode in this order on a substrate. The manufacturing method includes: using the composition of method 22 and utilizing a wet film-forming method to form the light-emitting layer. Effects of the Invention

[0059] The organic electroluminescent device of the present invention exhibits excellent device characteristics, and particularly has a long driving life. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic cross-sectional view showing a structural example of the organic electroluminescent element of the present invention. Description of Reference Numerals

[0686] 1 substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5. Luminous layer 6 Electron Transport Layer 7 Cathode 8 Organic electroluminescent elements DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of a material for a light-emitting layer of an organic electroluminescent element, an organic electroluminescent element, an organic EL display device having the organic electroluminescent element, an organic EL lighting having the organic electroluminescent element, a composition, and a method for manufacturing an organic electroluminescent element using the composition, which are one embodiment of the present invention, are described in detail.

[0062] [Materials for organic electroluminescent devices] <Materials for the First Embodiment> The light-emitting layer material of the first embodiment of the present invention is a light-emitting layer material for an organic electroluminescent element containing a light-emitting compound and an organic metal compound, wherein: The molecular weight of the organometallic compound is 1,200 or more, The luminescent compound is a compound represented by the following formula (1): The materials satisfy the following relational formula (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 of the light-emitting compound (eV).

[0063] [Chemistry 14]

[0064] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a five-membered or six-membered aromatic hydrocarbon ring or a five-membered or six-membered 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 each represent a group of molecules that 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 plural Rs, they may be the same or different. When R is a substituent, adjacent R may be bonded to each other to form a ring or R may be bonded to an adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0065] <Materials for the Second Embodiment> The material of the second embodiment of the present invention is a material for a light-emitting layer of an organic electroluminescent element containing a light-emitting compound, an organic metal compound and a host material, wherein: The luminescent compound is a compound represented by the following formula (1): The organometallic compound is a compound represented by the formula (201) described later, The host material is an organic electroluminescent element comprising at least one selected from the group consisting of a compound represented by formula (250) described below, a compound represented by formula (240) described below, and a compound represented by formula (260) described below, The materials satisfy the following relational formula (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.

[0066] [Organic electroluminescent element] The organic electroluminescent element according to another embodiment of the present invention is an organic electroluminescent element having an anode, a cathode and a light-emitting layer, wherein: The light-emitting layer is disposed between the anode and the cathode, The light-emitting layer contains the light-emitting layer material.

[0067] The reason why the driving life of the organic electroluminescent element containing the light-emitting layer material according to the first embodiment of the present invention in the light-emitting layer is long is presumed to be as follows. The organic electroluminescent device of the present invention comprises an organic metal compound and a light-emitting compound in the light-emitting layer, wherein the organic metal compound plays a role in efficiently transferring the energy of the excited state generated in the light-emitting layer to the light-emitting compound. When the excitation energy is transferred from the organometallic compound to the luminescent compound, when the molecular weight of the organometallic compound is small, the interaction between the organometallic compounds cannot be ignored, the energy transferred to the luminescent compound is lost, and high performance cannot be obtained. It is believed that by making the molecular weight of the organometallic compound have a certain size or more, and making the triplet energy level and the singlet energy level of the organometallic compound and the luminescent compound be in a specific relationship, the interaction between the organometallic compounds can be appropriately suppressed, showing high performance. It is believed that by making the molecular weight of the organometallic compound have a certain size or more, the interaction between the organometallic compounds can be suppressed, and the triplet excitation energy in the light-emitting layer can be smoothly transferred to the light-emitting compound. It is believed that by directly transferring the triplet excitation energy to the light-emitting compound, the light-emitting compound is less likely to become unstable, and a long-life element can be obtained.

[0068] The following description will describe an example (representative example) of an embodiment of the present invention as an organic electroluminescent device in which the light-emitting layer material of the present invention is contained in the light-emitting layer, but the present invention is not limited to this content unless it exceeds the gist of the present invention.

[0069] <Luminous Layer> The light-emitting layer of the organic electroluminescent device of the present invention contains the light-emitting compound represented by the above formula (1) and an organic metal compound, wherein: The molecular weight of the organometallic compound is 1,200 or more, The following relational expression (E-1) is satisfied. 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 of the light-emitting compound (eV).

[0070] In the present invention, by satisfying the above formula (E-1), the above organometallic compound efficiently transfers the energy of the triplet excited state generated in the light-emitting layer to the above light-emitting compound, so that the above light-emitting compound emits light with high efficiency.

[0071] In addition, the light-emitting 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 light-emitting compound (eV)) By satisfying the above formula (E-2), the triplet excited state energy of the light-emitting compound is efficiently converted internally to the singlet excited state, so that the light-emitting compound emits light with high efficiency. ΔEST in formula (E-2) is 0.30 eV or less, preferably 0.25 eV or less, and more preferably 0.20 eV or less. The lower limit of ΔEST is not particularly limited, but is usually 0.01 eV or more.

[0072] 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, further preferably 2.70 eV or less. It is believed that by setting T1A within this range, the decomposition of the organometallic compound is suppressed because the excited state of the organometallic compound is not too high in energy, and the excited state of the organometallic compound is quickly transferred to the light-emitting compound because the energy is not too low, thereby obtaining a higher performance element. It should be noted that the above-mentioned T1A, T1B and S1B can be obtained by the following method. S1B, as well as T1A and T1B, can be determined by the peak wavelengths of the fluorescence spectrum and the phosphorescence spectrum respectively. The fluorescence spectrum and the phosphorescence spectrum can be measured using a spectrophotometer. For example, the spectrofluorometer F-7000 manufactured by Hitachi High-Technologies Corporation can be used for measurement. During the measurement, the following solution is used as the sample, and the solution is prepared by dissolving the compound at a concentration of about 10 -6 ~10 -5 M in an appropriate organic solvent. The fluorescence spectrum is measured at room temperature. The phosphorescence is measured by cooling with liquid nitrogen to 77K.

[0073] Furthermore, the luminescent compound in the present invention preferably satisfies the following relational expression (E-3). PkA < PkB Formula (E-3) (In Formula (E-3), PkA: represents the maximum emission wavelength (nm) of the organometallic compound PkB: represents the maximum emission wavelength (nm) of the luminescent compound)

[0074] In the present invention, by satisfying the above formula (E-3), the excitation energy generated in the light-emitting layer by the above organometallic compound is efficiently transferred to the above luminescent compound, so that the above luminescent compound emits light with high efficiency.

[0075] PkA is preferably 550 nm or more and 650 nm or less. The lower limit is further preferably 560 nm or more, more preferably 570 nm or more, and the upper limit is further preferably 630 nm or less, more preferably 610 nm or less. PkB only needs to satisfy the above formula (E-3). Preferably, the difference between PkB and PkA is usually 80 nm or less, preferably 50 nm or less, further preferably 40 nm or less, more preferably 30 nm or less, and particularly preferably 25 nm or less. By making PkA and PkB within this range, the excitation energy of the organometallic compound is efficiently transferred to the luminescent compound, so that a higher-performance element is obtained. In addition, it is considered that by making the molecular weight of the organometallic compound 1,200 or more, the luminescent compound of the present invention in the relationship of formula (E-3) emits light efficiently in the long wavelength region, particularly in the red light-emitting region, and a higher-performance element is obtained.

[0076] (Maximum emission wavelength) PkA and PkB can be measured by the following method. At room temperature, a solution is prepared by dissolving the organometallic compound or the luminescent compound in the present invention at 1×10 -4The solution formed by dissolving the organic metal compound and the luminescent compound in a concentration of 10 mol / L or less in an organic solvent is measured by a spectrophotometer (organic EL quantum efficiency measuring device C9920-02 manufactured by Hamamatsu Photonics Co., Ltd.) to measure the luminescence spectrum of the above solution. The wavelength showing the maximum value of the luminescence spectrum intensity obtained is used as the maximum luminescence wavelength in the present invention. As an organic solvent for dissolving the organometallic compound and the luminescent compound, toluene, 2-methyltetrahydrofuran, etc. are suitable, and toluene is usually preferred.

[0077] <Luminescent Compound>

[0078] <Polycyclic Heterocyclic Compounds> The light-emitting compound in the present invention is a polycyclic heterocyclic compound represented by the following formula (1).

[0079] [Chemistry 15]

[0080] [In formula (1), ring Cy 1 , Cy 2 , Cy 3 Cy 4 Each independently represents a five-membered or six-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 each represent a group of molecules that 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 plural Rs, they may be the same or different. When R is a substituent, adjacent R may be bonded to each other to form a ring or R may be bonded to an adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 bonded to form a ring.]

[0081] <Preferred Light-Emitting Compounds> The light-emitting compound represented by the above formula (1) is preferably a compound represented by formula (2-1) or formula (2-2).

[0082] [Chemistry 16]

[0083] [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, adjacent R groups may be bonded to each other to form a ring.]

[0084] The light-emitting compound represented by the above formula (1) is more preferably a compound represented by formula (2-3).

[0085] [Chemistry 17]

[0086] [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, adjacent Rs may be bonded to form a ring. 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.]

[0087] In the luminescent compounds represented by the above formula (1), the above formula (2-1), the above formula (2-2) and the above formula (2-3), it is further preferred that R is a substituent selected from a hydrogen atom or the following [Substituent Group W1]. In the luminescent compound represented by the above formula (2-3), it is further preferred that R' is selected from the following [R'].

[0088] [R] R is a hydrogen atom or a substituent. When R is a substituent, it is an arbitrary substituent, and 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 a carbon number of 2 to 30, a linear, branched or cyclic alkynyl group having a carbon number of 2 to 30, an aromatic hydrocarbon group having a carbon number of 5 to 60, a heteroaromatic group having a carbon number of 5 to 60, an aryloxy group having a carbon number of 5 to 40, an arylthio group having a carbon number of 5 to 40, an aralkyl group having a carbon number of 5 to 60, a heteroaralkyl group having a carbon number of 5 to 60, a diarylamino group having a carbon number of 10 to 40, an arylheteroarylamino group having a carbon number of 10 to 40, or a diheteroarylamino group having a carbon number of 10 to 40. Two or more adjacent R's may be bonded to each other to form a single or condensed ring of an aliphatic hydrocarbon, an aromatic hydrocarbon, or a heteroaromatic hydrocarbon. The alkyl, alkoxy, alkylthio, alkenyl and alkynyl groups may be further substituted by one or more R', and one -CH2- group or two or more non-adjacent -CH2- groups in these groups may be substituted by -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 by D, F, Cl, Br, I or -CN. The aromatic hydrocarbon group, the heteroaromatic group, the aryloxy group, the arylthio group, the aralkyl group, the heteroaralkyl group, the diarylamino group, the arylheteroarylamino group and the diheteroarylamino group may each independently be further substituted by one or more R′.

[0089] [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 alkenyl, a linear, branched or cyclic alkynyl group having 2 to 30 carbon atoms, an aromatic hydrocarbon group having 5 to 60 carbon atoms, a heteroaromatic 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 an aliphatic, aromatic, or heteroaromatic monocyclic or condensed ring. The alkyl group, the alkoxy group, the alkylthio group, the alkenyl group and the alkynyl group may be further substituted by one or more R", and one -CH2- group or two or more non-adjacent -CH2- groups in these groups may be substituted by -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 by D, F, Cl, Br, I or -CN. The aromatic hydrocarbon group, the heteroaromatic group, the aryloxy group, the arylthio group, the aralkyl group, the heteroaralkyl group, the diarylamino group, the arylheteroarylamino group and the diheteroarylamino group may be further substituted by one or more R″.

[0090] [R”] R" is 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 heteroaromatic group having 1 to 20 carbon atoms. Two or more adjacent R" may be bonded to each other to form an aliphatic, aromatic, or heteroaromatic monocyclic or condensed ring.

[0091] (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.

[0092] [Chemistry 18]

[0093] [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 the organometallic compound, it is preferably a Werner type complex or an organometallic complex. As the ligand of the complex, it is preferably a ligand formed by connecting (hetero)aryl pyridine ligand, (hetero)aryl pyrazole ligand, (hetero)aryl pyridine ligand, (hetero)aryl pyrazole ligand, 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.

[0094] 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 speculated that even through electron exchange interaction and dipole-dipole interaction, the excited state generated by applying voltage to the organic electroluminescent element can be transferred to the luminescent compound, and it is speculated that even through electron exchange interaction and dipole-dipole interaction, the luminescent compound can emit light efficiently. Particularly preferred are organometallic complexes containing iridium. As the organometallic complex containing iridium, a metal compound represented by formula (201) is preferred.

[0095] [Chemistry 19]

[0096] [Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ring A202 represents an aromatic heterocyclic structure which may have a substituent. R 201 , R 202 Each independently has a structure represented by the above formula (202). R 201 , R 202 When there are multiple of each, they can be the same or different Ar 201 ,Ar 203 Each independently represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent. Ar 202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. * indicates bonding to ring A201 or ring A202. B 201 -L 200 -B 202 Indicates anionic bidentate ligand. 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. When they are atoms constituting a ring, B 201 and / or B 202 Represents a ring structure. 200 Represents a single bond or with B 201 and B 202 A group of atoms that together form a bidentate ligand. B 201 -L 200 -B 202 When there are multiple ones, they may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 is capable of 202 The number of substitutions in is an integer greater than or equal to 0, which is the upper limit. j is to be able to 201 The number of substitutions in 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 substitutable atoms in ring A201 and ring A202 being the upper limit. m is an integer from 1 to 3.]

[0097] (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, preferably a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an acenaphthene ring, a fluoranthene ring, or a fluorene ring.

[0098] 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.

[0099] 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.

[0100] The aromatic heterocycle in Ring A202 is preferably an aromatic heterocycle having 3 to 30 carbon atoms 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.

[0101] When m is 2 or 3, the plurality of rings A201 and the plurality of rings A202 may be the same or different.

[0102] The preferred combination of Ring A201 and Ring A202, when expressed as (Ring A201-Ring A202), is (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring-quinazoline ring), (benzene ring-imidazole ring), (benzene ring-benzothiazole ring), and the most preferred combination is (benzene ring-pyridine ring).

[0103] 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.

[0104] 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.

[0105] (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 can be the same or different. 202 When there are multiple ones, they may be the same or different.

[0106] (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. Ar202 It represents an aromatic hydrocarbon ring structure which may have a substituent, an aromatic heterocyclic structure which may have a substituent, or an aliphatic hydrocarbon structure which may have a substituent. Ar 201 ,Ar 202 and Ar 203 When there are plural of each, they may be the same or different. 201 When there are multiple, they can be the same or different. 202 When there are multiple, they can be the same or different. 203 When there are multiple ones, 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] In Ar 201 ,Ar202 ,Ar 203 When any one of them is a carbazole ring which may have a substituent, the N position of the carbazole ring preferably has a substituent or is bonded to an adjacent structure.

[0111] In Ar 202 In the case of an aliphatic hydrocarbon structure that may have a substituent, the aliphatic hydrocarbon structure is an aliphatic hydrocarbon structure having a straight chain, branched chain or cyclic structure, preferably an aliphatic hydrocarbon having 1 to 24 carbon atoms, further preferably an aliphatic hydrocarbon having 1 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon having 1 to 8 carbon atoms.

[0112] (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.

[0113] i3 is preferably an integer of 0 to 5, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

[0114] j represents an integer of preferably 0 to 2, more preferably 0 or 1.

[0115] 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.

[0116] Ar 201 ,Ar 202 ,Ar 203 The substituents that may be present can 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, alkyl group, and most preferably unsubstituted (hydrogen atom).

[0117] Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

[0118] (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.

[0119] 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.

[0120] Unless otherwise specified, an aryl group is an aromatic hydrocarbon, and a heteroaryl group is an aromatic heterocycle.

[0121] (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.

[0122] 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.

[0123] (Preferred structure of formula (201)) Among the structures represented by the above formula (202) in the above formula (201), preferred are structures having a group formed by connecting benzene rings, structures having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded in ring A201 or ring A202, and structures having a dendron bonded in ring A201 or ring A202.

[0124] In the structure having a group formed by connecting benzene rings, 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.

[0125] In the structure in which the ring A201 or the ring A202 has an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded, 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 201The 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.

[0126] 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.

[0127] (By B 201 -L 200 -B 202 Structure of representation) B 201 -L 200 -B 202 When there are multiple ones, they may be the same or different. By B 201 -L 200 -B 202 The structure represented is preferably a structure represented by the following formula (203) or (204).

[0128] [Chemistry 20]

[0129] 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.

[0130] [Chemistry 21]

[0131] 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.

[0132] (Molecular weight) The upper limit of the molecular weight of the organometallic compound is not particularly limited, but is preferably 10000 or less, more preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. In addition, the molecular weight of the organometallic compound is 1200 or more, preferably 1300 or more, and more preferably 1700 or more. It is believed that by having a molecular weight within this range, the organometallic compound can be uniformly mixed with the aromatic compound of the present invention and / or other charge transport materials without agglomeration, thereby obtaining a light-emitting layer with high luminous efficiency and long luminous life.

[0133] The molecular weight of the organometallic compound is preferably large because of the high Tg, melting point, decomposition temperature, etc., the excellent heat resistance of the organometallic compound and the formed light-emitting layer, and the difficulty in causing the film quality to deteriorate due to gas generation, recrystallization, and molecular migration, and the increase in impurity concentration accompanying the 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.

[0134] 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 luminescent 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 by appropriately generating energy from the organic metal compound to the luminescent compound within the range of MwA / MwB, a luminescent layer with high luminescent efficiency and long luminescent life can be obtained.

[0135] (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. It should be noted that Me means methyl group, and Ph means phenyl group.

[0136] [Chemistry 22]

[0137] [Chemistry 23]

[0138] [Main material] The light-emitting layer further preferably contains a host material. That is, the material for the light-emitting layer of the organic electroluminescent element of the present invention further 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 that can transport both electrons and holes. Further, in the present invention, the charge transport material also includes a material that adjusts the transport properties of the charge. 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, acetyl naphthofluoranthene, coumarin, p-bis(2-phenylvinyl)benzene and its derivatives, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran, (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-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.

[0139] These may be used alone or in any combination and ratio of two or more.

[0140] Among these, pyridine, pyrimidine, triazine, carbazole, naphthalene, perylene, pyrene, anthracene, Naphthacene, phenanthrene, coronene, fluoranthene, triphenylene, fluorene, acetylnaphthofluoranthene and derivatives thereof, and anthracene derivatives are more preferred.

[0141] 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, or imidazole structures.

[0142] 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.

[0143] The hole transport material is a compound having a structure with excellent hole transport properties, and among the skeletons with excellent charge transport properties, the structure with excellent hole transport properties is preferably a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure or a pyrene structure, and more preferably a carbazole structure, a dibenzofuran structure or a triarylamine structure. As the hole transport material, a compound represented by formula (240) described later is particularly preferred.

[0144] As the bipolar material capable of transporting both electrons and holes, a material having both a skeleton having excellent electron-transporting properties and a skeleton having excellent hole-transporting properties is preferable. As a material for adjusting the charge transport property, a compound having a structure formed by connecting multiple benzene rings, i.e., a compound represented by formula (260) described later, is preferred. It is believed that by including this compound as a host material, the excitons generated in the light-emitting layer will efficiently recombine to increase the luminous efficiency. In addition, it is believed that the charge transport property in the light-emitting layer is appropriately adjusted to suppress the degradation of the light-emitting material, thereby extending the driving life.

[0145] 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. Further, 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 heterocycles.

[0146] 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.

[0147] 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.

[0148] [(Group A), (Group B), (Group C)] Here, in this specification, for convenience, host materials that may be included 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):

[0149] In the present invention, the host material that can be contained in the light-emitting layer preferably contains at least one compound selected from at least one of the three groups represented by (Group A), (Group B) and (Group C). It is more preferred that the compound contains at least one compound selected from the above (Group A) or the above (Group B), It is further preferred that the compound contains at least two compounds selected from at least one of at least two of the three groups represented by the above (Group A), the above (Group B) and the above (Group C). It is more preferred that the compound contains at least two compounds selected from each of the two groups represented by the above (Group A) and the above (Group B), It is particularly preferred that the compound contains at least three compounds selected from at least one of each of the three groups represented by the above (Group A), the above (Group B), and the above (Group C). It should be noted that the number of compounds selected from each group may be one or two or more.

[0150] Since the compound selected from (Group A) is preferably a compound represented by the following formula (250), the compound selected from (Group B) is preferably a compound represented by the following formula (240), and the compound selected from (Group C) is preferably a compound represented by the following formula (260), The host material contained in the light-emitting layer further 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). More preferably, 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).

[0151] It is believed that the organic electroluminescent element of the present invention contains a compound having a structure formed by a nitrogen-containing six-membered aromatic heterocyclic ring connected to a benzene ring, that is, a compound represented by the above formula (250) as a main material in the light-emitting layer, and the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, the luminous efficiency is improved, and the degradation of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material can be suppressed, and the driving life becomes longer. In particular, in the case of a triazine structure in which all W of the above formula (250) are nitrogen atoms, the LUMO is relatively deep, and in addition to the electron transport property, it also has moderate electron capture. By not excessively supplying electrons to the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201), the durability of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material is improved, and as a result, it is believed that the driving life of the organic electroluminescent element becomes longer. In particular, it is believed that electrons entering the empty p orbital of the boron atom of the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material may inhibit the degradation of the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material and the organic metal compound represented by the above formula (201).

[0152] In addition, the compound represented by the above formula (250) has an aromatic six-membered ring containing a nitrogen atom at the center, so it has high electron transport properties. Therefore, it is believed that when using the compound represented by the above formula (250) as a main material, further using a main material with high hole transport properties as another main material will further reduce the voltage and extend the driving life.

[0153] It is believed that when the organic electroluminescent element of the present invention contains a compound having a structure with two carbazole rings, i.e., a compound represented by the above formula (240), as a main material in the light-emitting layer, the charge transport property in the light-emitting layer is appropriately adjusted, the voltage is reduced, and the degradation of the polycyclic heterocyclic compound represented by the above formula (1) and the organic metal compound represented by the above formula (201) as the light-emitting material can be suppressed, and the driving life becomes longer. It is believed that when the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material directly accepts holes injected from the layer on the anode side and becomes an oxidized state, there is a possibility of deterioration. The compound represented by the above formula (240) has a hole transport property and is easy to accept holes from the layer on the anode side. Therefore, the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as the light-emitting material is not easy to be directly oxidized, so that the degradation is suppressed. On the contrary, it is believed that when the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as a light-emitting material directly receives electrons injected from the cathode side and becomes a reduced state and is easily degraded, holes are quickly transferred from the compound represented by the formula (240) to the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as a light-emitting material, and the degradation is suppressed by recombination of the light-emitting material to emit light.

[0154] The hole transport property of the compound represented by formula (240) is excellent, and the hole transport property of the organometallic compound represented by the above formula (201) is excellent. In addition, it is believed that the compound represented by formula (240) has two highly planar carbazole structures, so the hole transport property of the polycyclic heterocyclic compound with high planarity, that is, the polycyclic heterocyclic compound represented by the above formula (1), is improved. At this time, it is believed that by also quickly supplying electrons to the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material and quickly recombine the light emission, the degradation of the light-emitting material is also suppressed. Therefore, it is believed that by using the compound represented by the above formula (240) as the first host material, and using a material with high electron transport as the second host material, it is possible to obtain an organic electroluminescent element with low voltage and long driving life. As a host with high electron transport, it is preferably a compound represented by the above formula (250).

[0155] It is believed that the organic electroluminescent element of the present invention contains a compound having a structure formed by connecting multiple benzene rings, that is, a compound represented by the above formula (260) as a main material in the light-emitting layer, and the charge transport property in the light-emitting layer is appropriately adjusted, and the degradation of the polycyclic heterocyclic compound represented by the above formula (1) or the organic metal compound represented by the above formula (201) as a light-emitting material can be suppressed, and the driving life becomes longer. In particular, the compound represented by the above formula (260) has the effect of suppressing charge transport. In particular, it is believed that in the case where the compound represented by the formula (250) with excellent electron transport is used as a main material, by further adding the compound represented by the formula (260) as a main material, the polycyclic heterocyclic compound represented by the above formula (1) as a light-emitting material or the organic metal compound represented by the above formula (201) will not be excessively reduced and degraded, and the electron transport property in the light-emitting layer can be suppressed, and the driving life of the element becomes longer.

[0156] <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.

[0157] More specifically, the following structures can be mentioned as the substituent group Z2. For example, a linear, branched or cyclic alkyl group having usually 1 or more, preferably 4 or more and usually 24 or less, preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, and a dodecyl group; For example, an alkoxy group such as a methoxy group and an ethoxy group usually has 1 or more carbon atoms and usually has 24 or less carbon atoms, preferably has 12 or less carbon atoms; For example, an aryloxy or heteroaryloxy group having usually 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenoxy group, a naphthoxy group, and a pyridyloxy group; For example, an alkoxycarbonyl group having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group; For example, a dialkylamino group having a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less, such as a dimethylamino group and a diethylamino group; For example, a diarylamino group having usually 10 or more, preferably 12 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a diphenylamino group and a ditolylamino group; For example, an arylalkylamino group having usually 7 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenylmethylamino group; For example, an acyl group such as an acetyl group and a benzoyl group usually has 2 or more and usually 24 or less, preferably 12 or less carbon atoms; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a halogenated alkyl group having usually 1 or more and usually 12 or less, preferably 6 or less carbon atoms, such as a trifluoromethyl group; For example, an alkylthio group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methylthio group and an ethylthio group; For example, an arylthio group having usually 4 or more, preferably 5 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenylthio group, a naphthylthio group, and a pyridylthio group; For example, a silyl group having usually 2 or more, preferably 3 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a trimethylsilyl group and a triphenylsilyl group; For example, a silyloxy group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a trimethylsilyloxy group and a triphenylsilyloxy group; Cyano; For example, an aromatic hydrocarbon group having usually 6 or more and usually 36 or less, preferably 24 or less carbon atoms, such as a phenyl group and a naphthyl group; For example, an aromatic heterocyclic group having usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a thienyl group and a pyridyl group.

[0158] 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.

[0159] 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 transport properties, each substituent of the above-mentioned substituent group Z2 preferably has no further substituent.

[0160] <Compound represented by formula (250)>

[0161] [Chemistry 24]

[0162] (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, multiple Xa 1 Can be the same or different. When h11 is 2 or more, multiple Ya 1 Can be the same or different. When g11 is 2 or more, 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.)

[0163] XA 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 and Za 2The substituents that the above-mentioned aromatic hydrocarbon group having 6 to 30 carbon atoms may have and the substituents that the above-mentioned aromatic heterocyclic group having 3 to 30 carbon atoms may have are each independently preferably selected from the above-mentioned substituent group Z2, and the substituents selected from the substituent group Z2 more preferably have no further substituents.

[0164] The compound represented by the above formula (250) is preferably a charge transporting compound, that is, preferably a charge transporting host material.

[0165] <w> W in the above formula (250) represents CH or N, at least one of which is N. However, from the viewpoint of electron transportability and electron durability, at least two are preferably N, and all are more preferably N.

[0166] <Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , Za 2 > As Xa in the above 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, A benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring or a fluorene ring is preferred, a benzene ring, a naphthalene ring, a phenanthrene ring or a fluorene ring is more preferred, and a benzene ring, a naphthalene ring or a fluorene ring is further preferred. In addition, a partial structure of the terminal when g11 is 2 or more, i.e. -Xa 1 -Xa 2 、When h11 is 2 or more, the terminal partial structure is -Ya 1 -Ya 2 When j11 is 2 or more, the terminal partial structure is -Za 1 -Za 2 In the compound represented by formula (250), when g11 is 2 or more, the terminal partial structure, i.e., -Xa 1 -Xa 2 、When h11 is 2 or more, the terminal partial structure is -Ya 1 -Ya 2 When j11 is 2 or more, the terminal partial structure is -Za 1 -Za 2 At least one of them is a spirofluorene structure.

[0167] As Xa in the above formula (250) 1 , Ya 1 , Za 1 is a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent and Xa 2 , Ya 2 , Za 2 In the case of an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a 5-membered or 6-membered monocyclic ring or a 2- to 5-membered condensed ring. Specific examples include a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, an indolocarbazole ring, an indenocarbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a pyridine ring, a quinazoline ring, and a quinazolinone ring. Among them, preferred are thiophene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, indolecarbazole ring, phenanthroline ring or indenocarbazole ring, more preferred are pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, indolecarbazole ring, indenocarbazole ring, dibenzofuran ring or dibenzothiophene ring, further preferred are carbazole ring, indolecarbazole ring, dibenzofuran ring or dibenzothiophene ring.

[0168] In the above formula (250), Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 and Za 2 Among them, particularly preferred aromatic hydrocarbon rings are benzene rings, naphthalene rings or phenanthrene rings, and particularly preferred aromatic heterocyclic rings are carbazole rings, indolocarbazole rings, dibenzofuran rings or dibenzothiophene rings.

[0169] Xa in the above 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 each independently preferably selected from the substituent group Z2, and the substituents selected from the substituent group Z2 more preferably have no further substituents. It is considered that the substituents selected from the substituent group Z2 have no further substituents, which is preferred because high charge transport properties and durability can be maintained. 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.

[0170] <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.

[0171] The compound represented by the above formula (250) also includes a ring having three central Ws, and the number of these rings in total is 8 to 18, which is preferred from the viewpoint of charge transport properties, durability, and solubility in organic solvents.

[0172] <(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 groups independently preferably has a partial structure selected from the partial structure represented by the following formula (11), the partial structure represented by the following formula (12) and the partial structure 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 partial structure selected from the group consisting of the partial structure represented by the following formula (11), the partial structure represented by the following formula (12), and the partial structure represented by the following formula (13).

[0173] [Chemistry 25]

[0174] In each of the above formulae (11) to (13), * represents the bonding position with the 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 with an adjacent structure. In the following description, unless otherwise specified, the definition of * is the same.

[0175] 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 partial structure represented by formula (11) or a partial structure 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 partial structure represented by formula (11) and a partial structure represented by formula (12).

[0176] The partial structure represented by the formula (12) is preferably a partial structure represented by the following formula (12-2).

[0177] [Chemistry 26]

[0178] As the partial structure represented by formula (12), a partial structure represented by the following formula (12-3) is more preferable.

[0179] [Chemistry 27]

[0180] The partial structure having the partial structure represented by the formula (11) and the partial structure represented by the formula (12) is preferably a structure including a plurality of the following structures, the structures being selected from the partial structure represented by the formula (11) and the partial structure represented by the formula (12), that is, the partial structures selected from the following formulas (14) to (17). That is, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently preferably has a partial structure selected from the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17). In other words, from the viewpoint of solubility, when g11 is 1 or more, (Xa 1 ) g11 、When h11 is 1 or more (Ya 1 ) h11 When j11 is greater than 1 (Za 1 ) j11 Each independently preferably has a partial structure selected from formula (11) to formula (17).

[0181] [Chemistry 28]

[0182] A structure comprising a plurality of the following structures, wherein the structures are selected from the partial structures represented by formula (11) and the partial structures represented by formula (12), which means, for example, that the partial structure represented by formula (14) is the following partial structure, and the partial structure can be regarded as having one partial structure represented by formula (11) and two partial structures represented by formula (12) as in the following formula (14a).

[0183] [Chemistry 29]

[0184] More preferably, (Xa 1 ) g11 、(Ya 1 ) h11 and (Za 1 ) j11 At least one of the above has at least a partial structure represented by formula (14) or a partial structure 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 partial structure represented by formula (14) or a partial structure represented by formula (15).

[0185] The partial structure represented by the formula (14) is preferably a partial structure represented by the following formula (14-2).

[0186] [Chemistry 30]

[0187] As the partial structure represented by formula (14), a partial structure represented by the following formula (14-3) is more preferable.

[0188] [Chemistry 31]

[0189] The partial structure represented by the formula (15) is preferably a partial structure represented by the following formula (15-2).

[0190] [Chemistry 32]

[0191] As the partial structure represented by formula (15), a partial structure represented by the following formula (15-3) is more preferable.

[0192] [Chemistry 33]

[0193] The partial structure represented by the formula (17) is preferably a partial structure represented by the following formula (17-2).

[0194] [Chemistry 34]

[0195] As a partial structure including the partial structure represented by formula (13), (Xa 1 ) g11 ,(Ya 1 ) h11 and (Za 1 ) j11 More preferably, at least one of them has a partial structure represented by the following formula (19) or a partial structure represented by the following formula (20).

[0196] [Chemistry 35]

[0197] In each of the above formulae (14) to (20), * represents the bonding position with the 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.

[0198] Among the partial structures represented by formula (14) to formula (20), the partial structure represented by formula (14-3) and the partial structure represented by formula (15-3) are preferred, and formula (14-3) is more preferred.

[0199] -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) each independently preferably has a partial structure represented by formula (11), a partial structure represented by formula (12-3), a partial structure represented by formula (14-3) or a partial structure represented by formula (15-3).

[0200] In addition, -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) preferably has any one of the partial structures or terminal structures represented by the following formula (250-1) to the following formula (250-10).

[0201] [Chemistry 36]

[0202] [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.]

[0203] The substituents that these structures can have are similar to R 32 same.

[0204] 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.

[0205] In the case of having 2 R 32 In the structure of 32 It can be the same or different. R 32 Preferably, it is an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms, or a heteroaryl group having 3 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms, and more preferably a heteroaryl group having 1 to 2 Preferably, the alkyl group is an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms; more preferably, the alkyl group is an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, or an aryl group having 6 to 14 carbon atoms which may be substituted with an alkyl group having 1 to 8 carbon atoms.

[0206] <R 31 > When R is 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. 31 When there are multiple ones, they can be different from each other.

[0207] As 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, R being a substituent 31 The substituents that may be present may be selected from the above-mentioned substituent group Z2.

[0208] From the perspective of charge transport, R 31 Preferred is a hydrogen atom.

[0209] 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.

[0210] <Molecular weight> The compound represented by the above formula (250) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less. The lower limit of the molecular weight of the compound is usually 400 or more, preferably 500 or more, and more preferably 600 or more.

[0211] <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.

[0212] [Chemistry 37]

[0213] [Chemistry 38]

[0214] [Chemistry 39]

[0215] [Chemistry 40]

[0216] [Chemistry 41]

[0217] [Chemistry 42]

[0218] The light-emitting layer and composition of the organic electroluminescent device of the present invention may contain only one type of the compound represented by the above formula (250) or two or more types of the compound.

[0219] <Compound represented by formula (240)>

[0220] [Chemistry 43]

[0221] (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.)

[0222] <Ar 611 ,Ar 612 > Ar 611 ,Ar 612 Each independently represents a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 50, more preferably 6 to 30, and still more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, A monovalent group of an aromatic hydrocarbon structure having a carbon number of usually 6 or more and usually 30 or less, preferably 18 or less, and more preferably 14 or less, such as a pyrene ring, a benzanthracene ring or a perylene ring, or a monovalent group of a structure in which a plurality of structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, a structure in which 2 to 8 are linked can be generally cited, and a structure in which 2 to 5 are preferably linked can be cited. When multiple aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0223] Ar 611 ,Ar 612 Preferably, they are independently: Phenyl, A monovalent group formed by multiple benzene rings connected in chains or branches. A monovalent group formed by one or more benzene rings and at least one naphthalene ring connected in a chain or branched manner, A monovalent group formed by one or more benzene rings and at least one phenanthrene ring connected in a chain or branched manner, or A monovalent group formed by one or more benzene rings and at least one tetraphenylene ring connected in a chain or branched manner. More preferably, it is a monovalent group in which a plurality of benzene rings are linked in a plurality of chains or branches. In either case, the linking order is not limited. Ar 611 ,Ar 612 Particularly preferably, each independently of the other, is a monovalent group in which a plurality of benzene rings which may have a substituent are linked in a chain or branched form. Most preferably, each independently of the other, is a monovalent group in which a plurality of benzene rings are linked in a chain or branched form.

[0224] The number of the connected benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is as described above, and is usually 2 to 8, preferably 2 to 5. Among them, a monovalent structure in which 1 to 4 benzene rings are connected, a monovalent structure in which 1 to 4 benzene rings are connected to a naphthalene ring, a monovalent structure in which 1 to 4 benzene rings are connected to a phenanthrene ring, or a monovalent structure in which 1 to 4 benzene rings are connected to a tetraphenylene ring is preferred.

[0225] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0226] From the viewpoint of solubility and durability of the compound, Ar 611 ,Ar 612 At least one of them preferably has a partial structure selected from the following formulae (11) to (13) and (21) to (24), Ar 611 and Ar 612 It is further preferred that each independently has a partial structure selected from the following formulae (11) to (13) and (21) to (24).

[0227] [Chemistry 44]

[0228] 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.

[0229] More preferably, Ar 611 ,Ar 612 Each independently has a partial structure represented by formula (11) or a partial structure represented by formula (12). More preferably, Ar 611 ,Ar 612 Each independently has a partial structure represented by formula (11) and a partial structure represented by formula (12).

[0230] The partial structure represented by the formula (12) is preferably a partial structure represented by the following formula (12-2).

[0231] [Chemistry 45]

[0232] As the partial structure represented by formula (12), a partial structure represented by the following formula (12-3) is more preferable.

[0233] [Chemistry 46]

[0234] The partial structure having the partial structure represented by the formula (11) and the partial structure represented by the formula (12) is preferably a structure including a plurality of the following structures, wherein the structures are selected from the partial structure represented by the formula (11) and the partial structure represented by the formula (12), that is, partial structures selected from the following formulas (14) to (17). 611 and Ar 612 Each independently preferably has a partial structure selected from the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17).

[0235] [Chemistry 47]

[0236] A structure comprising a plurality of the following structures, wherein the structures are selected from the partial structures represented by formula (11) and the partial structures represented by formula (12), which means, for example, that the partial structure represented by formula (14) is the following partial structure, and the partial structure can be regarded as having one partial structure represented by formula (11) and two partial structures represented by formula (12) as in the following formula (14a).

[0237] [Chemistry 48]

[0238] More preferably, Ar 611 ,Ar 612 At least one of them has at least a partial structure represented by formula (14) or a partial structure represented by formula (15). More preferably, Ar 611 ,Ar 612 It has a partial structure represented by formula (14) or a partial structure represented by formula (15).

[0239] The partial structure represented by the formula (14) is preferably a partial structure represented by the following formula (14-2).

[0240] [Chemistry 49]

[0241] As the partial structure represented by formula (14), a partial structure represented by the following formula (14-3) is more preferable.

[0242] [Chemistry 50]

[0243] The partial structure represented by the formula (15) is preferably a partial structure represented by the following formula (15-2).

[0244] [Chemistry 51]

[0245] As the partial structure represented by formula (15), a partial structure represented by the following formula (15-3) is more preferable.

[0246] [Chemistry 52]

[0247] The partial structure represented by the formula (17) is preferably a partial structure represented by the following formula (17-2).

[0248] [Chemistry 53]

[0249] As a partial structure including the partial structure represented by formula (13), Ar 611 ,Ar 612 More preferably, at least one of them has a partial structure represented by the following formula (19) or a partial structure represented by the following formula (20).

[0250] [Chemistry 54]

[0251] 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.

[0252] Among the partial structures represented by formula (14) to formula (20), the partial structure represented by formula (14-3) and the partial structure represented by formula (15-3) are preferred, and formula (14-3) is more preferred.

[0253] Ar 611 ,Ar 612 Each independently preferably has a partial structure represented by formula (11), a partial structure represented by formula (12-3), a partial structure represented by formula (14-3), or a partial structure represented by formula (15-3).

[0254] <R 611 , R 612 > R 611 , R 612 Each is independently a halogen atom such as a deuterium atom or a fluorine atom, or a monovalent aromatic hydrocarbon group 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 preferred aromatic hydrocarbon groups are also the same, with phenyl being particularly preferred. These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0255] <n 611 、n 612 > n 611 、n 612 Each independently represents an integer of 0 to 4. Preferably it is 0 to 2, and more preferably 0 or 1. Ar 611 When it is unsubstituted phenyl, n 611 is an integer from 1 to 4, Ar 612 When it is unsubstituted phenyl, n 612 It is an integer of 1 to 4, and is preferably from the viewpoint of having high solubility in an organic solvent.

[0256] <Substituent> Ar 611 ,Ar 612 , R 611 , R 612 When it is a monovalent aromatic hydrocarbon group, the substituent that it may have is preferably a substituent selected from the above-mentioned substituent group Z2.

[0257] <g> G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

[0258] The number of carbon atoms of the aromatic hydrocarbon group of G is preferably 6 to 50, more preferably 6 to 30, and even more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a tetraphenylene ring, a phenanthrene ring, A divalent group of an aromatic hydrocarbon structure having a carbon number of usually 6 or more and usually 30 or less, preferably 18 or less, and more preferably 14 or less, such as a pyrene ring, a benzanthracene ring or a perylene ring, or a divalent group of a structure in which a plurality of structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, a structure in which 2 to 8 are linked can be generally cited, and a structure in which 2 to 5 are preferably linked can be cited. When multiple aromatic hydrocarbon rings are linked, they can be linked to the same structure or to different structures.

[0259] G is preferably a single bond, a phenylene group, a divalent group formed by combining a plurality of benzene rings in a plurality of chains or branches, a divalent group formed by combining one or more benzene rings and at least one naphthalene ring in a chain or branch, a divalent group formed by combining one or more benzene rings and at least one phenanthrene ring in a chain or branch, or The divalent group is formed by one or more benzene rings and at least one tetraphenylene ring connected in a chain or branched form, and more preferably a divalent group is formed by multiple benzene rings connected in a plurality of chains or branches. In either case, the connection order is not limited.

[0260] The number of connected benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is as described above, usually 2 to 8, preferably 2 to 5. Among them, a divalent structure formed by connecting 1 to 4 benzene rings, a divalent structure formed by connecting 1 to 4 benzene rings and a naphthalene ring, a divalent structure formed by connecting 1 to 4 benzene rings and a phenanthrene ring, or a divalent structure formed by connecting 1 to 4 benzene rings and a tetraphenylene ring is more preferred.

[0261] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically may be selected from the above-mentioned substituent group Z2. Preferred substituents are the preferred substituents of the above-mentioned substituent group Z2.

[0262] <Molecular weight> The compound represented by the above formula (240) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, further preferably 2,000 or less, particularly preferably 1,500 or less, and is usually 400 or more, preferably 500 or more, and more preferably 600 or more.

[0263] <Specific example of compound IV represented by the above formula (240)> Preferred specific examples of the compound IV represented by the above formula (240) are shown below, but the present invention is not limited to these.

[0264] [Chemistry 55]

[0265] [Chemistry 56]

[0266] The light-emitting layer and composition of the organic electroluminescent device of the present invention may contain only one type of compound represented by the above formula (240) or two or more types of compound.

[0267] <Compound represented by formula (260)>

[0268] [Chemistry 57]

[0269] (In formula (260), Ar 61 ~Ar 65 are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, L 1 ~L 5 are each independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, R 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 n is 1 or more when at least one Ar 65 At least one of the groups is not a hydrogen atom.)

[0270] (Ar 61 ,Ar 62 ,Ar 65 ) Ar in formula (260) 61 ,Ar 62 and Ar 65 Each independently represents a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

[0271] 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, one or more and three or less groups are preferably the following formula (261) or the following formula (262), Ar 61 ,Ar 62 and at least one and Ar 65 Among them, the group of 1 or more and 3 or less is more preferably the following formula (262). From the viewpoint of charge transport and solubility, Ar 61 ,Ar 62 and at least one Ar 65 Among them, one group is preferably represented by the following formula (262). From the perspective of durability, Ar 61 ,Ar 62 and at least one Ar 65 Among them, two or more groups are preferably represented by the following formula (262), and three groups are more preferably represented by the following formula (262).

[0272] (Formula (261), Formula (262))

[0273] [Chemistry 58]

[0274] (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. )

[0275] Ar 61 In the case of formula (261) or formula (262), m1 is preferably 0 or 1, and more preferably 0. 62 In the case of formula (261) or formula (262), m2 is preferably 0 or 1, and more preferably 0. 65 In the case of formula (261) or formula (262), m5 is preferably 0 or 1, and more preferably 0.

[0276] (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.

[0277] Examples of the monovalent aromatic hydrocarbon group having 6 to 60 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, ...

[0278] 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.

[0279] (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.

[0280] Examples of the divalent aromatic hydrocarbon group having 6 to 60 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 of them is independently preferably 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.

[0281] (R 60 ) R in formula (260) 60 Each independently represents a substituent. As a substituent, a substituent selected from the above-mentioned 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.

[0282] (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.

[0283] 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 and Ar are formula (261) or formula (262), 65 When it is formula (261) or formula (262), m5 is preferably 0.

[0284] 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.

[0285] 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.

[0286] ((L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 ,(L 5 ) m5 ) From the viewpoint of solubility and durability of the compound, (L 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 In the embodiment, at least one group preferably has a partial structure selected from the partial structure represented by the following formula (11), the partial structure represented by the following formula (12) and the partial structure represented by the following formula (13), and when m1 is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When n is 1 or more and m5 is 1 or more (L 5 ) m5 , and when m3 is 1 or more (L 3 ) m3 When m4 is greater than 1 (L 4 ) m4 It is further preferred that the partial structure be selected from the partial structure represented by the following formula (11), the partial structure represented by the following formula (12), and the partial structure represented by the following formula (13). As a preferred embodiment, for example, when m1 in formula (260) is 1 or more, (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each independently may have a partial structure selected from the partial structures represented by the following formulae (11) to (17).

[0287] [Chemistry 59]

[0288] In each of the above formulae (11) to (13), * represents the bonding position with the adjacent structure or Ar 61 ,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, the definition of * is the same unless otherwise specified.

[0289] 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 partial structure represented by formula (11) or a partial structure represented by formula (12). More preferably, 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 partial structure represented by formula (11) or a partial structure 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 partial structure represented by formula (11) and a partial structure represented by formula (12).

[0290] In formula (260), as formula (12), the following formula (12-2) is preferred.

[0291] [Chemistry 60]

[0292] In formula (260), as formula (12), the following formula (12-3) is more preferred.

[0293] [Chemistry 61]

[0294] 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 It is preferred that at least one group has a partial structure having a partial structure represented by the formula (11) and a partial structure represented by the formula (12).

[0295] In formula (260), the partial structure having the partial structure represented by formula (11) and the partial structure represented by formula (12) is preferably a structure including a plurality of the following structures, wherein the structures are selected from the partial structure represented by formula (11) and the partial structure represented by formula (12), that is, partial structures 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 partial structure selected from the above formula (11) to the above formula (13) and the following formula (14) to the following formula (17).

[0296] [Chemistry 62]

[0297] In formula (260), there is a structure containing multiple structures below, wherein the structures are selected from the partial structures represented by formula (11) and the partial structures represented by formula (12), which means, for example, that formula (14) is the following partial structure, and the partial structure can be regarded as having one partial structure represented by formula (11) and two partial structures represented by formula (12) as in formula (14a).

[0298] [Chemistry 63]

[0299] In addition, it is further preferred that (L in formula (260) 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 partial structure 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 partial structure represented by formula (14) or a partial structure represented by formula (15).

[0300] In formula (260), as formula (14), the following formula (14-2) is preferred.

[0301] [Chemistry 64]

[0302] In formula (260), as formula (14), the following formula (14-3) is more preferred.

[0303] [Chemistry 65]

[0304] In formula (260), as formula (15), the following formula (15-2) is preferred.

[0305] [Chemistry 66]

[0306] In formula (260), as formula (15), the following formula (15-3) is more preferred.

[0307] [Chemistry 67]

[0308] In formula (260), as formula (17), the following formula (17-2) is preferred.

[0309] [Chemistry 68]

[0310] In addition, as a partial structure including the partial structure represented by formula (13), (L) in formula (260) 1 ) m1 ,(L 2 ) m2 ,(L 3 ) m3 ,(L 4 ) m4 and at least one (L 5 ) m5 More preferably, at least one of them has a partial structure represented by the following formula (19) or a partial structure represented by the following formula (20).

[0311] [Chemistry 69]

[0312] 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.

[0313] In formula (260), among formulas (14) to (20), formula (14-3) and formula (15-3) are preferred, and formula (14-3) is more preferred.

[0314] (L 1 ~L 5 Preferred partial structure of In formula (260), L 1 ~L 5 It preferably has a partial structure represented by formula (11), a partial structure represented by formula (12-3), a partial structure represented by formula (14-3), or a partial structure represented by formula (15-3).

[0315] (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.

[0316] (a1~a3) a1 to a3 each independently represent an integer of 0 to 3. a1 to a3, from the viewpoint of solubility and durability of the compound, a1 to a3 are each independently preferably 0 or 1, a1=a2=a3=0 is the most preferred value.

[0317] (R 101 ~R 126 ) In formula (260), R 101 ~R 126 Each independently represents a hydrogen atom or a substituent. As a substituent, a substituent selected from the above-mentioned 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 or an aromatic hydrocarbon group, and particularly preferably a hydrogen atom.

[0318] (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-mentioned 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.

[0319] (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, more preferably 600 or more.

[0320] (specific example) Specific examples of the compound represented by formula (260) are shown below, but the compound is not limited to these.

[0321] [Chemistry 70]

[0322] [Chemistry 71]

[0323] [Chemistry 72]

[0324] The light-emitting layer and composition of the organic electroluminescent device of the present invention may contain only one type of compound represented by the above formula (260) or two or more types of compound.

[0325] [Composition] The composition of the present invention is a composition containing the material for the light-emitting layer of the organic electroluminescent element of the present invention and an organic solvent. That is, the composition of the present invention is a composition for forming a light-emitting layer of an organic electroluminescent element containing the light-emitting compound, the organometallic compound and an organic material.

[0326] In more detail, the composition of the first embodiment of the present invention is a composition containing a material for the light-emitting layer of the organic electroluminescent element of the first embodiment of the present invention and an organic solvent. That is, the composition of the first embodiment of the present invention is a composition for forming a light-emitting layer of an organic electroluminescent element, which contains a light-emitting compound represented by the above formula (1), an organic metal compound having a molecular weight of 1,200 or more, and an organic material, wherein the light-emitting compound and the organic metal compound satisfy the relationship (E-1).

[0327] Preferred embodiments of the light-emitting compound represented by the formula (1) and the organometallic compound contained in the composition of the first embodiment of the present invention are as described above. The composition of the first embodiment of the present invention is preferably a composition for forming a light-emitting layer.

[0328] In addition, in more detail, the composition of the second embodiment of the present invention is a composition containing a material for the light-emitting layer of the organic electroluminescent element of the second embodiment of the present invention and an organic solvent. That is, the composition of the second embodiment of the present invention is a composition for forming a light-emitting layer of an organic electroluminescent element, which contains a light-emitting compound represented by the above formula (1), an organic metal compound represented by the above formula (201), a host material and an organic solvent, wherein the light-emitting compound and the organic metal compound satisfy the relationship (E-1), and the host material comprises at least one selected from the compound represented by the above formula (250), the compound represented by the above formula (240) and the compound represented by the above formula (260).

[0329] Preferred embodiments of the luminescent compound represented by the above formula (1), the organometallic compound represented by the above formula (201), the compound represented by the above formula (250), the compound represented by the above formula (240), and the compound represented by the above formula (260) contained in the composition of the second embodiment of the present invention are as described above. The composition of the second embodiment of the present invention is preferably a composition for forming a luminescent layer.

[0330] The light-emitting layer may be formed by vacuum deposition or wet film formation, and is preferably formed by wet film formation. In the wet film formation, the light-emitting layer is formed by applying a light-emitting layer-forming composition containing an organic solvent and drying the composition.

[0331] The composition of the first embodiment of the present invention further preferably contains the above-mentioned main material. The composition may be a composition obtained by dissolving or dispersing the polycyclic heterocyclic compound represented by the above formula (1) and the organometallic compound represented by the above formula (201) in an organic solvent. The composition may be a composition obtained by dissolving or dispersing the polycyclic heterocyclic compound represented by the above formula (1), the organometallic compound represented by the above formula (201) and the main material in an organic solvent.

[0332] (Organic Solvent) The organic solvent that may be contained in the composition is a liquid component having volatility for forming a layer containing a polycyclic heterocyclic compound by wet film formation.

[0333] The organic solvent is not particularly limited as long as it is an organic solvent that can well dissolve the polycyclic heterocyclic compound and the charge transporting compound as solutes.

[0334] 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; fatty ketones such as methyl ethyl ketone and dibutyl ketone; fatty alcohols such as butanol and hexanol; fatty ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); etc.

[0335] 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.

[0336] These organic solvents may be used alone or in any combination and ratio.

[0337] 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.

[0338] 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 facilitates formation of a more uniform coating film, which is therefore preferred.

[0339] (content) The content of the polycyclic heterocyclic compound represented by the formula (1) in the composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less. The content of the organometallic compound represented by the formula (201) in the composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less. By making the content the range, it is possible to efficiently inject holes or electrons from adjacent layers (for example, hole transport layer, hole blocking layer) to the light-emitting layer, reducing the driving voltage. It should be noted that the polycyclic heterocyclic compound represented by the formula (1) and the organometallic compound represented by the formula (201) may contain only one in the composition, or may contain two or more in combination. The content of the organometallic compound represented by formula (2) contained in the composition is usually 100 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, and is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, relative to 1 part by mass of the polycyclic heterocyclic compound represented by formula (1).

[0340] When the composition contains a host material, the content of the host material is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less.

[0341] The content of the main material contained in the composition is usually 1000 parts by mass or less, preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and more preferably 1 parts by mass or more, relative to 1 part by mass of the organic metal compound represented by formula (201).

[0342] The content of the organic solvent contained in the composition 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 above lower limit, it has a moderate viscosity and improves the coating property, and if it is below the above upper limit, it is easy to obtain a uniform film and make the film-forming property good.

[0343] (Other ingredients) The composition may contain other compounds in addition to the above-mentioned compounds as necessary. Preferred examples of other compounds include phenols such as dibutylhydroxytoluene and dibutylphenol, which are known antioxidants.

[0344] (Film Forming Method) The formation method of the luminescent layer is preferably a wet film-forming method. The wet film-forming method refers to a method of applying a composition to form a liquid film, drying and removing an organic solvent to form a film of the luminescent layer. 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 coating is dried to form a film. Among these coating methods, spin coating, spray coating, inkjet, nozzle printing, etc. are preferably used. When manufacturing an organic EL display device having an organic electroluminescent element, an inkjet method or a nozzle printing method is preferably used, and an inkjet method is particularly preferably used.

[0345] 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.

[0346] The reduced pressure for drying under reduced pressure is preferably reduced to a pressure not more than the vapor pressure of the organic solvent contained in the composition.

[0347] In the case of heating, the heating method is not particularly limited, and heating using a hot plate, heating in an oven, infrared heating, etc. can be used. The heating temperature is usually 80° C. or higher, preferably 100° C. or higher, more preferably 110° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower.

[0348] 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.

[0349] [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 the function of transporting holes, and therefore contains a hole transport material. Furthermore, the hole injection layer preferably contains tetraarylborate ions. In addition, it is also preferred to contain a crosslinked product of an electron accepting compound having a crosslinking group.

[0350] In order to improve the hole injectability from the anode to the hole injection layer and improve the hole transportability in the hole injection layer, the hole transport material contained in the hole injection layer preferably contains a cation radical site. In order to make the hole transport material cation radical, an electron accepting compound is used when forming the hole injection layer. As the basic skeleton of the electron accepting compound, an ionic compound composed of a tetraaryl borate ion and a counter cation as an anion of an ion valence 1 described later is preferred because it has high stability.

[0351] 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, when a tetraarylborate with a diaryliodonium as a counter cation is used as an electron accepting compound, when the hole injection layer is formed, the counter cation shown in the following formula can be changed from diaryliodonium to triarylamine.

[0352] [Chemistry 73]

[0353] (e.g., Ar, Ar 1 ~Ar 4 Each is independently a monovalent group formed by connecting multiple structures selected from an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an aromatic hydrocarbon ring group which may have a substituent and an aromatic heterocyclic group which may have a substituent.)

[0354] 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.

[0355] 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.

[0356] [Electron-accepting compound having a cross-linking group] As described above, examples of the electron accepting compound include a compound having an ionic compound composed of a tetraarylborate ion and a counter cation as a basic skeleton, or a compound having an ionic compound composed of a tetraarylborate ion and a counter cation as a basic skeleton and having the following crosslinking group.

[0357] (Cross-linking group) The crosslinking group of the electron accepting compound that may be included in the hole injection layer of the organic electroluminescent element of the present invention to form a crosslinked product of the electron accepting compound having a crosslinking group refers to a group that reacts with other groups located near the crosslinking group by irradiation with heat and / or active energy rays to generate a new chemical bond. In this case, the reactive group may be the same group as the crosslinking group or a different group.

[0358] It is believed that when the electron accepting compound includes a crosslinking group, a crosslinking reaction is carried out when forming a hole injection layer, and 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 extend to the layer on the hole injection layer. Therefore, it is inferred that by using an electron accepting compound with a crosslinking group, the degradation reaction in the drive can be suppressed.

[0359] The crosslinking group is preferably a crosslinking group represented by any one of the following formulae (X1) to (X18).

[0360] [Chemistry 74]

[0361] 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. )

[0362] By R X The alkyl group represented by is a linear, branched or cyclic structure, and has 1 or more carbon atoms, preferably 24 or less, more preferably 12 or less, and further preferably 8 or less.

[0363] 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 present is preferably an alkyl group, an aromatic hydrocarbon group, an alkoxy group, or an aralkyl group.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] As the crosslinking group, a crosslinking group represented by any one of formulae (X1) to (X3) is preferred from the viewpoint that it undergoes a crosslinking reaction only by heat, has a small polarity, and has a small influence on charge transport.

[0369] The crosslinking group represented by the formula (X1) is as shown below. The cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0370] [Chemistry 75]

[0371] The crosslinking group represented by the formula (X2) is as shown below: the cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0372] [Chemistry 76]

[0373] The crosslinking group represented by the formula (X3) is as shown below: the cyclobutene ring is opened by heat, and the groups after the ring opening are bonded to each other to form a crosslinking structure.

[0374] [Chemistry 77]

[0375] Regarding the crosslinking group represented by any one of formulas (X1) to (X3), the cyclobutene ring is opened by heat, and when there is a double bond nearby, the group after the ring opening reacts with the double bond to form a crosslinking structure. The following is an example of the crosslinking group represented by formula (X1) after the ring opening and the crosslinking group represented by formula (X4) having a double bond site forming a crosslinking structure. (Wherein, R of formula (X4) X Not shown.)

[0376] [Chemistry 78]

[0377] As a group containing a double bond that can react with a crosslinking group represented by any one of formulas (X1) to (X3), in addition to the crosslinking group represented by formula (X4), a crosslinking group represented by any one of formulas (X5), (X6), (X12), (X15), (X16), (X17), and (X18) can also be mentioned. When these groups containing double bonds are used as crosslinking groups in electron accepting compounds, it is preferred to contain a crosslinking group represented by any one of formulas (X1) to (X3) in other components forming a hole injection layer such as a hole transporting compound, as this increases the possibility of forming a crosslinked structure.

[0378] 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 low polarity and is unlikely to hinder charge transport.

[0379] As the crosslinking group, a crosslinking group represented by formula (X7) is preferred from the viewpoint of improving electron accepting property. When a crosslinking group represented by formula (X7) is used, the following crosslinking reaction proceeds.

[0380] [Chemistry 79]

[0381] From the perspective of high reactivity, the crosslinking group represented by any one of formulas (X8) and (X9) is preferred. It should be noted that when the crosslinking group represented by formula (X8) and the crosslinking group represented by formula (X9) are used, the following crosslinking reaction is carried out.

[0382] [Chemistry 80]

[0383] 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.

[0384] (Cross-linked product of electron accepting compound) As described later, the hole injection layer of the organic electroluminescent element of the present invention is preferably obtained by wet film formation of a composition for hole injection layer formation, and the composition for hole injection layer formation is preferably a composition obtained by dissolving or dispersing the first ionic compound having a tetraaryl borate ion structure described later and the hole transport material described later in an organic solvent. Moreover, in the hole transport layer of the organic electroluminescent element of the present invention, it is preferred to contain a charge transporting ionic compound having a tetraaryl borate ion structure in the present invention as an anion and a cation of the hole transport material as a counter cation.

[0385] Therefore, as the electron accepting compound in the electron accepting compound having a crosslinking group, it is preferably an electron accepting compound as an ionic compound, and the ionic compound as the electron accepting 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. About the tetraaryl borate ion structure as described later.

[0386] 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.

[0387] Here, the “tetraarylborate ion in the present invention” includes the case where it exists as an ionic compound formed by the tetraarylborate ion described below and a counter cation, i.e., an electron-accepting compound, and the case where it exists as a charge-transporting ionic compound formed by the tetraarylborate ion described below and a cation of a hole transport material.

[0388] The two crosslinking groups in the crosslinking reaction may be the same crosslinking group or different crosslinking groups as long as the crosslinking reaction can proceed.

[0389] [Tetraarylborate ion] The tetraarylborate ion is an anion with an ionic valence of 1, in which 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 are substituted on a boron atom.

[0390] The polycyclic heterocyclic compound containing boron has an empty p orbital on boron, and is particularly easy to react with an electron-donating substance. The result of the reaction is to generate an oxide of an electron-donating substance, which may further cause a degradation reaction during driving. On the other hand, in the tetraaryl borate ion, which is a stable structure that satisfies the octet rule and does not have an empty p orbital on boron, the electron-donating substance has the effect of stabilizing the oxidized cation. Therefore, it is speculated that by using tetraaryl borate ions, the degradation reaction during driving can be suppressed, the durability is improved, and the driving life of the element is prolonged.

[0391] The tetraarylborate ion that may be contained in the organic electroluminescent device of the present invention preferably has a fluorine atom or an alkyl group substituted with fluorine as a substituent of the aryl group, from the viewpoint of further improving stability. That is, it is preferably represented by the following formula (112).

[0392] [Chemistry 81]

[0393] (In formula (112), Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a monovalent group formed by connecting a plurality of structures selected from an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group, an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, or an aromatic hydrocarbon ring group which may have a substituent and / or a crosslinking group and an aromatic heterocyclic group which may have a substituent and / or a crosslinking group, Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of the groups has a fluorine atom or an alkyl group substituted with fluorine as a substituent.

[0394] Ar 1 ,Ar 2 ,Ar 3 and Ar 4 At least one of them preferably has a cross-linking group.

[0395] 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 includes 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.

[0396] 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 be: 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.

[0397] 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.

[0398] 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 even more preferably 3 or less.

[0399] 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.

[0400] As Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The substituent of Ar is preferably a fluorine atom or an alkyl group substituted with fluorine from the viewpoint of increasing the stability of the anion and improving the effect of stabilizing the cation. 1 ,Ar 2 ,Ar 3 and Ar 4 Preferably, 2 or more substitutions are made, more preferably 3 or more substitutions are made, and most preferably 4 substitutions are made.

[0401] 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 of the crosslinked product of the electron accepting compound containing tetraarylborate ions or a crosslinking group or the coating film stacked thereon becomes stable.

[0402] Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The cross-linking groups that may be present are shown as the above-mentioned cross-linking groups.

[0403] From the perspective of further increasing the stability of the anion and further improving the effect of stabilizing the cation, the tetraarylborate ion that can be contained in the organic electroluminescent element of the present invention is preferably Ar in the above 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 4 All of them are independently a group represented by the formula (113).

[0404] [Chemistry 82]

[0405] (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 an aromatic hydrocarbon ring group which may have a substituent and / or a cross-linking group and an aromatic heterocyclic group which may have a substituent and / or a cross-linking group, an alkyl group substituted with fluorine, a substituent or a cross-linking group, F4 represents 4 fluorine atoms. F (5-m) Each independently represents 5 to m fluorine atoms, k each independently represents an integer from 0 to 5, m each independently represents an integer of 0 to 5.)

[0406] From the perspective of further improving the stability of the anion, k is preferably 1 or more, and more preferably 2 or more. From the perspective of facilitating uniform dispersion, k is preferably 0 or 1, and preferably 0.

[0407] 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 from the perspective of achieving durability, it is more preferably 1 or 2. From the viewpoint that the stability of the anion is improved and the durability is excellent, k+m≥1 is preferred.

[0408] As R A The preferred structure and the substituents that can be possessed by the aromatic hydrocarbon ring group or aromatic heterocyclic group are the same as those of Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The structure and the substituents that may be possessed are the same.

[0409] As R A The substituents and R A When it is a substituent, the substituent includes the groups described in the substituent group W described later.

[0410] 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.

[0411] As R A The cross-linking groups and R A When it is a cross-linking group, the cross-linking group is as described above for the cross-linking group.

[0412] In order to balance crosslinking and electron accepting properties, it is preferred that at least one R A Contains the above cross-linking group. In this case, as R A , preferably a structure in which the cross-linking group or one or more cross-linking groups are bonded to an aromatic hydrocarbon group.

[0413] Further, 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.

[0414] [Chemistry 83]

[0415] 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.

[0416] 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.

[0417] As R A In the case where the aromatic hydrocarbon group is a structure in which one or more of the crosslinking groups are bonded to the 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 benzene rings and naphthalene rings are connected, and the number of connections is preferably 4 or less. In this case, a further preferred R A The structure in which the crosslinking group is bonded to a benzene ring or a naphthalene ring is more preferably a structure in which the crosslinking group is bonded to a benzene ring, and a structure in which one or two crosslinking groups are bonded is particularly preferably a structure in which one or two crosslinking groups are bonded.

[0418] 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 A 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 (115) are combined.

[0419] 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.

[0420] (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.

[0421] 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.

[0422] Examples of the aromatic hydrocarbon ring group composed of 1 to 5 aromatic hydrocarbon rings include phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, triphenylene, naphthylphenyl and the like. In view of the stability of the compound, phenyl, naphthyl, biphenyl, terphenyl or quaterphenyl is preferred.

[0423] Examples of the aliphatic hydrocarbon ring group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0424] The number of carbon atoms in the alkyl group is usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, more preferably 8 or less, and more preferably 6 or less. Specifically, there can be mentioned a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, an octyl group, a 2-ethylhexyl group, and a dodecyl group.

[0425] The alkenyl group usually has 2 or more carbon atoms and usually has 24 or less carbon atoms, and preferably has 12 or less carbon atoms. Specific examples thereof include ethenyl, propenyl, and butenyl.

[0426] The alkynyl group usually has 2 or more carbon atoms and usually has 24 or less carbon atoms, preferably 12 or less carbon atoms. Specific examples thereof include acetyl, propynyl, and butynyl.

[0427] Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenylhexyl group.

[0428] The alkoxy group usually has 1 or more and 24 or less, preferably 12 or less, and more preferably 6 or less carbon atoms. Specific examples thereof include methoxy, ethoxy, butoxy, hexyloxy, and octyloxy.

[0429] 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.

[0430] The alkylthio group usually has 1 or more and 24 or less, preferably 12 or less carbon atoms. Specific examples thereof include a methylthio group, an ethylthio group, a butylthio group, and a hexylthio group.

[0431] 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.

[0432] The alkyl ketone group usually has 1 or more and 24 or less, preferably 12 or less, and more preferably 6 or less carbon atoms. Specific examples thereof include acetyl, ethylcarbonyl, butylcarbonyl, and octylcarbonyl.

[0433] The aryl keto group has usually 5 or more, preferably 7 or more, and usually 25 or less, preferably 13 or less carbon atoms. Specific examples thereof include benzoyl and naphthylcarbonyl.

[0434] 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.

[0435] 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 above-mentioned crosslinking group.

[0436] 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.

[0437] [Specific examples of tetraarylborate ions] Specific examples of the tetraarylborate ion used in the organic electroluminescent device of the present invention are given below, but the present invention is not limited to these.

[0438] [Chemistry 84]

[0439] [Chemistry 85]

[0440] [Chemistry 86]

[0441] [Chemistry 87]

[0442] [Chemistry 88]

[0443] [Chemistry 89]

[0444] [Chemistry 90]

[0445] [Chemistry 91]

[0446] [Chemistry 92]

[0447] [Chemistry 93]

[0448] 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.

[0449] It should be noted that the tetraarylborate ions of (A-18), (A-19), (A-20), (A-21), (A-25), (A-26), (A-28), and (A-29) can form "crosslinked products of electron accepting compounds" because they have crosslinking groups.

[0450] [Electron-accepting ionic compounds containing tetraarylborate ions] Tetraaryl borate ions are also preferably used as electron accepting ionic compounds containing tetraaryl borate ions. The electron accepting ionic compound containing tetraaryl borate ions is referred to as a first ionic compound. The first ionic compound is composed of the tetraaryl borate ions as anions and counter cations. The first ionic compound is used as an electron accepting compound.

[0451] 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.

[0452] As the iodonium cation, a structure represented by the general formula (6) described below is preferred, and the more preferred structure is the same.

[0453] Specifically, the iodonium cation is preferably a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, a 4-tert-butyloxyphenylphenyliodonium cation, a 4-methoxyphenylphenyliodonium cation, a 4-isopropylphenyl-4-methylphenyliodonium cation, or the like.

[0454] Specific examples of the sulfonium cation include triphenylsulfonium cation, 4-hydroxyphenyldiphenylsulfonium cation, 4-cyclohexylphenyldiphenylsulfonium cation, 4-methanesulfonylphenyldiphenylsulfonium cation, (4-tert-butoxyphenyl)diphenylsulfonium cation, bis(4-tert-butoxyphenyl)phenylsulfonium cation, and 4-cyclohexylsulfonylphenyldiphenylsulfonium cation.

[0455] Specifically, preferred examples of the carbocation include trisubstituted carbocations such as triphenylcarbocation, tri(methylphenyl)carbocation, and tri(dimethylphenyl)carbocation.

[0456] 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.

[0457] 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.

[0458] 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.

[0459] The iodonium cation as the counter cation of the first ionic compound is preferably a structure represented by the following formula (116).

[0460] [Chemistry 94]

[0461] 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 selected from Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure, the preferred structure can also be selected from Ar 1 ,Ar 2 ,Ar 3 and Ar 4 The same structure.

[0462] In addition, the counter cation represented by the above formula (116) is preferably represented by the following formula (117).

[0463] [Chemistry 95]

[0464] In the above formula (117), Ar 7 and Ar 8 and Ar in the above formula (116) 5 and Ar 6 The substituents that may be possessed are the same.

[0465] 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 usually 10000 or less, preferably 5000 or less, more preferably 3000 or less. When the molecular weight is too small, the delocalization of positive and negative charges is insufficient, so the electron accepting ability may be reduced, and when the molecular weight is too large, it may hinder the charge transport.

[0466] [Specific example] Hereinafter, specific examples of ionic compounds with iodonium cations will be given as the first ionic compound in the present invention, but the first ionic compound is not limited to these.

[0467] [Chemistry 96]

[0468] [Chemistry 97]

[0469] [Chemistry 98]

[0470] [Chemistry 99]

[0471] [Chemical 100]

[0472] [Chemistry 101]

[0473] [Chemistry 102]

[0474] [Chemistry 103]

[0475] [Chemistry 104]

[0476] [Chemistry 105]

[0477] [Chemistry 106]

[0478] [Chemistry 107]

[0479] [Chemistry 108]

[0480] 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.

[0481] [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.

[0482] Among the aromatic amine compounds, aromatic tertiary amine compounds are particularly preferred in the present invention. It should be noted that the aromatic tertiary amine 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.

[0483] The type of aromatic tertiary amine compound is not particularly limited, but an aromatic tertiary amine polymer compound as a polymer compound is preferred. Regarding the molecular weight of the polymer compound, from the perspective of the surface smoothing effect, the weight average molecular weight is preferably 5000 or more, more preferably 7000 or more, particularly preferably 10000 or more, and preferably 1000000 or less, more preferably 200000 or less, particularly preferably 100000 or less. From the perspective of hole transport, among the aromatic tertiary amine polymer compounds, a polymer compound having a triphenylamine structure in the main chain is further preferred.

[0484] [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).

[0485] [Chemistry 109]

[0486] 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.

[0487] 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).

[0488] Ar 11 ,Ar 12 ,Ar 14 The aromatic ring group is a divalent group formed by connecting a plurality of at least two groups selected from a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent. 11 ,Ar 12 ,Ar 14 The aromatic ring group preferably has 60 or less carbon atoms.

[0489] The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms, and specific examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, A monocyclic six-membered ring or a divalent group of a two- to five-membered condensed ring such as a phenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring or a fluorene ring.

[0490] The aromatic heterocyclic group preferably has 3 to 30 carbon atoms, and specifically includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring or an azulene ring.

[0491] Among them, from the perspective of excellent charge transport properties, as well as excellent durability and heat resistance, divalent groups or divalent biphenyl groups derived from benzene rings, naphthalene rings, fluorene rings, pyridine rings or carbazole rings are preferred, and divalent groups or divalent biphenyl groups derived from benzene rings, fluorene rings or carbazole rings are more preferred.

[0492] 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.

[0493] The substituent that these aromatic ring groups may have may be selected from the above-mentioned substituent group Z2 which is the substituent that the above-mentioned host material may have.

[0494] Ar 13 When it is an aromatic ring group, 11 ,Ar 12 ,Ar 14 The same situation. Ar 13 Furthermore, a divalent group represented by the following formula (102) is preferred.

[0495] [Chemistry 110]

[0496] In the above formula (102), R 11 represents a trivalent group consisting of an alkyl group, an aromatic ring group, or an alkyl group having 40 or less carbon atoms and an aromatic ring group, which may have a substituent. 12 Ar represents a divalent group consisting of an alkyl group, an aromatic ring group, or an alkyl group having 40 or less carbon atoms and an aromatic ring group, which 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).

[0497] 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.

[0498] As R 11 Specific examples of the alkyl group include trivalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0499] 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.

[0500] As R 12 Specific examples of the alkyl group include divalent groups derived from methane, ethane, propane, isopropane, butane, isobutane, and pentane.

[0501] 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.

[0502] As Ar 31 The crosslinking group is not particularly limited, and is the same as the crosslinking group of the electron accepting compound having the crosslinking group contained in the hole injection layer of the organic electroluminescent element of the present invention, and is preferably a crosslinking group represented by any one of the above 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, an acryloyl group. From the perspective of the stability of the compound, a group derived from a benzocyclobutene ring or a naphthalenecyclobutene ring is more preferred.

[0503] S 1 ~S 4 Each is independently a group represented by the following formula (103).

[0504] [Chemistry 111]

[0505] In the above formula (103), q1 and r1 each independently represent an integer of 0 to 6. q1 and r1 are each independently preferably 0 to 4, more preferably 0 or 1.

[0506] 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 a divalent group consisting of an alkyl group, an aromatic ring group, or an alkyl group and an aromatic ring group, which 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).

[0507] As Ar 21 ,Ar 23 Examples of aromatic ring groups, with Ar 11 ,Ar 12 ,Ar 14 The same situation.

[0508] Ar 22 ,Ar 32 The aromatic ring group represents a monovalent group formed by connecting a plurality of at least two groups selected from a monovalent aromatic hydrocarbon group which may have a substituent, a monovalent aromatic heterocyclic group which may have a substituent, or a monovalent aromatic hydrocarbon group which may have a substituent and a monovalent aromatic heterocyclic group which may have a substituent. 22 ,Ar 32 The aromatic ring group preferably has 60 or less carbon atoms.

[0509] 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.

[0510] The aromatic heterocyclic group preferably has 3 to 30 carbon atoms, and specifically includes a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furanopyrrole ring, a furanofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a phenanthridine ring, a quinazoline ring, a quinazolinone ring or azulene ring.

[0511] Among them, a monovalent group derived from a benzene ring, a naphthalene ring, a fluorene ring, a pyridine ring or a carbazole ring, or a biphenyl group is preferred from the viewpoint of excellent charge transport properties, and excellent durability and heat resistance.

[0512] These aromatic ring groups may have a substituent, and the substituent may be selected from the above-mentioned substituent group Z2.

[0513] As R 13 Examples of alkyl groups or aromatic ring groups, with R 12 same.

[0514] Ar 32 The crosslinking group is not particularly limited, but 31 Examples of the cross-linking group are the same as those of the above, and preferred examples are also the same.

[0515] The above Ar 11 ~Ar 14 , R 11 , R 12 ,Ar 21 ~Ar 23 ,Ar 31 ~Ar 32 , Q 11 , Q 12 Unless it violates the gist of the present invention, it may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. The type of the substituent is not particularly limited, but as an example, one or more substituents selected from the substituent group Z2 can be cited.

[0516] In particular, among the polymer compounds having a repeating unit represented by the formula (101), a polymer compound having a repeating unit represented by the following formula (104) is preferred because it has extremely high hole injection / transport properties.

[0517] [Chemistry 112]

[0518] In the above formula (104), R 21 ~R 25 Each independently represents an arbitrary substituent. 21 ~R 25 Specific examples of the substituent are the same as the substituents described in the above substituent group Z2.

[0519] Y' represents a divalent aromatic ring group having 30 or less carbon atoms which may have a substituent. Examples of the aromatic ring group of Y' are the same as those of Ar 11 ,Ar 12 and Ar 14 The same is true for , and the substituents that may be possessed are also the same.

[0520] 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.

[0521] 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).

[0522] [Chemistry 113]

[0523] [Chemistry 114]

[0524] 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.

[0525] Ar 45 ,Ar 47 and Ar 48 Specific examples, preferred examples, examples of substituents that may be possessed, and preferred examples of substituents are independently the same as Ar 22 and Ar 32 The same situation.

[0526] Ar 44 and Ar 46 Specific examples, preferred examples, examples of substituents that may be possessed, and preferred examples of substituents are independently the same as Ar 11 and Ar 14 The same situation.

[0527] As R 41 ~R 43 , preferably a hydrogen atom or a substituent described in the above 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.

[0528] r is preferably 0 or 1, and more preferably 0.

[0529] 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.

[0530] [Chemistry 115]

[0531] 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 represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl containing two or more tertiary amines and two or more fused aromatic rings substituted with nitrogen atoms (Japanese Patent Publication No. 5-234681); aromatic triamines having a starburst structure derived from a derivative of triphenylbenzene (U.S. Patent No. 4,923,774); N,N'-diphenyl-N-phenylamino]biphenyl; , 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 stereo asymmetric molecules as a whole (Japanese Patent Publication No. 4-129271); compounds with multiple aromatic diamines substituted on the pyrene group (Japanese Patent Publication No. 4-175395); aromatic diamines with tertiary aromatic amine units connected by ethylene (Japanese Patent Publication No. 4-2641 89); 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); benzylbenzene 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); dipyridylaminobiphenyl (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.

[0532] 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.

[0533] 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, magnesium phthalocyanine oxide, phthalocyanine lead, phthalocyanine copper (II), 4,4',4",4"'-tetraaza-29H,31H-phthalocyanine, etc.

[0534] In addition, specific preferred examples of oligothiophene derivatives that can be used as hole transport materials include α-sixithiophene and the like.

[0535] It should be noted that the molecular weight of these hole transport materials 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, except for the polymer compound having the above-mentioned specific repeating unit. 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.

[0536] The hole injection layer of the organic electroluminescent element of the present invention may contain any one of the above-mentioned hole transport materials alone, or may contain two or more. In the case where the hole injection layer contains two or more hole transport materials, the combination is arbitrary, preferably using one or two or more aromatic tertiary amine polymer compounds and one or two or more other hole transport materials. As the type of hole transport material used in combination with the aforementioned polymer compound, an aromatic amine compound is preferred.

[0537] The content of the hole transport material in the hole injection layer of the organic electroluminescent element of the present invention is within the range satisfying the ratio with the electron accepting compound described above. When two or more charge transport film compositions are used in combination, the total content of these is within the above range.

[0538] [Charge transport ionic compounds] The hole injection layer of the organic electroluminescent device of the present invention preferably contains a charge-transporting ionic compound in which the above-mentioned tetraarylborate ions are ionically bonded to cation radicals of a hole transport material.

[0539] The hole injection layer of the organic electroluminescent device of the present invention particularly preferably contains a charge transporting ionic compound in which the tetraarylborate ion is ionically bonded to a cation radical of the aromatic tertiary amine polymer compound as a hole transporting material.

[0540] The charge-transporting ionic compound can be obtained by any of the following methods. i) The first ionic compound and the hole transport material are dissolved or dispersed in an organic solvent and mixed. ii) The first ionic compound and the hole transport material are dissolved or dispersed in an organic solvent, mixed, and further heated. iii) The composition obtained in the above i) or ii) is subjected to wet film formation, and the film is heated.

[0541] The first ionic compound is an electron accepting compound, so in any of the above methods, the hole transport material is oxidized by the first ionic compound 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.

[0542] The hole injection layer of the organic electroluminescent element of the present invention preferably comprises a first ionic compound containing the above-mentioned tetraarylborate ion as a counter anion and a hole transport material. From the viewpoint of charge transportability, it is further preferred to comprise a charge transporting ionic compound containing the above-mentioned tetraarylborate ion as a counter anion and a cation radical of the hole transport material as a counter cation.

[0543] [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.

[0544] 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.

[0545] 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.

[0546] Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the above method i), the charge-transporting ionic compound can be obtained by the above method ii) or the above method iii). Even if the charge-transporting ionic compound is not contained in the composition for forming a hole injection layer obtained by the above method ii), the charge-transporting ionic compound can be obtained by the above method iii).

[0547] Regarding the ratio of the above-mentioned first ionic compound and the above-mentioned hole transport material for obtaining a hole injection layer forming composition, relative to 100 parts by mass of the hole transport material, the amount of the first ionic compound is usually 0.1 parts by mass or more, preferably 1 part by mass or more, and usually 100 parts by mass or less, preferably 40 parts by mass or less. If the content of the first ionic compound is above the above lower limit, free carriers (cation radicals of hole transport materials) can be fully generated, and hole transport properties are improved and preferably, if it is below the above upper limit, it is possible to fully ensure charge transport capacity and preferably. 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.

[0548] (Organic Solvent) The concentration of the organic solvent in the hole injection layer forming composition is usually 10 mass % or more, preferably 30 mass % or more, more preferably 50 mass % or more, further preferably 70 mass % or more, and usually 99.999 mass % or less, preferably 99.99 mass % or less, further preferably 99.9 mass % or less. It should be noted that when two or more organic solvents are mixed, the total amount of these organic solvents is made to meet this range.

[0549] As preferred organic solvents, for example, ether solvents and ester solvents can be mentioned. Specifically, as ether solvents, for example, fatty ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA) can be mentioned; aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole can be mentioned. As ester solvents, for example, fatty esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate can be mentioned; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate can be mentioned. Any one of these can be used alone, or two or more can be used in any combination and ratio.

[0550] As the solvent that can be used except the above-mentioned ether solvent and ester solvent, for example, can enumerate: aromatic hydrocarbon solvents such as benzene, toluene, xylene, N, N-dimethylformamide, N, N-dimethylacetamide and other amide solvents, dimethyl sulfoxide etc..These can be used alone any one, also can use two or more in any combination and ratio.In addition, one or two or more of these solvents can be used in combination with one or two or more of the above-mentioned ether solvent and ester solvent.In particular, the ability of aromatic hydrocarbon solvents such as benzene, toluene, xylene to dissolve electron accepting compounds, free carriers (cation radicals) is low, therefore preferably mixed with ether solvent and ester solvent for use.

[0551] Among these organic solvents, a solvent having an aromatic hydrocarbon structure is more preferred.

[0552] (Film Forming Method) The hole injection layer can be formed by wet film formation using a composition for forming a hole injection layer. As a wet film formation method, the same as the method of forming a film of a composition for forming a light-emitting layer by wet film formation, it is preferred to apply and dry and then heat. The heating temperature is preferably 120°C or more, more preferably 150°C or more, more preferably 180°C or more, and preferably 300°C or less, more preferably 260°C or less.

[0553] 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.

[0554] The cross-linking groups of the hole transport material are mutually · Crosslinking groups of hole transport materials and crosslinking groups of electron accepting compounds · The cross-linking groups of the electron accepting compound The cross-linking groups of the hole transport material and the cross-linking groups of the tetraarylborate ions in the present invention The crosslinking groups of the tetraarylborate ions in the present invention are mutually The crosslinking group of the electron accepting compound and the crosslinking group of the tetraarylborate ion in the present invention Through this step, a cross-linked product of the electron accepting compound is formed in the hole injection layer.

[0555] 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.

[0556] <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.

[0557] [Substrate] Substrate 1 is the support of organic electroluminescent element, and quartz or glass plate, metal plate or metal foil, plastic film or sheet etc. are usually used. Among these, preferably glass plate or transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, polysulfone etc. are used. Because it is not easy to cause the deterioration of organic electroluminescent element caused by external gas, substrate preferably adopts material with high gas barrier property. Therefore, particularly when using synthetic resin substrate etc. such material with low gas barrier property, preferably dense silicon oxide film etc. are set on at least one side of substrate to improve gas barrier property.

[0558] [anode] The anode 2 has a function of injecting holes into the layer on the light-emitting layer 5 side.

[0559] 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.

[0560] 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 anodes are formed using metal particles such as silver, particles such as copper iodide, carbon black, conductive metal oxide particles, conductive polymer powders, etc., they can also be dispersed in a suitable binder resin solution and coated on a substrate. In addition, in the case of conductive polymers, a thin film can be directly formed on a substrate by electrolytic polymerization, or a conductive polymer can be coated on a substrate to form an anode (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0561] 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.

[0562] The thickness of the anode 2 can be determined according to the required transparency and material, etc. In particular, when high transparency is required, the thickness is preferably 60% or more for visible light transmittance, and more preferably 80% or more for visible light transmittance. 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.

[0563] When forming other layers on the surface of the anode 2, it is preferred to perform ultraviolet / ozone, oxygen plasma, argon plasma or other treatments before film formation to remove impurities on the anode 2 and adjust its ionization potential to improve hole injection properties.

[0564] [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, but a vacuum deposition method may be used.

[0565] [Formation of Hole Injection Layer by Vacuum Deposition] In the case of forming the hole injection layer of the organic electroluminescent element of the present invention by vacuum evaporation, the above-mentioned first ionic compound is used as the material containing tetraarylborate ions, and a low-molecular hole transport material that can be evaporated can be used as the 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.

[0566] When the hole injection layer 3 is formed by vacuum deposition, one or more constituent materials of the hole injection layer 3 are usually placed in a crucible disposed 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 Pa. Then, the crucible is heated (when two or more materials are used, each crucible is usually heated), and the evaporation amount of the material in the crucible is controlled while evaporating (when two or more materials are used, each is usually independently controlled while evaporating), and a hole injection layer is formed on the anode on the substrate placed facing the crucible. It should be noted that when two or more materials are used, their mixture can also be placed in a crucible and heated to evaporate to form a hole injection layer.

[0567] The vacuum degree during vapor deposition is not limited unless the effect of the present invention is significantly impaired, but is usually 0.1×10 - 6 Torr(0.13×10 -4 Pa) or above, 9.0×10 -6 Torr(12.0×10 -4 Pa) or less. As long as the effect of the present invention is not significantly impaired, the evaporation rate is not limited, and is usually Above and 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.

[0568] [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.

[0569] The film thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and on the other hand, is usually 300 nm or less, preferably 100 nm or less.

[0570] 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.

[0571] The hole transport layer 4 generally contains a hole transport compound.

[0572] As hole transporting compounds, preferred compounds include: aromatic diamines represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl containing two or more tertiary amines and two or more condensed aromatic rings substituted with nitrogen atoms (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. C 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.

[0573] [Formation of hole transport layer by wet film formation method] When the hole transport layer is formed by a wet film forming method, it can be formed using a hole transport layer forming composition instead of a hole injection layer forming composition, as in the case of forming the hole injection layer by the wet film forming method.

[0574] When the hole transport layer is formed by a wet film forming method, the hole transport layer forming composition generally further contains a solvent. The organic solvent used in the hole transport layer forming composition can be the same organic solvent as that used in the hole injection layer forming composition described above.

[0575] The concentration of the hole transporting compound in the hole transport layer forming composition may be in the same range as the concentration of the hole transporting compound in the hole injection layer forming composition.

[0576] [Formation of hole transport layer by vacuum deposition method] When the hole transport layer is formed by vacuum deposition, it can be formed by using a hole transport layer forming composition instead of a hole injection layer forming composition, as in the case of forming the hole injection layer by vacuum deposition. The film forming conditions such as the vacuum degree, deposition rate and temperature during deposition can be the same as those during vacuum deposition of the hole injection layer.

[0577] [Luminous layer] The light-emitting layer 5 is a layer that has the following function: when an electric field is applied between a pair of electrodes, holes injected from the anode 2 are excited by recombination with electrons injected from the cathode 7, thereby emitting light. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7. When a hole injection layer is present on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. When a hole transport layer is present on the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0578] As described above, the light-emitting layer of the organic electroluminescent device in the present invention preferably contains the polycyclic heterocyclic compound represented by formula (1) and the organic metal compound represented by formula (201), and more preferably contains a host material.

[0579] 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 from the perspective of not being easy to produce defects in the film, the film thickness is preferably thicker, and on the other hand, from the perspective of easily forming a low driving voltage, the film thickness is preferably thinner. Therefore, it is preferably 3 nm or more, more preferably 5 nm or more, and on the other hand, it is usually preferably 200 nm or less, and more preferably 100 nm or less.

[0580] 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).

[0581] [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.

[0582] 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).

[0583] 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). Furthermore, 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.

[0584] 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.

[0585] 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.

[0586] [Electron transport layer] The electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 for the purpose of further improving the current efficiency (cd / A) of the element.

[0587] 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.

[0588] Specific examples of electron transport compounds 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, and the like.

[0589] 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.

[0590] 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.

[0591] [Electron injection layer] In order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5 , an electron injection layer may be provided.

[0592] In order to efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. As an example, alkali metals such as sodium or cesium, alkaline earth metals such as barium or calcium, etc. are used. The film thickness is usually preferably not less than 0.1 nm and not more than 5 nm.

[0593] Furthermore, in organic electron transport materials represented by nitrogen-containing heterocyclic compounds such as bathophenanthroline or metal complexes such as aluminum complexes of 8-hydroxyquinoline, doping with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (recorded in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) can also improve electron injection / transport properties and have excellent film quality, so it is preferred.

[0594] The film thickness of the electron injection layer is usually in the range of 5 nm or more, preferably 10 nm or more, and usually in the range of 200 nm or less, preferably 100 nm or less.

[0595] The electron injection layer is formed by a wet film forming method or a vacuum deposition method by stacking on the light emitting layer 5 or the hole blocking layer or the electron transporting layer 6 thereon. The details of the wet film formation method are the same as those of the above-mentioned light-emitting layer.

[0596] 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.

[0597] [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 .

[0598] 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.

[0599] 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.

[0600] The cathode film thickness is usually the same as the anode film thickness.

[0601] [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.

[0602] [Other components] The organic electroluminescent element of the present invention may also have a structure opposite to that described above, that is, for example, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode are stacked in this order on a substrate.

[0603] When the organic electroluminescent element of the present invention is applied to an organic electroluminescent device, it can be used as a single organic electroluminescent element, or it can be made into a structure in which a plurality of organic electroluminescent elements are arranged in an array, or it can be made into a structure in which the anode and cathode are arranged in an XY matrix.

[0604] <Method for producing organic electroluminescent element> The method for producing the organic electroluminescent element of the present invention is not particularly limited. Preferably, as described above, the organic electroluminescent element having an anode, a light-emitting layer and a cathode in sequence on a substrate can be produced by using the composition of the present invention and forming a light-emitting layer by a wet film-forming method.

[0605] <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.

[0606] For example, the organic EL display device of the present invention can be formed by the method described in “Organic EL Display” (Ohmsha Co., Ltd., published on August 20, 2004, written by Shizuo Tokito, Chibashi Adachi, and Hideyuki Murata).

[0607] <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.

[0608] <Implementation Example> [Production Example of Organic Electroluminescent Device] The organic electroluminescent element can be produced by the following method. The glass substrate on which the ITO pattern was formed was cleaned. The hole injection layer is formed into a film by a wet process on a substrate using the composition for forming a hole injection layer, and then heated and dried to form a hole injection layer. The hole transport layer is formed into a film by a wet process on the hole injection layer, and then heated and dried to form a hole transport layer. The composition for forming a light-emitting layer is formed into a film on the hole transport layer by a wet method, and then heated and dried to form a light-emitting layer.

[0609] [Example 1 of implementation method] Although not particularly limited, the organic electroluminescent element can be produced by, for example, the following method: A product in which 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) was patterned into 2 mm wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate on which the ITO pattern was formed was cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, dried with compressed air, and finally cleaned with ultraviolet ozone. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0 wt % of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6 wt % of an electron accepting compound (HI-1) in ethyl benzoate.

[0610] [Chemistry 116]

[0611] [Chemistry 117]

[0612] The solution is spin-coated on the substrate in the air, and dried at 240° C. for 30 minutes using a hot plate in the air to form a uniform thin film with a film thickness of, for example, 40 nm as a hole injection layer.

[0613] 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 is 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, for example, 40 nm as a hole transport layer.

[0614] [Chemistry 118]

[0615] Next, as materials for the light-emitting layer, a main material (H-1) having the following structure at a concentration of 2.6 wt %, a main material (H-2) at a concentration of 2.6 wt %, an organic metal compound (A-a1) (molecular weight 1592.16) at a concentration of 1.56 wt % and a polycyclic heterocyclic compound (D-1), (D-2) or (D-3) as a light-emitting compound at a concentration of 0.26 wt % were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

[0616] [Chemistry 119]

[0617] [Chemistry 120]

[0618] [Chemistry 121]

[0619] In a nitrogen glove box, the solution is spin-coated on a substrate coated with the above-mentioned hole transport layer, and dried at 120°C for 20 minutes using a heating plate in the nitrogen glove box to form, for example, a uniform thin film with a thickness of 70 nm as a light-emitting layer. It should be noted that the molecular weight of the organic metal compound represented by formula (A-a1) is 1592.16, and the maximum emission wavelength is 555 nm. The maximum emission wavelengths of the light-emitting compounds represented by formula (D-1), formula (D-2), and formula (D-3) are 613 nm, 628 nm, and 619 nm, respectively, and satisfy formula (E-3). The substrate on which the light-emitting layer was formed was placed in a vacuum deposition device, and the inside of the device was evacuated to 2×10 -4 Below Pa.

[0620] Next, the following structural formula (ET-1) 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.

[0621] [Chemistry 122]

[0622] Next, as a mask for cathode evaporation, 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 aluminum is heated by a molybdenum boat to form, for example, an aluminum layer with a film thickness of 80 nm, thereby forming a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm×2 mm can be obtained.

[0623] [Example 2 of implementation method]

[0624] As the charge transporting polymer compound for the hole transporting layer, a polymer compound represented by the following structural formula (HT-a1) can also be used.

[0625] [Chemistry 123]

[0626] [Example 3 of implementation method] As the material for the light-emitting layer, the following main material (H-a1) at a concentration of 1.17 weight %, the following main material (H-a2) at a concentration of 1.17 weight %, the compound (H-2) at a concentration of 0.78 weight %, the organic metal compound (A-a1) at a concentration of 0.93 weight %, and the polycyclic heterocyclic compound (D-1) at a concentration of 0.16 weight % can be dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer, thereby using the composition for forming a light-emitting layer.

[0627] [Chemistry 124]

[0628] It should be noted that, regarding Example 1 of the embodiment and Example 3 of the embodiment, when T1A, T1B, and S1B are obtained by the method described herein, the relationship between Formula (E-1) and Formula (E-2) is satisfied. [Example]

[0629] [Example 1] An organic electroluminescent element was produced by the following method. A product in which an indium tin oxide (ITO) transparent conductive film was deposited to a thickness of 50 nm on a glass substrate (manufactured by Gioma Technology, a sputtered film product) was patterned into 2 mm wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate on which the ITO pattern was formed was cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, dried with compressed air, and finally cleaned with ultraviolet ozone. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0 wt % of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6 wt % of an electron accepting compound (HI-1) in ethyl benzoate.

[0630] [Chemistry 125]

[0631] [Chemistry 126]

[0632] This 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 as a hole injection layer.

[0633] 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 as a hole transport layer.

[0634] [Chemistry 127]

[0635] 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) (molecular weight 2168.94) at a concentration of 0.96 wt%, and a light-emitting compound (D-1) at a concentration of 0.064 wt% were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

[0636] [Chemistry 128]

[0637] [Chemistry 129]

[0638] [Chemistry 130]

[0639] [Chemistry 131]

[0640] 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 as a light-emitting layer. The substrate on which the light-emitting layer was formed was placed in a vacuum deposition device, and the inside of the device was evacuated to 2×10 -4 Below Pa.

[0641] Next, a 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.

[0642] [Chemistry 132]

[0643] Next, as a mask for cathode evaporation, 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 aluminum was heated by a molybdenum boat to form an aluminum layer with a thickness of 80 nm, thereby forming a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm×2 mm was obtained.

[0644] [Example 2] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (A-2) (molecular weight 1922.51) represented by the following structural formula was used instead of the organic metal compound (A-1) as a material for the light-emitting layer.

[0645] [Chemistry 133]

[0646] [Example 3] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (A-3) (molecular weight 1694.21) represented by the following structural formula was used instead of the organic metal compound (A-1) as a material for the light-emitting layer.

[0647] [Chemistry 134]

[0648] [Example 4] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (A-4) (molecular weight 1347.74) represented by the following structural formula was used instead of the organic metal compound (A-1) as a material for the light-emitting layer.

[0649] [Chemistry 135]

[0650] [Comparative Example 1] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (CA-1) (molecular weight 1177.65) represented by the following structural formula was used instead of the organic metal compound (A-1) as a material for the light-emitting layer.

[0651] [Chemistry 136]

[0652] [Comparative Example 2] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (CA-2) (molecular weight 823.11) represented by the following structural formula was used instead of the organic metal compound (A-1) as a material for the light-emitting layer.

[0653] [Chemistry 137]

[0654] [Example 5] An organic electroluminescent device was prepared in the same manner as in Example 1 except that an organic metal compound (A-11) (molecular weight: 1592.16) having the following structure was used at 0.96 wt % as the organic metal compound of the light emitting layer.

[0655] [Chemistry 138]

[0656] [Example 6] An organic electroluminescent element was prepared in the same manner as in Example 5 except that 3.2 wt % of a host material (CH-1) represented by the following structural formula was used as the material for the light-emitting layer instead of the host material (H-1) and the host material (H-2).

[0657] [Chemistry 139]

[0658] [Triplet energy levels of organometallic compounds and luminescent compounds] The triplet energy levels of the organometallic compounds and the light-emitting compounds in Examples 1 to 4, Comparative Examples 1 and 2, and Examples 5 and 6 satisfy the formula (E-1).

[0659] The triplet energy level of the organometallic compounds in Examples 1 to 4, Comparative Examples 1 and 2, and Examples 5 and 6 is calculated from the peak wavelength of the phosphorescence spectrum of the solution at room temperature. In addition, the singlet energy level of the luminescent compound is similarly calculated from the peak wavelength of the fluorescence spectrum at room temperature. The energy difference (ΔEST) between the singlet energy level and the triplet energy of the luminescent compound is calculated from the peak wavelengths of the fluorescence spectrum and the phosphorescence spectrum at 77K. Using these data, the triplet energy level of the luminescent compound at room temperature is calculated. These results are summarized in Table 1. It can be seen that the triplet energy levels of the organometallic compounds and the luminescent compounds in Examples 1 to 4, Comparative Examples 1 and 2, and Examples 5 and 6 satisfy formula (E-1).

[0660] [Table 1] Table 1

[0661] [Evaluation of components] The organic electroluminescent elements obtained in Examples 1 to 4, Comparative Examples 1 and 2, and Examples 5 and 6 were irradiated at 60 mA / cm 2 The time (LT90) for the brightness to decrease to 90% of the initial brightness when the element is continuously energized with a current density of 1.50 is shown in Table 2. The values ​​of Examples 1 to 6 and Comparative Examples 1 and 2 are shown as the relative lifespan of each Example and Comparative Example when the LT90 of Comparative Example 2 is set to 1.00. From the results in Table 2, it is understood that a long-life organic electroluminescent element can be obtained by using the organic electroluminescent element of the present invention.

[0662] [Example 7] An organic electroluminescent element was produced by the following method. A product in which an indium tin oxide (ITO) transparent conductive film was deposited to a thickness of 50 nm on a glass substrate (manufactured by Gioma Technology, a sputtered film product) was patterned into 2 mm wide stripes using conventional photolithography and hydrochloric acid etching to form an anode. The substrate on which the ITO pattern was formed was cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, dried with compressed air, and finally cleaned with ultraviolet ozone. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0 wt % of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6 wt % of an electron accepting compound (HI-1) in ethyl benzoate.

[0663] [Chemistry 140]

[0664] [Chemistry 141]

[0665] This 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 as 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 as a hole transport layer.

[0666] [Chemistry 142]

[0667] 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-12) (molecular weight 1271.64) at a concentration of 0.96 wt%, and a light-emitting compound (D-1) at a concentration of 0.064 wt% were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

[0668] [Chemistry 143]

[0669] [Chemistry 144]

[0670] [Chemistry 145]

[0671] [Chemistry 146]

[0672] 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 as a light-emitting layer. The substrate on which the light-emitting layer was formed was placed in a vacuum deposition device, and the inside of the device was evacuated to 2×10 -4 Below Pa. Next, a 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.

[0673] [Chemistry 147]

[0674] Next, as a mask for cathode evaporation, 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 aluminum was heated by a molybdenum boat to form an aluminum layer with a thickness of 80 nm, thereby forming a cathode. As described above, an organic electroluminescent element having a light-emitting area of ​​2 mm×2 mm was obtained.

[0675] [Example 8] As the main material of the light-emitting layer, only the main material (H-1) is used instead of using the main material (H-1) and the main material (H-2), and the main material (H-1) is dissolved in cyclohexylbenzene at a concentration of 2.8 weight%, the organic metal compound (A-12) is dissolved in a concentration of 0.84 weight%, and the light-emitting compound (D-1) is dissolved in a concentration of 0.056 weight% to prepare a composition for forming a light-emitting layer. Except for this, an organic electroluminescent element is prepared in the same manner as in Example 7.

[0676] [Example 9] As the main material of the light-emitting layer, only the main material (H-3) having the following structure is used instead of the main material (H-1) and the main material (H-2), and the main material (H-3) is dissolved in cyclohexylbenzene at a concentration of 3.2 weight%, the organic metal compound (A-12) is dissolved in a concentration of 0.96 weight%, and the light-emitting compound (D-1) is dissolved in a concentration of 0.064 weight% to prepare a composition for forming a light-emitting layer. Except for this, an organic electroluminescent element is prepared in the same manner as in Example 7.

[0677] [Chemistry 148]

[0678] [Example 10] As the main material of the light-emitting layer, only the main material (H-4) of the above structure is used instead of the material (H-1) and the main material (H-2), and the main material (H-4) is dissolved in cyclohexylbenzene at a concentration of 3.2 weight%, the organic metal compound (A-12) is dissolved in a concentration of 0.96 weight%, and the light-emitting compound (D-1) is dissolved in a concentration of 0.064 weight% to prepare a composition for forming a light-emitting layer. Except for this, an organic electroluminescent element is prepared in the same manner as in Example 7.

[0679] [Chemistry 149]

[0680] [Triplet energy levels of organometallic compounds and luminescent compounds] The triplet energy level of the compound (A-12) used in Examples 7 to 10 was calculated according to the above method and found to be 2.5 eV. In addition, as shown in Table 1, the triplet energy level of the light-emitting compound (D-1) was 1.84 eV. Therefore, the triplet energy levels of the organometallic compounds and the light-emitting compounds in Examples 7 to 10 satisfy the formula (E-1).

[0681] [Evaluation of components] The organic electroluminescent devices obtained in Examples 7 to 10 were measured at 60 mA / cm 2 The time (LT97) for the luminance to decrease to 97% of the initial luminance when the device is continuously energized with a current density of 1.5 %. The results of these measurements are shown in Table 2. The values ​​of Examples 7 to 10 are "relative life" when Example 10 is set to 1.00. The results in Table 2 show that the organic electroluminescent device of the present invention in combination with a host material having a specific structure can achieve a particularly long life.

[0682] [Table 2] Table 2

[0683] Above, various embodiments have been described, 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.

[0684] It should be noted that this application is based on the Japanese patent application filed on August 31, 2022 (Special Application No. 2022-138447), the Japanese patent application filed on August 31, 2022 (Special Application No. 2022-138449), the Japanese patent application filed on October 7, 2022 (Special Application No. 2022-162631), and the Japanese patent application filed on October 7, 2022 (Special Application No. 2022-162633), the contents of which are incorporated into this application as a reference. Industrial Applicability

[0685] The organic electroluminescent element of the present invention and the composition of the present invention can be suitably used in, for example, an organic EL display device and an organic EL lighting.< / g> < / w>

Claims

1. A light-emitting layer material, which is a light-emitting layer material for an organic electroluminescent element containing a light-emitting compound and an organic metal compound, wherein: The molecular weight of the organometallic compound is 1,200 or more, The luminescent compound is a compound represented by the following formula (1): The following relationship (E-1) is satisfied: T1A≥T1B formula (E-1) In formula (E-1), T1A: represents the triplet energy level of the organometallic compound, in eV, T1B: represents the triplet energy level of the luminescent compound, in eV, [Chemistry 1] In formula (1), the ring Cy 1 , Cy 2 , Cy 3 Cy 4 each independently represents a five-membered or six-membered aromatic hydrocarbon ring or a five-membered or six-membered 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 each represent a group of molecules that 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, adjacent R may be bonded to each other to form a ring or not, or R may be bonded to an adjacent ring Cy 1 , Cy 2 , Cy 3 Cy 4 The bonding may form a ring or not.

2. The material for a light-emitting layer according to claim 1, wherein The organometallic compound is represented by the following formula (201): [Chemistry 2] Ring A201 represents an aromatic hydrocarbon ring structure which may have a substituent, or an aromatic heterocyclic structure which may have a substituent, Ring A202 represents an aromatic heterocyclic structure which may have a substituent, R 201 , R 202 Each is independently a structure represented by the above formula (202), R 201 , R 202 When there are 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 B represents anionic bidentate ligand; 201 and B 202 Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which may or may not be atoms constituting a ring. When it is an atom constituting a ring, B 201 and / or B 202 Represents a ring structure, L 200 Represents a single bond or with B 201 and B 202 The atomic groups that together form the bidentate ligand, B 201 -L 200 -B 202 When there are multiple, they are the same or different, i1 and i2 each independently represent an integer greater than or equal to 0 and less than or equal to 12, i3 is capable of 202 The number of substitutions in is an integer greater than or equal to 0, j is to be able to 201 The number of substitutions in is an integer greater than or equal to 0, k1 and k2 are each independently an integer greater than or equal to 0, with the upper limit being the number of substitutions that can be made in ring A201 and ring A202, m is an integer of 1-3.

3. The material for a light-emitting layer according to claim 1, wherein The T1A is greater than or equal to 2.10 eV and less than or equal to 2.80 eV.

4. The material for a light-emitting layer according to claim 1, wherein The luminescent compound represented by the formula (1) is represented by the formula (2-1) or the formula (2-2): [Chemistry 3] In formula (2-1) and formula (2-2), Q 31 and Q 32 Indicates O or S, R is the same as in 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, adjacent Rs may be bonded to each other to form a ring or may not form a ring.

5. The material for a light-emitting layer according to claim 1, wherein The luminescent compound represented by the formula (1) is represented by the formula (2-3): [Chemistry 4] 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 Rs, they are independent of each other and may be the same or different. When R is a substituent, adjacent R may be bonded to each other to form a ring or not. 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.

6. The material for a light-emitting layer according to claim 1, wherein When the molecular weight of the organometallic compound is MwA and the molecular weight of the light-emitting compound is MwB, MwA / MwB is 2.0 or more. 7 . The material for a light-emitting layer according to claim 1 , further comprising a host material.

8. The material for a light-emitting layer according to claim 7, wherein The host material comprises at least one selected from the group consisting of a compound represented by the following formula (250), a compound represented by the following formula (240), and a compound represented by the following formula (260), [Chemistry 5] 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, multiple Xa 1 Same or different, When h11 is 2 or more, multiple Ya 1 Same or different, When g11 is 2 or more, multiple Za 1 Same or different, R 31 Represents a hydrogen atom or a substituent, 4 R 31 Same or different, When g11, h11 or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 Not a hydrogen atom; [Chemistry 6] 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 is an integer from 0 to 4; [Chemistry 7] In formula (260), Ar 61 ~Ar 65 are each independently a hydrogen atom, or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, L 1 ~L 5 are each independently a divalent aromatic hydrocarbon group having 6 to 60 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 n is 1 or more when at least one Ar 65 Among them, at least one group is not a hydrogen atom.

9. The material for a light-emitting layer according to claim 8, wherein The host material contains at least the compound represented by the formula (250).

10. The material for a light-emitting layer according to claim 8, wherein In the formula (250), -(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) are not unsubstituted phenyl at the same time.

11. The material for a light-emitting layer according to claim 8, wherein In the formula (250), when the aromatic hydrocarbon group having 6 to 30 carbon atoms has a substituent, the substituent and when the aromatic heterocyclic group having 3 to 30 carbon atoms has a substituent, the substituent is selected from the following substituent group Z2, and the substituent selected from the following substituent group Z2 has no further substituent: <Substituent Group Z2> 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 halogenated alkyl 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.

12. The material for a light-emitting layer according to claim 8, wherein At least two of W in the formula (250) are N.

13. The material for a light-emitting layer according to claim 8, wherein When g11 in the formula (250) 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 , Ar in the formula (240) 611 and Ar 612 , and when m1 in the formula (260) is 1 or more (L 1 ) m1 , when m2 is 1 or more (L 2 ) m2 When m3 is 1 or more (L 3 ) m3 When m4 is 1 or more (L 4 ) m4 When n is 1 or more and m5 is 1 or more (L 5 ) m5 Each independently has a partial structure selected from the partial structures represented by the following formula (11) to the following formula (17), [Chemistry 8] [Chemistry 9] In each of formulae (11) to (17), * indicates the bonding position with the adjacent structure, or for formula (250), Xa 2 , Ya 2 or Za 2 When the hydrogen atom is a hydrogen atom, for formula (260), Ar 61 ,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.

14. The material for a light-emitting layer according to claim 8, wherein In the formula (250), -(Xa 1 ) g11 -(Xa 2 )、-(Ya 1 ) h11 -(Ya 2 ) and -(Za 1 ) j11 -(Za 2 ) has any one of the partial structures or terminal structures represented by the following formulae (250-1) to (250-10), [Chemistry 10] In formula (250-1) to formula (250-10), * represents the bonding position; Ar 250 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms; R 32 represents a substituent, and the structures represented by formula (250-1) to formula (250-10) may or may not have a substituent.

15. The material for a light-emitting layer according to claim 8, wherein The host material contains at least the compound represented by the formula (240).

16. The material for a light-emitting layer according to claim 8, wherein The Ar in the compound represented by the formula (240) 611 and the Ar 612 Each independently has a partial structure selected from the following formulae (11) to (17) and (21) to (24), [Chemistry 11] [Chemistry 12] * 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.

17. The material for a light-emitting layer according to claim 8, wherein The host material contains at least the compound represented by the formula (260).

18. The material for a light-emitting layer according to claim 8, wherein Ar in the formula (260) 61 ,Ar 62 and at least one Ar 65 Among them, one or more and three or less groups are of the following formula (261) or the following formula (262), [Chemistry 13] In formula (261) or formula (262), The asterisk * indicates the bonding position with formula (260), R 101 ~R 126 Each independently represents a hydrogen atom or a substituent.

19. The material for a light-emitting layer according to claim 8, wherein When the compound represented by the formula (250) is set as Group A, the compound represented by the formula (240) is set as Group B, and the compound represented by the formula (260) is set as Group C, the main material contains at least two compounds selected from at least one of at least two of the three groups represented by Group A, Group B, and Group C.

20. An organic electroluminescent element, comprising an anode, a cathode and a light-emitting layer, wherein: The light-emitting layer is disposed between the anode and the cathode, The light-emitting layer comprises the material for a light-emitting layer according to any one of claims 1 to 19. 21 . An organic EL display device or organic EL lighting, comprising the organic electroluminescent element according to claim 20 .

22. A composition comprising the material for a light-emitting layer according to any one of claims 1 to 19 and an organic solvent.

23. A method for manufacturing an organic electroluminescent element, which is a method for manufacturing an organic electroluminescent element having an anode, a light-emitting layer and a cathode in sequence on a substrate, The manufacturing method comprises: A step of forming the light-emitting layer using the composition according to claim 22 by a wet film-forming method.

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