Iridium coordination compounds, compositions containing iridium coordination compounds, organic electroluminescent element, method for manufacturing organic electroluminescent element, organic el display device, and organic el illuminating device

Abstract

The present application relates to an iridium coordination compound represented by the following formula (1). [In formula (1), Ir represents an iridium atom. R 5 ~R 14 , R 21 , and R 22 each independently represent a hydrogen atom, D, F, Cl, Br, I, or a substituent. Adjacent groups to each other can be further bonded to each other to form a ring. Among them, any one of R 12 and R 13 is a substituent represented by the following formula (2).]

Description

TECHNICAL FIELD

[0001] The present application relates to an iridium complex compound, particularly to an iridium complex compound useful as a material for a light-emitting layer of an organic electroluminescence (hereinafter, sometimes referred to as "organic EL") element, an iridium complex compound-containing composition containing the compound and a solvent, an organic electroluminescence element containing the compound, a method for manufacturing the same, and an organic EL display device and an organic EL illuminating device having the organic electroluminescence element. BACKGROUND

[0002] Various electronic devices utilizing organic EL elements, such as organic EL illuminations, organic EL displays (display devices), are being put into practical use. Organic electroluminescence elements consume less power because of low applied voltage, and also enable tricolor light emission, so that they are not only applied to large monitor displays, but also to small and medium-sized displays typified by mobile phones and smartphones.

[0003] An organic electroluminescence element is manufactured by layering a light-emitting layer, a charge injection layer, a charge transport layer, and the like. At present, organic electroluminescence elements are mostly manufactured by vacuum evaporation of organic materials, but in the vacuum evaporation method, the evaporation process is complicated, and the productivity is poor. In addition, it is extremely difficult to achieve large-scale of panels for illuminations and displays using organic electroluminescence elements manufactured by the vacuum evaporation method. Therefore, in recent years, as a process for efficiently manufacturing organic electroluminescence elements that can be used in large displays and illuminations, a wet film formation method as a coating method is being actively studied. The wet film formation method has the advantage that a stable layer can be easily formed compared to the vacuum evaporation method, and thus is expected to be used for mass production and large displays of display devices and illuminating devices.

[0004] In order to manufacture an organic electroluminescence element using a wet film formation method, the materials used must all be materials that are dissolved in an organic solvent and can be used as an ink. In the case where the solvent solubility of the materials is poor, a long time of heating or the like is required, and thus there is a possibility that the materials deteriorate before use. In addition, if the uniform state cannot be maintained for a long time in a solution state, the materials are precipitated from the solution, and film formation using an inkjet device or the like cannot be performed. That is, for the materials used in the wet film formation method, solubility in the sense of rapid dissolution in an organic solvent and maintenance of a uniform state after dissolution is required.

[0005] However, in organic EL displays, in addition to long driving life, wide color gamut, i.e., high color reproduction, high luminous efficiency is also required to be achieved. In particular, the red region requires a fairly deep red color in which the x coordinate in the XYZ colorimetric system of the CIE (Commission Internationale de l'Eclairage) is 0.68 to 0.71. In order to color a deep red color, it is necessary to set the emission maximum wavelength of the light-emitting material to a longer wavelength, for example, a wavelength of 615 nm or more. In addition, human visual acuity also greatly decreases in the red region as the wavelength becomes longer, and thus a greater luminous intensity is required in the deep red region.

[0006] In addition, as the stacked structure of the organic EL display, there are two modes in which the extraction direction of light is different. The bottom emission mode, which is relatively simple in the manufacturing process, is a mode in which light from the organic molecules is extracted from below the TFT (Thin Film Transistor) substrate side, but there is a difficulty in that the light utilization efficiency of the organic molecules is low. In contrast, the top emission mode extracts light from above the sealing glass without a pixel circuit or the like, and thus it is possible to efficiently take out the emitted light to the outside. However, when the top emission mode is used, light other than a specific wavelength is reflected and canceled within the stacked structure, and thus has a property of not being emitted to the outside of the stacked structure. Therefore, when the half-width of the emission spectrum of the light-emitting material is large, light other than the specific wavelength cannot be emitted to the outside of the stacked structure, and as a result, the efficiency of the light emission decreases. Therefore, making the half-width of the emission spectrum slightly narrower makes the display wider in color gamut and higher in brightness, and thus is preferred, and thus becomes a very important target of technical development.

[0007] As described above, in the red light-emitting material, properties such as 1. high solubility in a solvent, 2. high luminous efficiency, and 3. narrow half-width of the emission spectrum are required. For the above 1., techniques such as increasing a fused ring or the like in the ligand, not making it a too rigid structure, and introducing a longer chain alkyl group or the like are known. For the above 2., the so-called "energy gap rule" is dominant in the red region, and thus the proportion of thermal dissipation increases as the wavelength becomes longer, and thus there is an upper limit to the quantum yield of a specific wavelength. In contrast, in recent years, it has been clarified that techniques such as using a phosphorescent light-emitting material which originally has high efficiency, excluding substituents which damage the quantum yield of these materials, increasing the symmetry of the structure, and increasing the MLCT (Metal to Ligand Charge Transfer) to make the phosphorescent emission speed larger.

[0008] As a red light emitting material, an iridium coordination compound utilizing phosphorescent light emission has been used. In particular, an iridium coordination compound having a ligand in which a triazine type substituent is introduced in a phenyl-pyridine has been known as shown in Patent Documents 1 to 3. An iridium coordination compound having a specific structure is disclosed in Patent Document 1. Also, an iridium coordination compound having a specific structure is disclosed in Patent Documents 2 and 3.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: International Publication No. 2015 / 105014

[0012] Patent Document 2: U.S. Patent Application Publication No. 2016 / 359122 Specification

[0013] Patent Document 3: International Publication No. 2016 / 015815 SUMMARY

[0014] On the other hand, the understanding of the problem of narrowing the half-peak width of the emission spectrum of the above-mentioned 3 is not yet sufficient.

[0015] For example, an iridium coordination compound having a structure in which 2 aromatic rings are bonded to a triazine is disclosed in Patent Document 1, but the half-peak width still has room for improvement.

[0016] In addition, the ligand disclosed in Patent Document 2 is asymmetric, and the problem of broadening the half-peak width also exists in a so-called heteroleptic type iridium complex.

[0017] Although an iridium coordination compound emitting red light having a relatively narrow half-peak width is disclosed in Patent Document 3, it is considered that further improvement is required.

[0018] An object of the present application is to provide an iridium coordination compound in which the half-peak width is as narrow as possible, while not impairing the high solubility in a solvent and the high light emission efficiency.

[0019] An iridium coordination compound solving the above-mentioned problems is, for example, as follows.

[0020] [1] An iridium coordination compound represented by the following formula (1).

[0021]

[0022] [In formula (1), Ir represents an iridium atom. R 5 ~R 14 , R 21 and R 22each independently represents a hydrogen atom, D, F, Cl, Br, I, or a substituent. Mutually adjacent groups can be further bonded to each other to form a ring. Among them, R 12 and any one of R 13 is a substituent represented by the following formula (2).

[0023]

[0024] [In formula (2), the dotted line indicates a bonding site with formula (1). R 31 represents a hydrogen atom, D, an alkyl group, an aralkyl group, or a heteroaralkyl group, R 32 represents a hydrogen atom, D, an alkyl group, an aralkyl group, a heteroaralkyl group, an aromatic group, or a heteroaromatic group. R 31 and R 32 may be further substituted.]

[0025] [2] The iridium coordination compound according to the above [1], wherein R 5 to R 14 , R 21 , and R 22 are as follows.

[0026] [R 5 to R 14 , R 21 , and R 22 each independently is selected from a hydrogen atom, 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 or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, a linear or branched alkoxy group having 1 to 30 carbon atoms, a cyclic alkoxy group having 2 to 30 carbon atoms, a linear or branched alkylthio group having 1 to 30 carbon atoms, a cyclic alkylthio group having 2 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, a cyclic alkenyl group having 3 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, a cyclic alkynyl group having 3 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, a heteroaromatic group having 1 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 2 to 60 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an arylheteroarylamino group having 10 to 40 carbon atoms, or a bisheteroarylamino group having 10 to 40 carbon atoms.

[0027] At least one of the hydrogen atoms of the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group can be further substituted with R' (wherein hydrogen atoms are excluded), and one -CH2- group or two or more non-adjacent -CH2- groups in these groups can be replaced with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2-, -C(=O)-, -NR'-, -O-, -S-, -CONR'- or a bivalent aromatic group. In addition, one or more hydrogen atoms in these groups can be replaced with D, F, Cl, Br, I or -CN.

[0028] The aromatic group, the heteroaromatic group, the aryloxy group, the arylthio group, the aralkyl group, the heteroaralkyl group, the diarylamino group, the arylheteroarylamino group, and the bisheteroarylamino group can each independently have at least one of the hydrogen atoms further substituted with R' (wherein hydrogen atoms are excluded).

[0029] R' is each independently selected from the group consisting of 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 or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, a linear or branched alkoxy group having 1 to 30 carbon atoms, a cyclic alkoxy group having 2 to 30 carbon atoms, a linear or branched alkylthio group having 1 to 30 carbon atoms, a cyclic alkylthio group having 2 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, a cyclic alkenyl group having 3 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, a cyclic alkynyl group having 3 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, a heteroaromatic group having 1 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 2 to 60 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an arylheteroarylamino group having 10 to 40 carbon atoms, or a bisheteroarylamino group having 10 to 40 carbon atoms.

[0030] At least one of the hydrogen atoms of the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group can be further substituted with R" (wherein hydrogen atoms are excluded), and one -CH2- group or two or more non-adjacent -CH2- groups in these groups can be replaced with -C(-R")=C(-R")-, -C≡C-, -Si(-R")2-, -C(=O)-, -NR"-, -O-, -S-, -CONR"- or a bivalent aromatic group. In addition, one or more hydrogen atoms in these groups can be replaced with D, F, Cl, Br, I or -CN.

[0031] The aromatic 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 can each independently be further substituted with R" (excluding hydrogen atoms) at least one or more times. Two or more adjacent R" can be bonded to each other to form an aliphatic or aromatic or heteroaromatic monocyclic or fused ring.

[0032] R" is each independently selected from a hydrogen atom, D, F, -CN, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic group having 5 to 20 carbon atoms, or a heteroaromatic group having 1 to 20 carbon atoms.

[0033] Two or more adjacent R" can be bonded to each other to form an aliphatic or aromatic or heteroaromatic monocyclic or fused ring.

[0034] [3] The iridium complex compound according to the above [1] or [2], wherein R 31 as follows.

[0035] [R 31 is selected from a hydrogen atom, D, a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, or a heteroaralkyl group having 2 to 60 carbon atoms.

[0036] At least one or more hydrogen atoms of the alkyl group, the aralkyl group, the heteroaralkyl group can be further substituted with R' (excluding hydrogen atoms), one -CH2- group or two or more non-adjacent -CH2- groups in these groups can be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2, -C(=O)-, -NR'-, -O-, -S-, -CONR'- or a divalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I or -CN.

[0037] R' has the same meaning as R' in the above [2].

[0038] [4] The iridium complex compound according to any one of the above [1] to [3], wherein R 32 as follows.

[0039] [R 32 is selected from a hydrogen atom, D, a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, a heteroaralkyl group having 2 to 60 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or a heteroaromatic group having 1 to 60 carbon atoms.

[0040] At least one of the hydrogen atoms of the alkyl group, the aralkyl group, the heteroaralkyl group can be further substituted with R' (wherein hydrogen atom is excluded), one -CH2- group or two or more non-adjacent -CH2- groups in these groups can be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2, -C(=O)-, -NR'-, -O-, -S-, -CONR'- or a bivalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I or -CN.

[0041] At least one of the hydrogen atoms of the aromatic group and the heteroaromatic group can be further substituted with R' (wherein hydrogen atom is excluded).

[0042] R' has the same meaning as R' in the above [2].

[0043] [5] The iridium complex compound according to any one of the above [1] to [4], wherein R 21 and R 22 in the above formula (1) are each a linear or branched alkyl group having 1 to 30 carbon atoms.

[0044] [6] The iridium complex compound according to any one of the above [1] to [5], wherein R 13 in the above formula (1) is a substituent represented by the above formula (2).

[0045] [7] The iridium complex compound according to any one of the above [1] to [6], wherein at least any one of R 6 to R 9 in the above formula (1) has a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or an aralkyl group having 5 to 60 carbon atoms as a substituent.

[0046] [8] The iridium complex compound according to any one of the above [1] to [6], wherein mutually adjacent groups of R 6 to R 9 in the above formula (1) are bonded to each other to form a ring.

[0047] In addition, as the above iridium complex compound, for example, the following modes can be mentioned.

[0048] [9] A composition containing an iridium complex compound, comprising the iridium complex compound according to any one of the above [1] to [8] and an organic solvent.

[0049]

[10] The composition containing an iridium coordination compound according to the above [9], wherein further comprising a compound represented by the following formula (3) having a shorter maximum emission wavelength than the above iridium coordination compound.

[0050]

[0051] [In the above formula (3), R 35 is an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms. These groups can further have a substituent. R 35 When a plurality of R

[0052] c is an integer of 0 to 4.

[0053] Ring A is any one of a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, an azatriphenylene ring, a carboline ring, a benzothiazole ring, a benz azole ring.

[0054] Ring A can have a substituent, and the above substituent is F, Cl, Br, an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 2 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. In addition, adjacent substituents bonded to ring A can be bonded to each other to further form a ring. When a plurality of ring A exists, they can be the same or different.

[0055] L 2 represents an organic ligand, and n is an integer of 1 to 3.

[0056]

[11] The composition containing an iridium coordination compound according to the above [9] or

[10] , wherein further comprising a compound represented by the following formula (20).

[0057]

[0058] [In the above formula (20),

[0059] each W independently represents CH or N, at least one W is N,

[0060] Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0061] Xa 2 , Ya 2 , and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0062] each of g11, h11, and j11 independently represents an integer of 0 to 6,

[0063] at least one of g11, h11, and j11 is an integer of 1 or more,

[0064] when g11 is 2 or more, a plurality of Xa 1 may be the same or different,

[0065] when h11 is 2 or more, a plurality of Ya 1 may be the same or different,

[0066] when j11 is 2 or more, a plurality of Za 1 may be the same or different,

[0067] R 23 represents a hydrogen atom or a substituent, and 4 R 23 may be the same or different,

[0068] wherein, when g11, h11, or j11 is 0, the respective Xa 2 , Ya 2 , or Za 2 is not a hydrogen atom.

[0069]

[12] A production method of an organic electroluminescent element having an anode, a cathode, and at least one organic layer between the anode and the cathode on a substrate,

[0070] at least one of the organic layers is formed using the composition containing the iridium complex compound according to any one of [9] to

[11] by a wet film formation method.

[0071]

[13] An organic electroluminescent element having an anode, a cathode, and at least one organic layer between the anode and the cathode on a substrate, at least one of the organic layers being a light-emitting layer containing an iridium complex compound described in any one of the above [1] to [8].

[0072]

[14] The organic electroluminescent element according to the above

[13] , further comprising a compound represented by the following formula (3) having a shorter maximum emission wavelength than the iridium complex compound.

[0073]

[0074] [In the above formula (3), R 35 is an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms. These groups can further have a substituent. R 35 When a plurality of R

[0075] c is an integer of 0 to 4.

[0076] Ring A is any one of a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a benzophenanthrene ring, a carboline ring, a benzothiazole ring, a benz azole ring.

[0077] Ring A can have a substituent, and the substituent is F, Cl, Br, an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 2 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. In addition, adjacent substituents bonded to ring A can be bonded to each other to further form a ring. When a plurality of ring A's exist, they can be the same or different.

[0078] L 2 represents an organic ligand, and n is an integer of 1 to 3.

[0079]

[15] The organic electroluminescent element according to

[13] or

[14] above, wherein the light-emitting layer further comprises a compound represented by the following formula (20).

[0080]

[0081] [In the above formula (20),

[0082] each of W independently represents CH or N, at least one of W is N,

[0083] Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0084] Xa 2 , Ya 2 , and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0085] each of g11, h11, and j11 independently represents an integer of 0 to 6,

[0086] at least one of g11, h11, and j11 is an integer of 1 or more,

[0087] when g11 is 2 or more, a plurality of Xa 1 may be the same or different,

[0088] when h11 is 2 or more, a plurality of Ya 1 may be the same or different,

[0089] when j11 is 2 or more, a plurality of Za 1 may be the same or different,

[0090] R 23 represents a hydrogen atom or a substituent, and 4 R 23 may be the same or different,

[0091] wherein, when g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , or Za 2 is not a hydrogen atom.

[0092]

[16] An organic EL display device comprising the organic electroluminescent element according to any one of

[13] to

[15] above.

[0093]

[17] An organic EL illuminating device comprising the organic electroluminescent element described in any one of

[13] to

[15] above.

[0094] According to the above configuration, it is possible to provide an iridium complex compound having a narrowed half-value width, high solubility in a solvent, and a light-emitting efficiency equivalent to or higher than that of conventional ones. BRIEF DESCRIPTION OF DRAWINGS

[0095] Figure 1 is a cross-sectional view schematically showing one example of the structure of the organic electroluminescent element of the present application. DETAILED DESCRIPTION

[0096] Hereinafter, embodiments of the present application will be described in detail, but the present application is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist thereof.

[0097] Note that in the present specification, "aromatic ring" means "aromatic hydrocarbon ring", and is distinguished from "heteroaromatic ring" including a heteroatom as a ring-constituting atom. Similarly, "aromatic group" means "aromatic hydrocarbon group" or "aromatic hydrocarbon ring group", and "heteroaromatic group" means "heteroaromatic ring group".

[0098] In addition, "D" means deuterium. In the substituents, (hetero)aralkyl means an aralkyl group which can be substituted with a heteroatom, (hetero)aryloxy means an aryloxy group which can be substituted with a heteroatom, and (hetero)aryl means an aryl group which can be substituted with a heteroatom.

[0099] In the structural formula, Me means methyl group, Et means ethyl group, Bu t means tert-butyl group, Ph means phenyl group, Tf means trifluoromethylsulfonyl group, and Ac means acetyl group.

[0100] The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that an iridium complex compound having a specific chemical structure exhibits an extremely narrow half-value width as a red light-emitting material, and at the same time exhibits high solubility and photoluminescence (PL) quantum yield, as compared with conventional materials, thereby completing the present application.

[0101] [Iridium Complex Compound]

[0102] The iridium complex compound of the present embodiment is a compound represented by formula (1).

[0103]

[0104] [In formula (1), Ir represents an iridium atom. R 5 ~ R 14 , R 21 , and R22 each independently represents a hydrogen atom, D, F, Cl, Br, I, or a substituent. Mutually adjacent groups can be further bonded to each other to form a ring. Among them, R 12 and any one of R 13 is a substituent represented by the following formula (2).

[0105]

[0106] [In formula (2), the dotted line represents a bonding site with formula (1). R 31 represents a hydrogen atom, D, an alkyl group, an aralkyl group, or a heteroaralkyl group, R 32 represents a hydrogen atom, D, an alkyl group, an aralkyl group, a heteroaralkyl group, an aromatic group, or a heteroaromatic group. R 31 and R 32 may be further substituted.]

[0107] The iridium coordination compound of the present embodiment exhibits an extremely narrow half-peak width as a red light-emitting material compared with existing materials, while exhibiting high solubility and a solution PL quantum yield. The reason is presumed as follows.

[0108] Patent Document 1 discloses an iridium complex having a structure in which a triazine ring is bonded to a fluorene-pyridine ligand, and further 2 aromatic rings are bonded to the triazine ring. It is considered that by bonding 2 aromatic rings to the triazine, there is a tendency for the half-peak width to widen due to the rotational motion between these rings and the LUMO also spreading to the aromatic ring portion. On the other hand, the iridium coordination compound of formula (1) is limited to R 32 , when bonding an aromatic ring to the triazine, and thus it is considered that the half-peak width can be narrowed.

[0109] Although the LUMO is on the triazine ring, if an aromatic ring is bonded in a π-electron system conjugated manner, the LUMO also spreads to the aromatic ring, and thus the rotational motion of the bond of the triazine ring and the aromatic ring has a non-negligible influence on the shape of the spectrum and widens the half-peak width. This effect is very clear when 2 aromatic rings are substituted to the triazine ring. On the other hand, by substituting 1 or more alkyl groups or (hetero)aralkyl groups which do not spread the π-electron conjugated system to the triazine ring, the following effect is also produced, that is, effectively shielding the interaction with the external environment at the closest position to the triazine ring, that is, the interaction with the solvent molecules if in a solution state, or the interaction with the host molecules if in the light-emitting layer of an organic EL element, and thus the half-peak width can be further narrowed.

[0110] The ligand structure of the complex of the present embodiment is a structure in which a triazine ring as shown in Formula (2) is substituted at a specific site of the pyridine ring in the main skeleton of fluorene-pyridine. It is considered that the LUMO is localized on the triazine ring, and the decrease in MLCT due to the involvement of the iridium atom is compensated for in such a way that the fluorene-pyridine is linear, and the overlap of the HOMO and the LUMO on the ligand is large, so the quantum yield does not decrease, and the main peak with a relatively narrow half-peak width is observed without broadening of the spectrum, although vibration structure is observed.

[0111] If the involvement of the iridium atom decreases, the contribution of LC (Ligand Centered) emission increases, and thus the main peak with a relatively narrow half-peak width is observed without broadening of the spectrum, although vibration structure is observed. (Refer to: Sasaki, Y., Ishiguro, M., ed., Selected Papers of the Complex Chemistry Society 2, Photochemistry of Metal Complexes, pp. 83-98, Sanro Co., Ltd. 2007)

[0112] The synthesis of the iridium complex of the so-called heteroleptic type in which the ligand is asymmetric as disclosed in Patent Document 2 is not easy. In addition, since the ligand is asymmetric, there are more vibration modes compared with the hemoleptic type which has high symmetry, and further, the distribution of the HOMO and the LUMO also expands between different ligands, or the main ligand involved in the emission is disturbed by the side ligand, and thus the half-peak width is broadened as a result.

[0113] On the other hand, the iridium complex compound represented by Formula (1) of the present embodiment is a hemoleptic complex (L3Ir) in which all of the three ligands in the trivalent iridium are the same, and thus the half-peak width can be narrowed. In addition, the different ligands do not affect each other as in the heteroleptic complex (L 1 2L 2 Ir, L 1 L 2 2Ir or L 1 L 2 L 3 Ir) do not affect each other, and thus there is a tendency that the quantum yield is improved in this respect.

[0114] <R 5 ~R 14 , R 21 and R 22 >

[0115] R 5 ~R 14 in Formula (1) represents a hydrogen atom, D, F, Cl, Br, I, or a substituent. R 5 ~R 14 , R 21 and R 22 each independently can be the same or different.

[0116] R 5 ~R 14 ,R 21 and R 22 When R is a substituent, the kind thereof is not particularly limited, and the optimal substituent can be selected in consideration of precise control of the target emission wavelength, compatibility with the solvent used, compatibility with the host compound when an organic electroluminescent element is produced, and the like. In studying these optimizations, the preferred substituent is within the range described below.

[0117] R 5 ~R 14 ,R 21 and R 22 each independently is selected from the group consisting of a hydrogen atom, 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 or branched alkyl group with 1 to 30 carbon atoms, a cyclic alkyl group with 3 to 30 carbon atoms, a linear or branched alkoxy group with 1 to 30 carbon atoms, a cyclic alkoxy group with 2 to 30 carbon atoms, a linear or branched alkylthio group with 1 to 30 carbon atoms, a cyclic alkylthio group with 2 to 30 carbon atoms, a linear or branched alkenyl group with 2 to 30 carbon atoms, a cyclic alkenyl group with 3 to 30 carbon atoms, a linear or branched alkynyl group with 2 to 30 carbon atoms, a cyclic alkynyl group with 3 to 30 carbon atoms, an aromatic group with 5 to 60 carbon atoms, a heteroaromatic group with 1 to 60 carbon atoms, an aryloxy group with 5 to 40 carbon atoms, an arylthio group with 5 to 40 carbon atoms, an aralkyl group with 5 to 60 carbon atoms, a heteroaralkyl group with 2 to 60 carbon atoms, a diarylamino group with 10 to 40 carbon atoms, an arylheteroarylamino group with 10 to 40 carbon atoms, or a bisheteroarylamino group with 10 to 40 carbon atoms.

[0118] At least 1 or more hydrogen atoms of the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group can be further substituted with R' (wherein a hydrogen atom is excluded). One -CH2- group or 2 or more non-adjacent -CH2- groups in these groups, namely the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group, and R' (wherein a hydrogen atom is excluded) can be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2, -C(=O)-, -NR'-, -O-, -S-, -CONR'-, or a divalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I, or -CN.

[0119] The aromatic group, the heteroaromatic group, the aryloxy group, the arylthio group, the aralkyl group, the heteroaralkyl group, the diaryl amino group, the arylheteroaryl amino group, and the diheteroaryl amino group can each independently be further substituted with R' (wherein hydrogen atoms are excluded) at least 1 or more.

[0120] R' is described later.

[0121] Examples of the linear or branched alkyl group having 1 to 30 carbon atoms or the cyclic alkyl group having 3 to 30 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, isopropyl, isobutyl, t-butyl, cyclopentyl, cyclohexyl, n-octyl, norbornyl, adamantyl, and the like. In the case of an alkyl group, if the number of carbon atoms is too large, the complex is highly shielded, and durability is impaired, and thus the number of carbon atoms is preferably 1 or more, and is more preferably 30 or less, and is further more preferably 20 or less, and is still further more preferably 12 or less. Among them, in the case of a branched alkyl group, the shielding effect is larger than that of a linear alkyl group or a cyclic alkyl group, and thus the number of carbon atoms is most preferably 7 or less. In the case of a cyclic alkyl group, the number of carbon atoms is 3 or more.

[0122] Examples of the linear or branched alkoxy group having 1 to 30 carbon atoms or the cyclic alkoxy group having 2 to 30 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-hexyloxy, isopropoxy, cyclohexyloxy, 2-ethoxyethoxy, 2-ethoxyethoxyethoxy, and the like. From the viewpoint of durability, the number of carbon atoms is preferably 1 or more, and is more preferably 30 or less, and is further more preferably 20 or less, and is still further more preferably 12 or less. In the case of a cyclic alkoxy group, the number of carbon atoms is 2 or more.

[0123] Examples of the linear or branched alkylthio group having 1 to 30 carbon atoms or the cyclic alkylthio group having 2 to 30 carbon atoms include methylthio, ethylthio, n-propylthio, n-butylthio, n-hexylthio, isopropylthio, cyclohexylthio, 2-methylbutylthio, n-hexylthio, and the like. From the viewpoint of durability, the number of carbon atoms is preferably 1 or more, and is more preferably 30 or less, and is further more preferably 20 or less, and is still further more preferably 12 or less. In the case of a cyclic alkylthio group, the number of carbon atoms is 2 or more.

[0124] Examples of the linear or branched alkenyl group having 2 to 30 carbon atoms or the cyclic alkenyl group having 3 to 30 carbon atoms include vinyl, allyl, propenyl, butenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, and the like. From the viewpoint of durability, the number of carbon atoms is preferably 2 or more, and is more preferably 30 or less, and is further more preferably 20 or less, and is still further more preferably 12 or less. In the case of a cyclic alkenyl group, the number of carbon atoms is 3 or more.

[0125] Examples of linear or branched alkynyl groups having 2 to 30 carbon atoms or cyclic alkynyl groups having 3 to 30 carbon atoms include ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, and octynyl. From the perspective of durability, the number of carbon atoms is preferably 2 or more, and preferably 30 or less, more preferably 20 or less, and most preferably 12 or less. In the case of a cyclic alkynyl group, the number of carbon atoms is 3 or more.

[0126] The aromatic group having 5 to 60 carbon atoms and the heteroaromatic group having 1 to 60 carbon atoms may exist as a single ring or a condensed ring, or may be a group in which another type of aromatic group or heteroaromatic group is bonded or condensed to one ring.

[0127] Examples of these include phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, triphenylenyl, pyrenyl, yl, fluoranthenyl, peryl, benzopyrenyl, benzofluoranthenyl, tetracene, pentacene, biphenyl, terphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthrenyl, dihydropyrenyl, tetrahydropyrenyl, indenofluorenyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, pyrrolyl, indolyl, isoindolyl, carbazolyl, benzocarbazolyl, indolocarbazolyl, indenocarbazolyl, pyridinyl, cinnolinyl, isocinnolinyl, acridinyl, phenanthridinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridinimidazolyl, Azolyl, benzo Azolyl, naphtho oxazolyl, thiazolyl, benzothiazolyl, pyrimidinyl, benzopyrimidinyl, pyridazinyl, quinolyl Phenoyl, diazaanthryl, diazapyrenyl, pyrazinyl, phenanthrenyl Azinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazolyl (ベンゾカボリニルyl), phenanthrolinyl, triazolyl, benzotriazolyl, oxadiazolyl, thiadiazolyl, triazinyl, 2,6-diphenyl-1,3,5-triazin-4-yl, tetrazolyl, purinyl, benzothiadiazolyl, and the like.

[0128] From the viewpoint of the balance between solubility and durability, the number of carbon atoms in these groups is preferably 3 or more, more preferably 5 or more, and is preferably 50 or less, more preferably 40 or less, and most preferably 30 or less.

[0129] Examples of aryloxy groups having 5 to 40 carbon atoms include phenoxy, methylphenoxy, naphthoxy, and methoxyphenoxy groups. From the perspective of a balance between solubility and durability, the number of carbon atoms in these aryloxy groups is preferably 5 or more, and preferably 30 or less, more preferably 25 or less, and most preferably 20 or less.

[0130] Examples of the aralkyl group having 5 to 60 carbon atoms include 1,1-dimethyl-1- phenylmethyl, 1,1-di-n-butyl-1-phenylmethyl, 1,1-di-n-hexyl-1-phenylmethyl, 1,1-di-n- octyl-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n- butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n- hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, 4-phenylcyclohexyl, and the like. From the viewpoint of the balance between solubility and durability, the number of carbon atoms of these aralkyl groups is preferably 5 or more, and more preferably 40 or less.

[0131] Examples of the aralkyl group having 5 to 60 carbon atoms include 1,1-dimethyl-1- phenylmethyl, 1,1-di-n-butyl-1-phenylmethyl, 1,1-di-n-hexyl-1-phenylmethyl, 1,1-di-n- octyl-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl, 4-phenyl-1-n- butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl-1-n- hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, 4-phenylcyclohexyl, and the like. From the viewpoint of the balance between solubility and durability, the number of carbon atoms of these aralkyl groups is preferably 5 or more, and more preferably 40 or less.

[0132] Examples of the heteroaralkyl group having 2 to 60 carbon atoms include 1,1-dimethyl-1- (2-pyridyl)methyl, 1,1-di-n-hexyl-1-(2-pyridyl)methyl, (2-pyridyl)methyl, (2-pyridyl)ethyl, 3-(2-pyridyl)-1-propyl, 4-(2-pyridyl)-1-n-butyl, 1-methyl-1-(2-pyridyl)ethyl, 5-(2-pyridyl)-1-n-propyl, 6-(2-pyridyl)-1-n-hexyl, 6-(2-pyrimidyl)-1-n-hexyl, 6-(2,6-diphenyl-1,3,5-triazin-4-yl)-1-n-hexyl, 7-(2-pyridyl)-1-n-heptyl, 8-(2-pyridyl)-1-n-octyl, 4-(2-pyridyl)cyclohexyl, and the like. From the viewpoint of the balance between solubility and durability, the number of carbon atoms of these heteroaralkyl groups is preferably 5 or more, and more preferably 50 or less, and more preferably 40 or less, and most preferably 30 or less.

[0133] Examples of the diaryl amino group having 10 to 40 carbon atoms include diphenylamino, phenyl(naphthyl)amino, di(biphenyl)amino, di(p-triphenyl)amino, and the like. From the viewpoint of the balance between solubility and durability, the number of carbon atoms of these diaryl amino groups is preferably 10 or more, and more preferably 36 or less, and more preferably 30 or less, and most preferably 25 or less.

[0134] Examples of arylheteroarylamino groups having 10 to 40 carbon atoms include phenyl(2-pyridyl)amino and phenyl(2,6-diphenyl-1,3,5-triazin-4-yl)amino groups. From the perspective of a balance between solubility and durability, these arylheteroarylamino groups preferably have 10 or more carbon atoms, and preferably 36 or less, more preferably 30 or less, and most preferably 25 or less carbon atoms.

[0135] Examples of diheteroarylamino groups having 10 to 40 carbon atoms include di(2-pyridyl)amino and di(2,6-diphenyl-1,3,5-triazin-4-yl)amino groups. From the perspective of a balance between solubility and durability, these diheteroarylamino groups preferably have 10 or more carbon atoms, and preferably 36 or less, more preferably 30 or less, and most preferably 25 or less.

[0136] As R 5 ~R 14 , especially from the viewpoint of not damaging the durability of the organic electroluminescent element as a light-emitting material, each independently preferably is a hydrogen atom, F, -CN, a straight-chain or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aryloxy group having 5 to 40 carbon atoms, an arylthio group having 5 to 40 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or a heteroaromatic group having 1 to 60 carbon atoms, particularly preferably a hydrogen atom, F, -CN, an alkyl group, an aralkyl group, an aromatic group, or a heteroaromatic group, and most preferably a hydrogen atom, F, -CN, an alkyl group, an aromatic group, or a heteroaromatic group.

[0137] R 21 and R 22 Also due to R 5 ~R 14 For the same reason, each independently preferably is a hydrogen atom, F, -CN, a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aryloxy group having 5 to 40 carbon atoms, an arylthio group having 5 to 40 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or a heteroaromatic group having 1 to 60 carbon atoms, and particularly preferably is F, -CN, an alkyl group, an aralkyl group, an aromatic group, or a heteroaromatic group. A linear or branched alkyl group having 1 to 30 carbon atoms is particularly preferred, and R is most preferred. 21 and R 22 At least one of the alkyl groups is a linear or branched alkyl group having 1 to 30 carbon atoms. This is achieved by imparting appropriate solubility when used as a light-emitting layer in an organic EL device and by appropriately shielding the fluorene portion of the HOMO distribution, thereby suppressing extinction caused by interactions with adjacent host molecules within the layer.

[0138] From the viewpoint of improving the lifetime, at least one of R 6 9 is the aforementioned substituent, or mutually adjacent groups of R 6 9 bond to each other to form a ring.

[0139] By R 6 9 being the aforementioned substituent, or mutually adjacent groups of R 6 9 further bond to each other to form a ring, the probability of the fluorene trapping a hole can be increased.

[0140] In the case where the aromatic ring is bonded to the triazine in the iridium coordination compound of formula (1), since R 32 is limited, the half-peak width can be narrowed, on the other hand, the range of conjugation is narrowed, and there is a case where the electron resistance of the triazine decreases and the lifetime decreases. It is considered that by increasing the probability of the fluorene trapping a hole, the proportion of the triazine being consumed by recombination with a hole increases, and thus the decrease in the lifetime can be suppressed or improved.

[0141] From the viewpoint of improving the luminous efficiency, any one of R 6 9 is preferably a substituent selected from a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, and an aralkyl group having 5 to 60 carbon atoms. As specific examples thereof, the same groups as those described in the aforementioned R 5 14 can be given. These substituents can further have R' described above as a substituent.

[0142] A group particularly preferable as the linear or branched alkyl group having 1 to 30 carbon atoms is a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an iso-propyl group, an iso-butyl group, a t-butyl group.

[0143] A group particularly preferable as the aromatic group having 5 to 60 carbon atoms is a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, and a further preferable group is a phenyl group, a biphenyl group, a naphthyl group.

[0144] A group particularly preferable as the aralkyl group having 5 to 60 carbon atoms is a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di-n-butyl-1-phenylmethyl group, a 1,1-di-n-hexyl-1-phenylmethyl group, a 3-phenyl-1-propyl group, a 4-phenyl-1-n-butyl group, a 5-phenyl-1-n-propyl group, a 6-phenyl-1-n-hexyl group.​​​​​​

[0145] Among the aromatic groups having 5 to 60 carbon atoms, those further having as a substituent R' an aralkyl group having 5 to 60 carbon atoms are preferred, and specifically, for example, 1,1-dimethyl-l-phenylmethylphenyl, 1,1-di-n-butyl-l-phenylmethylphenyl, 1,1-di-n-hexyl-l-phenylmethylphenyl, 3-phenyl-l-propylphenyl, 4-phenyl-l-n-butylphenyl, 5-phenyl-l-n-propylphenyl, and 6-phenyl-l-n-hexylphenyl.

[0146] From the viewpoint of improving the lifetime and improving the luminous efficiency, R 6 in R 9 is particularly preferably a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. 8 Most preferably, R 6 , R 7 , and R 9 are hydrogen, and only R 8 is a substituent.

[0147] As the mutually adjacent groups of R 6 to R 9 bond to each other to form a ring structure, R 6 and R 7 form a 7H-benzo[c]fluorene or 2,3,4,7-tetrahydro-lH-benzo[c]fluorene ring, R 7 and R 8 form an 11H-benzo[b]fluorene or 7,8,9,11-tetrahydro-6H-benzo[b]fluorene ring, and R 8 and R 9 form an 11H-benzo[a]fluorene or 2,3,4,11-tetrahydro-lH-benzo[a]fluorene ring. Among these, 7H-benzo[c]fluorene is particularly preferred.

[0148] <R' >

[0149] R' in the present specification is selected from the group consisting of 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 or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, a linear or branched alkoxy group having 1 to 30 carbon atoms, a cyclic alkoxy group having 2 to 30 carbon atoms, a linear or branched alkylthio group having 1 to 30 carbon atoms, a cyclic alkylthio group having 2 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, a cyclic alkenyl group having 3 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, a cyclic alkynyl group having 3 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, a heteroaromatic group having 1 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 2 to 60 carbon atoms, a diarylamino group having 10 to 40 carbon atoms, an arylheteroarylamino group having 10 to 40 carbon atoms, or a bisheteroarylamino group having 10 to 40 carbon atoms. When a plurality of R' exist, they can be the same or different.

[0150] At least one or more hydrogen atoms of the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group can be further substituted with R" (excluding a hydrogen atom). One -CH2- group or two or more non-adjacent -CH2- groups in these groups, i.e., the alkyl group, the alkoxy group, the alkylthio group, the alkenyl group, and the alkynyl group, can be substituted with -C(-R")=C(-R")-, -C≡C-, -Si(-R")2-, -C(=O)-, -NR"-, -O-, -S-, -CONR"-, or a bivalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I, or -CN.

[0151] In addition, the aromatic group, the heteroaromatic group, the aryloxy group, the arylthio group, the aralkyl group, the heteroaralkyl group, the diarylamino group, the arylheteroarylamino group, and the bisheteroarylamino group can each independently have one or more hydrogen atoms further substituted with R" (excluding a hydrogen atom). R" is described later.

[0152] In addition, two or more adjacent R' can be bonded to each other to form an aliphatic or aromatic or heteroaromatic monocyclic or fused ring.

[0153] Examples of the above-mentioned groups are the same as R 5 ~R 14 The same applies to the description of one item.

[0154] <R">

[0155] R" is selected from a hydrogen atom, D, F, -CN, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an aromatic group having 5 to 20 carbon atoms, or a heteroaromatic group having 1 to 20 carbon atoms.

[0156] Two or more adjacent R" can be bonded to each other to form an aliphatic or aromatic or heteroaromatic monocyclic or fused ring. When there are a plurality of R", they can be the same or different.

[0157] <Formula (2)>

[0158] R of Formula (1) 12 and R 13 of Formula (1) is a substituent represented by Formula (2). The position provided with Formula (2) can be any one of R 12 or R 13 , from the viewpoints of durability and ability to make the half-peak width narrower, it is preferable that R 13 .

[0159] R 31 and R 32 > of Formula (1) is a substituent represented by Formula (2). The position provided with Formula (2) can be any one of R 31

[0160] R 5 is a hydrogen atom, D, or a substituent, and as the substituent, is selected from a linear or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, or a heteroaralkyl group having 2 to 60 carbon atoms.

[0161] At least one or more hydrogen atoms of the alkyl group, the aralkyl group, and the heteroaralkyl group can be further substituted with R' (excluding a hydrogen atom). One -CH2- group or two or more non-adjacent -CH2- groups in these groups, i.e., the alkyl group, the aralkyl group, and the heteroaralkyl group, and R' (excluding a hydrogen atom) can be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2, -C(=O)-, -NR'-, -O-, -S-, -CONR'-, or a divalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I, or -CN.

[0162] Preferred structures of these substituents are the same as those of R 14 to R 32 , described above. R' is also the same as described above. From the viewpoints of solubility and durability, it is further preferable that R' be an alkyl group, and particularly preferably a linear or branched alkyl group having 7 or fewer carbon atoms, such as a tert-butyl group.

[0163] R 32R is a hydrogen atom, D, or a substituent, and as the substituent, a straight chain or branched alkyl group having 1 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aralkyl group having 5 to 60 carbon atoms, a heteroaralkyl group having 2 to 60 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or a heteroaromatic group having 1 to 60 carbon atoms.

[0164] At least one or more hydrogen atoms of the alkyl group, the aralkyl group, and the heteroaralkyl group can be further substituted with R' (excluding a hydrogen atom). One -CH2- group or two or more non-adjacent -CH2- groups in these groups, i.e., the alkyl group, the aralkyl group, and the heteroaralkyl group, and R' (excluding a hydrogen atom) can be substituted with -C(-R')=C(-R')-, -C≡C-, -Si(-R')2, -C(=O)-, -NR'-, -O-, -S-, -CONR'-, or a bivalent aromatic group. In addition, one or more hydrogen atoms in these groups can be substituted with D, F, Cl, Br, I, or -CN.

[0165] At least one or more hydrogen atoms of the aromatic group and the heteroaromatic group can be further substituted with R' (excluding a hydrogen atom).

[0166] Preferred structures of these substituents are the same as the above R 5 ~R 14 Similarly, R' is also the same as the above. From the viewpoints of solubility and durability, an aromatic group or an alkyl group which can have a substituent is further preferred. A straight chain or branched alkyl group having 7 or fewer carbon atoms, an aromatic group having 6 to 30 carbon atoms, an aromatic group having 6 to 30 carbon atoms which has a straight chain or branched alkyl group having 7 or fewer carbon atoms, or an aromatic group having 6 to 30 carbon atoms which has an aralkyl group having 7 to 30 carbon atoms is particularly preferred.

[0167] As the straight chain or branched alkyl group having 7 or fewer carbon atoms, specifically, for example, a t-butyl group can be mentioned.

[0168] As the aromatic group having 6 to 30 carbon atoms, an aromatic hydrocarbon group is preferred, and specifically, for example, a phenyl group, a naphthyl group, a biphenyl group can be mentioned. It is preferred that the aromatic hydrocarbon group further has a substituent, or is a condensed ring. As the aromatic hydrocarbon having a substituent, an aromatic group having 6 to 30 carbon atoms which has a straight chain or branched alkyl group having 7 or fewer carbon atoms, or an aromatic group having 6 to 30 carbon atoms which has an aralkyl group having 7 to 30 carbon atoms is preferred, and as the condensed ring, a naphthyl group is preferred.

[0169] As the aromatic group having 6 to 30 carbon atoms which has a straight chain or branched alkyl group having 7 or fewer carbon atoms, specifically, for example, a 4-t-butylphenyl group can be mentioned.

[0170] As the aromatic group having 6 to 30 carbon atoms, specifically, for example, 1,1-dimethyl-1-phenylmethylphenyl, 1,1-di-n-butyl-1-phenylmethylphenyl, 1,1-di-n-hexyl-1-phenylmethylphenyl, 3-phenyl-1-propylphenyl, 4-phenyl-1-n-butylphenyl, 5-phenyl-1-n-propylphenyl, and 6-phenyl-1-n-hexylphenyl can be given.

[0171] From the viewpoint of half-value width, R 31 and R 32 are preferably an aromatic group, and particularly preferably an aromatic group having 6 to 30 carbon atoms, or an aromatic group having 6 to 30 carbon atoms of a linear or branched alkyl group having 7 or less carbon atoms, or an aromatic group having 6 to 30 carbon atoms of an aralkyl group having 7 to 30 carbon atoms. 32 are preferably an aromatic group, and particularly preferably an aromatic group having 6 to 30 carbon atoms, or an aromatic group having 6 to 30 carbon atoms of a linear or branched alkyl group having 7 or less carbon atoms, or an aromatic group having 6 to 30 carbon atoms of an aralkyl group having 7 to 30 carbon atoms.

[0172] <Specific Examples>

[0173] Preferred specific examples of the iridium complex compound of the present embodiment other than the compounds shown in the Examples described later are shown below, but the present application is not limited thereto.

[0174]

[0175]

[0176] Specific examples in a further preferred mode are shown below.

[0177]

[0178]

[0179] <Maximum Emission Wavelength>

[0180] The iridium complex compound of the present embodiment can further increase the emission wavelength to a longer wavelength. As an index indicating the length of the emission wavelength, the maximum emission wavelength measured according to the procedure shown below is preferably 600 nm or more, more preferably 610 nm or more, and further preferably 615 nm or more. In addition, the maximum emission wavelength is preferably 650 nm or less, more preferably 640 nm or less, and further preferably 635 nm or less. By being in these ranges, there is a tendency to exhibit a preferable color suitable as a red light-emitting material for an organic electroluminescent element.

[0181] (Measurement method of maximum emission wavelength)

[0182] At room temperature, the solution obtained by dissolving the iridium complex compound in toluene, 2-methyltetrahydrofuran, or the like at a concentration of 1 x 10 －4 mol / L or less was measured for phosphorescent spectrum using a spectrophotometer (Hamamatsu Photonics K.K., Organic EL Quantum Yield Measurement Device C9920-02). The wavelength showing the maximum value of the obtained phosphorescent spectrum intensity was regarded as the maximum emission wavelength in the present embodiment.

[0183] <Method for synthesizing iridium complex compound>

[0184] <Method for synthesizing ligand>

[0185] The ligand of the iridium complex compound of the present embodiment can be synthesized by a combination of known methods or the like. The fluorene ring can be introduced, for example, easily by using a compound having a bromine, -B(OH)2 group, acetyl group, or carboxyl group at the 2-position of the fluorene ring as a starting material. The synthesis of the fluorene-pyridine ligand can be synthesized by further subjecting these starting materials to a Suzuki-Miyaura coupling reaction with a halogenated pyridine. If the halogenated pyridine used is, for example, 5-bromo-2-iodopyridine, the obtained intermediate is a fluorene-pyridine having a bromine substituted on the pyridine, which is further directed to a boronate ester, whereby the final ligand can be synthesized by a Suzuki-Miyaura coupling reaction with a disubstituted chlorotriazine compound as follows.

[0186] There are various known methods for synthesizing a disubstituted chlorotriazine compound. In the case of introducing two identical substituents to the triazine ring, it can be synthesized, for example, by reacting 2 equivalents of Grignard reagent with cyanuric chloride as described in Japanese Patent Application Publication No. 2016-160180.

[0187] In addition, in the case of introducing an asymmetric substituent to the triazine ring, it is preferable to use a method of introducing the substituent in stages using Grignard reaction and Suzuki-Miyaura coupling reaction. This can be exemplified by the method described in Chinese Patent Application Publication No. 101544613.

[0188]

[0189] <Method for synthesizing iridium complex compound>

[0190] The iridium complex compound of the present embodiment can be synthesized by a combination of known methods or the like. The following will be described in detail.

[0191] As a method for synthesizing iridium coordination compounds, a method using a phenylpyridine ligand as an example for easy understanding, a method via a chloro-bridged iridium dinuclear complex represented by the following formula [A] (M. G. Colombo, T. C. Brunold, T. Riedener, H. U. Gudel, Inorg. Chem., 1994, 33, 545-550), a method in which a dinuclear complex is further converted into a mononuclear complex by exchanging a chloro-bridge with acetylacetone represented by the following formula [B] (S. Lamansky, P. Djurovich, D. Murphy, F. Abdel-Razzaq, R. Kwong, I. Tsyba, M. Borz, B. Mui, R. Bau, M. Thompson, Inorg. Chem., 2001, 40, 1704-1711), and the like can be exemplified, but are not limited thereto.

[0192] For example, typical reaction conditions represented by the following formula [A] are as follows.

[0193] As a first stage, a chloro-bridged iridium dinuclear complex is synthesized by a reaction of 2 equivalents of a ligand with 1 equivalent of iridium chloride n hydrate. A mixed solvent of 2-ethoxyethanol and water is generally used as a solvent, but a solventless or other solvent can also be used. An excess amount of the ligand, or an additive such as a base can also be used to promote the reaction. Other cross-linking anionic ligands such as bromine can also be used instead of chlorine.

[0194] The reaction temperature is not particularly limited, and is generally preferably 0°C or higher, and more preferably 50°C or higher. In addition, the reaction temperature is preferably 250°C or lower, and more preferably 150°C or lower. By being in these ranges, there is a tendency to obtain a high selectivity, since only the target reaction proceeds without accompanying a by-product, a decomposition reaction.

[0195]

[0196] A second stage is to obtain a target complex by adding a halide ion trapping agent such as silver triflate, and contacting with a newly added ligand. Ethoxyethanol or diglyme is generally used as a solvent, but a solventless or other solvent can also be used according to the kind of the ligand, and a plurality of solvents can also be used in combination. The reaction can sometimes proceed even without adding the halide ion trapping agent, and thus is not necessarily required, but the addition of the trapping agent is advantageous for improving the reaction yield, and selectively synthesizing a higher quantum yield fac isomer. The reaction temperature is not particularly limited, and is generally in the range of 0°C to 250°C.

[0197] In addition, typical reaction conditions represented by the following formula [B] are described.

[0198] The dinuclear complex of the first stage can be synthesized in the same manner as the formula [A] described above. The second stage is converted into a mononuclear complex coordinated with a 1,3-diketone ligand by reacting the dinuclear complex with 1 equivalent or more of a 1,3-dicarbonyl compound such as acetylacetone and 1 equivalent or more of a basic compound such as sodium carbonate which can extract the active hydrogen of the 1,3-dicarbonyl compound. Although a solvent such as ethoxyethanol, dichloromethane or the like which can dissolve the dinuclear complex of the usual raw material is used, the reaction can also be performed without a solvent when the ligand is liquid. The reaction temperature is not particularly limited and is usually in the range of 0°C to 200°C.

[0199]

[0200] The third stage is to react the ligand usually in 1 equivalent or more with the diketone complex. The kind and amount of the solvent are not particularly limited and the reaction can also be performed without a solvent when the ligand is liquid at the reaction temperature. The reaction temperature is also not particularly limited, but since the reactivity is slightly insufficient, the reaction is usually performed at a relatively high temperature of 100°C to 300°C. Therefore, it is preferable to use a high-boiling solvent such as glycerol.

[0201] After the final reaction, purification is performed in order to remove unreacted raw materials, reaction by-products and solvents. The purification can be performed by the usual purification operation in organic synthetic chemistry, and as described in the above non-patent literature, the purification is mainly performed by normal phase silica gel column chromatography. The eluent can use a single or mixed liquid of hexane, heptane, dichloromethane, chloroform, ethyl acetate, toluene, methyl ethyl ketone, methanol. The purification can be performed several times by changing the conditions. Other chromatographic techniques such as reverse phase silica gel chromatography, size exclusion chromatography, paper chromatography, and purification operations such as liquid-liquid washing, reprecipitation, recrystallization, suspension washing of powder, drying under reduced pressure, and the like can be performed as needed.

[0202] <Usage of Iridium Coordination Compound>

[0203] The iridium coordination compound of the present embodiment can be appropriately used as a material used in an organic electroluminescent element, that is, a red light-emitting material of an organic electroluminescent element, and can be appropriately used as a light-emitting material of an organic electroluminescent element or other light-emitting elements.

[0204] [Composition Containing Iridium Coordination Compound]

[0205] The iridium coordination compound of the present embodiment is excellent in solvent solubility, and is preferably used together with a solvent. Hereinafter, the composition of the present embodiment containing the iridium coordination compound of the present embodiment and a solvent (hereinafter, sometimes referred to as "composition containing iridium coordination compound") is described.

[0206] The composition containing the iridium complex of the present embodiment contains the above-described iridium complex and a solvent. The composition containing the iridium complex of the present embodiment is generally used for forming a layer, a film by a wet film formation method, and is particularly preferably used for forming an organic layer of an organic electroluminescent element. The organic layer is particularly preferably a light-emitting layer. That is, the composition containing the iridium complex is preferably a composition for an organic electroluminescent element, and is particularly preferably further used as a composition for forming a light-emitting layer.

[0207] The content of the iridium complex of the present embodiment in the composition containing the iridium complex is generally 0.001 mass% or more, preferably 0.01 mass% or more, and is generally 99.9 mass% or less, preferably 99 mass% or less. By setting the content of the iridium complex in the composition containing the iridium complex within this range, injection of holes and electrons from an adjacent layer such as a hole-transporting layer or a hole-blocking layer to a light-emitting layer can be efficiently performed, and the driving voltage can be reduced. Note that the iridium complex of the present embodiment can be contained alone or in combination with two or more kinds in the composition containing the iridium complex.

[0208] In the case where the composition containing the iridium complex of the present embodiment is used for an organic electroluminescent element, for example, a charge-transporting compound used in an organic electroluminescent element, particularly a light-emitting layer, can be contained in addition to the above-described iridium complex and a solvent.

[0209] In the case where the composition containing the iridium complex of the present embodiment is used for forming a light-emitting layer of an organic electroluminescent element, the iridium complex of the present embodiment is preferably contained as a light-emitting material, and another charge-transporting compound is preferably contained as a charge-transporting host material.

[0210] (Solvent)

[0211] The solvent contained in the composition containing the iridium complex of the present embodiment is a volatile liquid component used for forming a layer containing the iridium complex by a wet film formation, and is preferably an organic solvent.

[0212] Since the iridium complex compound of the present embodiment as a solute has high solvent solubility, the solvent is not particularly limited as long as it is an organic solvent in which the charge transportable compound described later is well dissolved. As a preferable solvent, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, bicyclohexane, and the like; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetrahydronaphthalene, and the like; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, and the like; aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, diphenyl ether, and the like; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, and the like; alicyclic ketones such as cyclohexanone, cyclooctanone, fenchone, and the like; alicyclic alcohols such as cyclohexanol, cyclooctanol, and the like; aliphatic ketones such as methyl ethyl ketone, dibutyl ketone, and the like; aliphatic alcohols such as butanol, hexanol, and the like; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), and the like can be exemplified.

[0213] Among them, alkanes and aromatic hydrocarbons, particularly phenylcyclohexane are preferable because they have a desirable viscosity and boiling point in the wet film formation process.

[0214] These solvents can be used singly or in combination of two or more in any ratio.

[0215] The boiling point of the solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and, on the other hand, is usually 270°C or lower, preferably 250°C or lower, more preferably 230°C or lower. By being the lower limit of this range, it is possible to suppress a decrease in film formation stability due to evaporation of the solvent from the composition containing the iridium complex compound at the time of wet film formation.

[0216] The content of the solvent in the composition containing the iridium complex compound is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and, on the other hand, is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, particularly preferably 99% by mass or less. Since the thickness of the light-emitting layer is usually about 3 to 200 nm, by being the lower limit of the content of the solvent, it is possible to suppress a decrease in film formation workability while the viscosity of the composition is not excessively high. On the other hand, by being the upper limit, there is a tendency that the film is easily formed in view of the thickness of the film obtained by removing the solvent after film formation.

[0217] As the other charge transportable compound which can be contained in the composition containing the iridium complex compound of the present embodiment, a substance which has been used as a material for an organic electroluminescent element in the past can be used. For example, pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, naphthacene, chrysene, coronene, fluoranthene, phenanthrene, fluorene, acenaphthofluoranthene, coumarin, p-bis(2-phenylvinyl)benzene and derivatives thereof, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, condensed aromatic ring compounds substituted with arylamino groups, styryl derivatives substituted with arylamino groups, and the like.

[0218] These can be used singly or in combination of two or more kinds at an arbitrary ratio.

[0219] In addition, the content of the other charge transportable compound in the composition containing the iridium complex compound is, in general, 1000 parts by mass or less, preferably 100 parts by mass or less, and further preferably 50 parts by mass or less, relative to 1 part by mass of the iridium complex compound 1 of the present embodiment in the composition containing the iridium complex compound, and in general, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and further preferably 1 part by mass or more.

[0220] The composition containing the iridium complex compound of the present embodiment can further contain other compounds, as needed, in addition to the above-described compounds and the like. For example, in addition to the above-described solvent, other solvents can be contained. As such solvents, for example, amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethyl sulfoxide and the like can be given. These can be used singly or in combination of two or more kinds at an arbitrary ratio.

[0221] [Auxiliary dopant]

[0222] The composition containing the iridium complex compound of the present embodiment can further contain a compound represented by the following formula (3).

[0223] The compound represented by formula (3) functions as an auxiliary dopant in the light-emitting layer of the organic electroluminescent element. The compound represented by formula (3) has a shorter wavelength of the maximum emission wavelength than the aforementioned iridium complex compound represented by formula (1) as a light-emitting dopant. Therefore, when the auxiliary dopant represented by formula (3) becomes in an excited state, energy migration to the light-emitting dopant represented by formula (1) having a smaller excitation energy occurs, the light-emitting dopant represented by formula (1) becomes in an excited state, and light emission from the light-emitting dopant represented by formula (1) is observed.

[0224] The compound represented by formula (3) can include only one or a plurality of compounds. In addition, the compound that becomes an auxiliary dopant can include a compound other than the compound represented by formula (3) as an auxiliary dopant, in which case, the content of the total of the compounds represented by formula (3) is preferably 50% by mass or more, more preferably 100% by mass, with respect to the total of the compounds that become auxiliary dopants. That is, it is more preferable that only the compound represented by formula (3) be the auxiliary dopant.

[0225] In addition, it is preferable that the composition ratio of the iridium complex compound represented by formula (1) be the composition ratio of the compound represented by formula (3) or more in terms of mass parts. Thereby, direct light emission from the auxiliary dopant represented by formula (3) can be suppressed, and energy is efficiently transferred from the auxiliary dopant represented by formula (3) to the light-emitting dopant represented by formula (1). Therefore, light emission from the light-emitting dopant is obtained with high efficiency.

[0226]

[0227] In the above formula (3), R 35 is an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms. These groups can further have a substituent. R 35 When a plurality of R

[0228] c is an integer of 0 to 4.

[0229] Ring A is any one of a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phenanthroline ring, a carboline ring, a benzothiazole ring, a benz azole ring.

[0230] Ring A can have a substituent.

[0231] The above substituent is a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms in the alkyl group, an arylsilyl group having 6 to 20 carbon atoms in the aryl group, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. In addition, adjacent substituents bonded to ring A can be bonded to each other to further form a ring. When a plurality of rings A exist, they can be the same or different.

[0232] L 2 represents an organic ligand, and n is an integer of 1 to 3.

[0233] R 35 The substituent that can further be present is preferably a substituent selected from the substituent group Z1 described below.

[0234] From the viewpoint of durability, R 35 is more preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms, and is further preferably an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms.

[0235] From the viewpoints of durability and solubility, R 35 is a phenyl group that can have a substituent and is bonded to the meta position of ring A and the para position of iridium. That is, a compound represented by the following formula (3-1) is preferred. The substituent that can be present is preferably a substituent selected from the substituent group Z1 described below.

[0236]

[0237] (In the above formula (3-1), ring A, L 2 , and n have the same meanings as ring A, L 2 , and n in formula (3), respectively.

[0238] R 36 is an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a (hetero)aryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or a (hetero)aryl group having 3 to 30 carbon atoms. These groups can further have a substituent. R36 The plurality of times can be the same or different.

[0239] f is an integer of 0 to 5.

[0240] R 36 The substituent group Z1 is preferably a substituent group selected from the substituent group Z1 described below.

[0241] From the viewpoint of easy production, f is preferably 0, from the viewpoint of durability and the viewpoint of improving solubility, it is preferably 1 or 2, and further preferably 1.

[0242] From the viewpoint of durability, ring A is preferably a pyridine ring, a pyrimidine ring, or an imidazole ring, and further preferably a pyridine ring.

[0243] From the viewpoint of durability and the viewpoint of improving solubility, the hydrogen atom on ring A is preferably substituted with an alkyl group having 1 to 20 carbon atoms, a (hetero)aralkyl group having 7 to 40 carbon atoms, or a (hetero)aryl group having 3 to 20 carbon atoms. In addition, from the viewpoint of easy production, the hydrogen atom on ring A is preferably not substituted. Since an exciton is easily generated when used as an organic electroluminescent element, the emission efficiency is improved, and from this viewpoint, the hydrogen atom on ring A is preferably substituted with a phenyl group or a naphthyl group which can have a substituent.

[0244] As ring A, from the viewpoint of easily generating an exciton on the auxiliary dopant and improving emission efficiency, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a nitrogen-containing benzophenanthrene ring, or a carboline ring is preferable. Among these, from the viewpoint of durability, a quinoline ring, an isoquinoline ring, or a quinazoline ring is preferable.

[0245] L 2 The organic ligand is not particularly limited, and is preferably a monovalent bidentate ligand, and a more preferable example is the same as the example shown as a preferable example of L 1 It should be noted that in the case where two organic ligands L 2 are present, the organic ligands L 2 may be different structures from each other. In addition, in the case where n is 3, L 2 is not present.

[0246] The following shows a preferable specific example of the compound represented by formula (3) as an auxiliary dopant included in the organic electroluminescent element composition of the present embodiment other than the compounds shown in the examples, but the present application is not limited thereto.

[0247]

[0248] [Substituent Group Z1]

[0249] As the substituent, an alkyl group, an aralkyl group, a heteroaralkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylsilyl group, an arylsilyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkylamino group, an arylamino group, an aryl group, or a heteroaryl group can be used.

[0250] Preferably, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 40 carbon atoms, a heteroaralkyl 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, a heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heteroaryl group having 3 to 30 carbon atoms, more specifically, the substituents described in the [Specific Examples of Substituents] below.

[0251] Further preferably, 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, or an aryl group having 6 to 30 carbon atoms.

[0252] [Specific Examples of Substituents]

[0253] The specific examples of the substituents in the structures of the above compounds and the substituents in the above substituent group Z1 are described below.

[0254] As the above alkyl group having 1 to 20 carbon atoms, any of a straight chain, a branched chain, or a cyclic alkyl group can be used. More specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an iso-propyl group, an iso-butyl group, an iso-pentyl group, a tert-butyl group, a cyclohexyl group, and the like can be mentioned. Among them, a straight chain alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, an n-butyl group, an n-hexyl group, and an n-octyl group is preferred.

[0255] The above (hetero)aralkyl group having 7 to 40 carbon atoms means a group in which a part of the hydrogen atoms constituting a straight chain alkyl group, a branched chain alkyl group, or a cyclic alkyl group is substituted with an aryl group or a heteroaryl group. More specifically, a 2-phenyl-l-ethyl group, a cumyl group, a 5-phenyl-l-pentyl group, a 6-phenyl-l-hexyl group, a 7-phenyl-l-heptyl group, a tetrahydronaphthyl group, and the like can be mentioned. Among them, a 5-phenyl-l-pentyl group, a 6-phenyl-l-hexyl group, and a 7-phenyl-l-heptyl group are preferred.

[0256] As the above alkoxy group having 1 to 20 carbon atoms, a methoxy group, an ethoxy group, a propoxy group, an iso-propoxy group, a hexyloxy group, a cyclohexyloxy group, an octadecyloxy group, and the like can be mentioned. Among them, a hexyloxy group is preferred.

[0257] Specific examples of the (hetero)aryloxy group having 3 to 20 carbon atoms include phenoxy and 4-methylphenoxy. Among them, phenoxy is preferred.

[0258] Specific examples of the alkylsilyl group having 1 to 20 carbon atoms include trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethylphenyl, tert-butyldimethylsilyl, and tert-butyldiphenylsilyl. Among them, triisopropyl, tert-butyldimethylsilyl, and tert-butyldiphenylsilyl are preferred.

[0259] Specific examples of the arylsilyl group having 6 to 20 carbon atoms include diphenylpyridylsilyl and triphenylsilyl groups, among which triphenylsilyl is preferred.

[0260] Specific examples of the alkylcarbonyl group having 2 to 20 carbon atoms include acetyl, propionyl, pivaloyl, hexanoyl, decanoyl, and cyclohexylcarbonyl groups, among which acetyl and pivaloyl are preferred.

[0261] Specific examples of the arylcarbonyl group having 7 to 20 carbon atoms include benzoyl, naphthoyl, anthracenoyl, etc. Among them, benzoyl is preferred.

[0262] Specific examples of the alkylamino group having 1 to 20 carbon atoms include methylamino, dimethylamino, diethylamino, ethylmethylamino, dihexylamino, dioctylamino, and dicyclohexylamino. Among them, dimethylamino and dicyclohexylamino are preferred.

[0263] Specific examples of the arylamino group having 6 to 20 carbon atoms include phenylamino, diphenylamino, di(4-tolyl)amino, and di(2,6-dimethylphenyl)amino. Among them, diphenylamino and di(4-tolyl)amino are preferred.

[0264] The (hetero)aryl group having 3 to 30 carbon atoms refers to an aromatic hydrocarbon group having one free atomic valence, an aromatic heterocyclic group, a linked aromatic hydrocarbon group in which a plurality of aromatic hydrocarbons are linked, a linked aromatic heterocyclic group in which a plurality of aromatic heterocyclic groups are linked, or a group in which at least one aromatic hydrocarbon and one aromatic heterocyclic ring are arbitrarily linked.

[0265] Specific examples 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, Ring, triphenylene ring, fluoranthene ring, furan ring, benzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a pyrrolopyridine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, and the like. As the linking aromatic hydrocarbon group in which a plurality of aromatic hydrocarbons are linked, a biphenyl group, a terphenyl group, and the like can be given. a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a pyrrolopyridine ring, a quinazoline ring, a quinazolinone ring, an azulene ring, and the like. As the linking aromatic hydrocarbon group in which a plurality of aromatic hydrocarbons are linked, a biphenyl group, a terphenyl group, and the like can be given.

[0266] Among the (hetero)aromatic groups, from the viewpoint of durability, a benzene ring having one free valence of an atom, a naphthalene ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a pyridine ring, a pyrimidine ring, a triazine ring are preferable, among which a benzene ring having one free valence of an atom which can be substituted with an alkyl group having 1 to 8 carbon atoms, an aromatic group having 6 to 18 carbon atoms such as a naphthalene ring or a phenanthrene ring, or a pyridine ring having one free valence of an atom which can be substituted with an alkyl group having 1 to 4 carbon atoms are more preferable, and a benzene ring having one free valence of an atom which can be substituted with an alkyl group having 1 to 8 carbon atoms, an aromatic group having 6 to 18 carbon atoms such as a naphthalene ring or a phenanthrene ring are further preferable.

[0267] When the group in the compound has a plurality of substituents, as the combination of these substituents, for example, a combination of an aryl group and an alkyl group, a combination of an aryl group and an aralkyl group, or a combination of an aryl group, an alkyl group, and an aralkyl group can be used, but the present application is not limited thereto. As the combination of an aryl group and an aralkyl group, for example, a combination of benzene, a biphenyl group, a terphenyl group, and 5-phenyl-l-pentyl, 6-phenyl-l-hexyl can be used.

[0268] [Maximum emission wavelength]

[0269] The following shows the method for measuring the maximum emission wavelength of the iridium complex compound in the present embodiment.

[0270] The maximum emission wavelength of the iridium complex compound can be found from the photoluminescence spectrum of a solution in which the material is dissolved in an organic solvent or the photoluminescence spectrum of a thin film of the material alone.

[0271] In the case of photoluminescence of a solution, at ordinary temperature, a solution in which the compound is dissolved at a concentration of 1 x 10 － 4 mol / L or less, preferably at a concentration of 1 x 10 －5 mol / L, is measured using a spectrophotometer (Hamamatsu Photonics K.K., Organic EL Quantum Yield Measurement Device C9920-02). The wavelength at which the maximum value of the spectrum intensity is shown is taken as the maximum emission wavelength.

[0272] In the case of thin film photoluminescence, the material is vacuum-deposited or solution-coated to form a thin film, and the photoluminescence is measured using the above-mentioned spectrophotometer. The wavelength showing the maximum value of the obtained luminescence spectrum intensity is defined as the maximum emission wavelength.

[0273] The maximum emission wavelengths of the compound used as the light-emitting dopant and the compound used as the assisting dopant must be determined by the same method and compared.

[0274] The compound represented by formula (3) as an auxiliary dopant contained in the composition for an organic electroluminescent element of this embodiment has a shorter maximum emission wavelength than the iridium complex represented by formula (1) as a luminescent dopant.

[0275] The maximum emission wavelength of the compound as the luminescent dopant is preferably more than 580nm, more preferably more than 590nm, further preferably more than 600nm, in addition, is preferably below 700nm, more preferably below 680nm.Be this scope by the maximum emission wavelength, thereby have the trend that can show the ideal color of the red luminescent material that is suitable as organic electroluminescent element.

[0276] Energy transfer can be performed efficiently if the maximum emission wavelength of the compound serving as the assisting dopant is at least 10 nm away from the maximum emission wavelength of the compound serving as the luminescent dopant and at most 50 nm away. The above difference is more preferably at most 40 nm.

[0277] The iridium complex represented by formula (1) preferably contains the same amount as or more than the compound represented by formula (3). That is, the composition ratio of the iridium complex represented by formula (1) in parts by mass is preferably greater than or equal to the composition ratio of the compound represented by formula (3). The iridium complex represented by formula (1) preferably further contains 1 to 3 times the amount of the compound represented by formula (3) in parts by mass.

[0278] From the perspectives of improving the luminous efficiency and extending the life of the device, a 1-2-fold content is particularly preferred. From the perspective of achieving more vivid luminescence, a 2-fold or greater content is even more preferred. From the perspective of reducing the driving voltage of the device, a content of less than 2-fold is even more preferred. This allows for more efficient transfer of energy from the auxiliary dopant to the luminescent dopant, resulting in higher luminous efficiency and potentially extending the device's life.

[0279] [Compound represented by formula (20)]

[0280] The composition containing the iridium complex of the present embodiment preferably further contains a compound represented by the following formula (20).

[0281]

[0282] [In the above formula (20),

[0283] W each independently represents CH or N, at least one of W is N,

[0284] Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0285] Xa 2 , Ya 2 , and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent,

[0286] g11, h11, and j11 each independently represents an integer of 0 to 6,

[0287] at least one of g11, h11, and j11 is an integer of 1 or more,

[0288] when g11 is 2 or more, a plurality of Xa 1 may be the same or different,

[0289] when h11 is 2 or more, a plurality of Ya 1 may be the same or different,

[0290] when j11 is 2 or more, a plurality of Za 1 may be the same or different,

[0291] R 23 represents a hydrogen atom or a substituent, and 4 R 23 may be the same or different,

[0292] wherein, when g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , or Za 2 is not a hydrogen atom.

[0293] The compound represented by the above formula (20) is preferably a charge transport compound, i.e., a charge transport host material.

[0294] W

[0295] W in the above formula (20) represents CH or N, at least one of which is N, and from the viewpoints of electron transport property and electron durability, preferably at least 2 are N, and more preferably all are N.

[0296] <Xa 1 、Ya 1 、Za 1 、Xa 2 、Ya 2 、Za 2 >

[0297] As Xa in the above formula (20) 1 、Ya 1 、Za 1 When Xa is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent 2 、Ya 2 、Za 2 In the case of an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, the aromatic hydrocarbon ring of the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a six-membered monocyclic ring or a di- to penta-condensed ring. Specific examples include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzopyrene ring, Among them, 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.

[0298] As Xa in the above formula (20) 1 、Ya 1 、Za 1 When Xa is a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent 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 monocyclic ring having 5 or 6 members, or a condensed ring having 2 to 5 members. Specifically, there can be mentioned 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, oxadiazole ring, indole ring, carbazole ring, indolecarbazole ring, indenocarbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisocyanate ring The present invention also includes an azole 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 quinoxaline ring, a quinazoline ring, a quinazolinone ring, and a phenanthroline ring. Among them, a thiophene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, an phenanthroline ring, or an indenocarbazole ring is preferred, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring is more preferred, and a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring is further preferred.

[0299] Xa in the above formula (20) 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, dibenzofuran rings or dibenzothiophene rings.

[0300] <g11, h11, j11>

[0301] 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 or equal to 1. From the viewpoint of charge transportability and durability, g11 is preferably greater than or equal to 2, or at least one of h11 and j11 is preferably greater than or equal to 3.

[0302] When g11 is 2 or more, there are multiple Xa 1 They may be the same or different. When h11 is 2 or more, there are multiple Ya 1 Can be the same or different. In addition, when j11 is 2 or more, there are multiple Za 1 Can be the same or different.

[0303] In addition, when g11 is 0, the corresponding Xa 2 Not a hydrogen atom means g11 is 0, that is, there is no Xa 1 In the case of Xa 2 It is 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. 1 In the case of Ya 2 It is 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. 1 In the case of Za2 The aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent or the aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent.

[0304] In addition, from the viewpoint of charge transportability, durability, and solubility in organic solvents, the compound represented by the above formula (20) preferably has a total of 8 to 18 of these rings including the ring having 3 Ws at the center.

[0305] R 23

[0306] R 23 , is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent. From the viewpoint of improvement of durability and charge transportability, it is further preferable to be an aromatic hydrocarbon group which can have a substituent. R 23 When there are a plurality of R

[0307] The substituent which the above aromatic hydrocarbon group having 6 to 30 carbon atoms can have, the substituent which the aromatic heterocyclic group having 3 to 30 carbon atoms can have, and the substituent R 23 may have can be selected from the following substituent group Z2.

[0308] <Substituent Group Z2>

[0309] 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 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. These substituents can include any of a linear structure, a branched structure, and a cyclic structure.

[0310] More specifically, as the substituent group Z2, the following structures can be given.

[0311] For example, a linear, branched, or cyclic alkyl group having a carbon number of usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, more preferably 8 or less, further preferably 6 or less, such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a t-butyl group, an n-hexyl group, a cyclohexyl group, a dodecyl group, and the like;

[0312] For example, an alkoxy group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methoxy group, an ethoxy group, and the like;

[0313] ​​An aryloxy group or heteroaryloxy group having usually 4 or more, preferably 5 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as phenoxy, naphthoxy, pyridyloxy, and the like;

[0314] An alkoxycarbonyl group having usually 2 or more, and also usually 24 or less, preferably 12 or less, carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and the like;

[0315] A dialkylamino group having usually 2 or more, and also usually 24 or less, preferably 12 or less, carbon atoms, such as dimethylamino, diethylamino, and the like;

[0316] A diarylamino group having usually 10 or more, preferably 12 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as diphenylamino, ditolylamino, and the like;

[0317] An arylalkylamino group having usually 7 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as phenylmethylamino, and the like;

[0318] An acyl group having usually 2 or more, and also usually 24 or less, preferably 12 or less, carbon atoms, such as acetyl, benzoyl, and the like;

[0319] A halogen atom, such as a fluorine atom, a chlorine atom, and the like;

[0320] A halogenated alkyl group having usually 1 or more, and also usually 12 or less, preferably 6 or less, carbon atoms, such as trifluoromethyl, and the like;

[0321] An alkylthio group having usually 1 or more, and also usually 24 or less, preferably 12 or less, carbon atoms, such as methylthio, ethylthio, and the like;

[0322] An arylthio group having usually 4 or more, preferably 5 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as phenylthio, naphthylthio, pyridylthio, and the like;

[0323] A silyl group having usually 2 or more, preferably 3 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as trimethylsilyl, triphenylsilyl, and the like;

[0324] A silyloxy group having usually 2 or more, preferably 3 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as trimethylsilyloxy, triphenylsilyloxy, and the like;

[0325] A cyano group;

[0326] An aromatic hydrocarbon group having usually 6 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as phenyl, naphthyl, and the like;

[0327] An aromatic heterocyclic group having 3 or more, preferably 4 or more, and also usually 36 or less, preferably 24 or less, carbon atoms, such as a thienyl group, a pyridyl group, and the like.

[0328] 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 transportability, as the substituent, an aromatic hydrocarbon group or an aromatic heterocyclic group is preferred, an aromatic hydrocarbon group is more preferred, and further, a substituent-free group is still more preferred. From the viewpoint of improving solubility, as the substituent, an alkyl group or an alkoxy group is preferred.

[0329] Further, each substituent of the above-mentioned substituent group Z2may further have a substituent. As such a substituent, the same groups as the above-mentioned substituents (substituent group Z2) can be given. Each substituent of the above-mentioned substituent group Z2is preferably an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group, and from the viewpoint of charge transportability, each substituent of the above-mentioned substituent group Z2is still more preferably free from a substituent.

[0330] < Molecular weight >

[0331] The compound represented by the above-mentioned formula (20) is a low molecular material, and the molecular weight is preferably 3000 or less, further preferably 2500 or less, particularly preferably 2000 or less, and most preferably 1500 or less. Further, the lower limit of the molecular weight is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0332] < Specific examples of the compound represented by formula (20) >

[0333] The compound represented by formula (20) is not particularly limited, and for example, the following compounds can be given.

[0334]

[0335]

[0336] The composition containing the iridium complex compound of the present embodiment can contain only one kind of the above-mentioned compound represented by formula (20), or two or more kinds thereof.

[0337] [Organic electroluminescent element]

[0338] The organic electroluminescent element of the present embodiment contains the iridium complex compound of the present embodiment.

[0339] The organic electroluminescent device of the present embodiment preferably has at least an anode, a cathode, and at least one organic layer between the anode and the cathode on a substrate, and at least one of the organic layers contains the iridium complex compound of the present embodiment. The organic layer contains a light-emitting layer. The organic electroluminescent device of the present embodiment contains the iridium complex compound of the present embodiment in the light-emitting layer.

[0340] The light-emitting layer of the organic electroluminescent device of the present embodiment preferably contains the auxiliary dopant in addition to the iridium complex compound of the present embodiment. The reason for preferably containing the auxiliary dopant is as described above.

[0341] The light-emitting layer of the organic electroluminescent device of the present embodiment preferably further contains the compound represented by the above formula (20) in addition to the iridium complex compound of the present embodiment. The reason for preferably further containing the compound represented by the above formula (20) is as described above.

[0342] The light-emitting layer of the organic electroluminescent device of the present embodiment preferably contains the compound represented by the above formula (20) and the auxiliary dopant in addition to the iridium complex compound of the present embodiment.

[0343] The organic layer containing the iridium complex compound of the present embodiment is more preferably a layer formed using the composition containing the iridium complex compound of the present embodiment, and is further preferably a layer formed by a wet film-forming method. The layer formed by the wet film-forming method is preferably the light-emitting layer.

[0344] The wet film-forming method in the present embodiment refers to a method in which a film is formed in a wet state by, for example, a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, a roll coating method, a spray coating method, a capillary coating method, an inkjet method, a nozzle printing method, a screen printing method, a gravure printing method, a flexographic printing method, or the like, and a method in which the film formed by these methods is dried to form a film.

[0345] Figure 1 is a schematic view showing a cross section of a preferred structural example of the organic electroluminescent device 10 of the present embodiment, Figure 1 In the figure, symbol 1 represents a substrate, symbol 2 represents an anode, symbol 3 represents a hole-injection layer, symbol 4 represents a hole-transport layer, symbol 5 represents a light-emitting layer, symbol 6 represents a hole-blocking layer, symbol 7 represents an electron-transport layer, symbol 8 represents an electron-injection layer, and symbol 9 represents a cathode.

[0346] The materials used for these structures can apply known materials without particular limitation, and representative materials and production methods for each layer will be described below as an example. In addition, in the case of citing a publication, a paper, or the like, the content can be appropriately applied within the scope of common knowledge of those skilled in the art.

[0347] <Substrate 1>

[0348] The substrate 1 is a support of an organic electroluminescent element, and a plate of quartz or glass, a metal plate, a metal foil, a plastic film or sheet, or the like is generally used. Among them, a glass plate or a plate of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, polysulfone, or the like is preferred. From the viewpoint that deterioration of the organic electroluminescent element by external air is less likely to occur, the substrate 1 is preferably of a material having high gas barrier properties. Therefore, particularly when a material having low gas barrier properties such as a synthetic resin substrate is used, it is preferred that a dense silicon oxide film or the like is provided on at least one side of the substrate 1 to improve the gas barrier properties.

[0349] <Anode 2>

[0350] The anode 2 functions to inject holes into the layer on the light-emitting layer side. The anode 2 is generally composed of a metal such as aluminum, gold, silver, nickel, palladium, platinum, or the like; a metal oxide such as an oxide of at least one of indium and tin; a halogenated metal such as copper iodide; carbon black; or a conductive polymer such as poly(3-methylthiophene), polypyrrole, polyaniline, or the like.

[0351] Formation of the anode 2 is generally performed by a dry method such as a sputtering method, a vacuum evaporation method, or the like. Alternatively, when the anode 2 is formed using metal fine particles of silver or the like, fine particles of copper iodide or the like, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, or the like, it can also be formed by dispersing them in a proper binder resin solution and coating the same on a substrate. In the case of a conductive polymer, a thin film can also be formed directly on a substrate by electrolytic polymerization, or the anode 2 can be formed by coating a conductive polymer on a substrate (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0352] The anode 2 is generally of a single layer structure, but can also be appropriately made of a laminated structure. In the case of a laminated structure, a different conductive material can also be laminated on the anode of the first layer.

[0353] The thickness of the anode 2 can be determined as appropriate depending on the transparency and material, or the like, required. Particularly in the case where high transparency is required, a thickness of 60% or more in transmittance of visible light is preferred, and a thickness of 80% or more in transmittance of visible light is further preferred. The thickness of the anode 2 is generally 5 nm or more, preferably 10 nm or more, and is generally 1000 nm or less, preferably 500 nm or less. On the other hand, in the case where transparency is not required, the thickness of the anode 2 can be any thickness as appropriate depending on the strength or the like required, and in this case, the anode 2 can be of the same thickness as the substrate 1.

[0354] In the case where a film is formed on the surface of the anode 2, it is preferable to remove impurities on the anode by performing ultraviolet + ozone, oxygen plasma, argon plasma, or the like before film formation, and to increase the ionization potential thereof to improve the hole-injection property.

[0355] < Hole injection layer 3 >

[0356] A layer that functions to transport holes from the anode 2 side to the light-emitting layer 5 side is generally referred to as a hole-injection-transport layer or a hole-transport layer. In addition, when the layer that functions to transport holes from the anode 2 side to the light-emitting layer 5 side is two or more layers, the layer closer to the anode 2 side is sometimes referred to as a hole-injection layer 3. The use of the hole-injection layer 3 is preferable in terms of enhancing the function of transporting holes from the anode 2 to the light-emitting layer 5 side. When the hole-injection layer 3 is used, the hole-injection layer 3 is generally formed on the anode 2.

[0357] The film thickness of the hole-injection layer 3 is generally 1 nm or more, and is preferably 5 nm or more, and is generally 1000 nm or less, and is preferably 500 nm or less.

[0358] The method of forming the hole-injection layer 3 can be either vacuum evaporation or wet film formation. The use of wet film formation is preferable in terms of excellent film formation property.

[0359] The hole-injection layer 3 preferably contains a hole-transporting compound, and more preferably contains a hole-transporting compound and an electron-accepting compound. Furthermore, it is preferable to contain a cationic radical compound in the hole-injection layer 3, and it is particularly preferable to contain a cationic radical compound and a hole-transporting compound.

[0360] (Hole-transporting compound)

[0361] The composition for hole-injection layer formation generally contains a hole-transporting compound that becomes the hole-injection layer 3. In the case of wet film formation, a solvent is generally further contained. The composition for hole-injection layer formation is preferably high in hole-transporting property, and can efficiently transport injected holes. Therefore, it is preferable to be large in hole mobility, and not to easily produce impurities that become traps at the time of manufacture, at the time of use, or the like. In addition, it is preferable to be excellent in stability, to have a small ionization potential, and to be high in transparency to visible light. In particular, in the case where the hole-injection layer 3 is in contact with the light-emitting layer 5, it is preferable not to quench the light emission from the light-emitting layer 5, and not to form an exciplex with the light-emitting layer 5 to reduce the light-emitting efficiency.

[0362] As the hole-transporting compound, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable from the viewpoint of charge injection barrier from the anode 2 to the hole-transporting layer 3. As examples of the hole-transporting compound, aromatic amine-based compounds, phthalocyanine-based compounds, porphyrin-based compounds, oligothiophene-based compounds, polythiophene-based compounds, benzylphenyl-based compounds, compounds in which a tertiary amine is connected with a fluorenyl group, hydrazone-based compounds, silazane-based compounds, quinacridone-based compounds, and the like can be given.

[0363] Among the above exemplified compounds, an aromatic amine compound is preferable from the viewpoints of amorphousness and visible light transmittance, and an aromatic tertiary amine compound is particularly preferable. Here, the aromatic tertiary amine compound refers to a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from an aromatic tertiary amine.

[0364] The kind of the aromatic tertiary amine compound is not particularly limited, and a high molecular compound having a weight average molecular weight of 1000 to 1000000, i.e., a polymer compound in which repeating units are linked, is preferable from the viewpoint of easy obtaining uniform light emission by utilizing the surface smoothing effect. As a preferable example of the aromatic tertiary amine high molecular compound, a high molecular compound having a repeating unit represented by the following formula (I) or the like can be given.

[0365]

[0366] (In the above formula (I), Ar 1 and Ar 2 each independently represents an aromatic group which can have a substituent or a heteroaromatic group which can have a substituent. Ar 3 ~ Ar 5 each independently represents an aromatic group which can have a substituent or a heteroaromatic group which can have a substituent. Q represents a linking group selected from the following linking group group. In addition, Ar 1 ~ Ar 5 Among them, two groups bonded to the same N atom can be bonded to each other to form a ring.)

[0367] The following shows the linking group.

[0368]

[0369] (In the above formula (I), Ar 6 ~ Ar 16 each independently represents an aromatic group which can have a substituent or a heteroaromatic group which can have a substituent. R a ~ R b each independently represents a hydrogen atom or an arbitrary substituent.)

[0370] As Ar 1~Ar 16 The aromatic group and heteroaromatic group are preferably a group derived from a benzene ring, naphthalene ring, phenanthrene ring, thiophene ring, pyridine ring, and more preferably a group derived from a benzene ring or naphthalene ring, from the viewpoints of solubility, heat resistance, and hole-transporting property of the high molecular compound.

[0371] As a specific example of the aromatic tertiary amine high molecular compound having a repeating unit represented by formula (I), a compound described in International Publication No. 2005 / 089024 can be given.

[0372] (electron-accepting compound)

[0373] The hole- injection layer 3 preferably contains an electron- accepting compound to be able to increase the conductivity of the hole- injection layer 3 by oxidation of the hole- transporting compound.

[0374] As the electron- accepting compound, a compound having an oxidizing ability and an ability to accept a single electron from the above- described hole- transporting compound is preferable, and specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 5 eV or more is further preferable.

[0375] As such an electron- accepting compound, for example, a compound selected from one or two or more of triarylboron compounds, halogenated metals, Lewis acids, organic acids, onium salts, salts of aromatic amines and halogenated metals, salts of aromatic amines and Lewis acids, and the like can be given. Specifically, onium salts (International Publication No. 2005 / 089024) such as 4-isopropyl-4'-methyl diphenyl iodonium tetrakis(pentafluorophenyl)borate, triphenyl sulfonium tetrafluoroborate; high-valence inorganic compounds such as iron (III) chloride (Japanese Patent Application Laid-Open No. 11-251067), ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris(pentafluorophenyl)borane (Japanese Patent Application Laid-Open No. 2003-31365); and fullerene derivatives and iodine can be given.

[0376] (cationic radical compound)

[0377] As the cationic radical compound, an ionic compound composed of a cationic radical which is a chemical substance that removes a single electron from the hole- transporting compound and a counter anion is preferable. In the case where the cationic radical is derived from a hole- transporting high molecular compound, the cationic radical is a structure that removes a single electron from the repeating unit of the high molecular compound.

[0378] As the cation radical, a chemical substance which removes one electron from the aforementioned compound as the hole-transporting compound is preferable. From the viewpoints of amorphousness, transmittance of visible light, heat resistance, solubility, and the like, a chemical substance which removes one electron from the compound which is preferable as the hole-transporting compound is preferable.

[0379] Here, the cation radical compound can be generated by mixing the aforementioned hole-transporting compound with an electron-accepting compound. That is, by mixing the aforementioned hole-transporting compound with an electron-accepting compound, electron transfer from the hole-transporting compound to the electron-accepting compound occurs, and a cationic ionic compound composed of a cation radical of the hole-transporting compound and a counter anion is generated.

[0380] A cation radical compound from a high molecular compound such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481), a squarylium hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716), and the like can also be generated by oxidative polymerization, that is, dehydrogenative polymerization.

[0381] The oxidative polymerization referred to here is chemical or electrochemical oxidation of a monomer in an acidic solution using a peroxydisulfate or the like. In the case of this oxidative polymerization (dehydrogenative polymerization), the monomer is polymerized by oxidation, and a cation radical which removes one electron from the repeating unit of the polymer with the anion from the acidic solution as the counter anion is generated.

[0382] (Formation of the hole injection layer 3 based on a wet film formation method)

[0383] When the hole injection layer 3 is formed by a wet film formation method, a material which becomes the hole injection layer 3 is generally mixed with a dissolvable solvent, that is, a hole injection layer solvent, to prepare a film formation hole injection layer-forming composition. This hole injection layer-forming composition is formed into a film on a layer corresponding to the lower layer of the hole injection layer 3, typically the anode 2, by using a wet film formation method, and is dried to form. The drying of the formed film can be performed similarly to the drying method in the formation of the light-emitting layer 5 based on a wet film formation method.

[0384] The concentration of the hole-transporting compound in the hole injection layer-forming composition is arbitrary as long as the effect of the present application is not significantly impaired, but from the viewpoint of uniformity of the film thickness, a lower concentration is preferable, and on the other hand, from the viewpoint that defects are less likely to occur in the hole injection layer 3, a higher concentration is preferable. Specifically, 0.01 mass% or more, further preferably 0.1 mass% or more, particularly preferably 0.5 mass% or more, and on the other hand, 70 mass% or less, further preferably 60 mass% or less, particularly preferably 50 mass% or less are preferable.

[0385] As the solvent, for example, an ether-based solvent, an ester-based solvent, an aromatic hydrocarbon-based solvent, an amide-based solvent, and the like can be given.

[0386] As the ether-based solvent, for example, an aliphatic ether such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), and the like, and an aromatic ether such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and the like can be given.

[0387] As the ester-based solvent, for example, an aromatic ester such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, and the like can be given.

[0388] As the aromatic hydrocarbon-based solvent, for example, toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, methylnaphthalene, and the like can be given.

[0389] As the amide-based solvent, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and the like can be given.

[0390] In addition to these, dimethyl sulfoxide and the like can also be used.

[0391] The formation of the hole injection layer 3 based on the wet film formation method is generally performed as follows: after preparing a hole injection layer-forming composition, the composition is applied to form a film on a layer corresponding to the lower layer of the hole injection layer 3, typically the anode 2, and dried. The hole injection layer 3 is generally dried by heating, reduced pressure drying, or the like after film formation to dry the applied film.

[0392] (Formation of the hole injection layer 3 based on the vacuum evaporation method)

[0393] In the case where the hole injection layer 3 is formed by the vacuum evaporation method, generally, one or two or more of the constituent materials of the hole injection layer 3, i.e., one or two or more of the aforementioned hole-transporting compound, electron-accepting compound, and the like are put into a crucible provided in a vacuum vessel, the inside of the vacuum vessel is exhausted with a vacuum pump to 10 －4 After the pressure is brought to about 1 Pa, the crucible is heated, and the materials in the crucible are evaporated by controlling the evaporation amount of the materials in the crucible, to form the hole injection layer 3 on the anode 2 of the substrate placed facing the crucible. Note that in the case where two or more materials are used, the constituent materials of the hole injection layer 3 are generally put into different crucibles, respectively, and the crucibles are heated, respectively. Further, as for evaporation, the evaporation amount is generally controlled independently, respectively, to evaporate. On the other hand, in the case where two or more materials are used, a mixture of the materials can be put into one crucible, heated, and evaporated to form the hole injection layer 3.

[0394] The degree of vacuum at the time of evaporation is not limited as long as the effect of the present application is not significantly impaired, and is usually 0.1 x 10 － 6 Torr (0.13 x 10 －4 Pa) or more, and is usually 9.0 x 10 －6 Torr (12.0 x 10 －4 Pa) or less. The evaporation rate is not limited as long as the effect of the present application is not significantly impaired, and is usually 0.1 A / sec or more, and is usually 10 A / sec or less. The film formation temperature at the time of evaporation is not limited as long as the effect of the present application is not significantly impaired, and is preferably 10°C or more, and is preferably performed at 50°C or less.

[0395] < Hole Transport Layer 4 >

[0396] The hole transport layer 4 is a layer that functions to transport 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 application, but is preferably provided in terms of enhancing the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is provided, the hole transport layer 4 is usually formed between the anode 2 and the light-emitting layer 5. When the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0397] The film thickness of the hole transport layer 4 is usually 5 nm or more, and is preferably 10 nm or more, and is usually 300 nm or less, and is preferably 100 nm or less.

[0398] The hole transport layer 4 can be formed by a vacuum evaporation method or a wet film formation method. In terms of excellent film formation properties, it is preferable to form by a wet film formation method.

[0399] ​The hole-transporting layer 4 generally contains a hole-transporting compound that becomes the hole-transporting layer 4. As the hole-transporting compound contained in the hole-transporting layer 4, an aromatic amine compound having a starburst structure (J. Lumin., Vol. 72-74, p. 985, 1997), an aromatic amine compound composed of a tetramer of triphenylamine (Chem. Commun., p. 2175, 1996), a spiro compound such as 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), a carbazole derivative such as 4,4'-N,N'-dicarbazolbiphenyl, and the like can be particularly mentioned. In addition, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Laid-Open No. 7-53953), a polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996), and the like can be preferably used.

[0400] (Formation of the hole-transporting layer 4 based on a wet film formation method)

[0401] In the case where the hole-transporting layer 4 is formed by a wet film formation method, generally, a hole-transporting layer-forming composition is used instead of the hole-injecting layer-forming composition as in the case where the hole-injecting layer 3 is formed by a wet film formation method.

[0402] In the case where the hole-transporting layer 4 is formed by a wet film formation method, generally, the hole-transporting layer-forming composition further contains a solvent. The solvent used in the hole-transporting layer-forming composition can use the same solvent as the solvent used in the hole-injecting layer-forming composition described above.

[0403] The concentration of the hole-transporting compound in the hole-transporting layer-forming composition can be in the same range as the concentration of the hole-transporting compound in the hole-injecting layer-forming composition.

[0404] The formation of the hole-transporting layer 4 based on a wet film formation method can be performed as in the film formation method of the hole-injecting layer 3 described above.

[0405] (Formation of the hole-transporting layer 4 based on a vacuum evaporation method)

[0406] When the hole transport layer 4 is formed by vacuum deposition, it can generally be formed by using the constituent materials of the hole transport layer 4 instead of the constituent materials of the hole injection layer 3, similarly to the case of forming the hole injection layer 3 by vacuum deposition. The film formation conditions such as the degree of vacuum during deposition, the deposition rate, and the temperature can be the same as those for the vacuum deposition of the hole injection layer 3.

[0407] <Luminescent layer 5>

[0408] The light-emitting layer 5 is a layer that emits light when an electric field is applied between a pair of electrodes. The light-emitting layer 5 is excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9. The light-emitting layer 5 is formed between the anode 2 and the cathode 9. If the hole-injection layer 3 is provided on the anode 2, the light-emitting layer 5 is formed between the hole-injection layer 3 and the cathode 9. If the hole-transport layer 4 is provided on the anode 2, the light-emitting layer 5 is formed between the hole-transport layer 4 and the cathode 9.

[0409] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. A thicker thickness is preferred to reduce the risk of film defects, while a thinner thickness is preferred to facilitate a low driving voltage. Therefore, the thickness of the light-emitting layer 5 is preferably 3 nm or greater, more preferably 5 nm or greater, and is generally preferably 200 nm or less, more preferably 100 nm or less.

[0410] The light-emitting layer 5 contains at least a material having a luminescent property (a light-emitting material), and preferably contains a material having a charge transport property (a charge transport material). As a light-emitting material, as long as the iridium coordination compound of the present embodiment is included in any light-emitting layer, other light-emitting materials can also be used as appropriate. Below, other light-emitting materials other than the iridium coordination compound of the present embodiment are described in detail.

[0411] (Luminescent material)

[0412] The luminescent material is not particularly limited as long as it emits light at the desired emission wavelength and does not impair the effects of the present invention, and known luminescent materials can be applied. The luminescent material can be a fluorescent luminescent material or a phosphorescent luminescent material, preferably a material with good luminous efficiency. From the perspective of internal quantum efficiency, a phosphorescent luminescent material is preferred.

[0413] Examples of the fluorescent material include the following materials.

[0414] Examples of fluorescent materials that emit blue light (blue fluorescent materials) include naphthalene, perylene, pyrene, anthracene, coumarin, 4-Bis(2-phenylvinyl)benzene and their derivatives, etc.

[0415] As a fluorescent light emitting material (green fluorescent light emitting material) that provides green light emission, for example, quinacridone derivatives, coumarin derivatives, aluminum complexes such as Al(C9H6NO)3, and the like can be given.

[0416] As a fluorescent light emitting material (yellow fluorescent light emitting material) that provides yellow light emission, for example, rubrene, pyrimidine derivatives, and the like can be given.

[0417] As a fluorescent light emitting material (red fluorescent light emitting material) that provides red light emission, for example, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran)-based compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, and the like can be given.

[0418] In addition, as a phosphorescent light emitting material, for example, an organic metal complex containing a metal selected from Groups 7 to 11 of the long-periodic type periodic table (hereinafter, unless otherwise specified, in the case of being referred to as "periodic table", the long-periodic type periodic table is meant) and the like can be given. As the metal selected from Groups 7 to 11 of the periodic table, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and the like can be preferably given.

[0419] As a ligand of the organic metal complex, a (hetero)arylpyridine ligand, a (hetero)arylpyrazole ligand, and the like in which a (hetero)aryl group is linked to a pyridine, a pyrazole, a phenanthroline, and the like are preferable, and a phenylpyridine ligand, a phenylpyrazole ligand, and the like are particularly preferable. Here, the (hetero)aryl group means an aryl group or a heteroaryl group.

[0420] As a preferable phosphorescent light emitting material, specifically, for example, phenylpyridine complexes such as tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, tris(2-phenylpyridine)rhenium, and the like, and porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, octaphenylpalladium porphyrin, and the like can be given.

[0421] As a high molecular weight light emitting material, poly(9,9-dioctylfluorene-2,7-diyl), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butyphenyl))diphenylamine)], poly[(9,9-dioctylfluorene-2,7-diyl)-co-(1,4-benzo-2{2,1'-3}-triazole)], and the like polyfluorene-based materials, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and the like polyphenylenevinylene-based materials can be given.

[0422] (charge transport material)

[0423] The charge transporting material is a material having a positive charge, ie, hole transporting property, or a negative charge, ie, electron transporting property. There are no particular limitations on the charge transporting material as long as the effects of the present invention are not impaired, and known materials can be used.

[0424] As the charge transport material, compounds conventionally used in the light-emitting layer 5 of an organic electroluminescent element can be used, and compounds used as a host material of the light-emitting layer 5 are particularly preferred.

[0425] As the charge transport material, specifically, there can be mentioned aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds obtained by linking a tertiary amine via a fluorenyl group, hydrazone compounds, silazane compounds, silaneamine compounds, phosphoramide compounds, quinacridone compounds, and the like, which are exemplified as the hole transport compound for the hole injection layer 3. In addition, there can be mentioned anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, o-phenanthroline compounds, Electron transporting compounds such as oxadiazole compounds and silole compounds.

[0426] In addition, aromatic diamines containing two or more tertiary amines and two or more condensed aromatic rings substituted on nitrogen atoms, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (Japanese Patent Application Laid-Open No. 5-234681), aromatic amine compounds having a starburst structure such as 4,4',4"-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), aromatic amine compounds composed of tetramers of triphenylamine, and the like can also be preferably used. Compounds exemplified as hole-transporting compounds for the hole-transporting layer 4 include compounds such as fluorene compounds (Chem. Commun., p. 2175, 1996), 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene and the like (Synth. Metals, vol. 91, p. 209, 1997), and carbazole compounds such as 4,4'-N,N'-dicarbazolebiphenyl and the like. In addition to these, 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4- oxadiazole (tBu-PBD), 2,5-bis(1-naphthyl)-1,3,4- BND, etc. Silole compounds such as oxadiazole compounds, 2,5-bis(6'-(2',2"-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), and o-phenanthroline compounds such as bathophenanthroline (BPhen) and 2,9-dimethyl-4,7-diphenyl-1,10-o-phenanthroline (BCP, bathocuproin).

[0427] (Formation of light-emitting layer 5 (wet method))

[0428] The method for forming the light-emitting layer 5 can be either a vacuum evaporation method or a wet film formation method. The wet film formation method is preferred because of its excellent film formation properties.

[0429] In the case of forming the light-emitting layer 5 using a wet film formation method, the light-emitting layer 5 is generally formed using a light-emitting layer-forming composition prepared by mixing the material to be the light-emitting layer 5 with a dissolvable solvent, i.e., a light-emitting layer solvent, instead of the hole-injection layer-forming composition, as in the case of forming the hole-injection layer 3 using a wet film formation method. In the present embodiment, as the light-emitting layer-forming composition, the aforementioned composition containing an iridium complex compound of the present embodiment is preferably used.

[0430] As the solvent, for example, in addition to the ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents exemplified above for the formation of the hole-injection layer 3, there are also alkanes-based solvents, halogenated aromatic hydrocarbon-based solvents, aliphatic alcohol-based solvents, alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents, etc. The solvent used is as exemplified above as the solvent for the composition containing an iridium complex compound of the present embodiment, and specific examples of the solvent are given below, but are not limited thereto as long as the effects of the present application are not impaired.

[0431] For example, there are aliphatic ether-based solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether-based solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; aromatic ester-based solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; aromatic hydrocarbon-based solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, tetralin, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene; amide-based solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkanes-based solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; halogenated aromatic hydrocarbon-based solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol-based solvents such as butanol and hexanol; alicyclic alcohol-based solvents such as cyclohexanol and cyclooctanol; aliphatic ketone-based solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone-based solvents such as cyclohexanone, cyclooctanone, and fenchone. Among these, alkanes-based solvents and aromatic hydrocarbon-based solvents are particularly preferred.

[0432] In addition, in order to obtain a more uniform film, it is preferable that the solvent evaporate from the liquid film after film formation at an appropriate rate. Therefore, as described above, the boiling point of the solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and in addition, is usually 270°C or lower, preferably 250°C or lower, more preferably 230°C or lower.

[0433] The amount of solvent used is arbitrary as long as the effect of the present application is not significantly impaired, and the total content in the composition containing the iridium complex, i.e., the composition for forming a light-emitting layer, is preferably higher in terms of easy film formation due to low viscosity, and is preferably lower in terms of easy film formation with a thick film. As described above, the content of the solvent in the composition containing the iridium complex is preferably 1% by mass or more, more preferably 10% by mass or more, and particularly preferably 50% by mass or more, and is preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and particularly preferably 99% by mass or less.

[0434] As the method for removing the solvent after wet film formation, heating or reduced pressure can be used. As the heating means used in the heating method, since heat is uniformly supplied to the entire film, a clean oven, a hot plate is preferable.

[0435] The heating temperature in the heating step is arbitrary as long as the effect of the present application is not significantly impaired, and is preferably higher in terms of shortening the drying time, and is preferably lower in terms of less damage to the material. The upper limit of the heating temperature is usually 250°C or lower, preferably 200°C or lower, and further preferably 150°C or lower. The lower limit of the heating temperature is usually 30°C or higher, preferably 50°C or higher, and further preferably 80°C or higher. By being the above upper limit temperature, decomposition and crystallization are suppressed within the range of the heat resistance of the commonly used charge transport material or phosphorescent light-emitting material, which is preferable from the above aspect. By being the above lower limit temperature, removal of the solvent does not require an excessively long time, which is preferable from the above aspect. The heating time in the heating step is appropriately determined depending on the boiling point, vapor pressure of the solvent in the composition for forming a light-emitting layer, the heat resistance of the material, and the heating conditions.

[0436] (Formation of the light-emitting layer 5 based on the vacuum evaporation method)

[0437] In the case where the light-emitting layer 5 is formed by the vacuum evaporation method, usually, one or two or more of the constituent materials of the light-emitting layer 5, i.e., the aforementioned light-emitting material, the charge transport compound, and the like, are put into a crucible provided in a vacuum container, and the inside of the vacuum container is evacuated to 10 －4After the temperature of the crucible is raised to about 400°C, the amount of evaporation of the material in the crucible is controlled to evaporate the material, and the light emitting layer 5 is formed on the hole injection layer 3 or the hole transport layer 4 placed facing the crucible. Note that when two or more kinds of materials are used, the materials constituting the light emitting layer 5 are usually separately sealed in different crucibles, and the crucibles are heated separately. Further, the amount of evaporation is usually controlled to evaporate each material independently. Alternatively, when two or more kinds of materials are used, a mixture of the materials can be placed in one crucible, heated, and evaporated to form the light emitting layer 5.

[0438] The degree of vacuum at the time of evaporation is not limited as long as the effect of the present application is not significantly impaired, and is usually 0.1 x 10 － 6 Torr (0.13 x 10 －4 Pa) or more, and is usually 9.0 x 10 －6 Torr (12.0 x 10 －4 Pa) or less. The evaporation rate is not limited as long as the effect of the present application is not significantly impaired, and is usually 0.1 A / sec or more, and is usually 10 A / sec or less. The film formation temperature at the time of evaporation is not limited as long as the effect of the present application is not significantly impaired, and is preferably 10°C or more, and is preferably performed at 50°C or less.

[0439] < Hole Blocking Layer 6 >

[0440] The hole blocking layer 6 can be provided between the light emitting layer 5 and the electron injection layer 8 described later. The hole blocking layer 6 is a layer stacked on the light emitting layer 5 in contact with the interface on the cathode 9 side of the light emitting layer 5.

[0441] The hole blocking layer 6 has a function of preventing holes migrated from the anode 2 from reaching the cathode 9, and a function of efficiently transporting electrons injected from the cathode 9 in the direction of the light emitting layer 5. As the physical properties required for the material constituting the hole blocking layer 6, a high electron mobility and a low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet state (T1) can be given.

[0442] ​Examples of materials for the hole blocking layer 6 that satisfy such conditions include mixed ligand complexes such as bis(2-methyl-8-hydroxyquinolinolato)(phenol)aluminum, bis(2-methyl-8-hydroxyquinolinolato)(triphenylsilanol)aluminum, metal complexes such as bis(2-methyl-8-hydroxyquinolinolato)aluminum-μ-oxo-bis-(2-methyl-8-hydroxyquinolinolato)aluminum dinuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Application Laid-Open No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Application Laid-Open No. 7-41759), and o-phenanthroline derivatives such as bathocuproin (Japanese Patent Application Laid-Open No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2-, 4-, or 6-position as described in International Publication No. 2005 / 022962 are also preferred as materials for the hole-blocking layer 6 .

[0443] The method for forming the hole blocking layer 6 is not limited, and the hole blocking layer 6 can be formed in the same manner as the method for forming the light emitting layer 5 described above.

[0444] The thickness of the hole blocking layer 6 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.

[0445] <Electron transport layer 7>

[0446] In order to further improve the current efficiency of the device, the electron transport layer 7 is provided between the light emitting layer 5 or the hole blocking layer 6 and the electron injection layer 8 .

[0447] The electron transport layer 7 is formed of a compound that can efficiently transport electrons injected from the cathode 9 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 7 needs to have high electron injection efficiency from the cathode 9 or the electron injection layer 8, high electron mobility, and be able to efficiently transport the injected electrons.

[0448] Specific examples of electron-transporting compounds that satisfy such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Application Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, Oxadiazole derivatives, distyryl biphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzo Azole metal complexes, benzothiazole metal complexes, triphenyl imidazole phenyl (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Patent Laid-Open No. 6-207169), phenanthroline derivatives (Japanese Patent Laid-Open No. 5-331459), 2-t-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

[0449] The film thickness of the electron transport layer 7 is usually 1 nm or more, preferably 5 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

[0450] The electron transport layer 7 is formed by layering on the light emitting layer 5 or the hole blocking layer 6 using a wet film forming method or a vacuum evaporation method, similarly to the light emitting layer 5. The vacuum evaporation method is usually used.

[0451] <electron injection layer 8>

[0452] The electron injection layer 8 functions to efficiently inject electrons injected from the cathode 9 into the electron transport layer 7 or the light emitting layer 5.

[0453] In order to efficiently inject electrons, the material forming the electron injection layer 8 is preferably a metal having a low work function. As examples, alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like can be used.

[0454] The film thickness of the electron injection layer 8 is preferably 0.1 to 5 nm.

[0455] In addition, it is also an effective method for improving the element efficiency to insert an extremely thin insulating film such as LiF, MgF2, Li2O, Cs2CO3, and the like as the electron injection layer 8 at the interface between the cathode 9 and the electron transport layer 7 (Appl. Phys. Lett., Vol. 70, p. 152, 1997; Japanese Patent Laid-Open No. 10-74586; IEEE Trans. Electron. Devices, Vol. 44, p. 1245, 1997; SID 04 Digest, p. 154). The extremely thin insulating film refers to an insulating film having a film thickness of about 0.1 to 5 nm.

[0456] Further, by doping alkali metals such as sodium, potassium, cesium, lithium, and rubidium into organic electron transport materials represented by metal complexes such as red phenanthroline and the like nitrogen-containing heterocyclic compound, an aluminum complex of 8-hydroxyquinoline, and the like (described in Japanese Patent Laid-Open No. 10-270171, Japanese Patent Laid-Open No. 2002-100478, Japanese Patent Laid-Open No. 2002-100482, and the like), it is possible to improve the electron injection property and the transport property while having an excellent film quality, and thus is preferable. The film thickness in this case is usually 5 nm or more, preferably 10 nm or more, and is usually 200 nm or less, preferably 100 nm or less.

[0457] The electron injection layer 8 is formed by laminating on the light-emitting layer 5 or the hole blocking layer 6 or the electron transport layer 7 thereon by a wet film formation method or a vacuum deposition method, similarly to the light-emitting layer 5 .

[0458] The details in the case of the wet film formation method are the same as those in the case of the aforementioned light-emitting layer 5 .

[0459] <Cathode 9>

[0460] The cathode 9 plays a role in injecting electrons into the layer on the side of the light-emitting layer 5, that is, the electron injection layer 8 or the light-emitting layer 5. As the material of the cathode 9, the materials used for the anode 2 described above can be used. In terms of efficient electron injection, metals with low work functions are preferably used. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof can be used. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0461] In terms of device stability, it is preferable to stack a metal layer having a high work function and being stable to the atmosphere on the cathode 9 to protect the cathode 9 made of a metal having a low work function. Examples of the stacked metal include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0462] The cathode film thickness is usually the same as that of the anode 2 .

[0463] <Other constituent layers>

[0464] Above, with Figure 1 The description is centered on the elements composed of the layers shown in the figure. However, between the anode 2 and cathode 9 and the light-emitting layer 5 in the organic electroluminescent element of this embodiment, any layer other than the layers described above may be present, as long as the performance is not impaired, and any layer other than the light-emitting layer 5 may be omitted.

[0465] For example, it is also effective to provide an electron blocking layer between the hole transport layer 4 and the light-emitting layer 5 for the same purpose as the hole blocking layer 6. The electron blocking layer has the following functions: by preventing electrons migrating from the light-emitting layer 5 from reaching the hole transport layer 4, the electron blocking layer increases the probability of recombination with holes within the light-emitting layer 5 and confines the generated excitons within the light-emitting layer 5; and by efficiently transporting holes injected from the hole transport layer 4 toward the light-emitting layer 5.

[0466] Required properties of the electron-blocking layer include high hole-transporting properties, a large energy gap (i.e., the difference between the HOMO and LUMO) and a high excited triplet energy level (T1). Furthermore, when the light-emitting layer 5 is formed by a wet film formation method, it is preferred that the electron-blocking layer also be formed by the wet film formation method because this facilitates device manufacturing.

[0467] Therefore, the electron-blocking layer is preferably also adapted to wet film formation, and as a material used in such an electron-blocking layer, a copolymer of dioctylfluorene and triphenylamine represented by F8-TFB (International Publication No. 2004 / 084260) and the like can be given.

[0468] Note that the organic electroluminescent device of the present application can also be provided between two substrates each of which has high transparency, at least one of which is opposite in structure to the above-described structure, i.e., a structure in which a cathode 9, an electron-injection layer 8, an electron-transport layer 7, a hole-blocking layer 6, a light-emitting layer 5, a hole-transport layer 4, a hole-injection layer 3, and an anode 2 are sequentially stacked on a substrate 1. Figure 1 Note that the organic electroluminescent device of the present application can also be provided between two substrates each of which has high transparency, at least one of which is opposite in structure to the above-described structure, i.e., a structure in which a cathode 9, an electron-injection layer 8, an electron-transport layer 7, a hole-blocking layer 6, a light-emitting layer 5, a hole-transport layer 4, a hole-injection layer 3, and an anode 2 are sequentially stacked on a substrate 1.

[0469] Note that the organic electroluminescent device of the present application can also be provided between two substrates each of which has high transparency, at least one of which is opposite in structure to the above-described structure, i.e., a structure in which a cathode 9, an electron-injection layer 8, an electron-transport layer 7, a hole-blocking layer 6, a light-emitting layer 5, a hole-transport layer 4, a hole-injection layer 3, and an anode 2 are sequentially stacked on a substrate 1. Figure 1 Note that the organic electroluminescent device of the present application can also be provided between two substrates each of which has high transparency, at least one of which is opposite in structure to the above-described structure, i.e., a structure in which a cathode 9, an electron-injection layer 8, an electron-transport layer 7, a hole-blocking layer 6, a light-emitting layer 5, a hole-transport layer 4, a hole-injection layer 3, and an anode 2 are sequentially stacked on a substrate 1.

[0470] The present application can be applied to any of a structure in which the organic electroluminescent device is a single element, a structure in which the organic electroluminescent device is configured in an array shape, and a structure in which an anode and a cathode are configured in an X-Y matrix shape.

[0471] [Display device and lighting device]

[0472] The organic EL display device and the organic EL lighting device of the present embodiment each include the organic electroluminescent device of the present embodiment as described above. The form and structure of the organic EL display device and the organic EL lighting device of the present embodiment are not particularly limited, and the organic electroluminescent device of the present embodiment can be assembled in a conventional manner.

[0473] For example, the organic EL display device and the organic EL lighting device of the present embodiment can be formed by a method described in "Organic EL Display" (Ohmsha, Ltd., published on August 20, 2004, written by Kimihiro Toko, Chihaya Adachi, and Hideyuki Murata).

[0474] Examples

[0475] Hereinafter, the present application will be described more specifically with reference to examples. The present application is not limited to the following examples, and the present application can be implemented by arbitrarily changing the examples without departing from the gist thereof.

[0476] Note that in the following synthesis examples, all reactions were performed under a stream of nitrogen. The solvent and the solution used in the reaction were degassed by a suitable method such as bubbling nitrogen.

[0477] [Synthesis of iridium complex]

[0478]

[0479] [Reaction 1]

[0480]

[0481] Into a 1 L flask was placed 2-bromofluorene (20.4 g) and anhydrous tetrahydrofuran (500 mL), and while cooling with an ice water bath, potassium tert-butoxide (21.1 g) was added, followed by dropwise addition of 1-iodo-n-octane (50.9 g) over 15 minutes. The ice water bath was removed and stirring was continued at room temperature for 3 hours. The solvent was distilled off under reduced pressure, and water (300 mL) and dichloromethane (300 mL) were added to separate the layers. The oil phase was recovered and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 9) to obtain 2-bromo-9,9-di-n-octylfluorene as a yellowish oil (37.7 g).

[0482] [Reaction 2]

[0483]

[0484] Into a 1 L flask was placed 2-bromo-9,9-di-n-octylfluorene (37.7 g), bis(pinacolato)diboron (23.7 g), potassium acetate (26.0 g), (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (3.0 g), and dimethyl sulfoxide (DMSO) (350 mL), and stirring was continued at 85°C for 10 hours, and further at 90°C for 10 hours. After cooling to room temperature, water (350 mL) and dichloromethane (300 mL) were added to separate the layers. The oil phase was recovered and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 0 / 1 to 1 / 9) to obtain 2-[9,9-di-n-octylfluoren-2-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane as a blackish tea-colored oil (36.8 g).

[0485] [Reaction 3]

[0486]

[0487] ​To a 1 L flask was added 5-bromo-2-iodopyridine (9.0 g), 2-[9,9-di-n- octylfluorene-2-yl]-4,4,5,5-tetramethyl-l,3,2-dioxaborolane (15.1 g), [tetrakis(triphenylphosphine)palladium(0)] (1.5 g), 2 M aqueous potassium phosphate tribasic (40 mL), toluene (80 mL), and ethanol (40 mL), and stirred at 105°C in an oil bath for 9 hours. After cooling to room temperature, the aqueous phase was removed and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 9) to give 2-(5-bromopyridin-2-yl)-9,9-di-n- octylfluorene as a light green solid, 9.8 g.

[0488] [Reaction 4]

[0489]

[0490] To a 1 L flask was added 2-(5-bromopyridin-2-yl)-9,9-di-n- octylfluorene (9.8 g), bis(pinacolato)diboron (5.2 g), potassium acetate (5.5 g), (1,1'- bis(diphenylphosphino)ferrocene)palladium dichloromethane adduct (0.6 g), and dimethyl sulfoxide (100 mL), and stirred at 90°C for 9 hours. After cooling to room temperature, water (500 mL) and dichloromethane (300 mL) were added and partitioned. The oil phase was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 15 / 85 to 3 / 7) to give 2- [{9,9-di-n-octylfluorene-2-yl}pyridin-5-yl]-4,4,5,5-tetramethyl-l,3,2-dioxaborolane as a yellow solid, 7.8 g.

[0491] [Reaction 5]

[0492]

[0493] To a 1 L eggplant-shaped flask were added 2- [{9,9-di-n-octylfluorene-2-yl}pyridin-5-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (11.8 g), 2,4-di-tert-butyl-6-chloro-1,3,5-triazine (5.4 g, synthesized by using the method described in Japanese Patent Application Publication No. 2016-160180), [tetrakis(triphenylphosphine)palladium(0)] (0.9 g), 2 M aqueous potassium phosphate (25 mL), toluene (60 mL), and ethanol (20 mL), and stirring was performed in an oil bath at 105°C for 2 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 35 / 65), to thereby yield 113.5 g of the intermediate as a colorless amorphous substance.

[0494] [Reaction 6]

[0495]

[0496] To a 200 mL eggplant-shaped flask were added the intermediate 1 (7.1 g), iridium (III) chloride n hydrate (1.8 g), 2-ethoxyethanol (61 mL), and water (14 mL), and stirring was performed in an oil bath at 135 to 150°C for 12 hours. Concentration under reduced pressure was performed, and the obtained residue was purified by silica gel column chromatography (basic silica gel, dichloromethane), to thereby yield 27.5 g of the intermediate as a red solid substance.

[0497] [Reaction 7]

[0498]

[0499] To a 1 L eggplant-shaped flask were added the intermediate 2 (7.5 g), the intermediate 1 (6.4 g), silver (I) trifluoromethanesulfonate (1.3 g), and diglyme (25 mL), and stirring was performed in an oil bath at 145°C for 3 hours. Concentration under reduced pressure was performed, and the obtained residue was purified by silica gel column chromatography (neutral silica gel, hexane / dichloromethane = 8 / 2), to thereby yield 6.2 g of the compound D as a red solid substance.

[0500] <Synthesis Example 2: Synthesis of Compound D-2>

[0501]

[0502] Into a 10 L four-necked reactor was placed 2-acetylfluorene (228.1 g), ethylene glycol (2.0 L), and nitrogen was bubbled for 30 minutes. Potassium hydroxide (216.9 g) was added, and the mixture was stirred while being warmed to an internal temperature of 55°C. Thereafter, hydrazine monohydrate (164.5 g) was added dropwise. The internal temperature was raised to 109°C over 1 hour and 40 minutes, and the internal temperature was raised to 129°C over 40 minutes. The mixture was stirred at an internal temperature of 129 to 146°C for 6 hours. After cooling to room temperature, water (2 L) and concentrated hydrochloric acid (600 mL) were added dropwise, and extraction was performed with dichloromethane (3 L x 2 times). The recovered organic phase was washed with water (2 L) and saturated brine (1 L), and the solvent was removed. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4), and 2-ethylfluorene was obtained as a white solid (109.6 g).

[0503]

[0504] Into a 10 L four-necked reactor was placed 2-acetylfluorene (228.1 g), ethylene glycol (2.0 L), and nitrogen was bubbled for 30 minutes. Potassium hydroxide (216.9 g) was added, and the mixture was stirred while being warmed to an internal temperature of 55°C. Thereafter, hydrazine monohydrate (164.5 g) was added dropwise. The internal temperature was raised to 109°C over 1 hour and 40 minutes, and the internal temperature was raised to 129°C over 40 minutes. The mixture was stirred at an internal temperature of 129 to 146°C for 6 hours. After cooling to room temperature, water (2 L) and concentrated hydrochloric acid (600 mL) were added dropwise, and extraction was performed with dichloromethane (3 L x 2 times). The recovered organic phase was washed with water (2 L) and saturated brine (1 L), and the solvent was removed. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4), and 2-ethylfluorene was obtained as a white solid (109.6 g).

[0505]

[0506] Into a 10 L four-necked reactor was placed 2-acetylfluorene (228.1 g), ethylene glycol (2.0 L), and nitrogen was bubbled for 30 minutes. Potassium hydroxide (216.9 g) was added, and the mixture was stirred while being warmed to an internal temperature of 55°C. Thereafter, hydrazine monohydrate (164.5 g) was added dropwise. The internal temperature was raised to 109°C over 1 hour and 40 minutes, and the internal temperature was raised to 129°C over 40 minutes. The mixture was stirred at an internal temperature of 129 to 146°C for 6 hours. After cooling to room temperature, water (2 L) and concentrated hydrochloric acid (600 mL) were added dropwise, and extraction was performed with dichloromethane (3 L x 2 times). The recovered organic phase was washed with water (2 L) and saturated brine (1 L), and the solvent was removed. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4), and 2-ethylfluorene was obtained as a white solid (109.6 g).

[0507]

[0508] To a 10 L four-necked reaction vessel was charged with 2-bromo-7-ethyl-9,9-di-n- octylfluorene (314.8 g), N-methylpyrrolidone (3.1 L), and stirred for 30 minutes in an oil bath at 50°C. Thereafter, bis(pinacolato)diboron (192.8 g), potassium acetate (198.7 g), and (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (20.7 g) were added, and after warming to an internal temperature of 100°C over 1.5 hours, stirring was continued at 100°C for 4 hours. After cooling to room temperature, partitioned into ethyl acetate (3 L) and water (3 L). The organic phase was washed with water (2 L x 2 times) and saturated brine (1 L), and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 1) to give 2-[7-ethyl-9,9-di-n-octylfluoren-2-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane as a white solid (248.9 g).

[0509]

[0510] To a 5 L four-necked reaction vessel was charged with cyanuric chloride (136.9 g) and tetrahydrofuran (THF, 600 mL), and after cooling to an internal temperature of -23°C, a 1 M phenylmagnesium bromide-THF solution (779 mL) was added dropwise over 50 minutes such that the internal temperature was maintained between -23 and 0°C. The mixture was then allowed to warm to room temperature overnight. After cooling to an internal temperature of -20°C, 2 M hydrochloric acid (430 mL) was added dropwise over 15 minutes such that the internal temperature was maintained between -20 and -5°C. The mixture was then allowed to warm to room temperature and stirred for 20 minutes. The organic phase was extracted with ethyl acetate (1 L x 2 times), washed with saturated brine (500 mL x 2 times), and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 2) to give 2,4-dichloro-6-phenyl-1,3,5-triazine as a white solid (117.9 g).

[0511]

[0512] To a 5 L four-necked reactor was charged with 2,4-dichloro-6-phenyl- 1,3,5-triazine (117.9 g) and THF (1.2 L) to dissolve it, and then copper (I) iodide (3.0 g) was added. After cooling to an internal temperature of -35°C, 2M-tert- butylmagnesium bromide-THF solution (261 mL) was added dropwise over 15 minutes at an internal temperature of -35 to -4°C, and the internal temperature was allowed to reach 16°C over 1 hour. After cooling again to an internal temperature of -35°C, 2M-tert-butylmagnesium bromide-THF solution (78 mL) was added dropwise over 15 minutes at an internal temperature of -35 to -14°C, and the internal temperature was allowed to reach 15°C over 30 minutes. After cooling again to an internal temperature of -35°C, 2M-tert-butylmagnesium bromide-THF solution (52 mL) was added dropwise over 10 minutes at an internal temperature of -35 to -26°C, and stirring was continued at an internal temperature of 15 to 20°C for 1 hour. After cooling to an internal temperature of -15°C, 2M-hydrochloric acid (500 mL) was added dropwise over 7 minutes at an internal temperature of -15 to -6°C, and the temperature was allowed to return to room temperature while stirring for a short time. The oily phase was extracted with ethyl acetate (1.5 L x 2), and the oily phase was washed with saturated brine (500 mL) and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 8) to give 2-tert-butyl-4-chloro-6-phenyl- 1,3,5-triazine as a white solid (80.6 g).

[0513]

[0514] To a 1 L flask were added 5-bromo-2-iodopyridine (10.9 g), 2-[7-ethyl-9,9- di-n-octylfluorene-2-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (19.8 g), [tetrakis(triphenylphosphine)palladium(0)] (2.5 g), 2M aqueous potassium phosphate tribasic (45 mL), toluene (100 mL), and ethanol (50 mL), and stirring was continued at an oil bath temperature of 105°C for 20 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 1) to give 2-ethyl-7-(5-bromopyridin-2-yl)-9,9-di-n-octylfluorene as a pale yellow solid (17.3 g).

[0515]

[0516] To a 1 L flask was added 2-ethyl-7-(5-bromopyridin-2-yl)-9,9-di-n- octylfluorene (17.3 g), bis(pinacolato)diboron (9.1 g), potassium acetate (9.0 g), palladium (II) chloride complex with 1,1'-bis(diphenylphosphino) ferrocene (0.82 g), and dimethyl sulfoxide (100 mL), and stirred at 90°C for 15.5 hours. After cooling to room temperature, the mixture was partitioned between water (400 mL) and dichloromethane (300 mL). The organic phase was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 6 / 4 - 1 / 0, then ethyl acetate / dichloromethane = 1 / 4 - 1 / 1) to give 5-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-2-[7-ethyl-9,9-di-n- octylfluoren-2-yl]pyridine (13.3 g) as a tan solid.

[0517]

[0518] To a 300 mL flask was added 5-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-2- [7-ethyl-9,9-di-n-octylfluoren-2-yl]pyridine (8.6 g), 2-tert-butyl-4-chloro-6-phenyl- 1,3,5-triazine (4.1 g), [tetrakis(triphenylphosphine)palladium(0)] (0.64 g), 2M aqueous potassium phosphate (18 mL), toluene (40 mL), and tetrahydrofuran (20 mL), and stirred at 80°C in an oil bath for 9 hours. After cooling to room temperature, the aqueous phase was removed and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 15 / 85 - 1 / 1) to give intermediate 3 (6.7 g).

[0519]

[0520] To a 200 mL flask was added intermediate 3 (3.8 g), iridium (III) chloride n hydrate (0.92 g), 2-ethoxyethanol (80 mL), and water (10 mL), and stirred at 145°C in an oil bath for 9 hours while distilling. The amount of liquid distilled off was 60 mL. The resulting residue was concentrated under reduced pressure and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 35 / 65) to give intermediate 4 (3.4 g) as a red solid.

[0521]

[0522] To a 100 mL Erlenmeyer flask was added intermediate 4 (3.4 g), intermediate 3 (3.0 g), silver (I) trifluoromethanesulfonate (0.54 g), diglyme (11 mL) and stirred in an oil bath at 145 °C for 5 hours. Concentrated under reduced pressure and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 4 / 6) to give compound D as a red solid, 3.8 g.

[0523] <SYNTHESIS EXAMPLE 3: SYNTHESIS OF COMPOUND D-3>

[0524]

[0525] To a 3 L four-necked reactor was charged with cyanuric chloride (68.0 g), THF (680 mL) and dissolved, then copper (I) iodide (2.1 g) was added and cooled to an internal temperature of -25 °C. Then, 2 M - tert-butylmagnesium bromide • THF solution (277 mL) was added dropwise over 30 minutes at an internal temperature of -25 °C to -9 °C, and the temperature was raised to an internal temperature of 16 °C over 1 hour, and further stirred for 3 hours. After cooling to an internal temperature of -20 °C, 2 M - hydrochloric acid (430 mL) was added dropwise over 15 minutes at an internal temperature of -20 to -5 °C, and then the temperature was raised to room temperature, and the oil phase was extracted with ethyl acetate (1 L x 2 times), washed with saturated brine (500 mL x 2 times), and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4 to 1 / 2) to give 2-tert-butyl-4,6-dichloro-l,3,5-triazine as a white solid, 52.7 g.

[0526]

[0527] To a 3 L four-necked reactor was charged with cyanuric chloride (68.0 g), THF (680 mL) and dissolved, then copper (I) iodide (2.1 g) was added and cooled to an internal temperature of -25 °C. Then, 2 M - tert-butylmagnesium bromide • THF solution (277 mL) was added dropwise over 30 minutes at an internal temperature of -25 °C to -9 °C, and the temperature was raised to an internal temperature of 16 °C over 1 hour, and further stirred for 3 hours. After cooling to an internal temperature of -20 °C, 2 M - hydrochloric acid (430 mL) was added dropwise over 15 minutes at an internal temperature of -20 to -5 °C, and then the temperature was raised to room temperature, and the oil phase was extracted with ethyl acetate (1 L x 2 times), washed with saturated brine (500 mL x 2 times), and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4 to 1 / 2) to give 2-tert-butyl-4,6-dichloro-l,3,5-triazine as a white solid, 52.7 g.

[0528]

[0529] To a 1 L flask was added 2-bromo-7-iodofluorene (Tokyo Kasei Co., 46.3 g), 3-(6-phenyl-n-hexyl)phenylboronic acid (35.5 g), [tetrakis(triphenylphosphine)palladium(0)] (5.4 g), 2 M aqueous potassium phosphate tribasic (150 mL), toluene (300 mL), and ethanol (100 mL), and stirred for 3 hours with refluxing in an oil bath at 105°C. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 15 / 85 to 2 / 8), to give 2-bromo-7-{3-(6-phenyl-n-hexyl)phenyl}fluorene as a white solid substance, 51.3 g.

[0530]

[0531] To a 1 L flask was added 2-bromo-7-{3-(6-phenyl-n-hexyl)phenyl}fluorene (25.6 g) and anhydrous tetrahydrofuran (380 mL), and after adding potassium tert-butoxide (13.4 g) while cooling with an ice water bath, 1-iodo-n-octane (38.3 g) was added dropwise over 15 minutes. The ice water bath was removed, and stirring was performed in an oil bath at 40°C for 95 minutes. The solvent was distilled off under reduced pressure, and the liquid was partitioned with water (150 mL) and ethyl acetate (300 mL). The oil phase was recovered and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 8 / 2 to 7 / 3), to give 2-bromo-7-{3-(6-phenyl-n-hexyl)phenyl}-9,9-di-n-octylfluorene as a yellowish oil substance, 22.5 g.

[0532]

[0533] To a 500 mL Erlenmeyer flask was added 2-bromo-7-{3-(6-phenyl-n-hexyl)phenyl}-9,9-di-n- octylfluorene (22.5 g), bis(pinacolato)diboron (9.5 g), potassium acetate (9.3 g), (1,1'- bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.79 g), and dimethyl sulfoxide (200 mL), and stirred at 90 °C for 8 hours. After cooling to room temperature, further bis(pinacolato)diboron (4.6 g), potassium acetate (4.8 g), (1,1'-bis(diphenylphosphino)ferrocene) dichloropalladium dichloromethane adduct (0.79 g) were added, and further stirred at 90 °C for 5 hours in an oil bath. Then, cooled to room temperature, and partitioned with water (200 mL) and dichloromethane (200 mL). The oil phase was recovered and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7) to give 2-[7-{3-(6-phenyl-n-hexyl)phenyl}-9,9-di-n- octylfluoren-2-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 19.5 g as a yellowish oil.

[0534]

[0535] To a 1 L Erlenmeyer flask was added 5-bromo-2-iodopyridine (9.1 g), 2-[9,9-di-n- octyl-7-{3-(6-phenyl-n-hexyl)phenyl}fluoren-2-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (19.5 g), [tetrakis(triphenylphosphine)palladium(0)] (1.5 g), 2 M aqueous potassium phosphate tribasic (31 mL), toluene (80 mL), and ethanol (40 mL), and stirred at 105 °C for 7 hours in an oil bath. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 9) to give 9,9-di-n-octyl-2-{3-(6-phenyl-n-hexyl)phenyl}-7-(5-bromopyridin-2-yl)fluorene 15.7 g as a yellowish solid.

[0536]

[0537] To a 1 L flask was added 9,9-di-n-octyl-2-{3-(6-phenyl-n-hexyl)phenyl}-7-(5- bromopyridin-2-yl)fluorene (15.7 g), bis(pinacolato)diboron (6.0 g), potassium acetate (6.0 g), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (0.50 g), and dimethyl sulfoxide (100 mL), and stirred at 90°C for 5 hours. Then, bis(pinacolato)diboron (4.8 g), potassium acetate (3.0 g), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (0.92 g) were added, and stirred at 90°C for 5 hours. After cooling to room temperature, water (200 mL) and dichloromethane (200 mL) were added, and the mixture was partitioned. The organic layer was recovered, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 - 6 / 4, then ethyl acetate / hexane = 1 / 9 - 1 / 0) to give 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-[9,9-di-n-octyl-7-{3-(6-phenyl-n- hexyl)phenylfluoren-2-yl}pyridine (14.1 g) as a yellowish oil.

[0538]

[0539] To a 1 L flask was added 9,9-di-n-octyl-2-{3-(6-phenyl-n-hexyl)phenyl}-7-(5- bromopyridin-2-yl)fluorene (15.7 g), bis(pinacolato)diboron (6.0 g), potassium acetate (6.0 g), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (0.50 g), and dimethyl sulfoxide (100 mL), and stirred at 90°C for 5 hours. Then, bis(pinacolato)diboron (4.8 g), potassium acetate (3.0 g), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (0.92 g) were added, and stirred at 90°C for 5 hours. After cooling to room temperature, water (200 mL) and dichloromethane (200 mL) were added, and the mixture was partitioned. The organic layer was recovered, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 - 6 / 4, then ethyl acetate / hexane = 1 / 9 - 1 / 0) to give 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-[9,9-di-n-octyl-7-{3-(6-phenyl-n- hexyl)phenylfluoren-2-yl}pyridine (14.1 g) as a yellowish oil.

[0540]

[0541] To a 100 mL flask was added intermediate 5 (4.8 g), iridium (III) chloride n hydrate (0.82 g), 2-ethoxyethanol (40 mL), and water (10 mL), and stirred at 135-145°C in an oil bath while distilling for 6.5 hours. The amount of liquid distilled was 36 mL. The obtained residue was concentrated under reduced pressure, and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 - 1 / 1) to give intermediate 6 (4.1 g) as a red solid.

[0542]

[0543] To a 100 mL vial was added intermediate 6 (4.1 g), intermediate 5 (3.6 g), silver (I) trifluoromethanesulfonate (0.50 g), diglyme (14 mL), and stirred in an oil bath at 145 °C for 8 hours. The resulting residue was concentrated under reduced pressure and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 2 / 8) to give compound D-3 as a red solid, 5.2 g.

[0544] <Synthesis Example 4: Synthesis of Compound D-4>

[0545]

[0546] To a 2 L four-necked reactor was charged 3-bromo-3'-(6-phenyl-n-hexyl)-1,1'-biphenyl (38.2 g, synthesized by the method described in International Publication No. 2016 / 194784) and THF (380 mL) and dissolved, and cooled to an internal temperature of -76 °C, and 1.6 M-n-butyllithium·n-hexane solution (64 mL) was added dropwise over 30 minutes at an internal temperature of -76 to -66 °C, and further stirred for 1 hour. To another 2 L four-necked reactor was charged 2-tert-butyl-4,6-dichloro-1,3,5-triazine (20.0 g) and THF (300 mL), and cooled to an internal temperature of -85 °C, and the previously prepared organolithium solution was transferred over 20 minutes at an internal temperature of -85 to -80 °C. Further, the internal temperature was increased to 6 °C over 2 hours while stirring. After adding water (300 mL), extraction was performed with ethyl acetate (350 mL x 2 times), and the combined oil phase was washed successively with water (200 mL), saturated brine (100 mL), and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4 to 1 / 2) to give 2-tert-butyl-4-chloro-6-{3'-(6-phenyl-n-hexyl)-1,1'-biphenyl-3-yl}-1,3,5-triazine as a colorless oily substance, 17.9 g.

[0547]

[0548] To a 100 mL Erlenmeyer flask was added 9-bromo-7,7-dimethyl-7H-benzo[c]fluorene (Tokyo Kasei Kogyo Co., Ltd., 7.3 g), bis(pinacolato)diboron (6.6 g), potassium acetate (6.7 g), (l,l'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.60 g), and dimethyl sulfoxide (55 mL), and stirring was performed at 90°C for 3 hours. Then, cooling was performed to room temperature, water (300 mL) and dichloromethane (200 mL) were added, and liquid-liquid separation was performed. After recovering the oil phase and adding magnesium sulfate for drying, concentration was performed under reduced pressure, and the obtained residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 15 / 85), to thereby obtain 2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)-4,4,5,5-tetramethyl-l,3,2-dioxaborolane 7.4 g as a white amorphous solid.

[0549]

[0550] To a 1 L Erlenmeyer flask was added 2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)-4,4,5,5-tetramethyl-l,3,2-dioxaborolane (7.4 g), 5-bromo-2-iodopyridine (6.3 g), [tetrakis(triphenylphosphine)palladium(0)] (0.80 g), 2 M aqueous potassium phosphate tribasic (30 mL), toluene (40 mL), and ethanol (20 mL), and stirring was performed in an oil bath at 105°C for 17 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7), to thereby obtain 5-bromo-2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)pyridine 7.9 g as a white solid.

[0551]

[0552] To a 1 L flask was added 5-bromo-2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)pyridine (7.9 g), bis(pinacolato)diboron (5.9 g), potassium acetate (6.8 g), (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.74 g), and dimethyl sulfoxide (90 mL), and stirred at 90°C for 10 hours in an oil bath. After temporary cooling to room temperature, bis(pinacolato)diboron (1.2 g) and (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.22 g) were added, and stirred at 90°C for 5.5 hours. After cooling to room temperature, the mixture was partitioned with water (300 mL) and dichloromethane (100 mL). The organic layer was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 4 to 4 / 6) to give 2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine as a brown oil, 2.8 g.

[0553]

[0554] To a 1 L flask was added 5-bromo-2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)pyridine (7.9 g), bis(pinacolato)diboron (5.9 g), potassium acetate (6.8 g), (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.74 g), and dimethyl sulfoxide (90 mL), and stirred at 90°C for 10 hours in an oil bath. After temporary cooling to room temperature, bis(pinacolato)diboron (1.2 g) and (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.22 g) were added, and stirred at 90°C for 5.5 hours. After cooling to room temperature, the mixture was partitioned with water (300 mL) and dichloromethane (100 mL). The organic layer was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 4 to 4 / 6) to give 2-(7,7-dimethyl-7H-benzo[c]fluoren-9-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine as a brown oil, 2.8 g.

[0555]

[0556] To a 100 mL flask was added intermediate 7 (1.5 g), iridium (III) chloride n hydrate (0.34 g), 2-ethoxyethanol (26 mL), and water (6 mL), and stirred at 135 to 145°C for 10 hours in an oil bath while distilling. After 3.5 hours, 2-ethoxyethanol (20 mL) was added. Finally, the amount of liquid distilled was 30 mL. After the reaction, the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 1) to give intermediate 8 as a red solid, 1.53 g.

[0557]

[0558] To a 100 mL eggplant-shaped flask, Intermediate 8 (1.5 g), Intermediate 7 (1.2 g), silver (I) trifluoromethanesulfonate (0.28 g), and diethylene glycol dimethyl ether (5 mL) were added and stirred in an oil bath at 145°C for 2.5 hours. The mixture was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 2 / 8) to obtain 1.4 g of Compound D-4 as a red solid.

[0559] <Synthesis Example 5: Synthesis of Compound D-5>

[0560]

[0561] To a 1 L eggplant-shaped flask were added 2-bromo-7-iodofluorene (manufactured by Tokyo Chemical Industry Co., Ltd., 26.2 g), 2-naphthylboronic acid (12.7 g), [tetrakis(triphenylphosphine)palladium(0)] (1.4 g), a 2M aqueous solution of tripotassium phosphate (95 mL), toluene (100 mL), and ethanol (40 mL). The mixture was stirred in an oil bath at 105°C while refluxed for 5.5 hours. After cooling to room temperature, the aqueous phase was removed, and methanol (200 mL) was added to the remaining liquid. The precipitated solid was filtered, rinsed with methanol (100 mL), and dried to obtain 24.3 g of 2-bromo-7-(2-naphthyl)fluorene as a white solid.

[0562]

[0563] A 300 mL eggplant-shaped flask was charged with 2-bromo-7-(2-naphthyl)fluorene (9.4 g), 1-iodo-n-octane (15 mL), and dehydrated tetrahydrofuran (65 mL). Potassium tert-butoxide (8.6 g) was added while cooling in an ice-water bath. The ice-water bath was removed and the mixture was stirred in a 40°C oil bath for 5 hours. The solvent was evaporated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 15 / 85) to obtain 12.9 g of 2-bromo-7-(2-naphthyl)-9,9-di-n-octylfluorene as a yellow-green solid.

[0564]

[0565] 2-Bromo-7-(2-naphthyl)-9,9-dioctylfluorene (12.9 g), bis(pinacolato)diboron (7.0 g), potassium acetate (6.5 g), (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.67 g) and dimethyl sulfoxide (80 mL) were placed in a 1 L eggplant flask and stirred in an oil bath at 90°C for 2.5 hours. 1,4-dichloro- To a 1 L flask were added 7-(2-naphthyl)-9,9-di-n-octyl-2-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)fluorene (7.4 g), 5-bromo-2-iodopyridine (3.9 g), [tetrakis(triphenylphosphine)palladium(0)] (0.70 g), 2 M aqueous potassium phosphate tribasic (14 mL), toluene (30 mL), and ethanol (15 mL), and stirred at 105 °C in an oil bath for 8 h. After cooling to room temperature, the aqueous phase was removed and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, the product obtained with ethyl acetate / hexane = 1 / 9 was further purified with dichloromethane / hexane = 4 / 6) to give 5-bromo-2-(7-naphthyl-9,9-di-n-octylfluoren-2-yl)pyridine 6.4 g.

[0566]

[0567] To a 1 L flask were added 7-(2-naphthyl)-9,9-di-n-octyl-2-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)fluorene (7.4 g), 5-bromo-2-iodopyridine (3.9 g), [tetrakis(triphenylphosphine)palladium(0)] (0.70 g), 2 M aqueous potassium phosphate tribasic (14 mL), toluene (30 mL), and ethanol (15 mL), and stirred at 105 °C in an oil bath for 8 h. After cooling to room temperature, the aqueous phase was removed and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, the product obtained with ethyl acetate / hexane = 1 / 9 was further purified with dichloromethane / hexane = 4 / 6) to give 5-bromo-2-(7-naphthyl-9,9-di-n-octylfluoren-2-yl)pyridine 6.4 g.

[0568]

[0569] To a 500 mL Erlenmeyer flask was added 5-bromo-2-(7-naphthyl-9,9-di-n- octylfluoren-2-yl)pyridine (6.3 g), bis(pinacolato)diboron (2.8 g), potassium acetate (2.8 g), (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.24 g), and dimethyl sulfoxide (45 mL), and stirred at 90 °C for 4.5 hours in an oil bath. After temporary cooling to room temperature, bis(pinacolato)diboron (1.4 g), potassium acetate (1.5 g), and (1,1'-bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.15 g) were added again and stirred at 90 °C for 4.5 hours. After cooling to room temperature, water (200 mL) and dichloromethane (200 mL) were added and partitioned. The organic phase was recovered and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 1 / 9 to 1 / 1) to give 2-(7-naphthyl-9,9-di-n-octylfluoren-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine as a brown oil, 6.4 g.

[0570]

[0571] To a 1 L Erlenmeyer flask was added 2-(7-naphthyl-9,9-di-n-octylfluoren-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (6.2 g), 2-tert-butyl-4-chloro-6-{3'-(6-phenyl-n-hexyl)-1,1'-biphenyl-3-yl}-1,3,5-triazine (5.0 g), [tetrakis(triphenylphosphine)palladium(0)] (0.41 g), 2 M aqueous potassium phosphate tribasic (11 mL), toluene (36 mL), and ethanol (18 mL), and stirred at 105 °C for 9 hours in an oil bath. After cooling to room temperature, the aqueous phase was removed and the remaining liquid was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 to 4 / 6) to give intermediate 9 as a yellow amorphous solid, 5.9 g.

[0572]

[0573] To a 100 mL Erlenmeyer flask was added intermediate 9 (5.6 g), iridium (III) chloride n hydrate (0.94 g), 2-ethoxyethanol (50 mL), and water (12 mL), and stirred at 135 to 150 °C for 5.5 hours in an oil bath while distilling. Finally, the amount of liquid distilled out was 47 mL. After completion of the reaction, the obtained residue was concentrated under reduced pressure and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 4 / 6 to 1 / 1) to give intermediate 10 as a red solid, 4.9 g.

[0574]

[0575] To a 100 mL flask was added intermediate 10 (4.9 g), intermediate 9 (3.6 g), silver (I) trifluoromethanesulfonate (0.59 g), and diglyme (16 mL), and stirred in an oil bath at 145°C for 5.5 hours. The solvent was distilled off under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 4 / 6) to obtain compound D-5 as a red solid, 4.4 g.

[0576] <Synthesis Example 6: Synthesis of Compound D-6>

[0577]

[0578] To a 300 mL flask was added 2-bromo-7-(2-naphthyl)fluorene (9.4 g), iodomethane (7.5 mL), and anhydrous tetrahydrofuran (100 mL), and after adding potassium t-butoxide (13.2 g) while cooling with an ice water bath, the ice water bath was removed and stirred in an oil bath at 40°C for 3 hours. The solvent was distilled off under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 15 / 85 to 25 / 75) to obtain 2-bromo-9,9-dimethyl-7-(2-naphthyl)-fluorene as a white solid, 11.9 g.

[0579]

[0580] To a 1 L flask was added 2-bromo-9,9-dimethyl-7-(2-naphthyl)-fluorene (11.9 g), bis(pinacolato)diboron (8.9 g), potassium acetate (9.4 g), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride dichloromethane adduct (1.0 g), and dimethyl sulfoxide (60 mL), and stirred in an oil bath at 90°C for 4 hours. After cooling to room temperature, water (500 mL) and dichloromethane (300 mL) were added and partitioned. The oil phase was recovered and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 2 / 8) to obtain 9,9-dimethyl-7-(2-naphthyl)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)fluorene as a white solid, 11.1 g.

[0581]

[0582] To a 1 L flask was added 9,9-dimethyl-7-(2-naphthyl)-2-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)fluorene (11.1 g), 5-bromo-2-iodopyridine (8.1 g), [tetrakis(triphenylphosphine)palladium(0)] (1.2 g), 2 M aqueous potassium phosphate (35 mL), toluene (60 mL), and ethanol (35 mL), and stirred at 105°C in an oil bath for 8.5 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was filtered, and the solid thus obtained was washed with ethanol (200 mL) and dried, to give 5-bromo-2-(9,9-dimethyl-7-naphthylfluorene-2-yl)pyridine 8.5 g.

[0583]

[0584] To a 500 mL flask was added 5-bromo-2-(9,9-dimethyl-7-naphthylfluorene-2- yl)pyridine (8.5 g), bis(pinacolato)diboron (6.1 g), potassium acetate (6.3 g), (1,1'- bis(diphenylphosphino)ferrocene)dichloropalladium dichloromethane adduct (0.61 g), dimethyl sulfoxide (70 mL), and 1,4-dioxane (25 mL), and stirred at 90°C in an oil bath for 4 hours. After 2 hours, 1,4-dioxane (30 mL) was added. After cooling to room temperature, the mixture was partitioned with water (500 mL) and dichloromethane (300 mL). The organic phase was recovered and concentrated under reduced pressure, and the residue thus obtained was purified by silica gel column chromatography (neutral silica gel, dichloromethane / tetrahydrofuran = 1 / 0 to 8 / 2), to give 2-(9,9-dimethyl-7-naphthylfluorene-2-yl)-5-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)pyridine 6.4 g as a beige solid.

[0585]

[0586] ​​To a 1 L flask were added 2-(9,9-dimethyl-7-naphthylfluorene-2-yl)-5-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (6.4 g), 2-tert-butyl-4-chloro-6-{3'- (6-phenyl-n-hexyl)-1,1'-biphenyl-3-yl}-1,3,5-triazine (5.9 g), [tetrakis(triphenyl- phosphine)palladium(0)] (0.52 g), 2 M aqueous potassium phosphate tribasic (20 mL), toluene (40 mL), and ethanol (15 mL), and stirred at 105°C in an oil bath for 5 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 to 6 / 4) to give intermediate 117.1 g as a yellow-green amorphous solid.

[0587]

[0588] To a 100 mL flask were added intermediate 11 (5.1 g), iridium (III) chloride n-hydrate (1.0 g), 2-ethoxyethanol (60 mL), and water (10 mL), and stirred at 140 to 150°C in an oil bath while distilling for 7 hours. After 1.5 hours, 2-ethoxyethanol (16 mL) was added. Finally, the amount of liquid distilled off was about 50 mL. After the reaction was completed, the resulting residue was concentrated under reduced pressure, and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 1) to give intermediate 12 5.0 g as a red solid.

[0589]

[0590] To a 100 mL flask were added intermediate 12 (5.0 g), intermediate 11 (2.0 g), silver (I) trifluoromethanesulfonate (0.77 g), and diglyme (12 mL), and stirred at 145°C in an oil bath for 1.5 hours, and then at 150°C for 2 hours. The resulting residue was concentrated under reduced pressure, and purified by silica gel column chromatography (neutral silica gel, toluene / hexane = 1 / 1 to 2 / 1) to give compound D-6 2.7 g as a red solid.

[0591] <SYNTHESIS EXAMPLE 7: SYNTHESIS OF COMPOUND D-7>

[0592]

[0593] Into a 300 mL four-necked flask was placed 2-(4-biphenylyl)-4,6-dichloro-l,3,5-triazine (10.0 g, manufactured by Tokyo Kasei K.K.), copper (I) iodide (0.21 g), and dehydrated tetrahydrofuran (100 mL), and after dropwise addition of a 2 M-THF (tetrahydrofuran) solution of tert-butylmagnesium bromide (manufactured by Tokyo Kasei K.K., 18.5 mL) at an internal temperature of -63°C, the temperature was raised to -10°C and stirring was performed for 2.5 hours. After addition of IN-hydrochloric acid (120 mL), extraction was performed with ethyl acetate (200 mL), and the oil phase was washed with brine (200 mL). After removal of the solvent from the oil phase under reduced pressure, purification was performed by silica gel column chromatography (dichloromethane / hexane = 35 / 65), and as a result, 6.8 g of the target 2-(4-biphenylyl)-4-tert-butyl-6-chloro-l,3,5-triazine was obtained.

[0594]

[0595] Into a 1 L eggplant-shaped flask were placed [2-{9,9-di-n-octylfluorene-2-yl}pyridin-5-yl]4,4,5,5-tetramethyl-l,3,2-dioxaborolane (12.2 g), 2-(4-biphenylyl)-4-tert-butyl-6-chloro-l,3,5-triazine (7.7 g), tetrakis(triphenylphosphine)palladium (0)] (1.0 g), 2 M-potassium phosphate aqueous solution (30 mL), toluene (75 mL), and ethanol (50 mL), and stirring was performed in an oil bath at 105°C for 9.5 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 4 / 6), and as a result, 14.5 g of intermediate 13 was obtained as a colorless amorphous substance.

[0596]

[0597] Into a 300 mL eggplant-shaped flask were placed intermediate 13 (9.4 g), iridium (III) chloride n hydrate (2.06 g), 2-ethoxyethanol (90 mL), and water (21 mL), and while distilling, the temperature of the oil bath was raised to 135 to 150°C, and stirring was performed for 13 hours. Concentration under reduced pressure was performed, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 6 / 4), and as a result, 9.6 g of intermediate 14 was obtained as a red solid.

[0598]

[0599] To a 1 L eggplant shaped flask was added intermediate 14 (9.6 g), intermediate 13 (5.1 g), silver (I) trifluoromethanesulfonate (1.5 g), diglyme (32 mL), and stirred in an oil bath at 145°C for 4.5 hours. The resulting residue was concentrated under reduced pressure and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 1) to give compound D-7 as a red solid, 7.6 g.

[0600]

[0601]

[0602] To a 2 L four-necked flask was charged with magnesium turnings (26.5 g), diethyl ether (180 mL), and 2 mL of 1-chloro-2,2-dimethylpropane (84.9 g) in diethyl ether (430 mL) was added dropwise over 3 hours and 40 minutes while maintaining the internal temperature at 30 to 40°C. After further stirring with reflux for 2 hours, the mixture was cooled to room temperature. To another 3 L four-necked flask was charged with 2,4-dichloro-6-phenyl-1,3,5-triazine (120.0 g) and THF (900 mL) to form a solution, and then copper (I) iodide (3.0 g) was added and the mixture was cooled to an internal temperature of -23°C. Next, the previously prepared Grignard reagent solution was added dropwise over 25 minutes while maintaining the internal temperature at -23 to -4°C, and the mixture was warmed to an internal temperature of 20°C over 1 hour. After the internal temperature was again cooled to -20°C, 2M-hydrochloric acid (800 mL) was added dropwise over 10 minutes while maintaining the internal temperature at -20 to 0°C, and the mixture was stirred for 15 minutes while returning to room temperature. The oil phase was extracted with ethyl acetate (500 mL x 2), washed with a mixture of water (250 mL) and saturated brine (250 mL), and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 9 to 1 / 5) to give 2-chloro-4-neopentyl-6-phenyl-1,3,5-triazine as a white solid, 62.4 g.

[0603]

[0604] ​To a 1 L flask were added 2-(7-ethyl-9,9-di-n-octylfluorene-2-yl)-5-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (6.9 g), 2-chloro-4-neopentyl-6- phenyl-1,3,5-triazine (4.0 g), [tetrakis(triphenylphosphine)palladium(0)] (0.68 g), 2 M aqueous potassium phosphate (20 mL), toluene (40 mL), and ethanol (20 mL), and stirred at 105°C for 3 hours in an oil bath. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 15 / 85) to give intermediate 15 as a white solid, 6.6 g.

[0605]

[0606] To a 300 mL flask were added intermediate 15 (4.2 g), iridium (III) chloride n hydrate (0.97 g), 2-ethoxyethanol (40 mL), and water (10 mL), and stirred at 140 to 170°C for 16 hours while distilling. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 6 / 4) to give intermediate 16 as a red solid, 9.6 g.

[0607]

[0608] To a 1 L flask were added intermediate 16 (1.4 g), intermediate 15 (2.4 g), silver (I) trifluoromethanesulfonate (0.22 g), and diglyme (3 mL), and stirred at 145°C for 2 hours in an oil bath. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 2 / 8 to 1 / 1) to give compound D-8 as a red solid, 1.7 g.

[0609] <SYNTHESIS EXAMPLE 9: SYNTHESIS OF COMPOUND D-9>

[0610]

[0611] To a 1 L flask were added 5-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-2-[9,9-di-n- octylfluorene-2-yl]pyridine (37.2 g), 2-tert-butyl-4-chloro-6-phenyl-l,3,5-triazine (18.7 g), [tetrakis(triphenylphosphine)palladium(0)] (2.9 g), 2 M aqueous potassium phosphate tribasic (78 mL), toluene (200 mL), and tetrahydrofuran (100 mL), and stirring was performed in an oil bath at 105°C for 5 hours. After cooling to room temperature, the aqueous phase was removed, and the remaining liquid was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 1) to thereby yield intermediate 17 (29.1 g) as a yellow oil.

[0612]

[0613] To a 300 mL flask were added intermediate 17 (16.4 g), iridium (III) chloride n hydrate (4.0 g), 2-ethoxyethanol (140 mL), and water (33 mL), and the temperature of an oil bath was increased to 135-140°C while distilling, and stirring was performed for 6.5 hours. Thereafter, the resulting residue was concentrated under reduced pressure, and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 6 / 4) to thereby yield intermediate 18 (17.4 g) as a red solid.

[0614]

[0615] To a 1 L flask were added intermediate 18 (17.4 g), intermediate 17 (6.5 g), silver (I) trifluoromethanesulfonate (2.8 g), and diglyme (58 mL), and stirring was performed in an oil bath at 145°C for 5 hours. The resulting residue was concentrated under reduced pressure, and purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 2 / 8) to thereby yield compound D-9 (10.3 g) as a red solid.

[0616] <Comparative Compound D-C1>

[0617] Comparative compound D-C1 shown by the following formula was synthesized according to the method described in Patent Literature 1.

[0618]

[0619] <Comparative Compound D-C2>

[0620] Comparative compound D-C2 shown by the following formula was synthesized according to the method described in Patent Literature 3 and the method described in the synthesis example of compound D-2.

[0621]

[0622] [Measurement of maximum wavelength and half width of emission]

[0623] A solution of Compound 1 was prepared at room temperature at a concentration of 1 x 10 －5 mol / L in 2-methyltetrahydrofuran (manufactured by Aldrich Corporation, dehydrated, not containing a stabilizer). The solution was introduced into a quartz cell with a Teflon (registered trademark) stopcock, and phosphorescence spectrum was measured at room temperature after nitrogen bubbling for 20 minutes or more. The wavelength showing the maximum value of the intensity of the obtained phosphorescence spectrum was taken as the maximum emission wavelength. In addition, the width of the spectrum intensity at half the maximum emission wavelength was taken as the half width. The half width expressed in cm -1 was read from the data of the spectrum normalized to a conversion height of 1, the shorter wavelength exceeding a height of 0.5 and the longer wavelength being lower than the height of 0.5 were converted to cm -1 , and the difference was taken as the half width in cm -1 .

[0624] It should be noted that the following instrument was used in the measurement of the emission spectrum.

[0625] Apparatus: Organic EL Quantum Yield Measurement Apparatus C9920-02 manufactured by Hamamatsu Photonics K.K. Light source: Monochromatic light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380 nm

[0626] [Measurement of PL quantum yield]

[0627] As the emission efficiency, the PL quantum yield was measured. The PL quantum yield is an index indicating to what extent emission can be obtained with what efficiency from light (energy) absorbed by the material, and was measured using the following instrument as well.

[0628] Apparatus: Organic EL Quantum Yield Measurement Apparatus C9920-02 manufactured by Hamamatsu Photonics K.K. Light source: Monochromatic light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380 nm As for Comparative Compound 1 as well, the half width, the maximum wavelength, and the PL quantum yield were measured.

[0629] [Table 1]

[0630]

[0631] As is apparent from the above, Compound D-1 has a particularly narrow half width as compared with Comparative Compound D-C1.

[0632] [Measurement 2 of maximum wavelength and half width of emission]

[0633] A solution of Compound D-1 was prepared at room temperature at a concentration of 1 x 10－5 mol / L solution. The solution was put into a quartz cell with a Teflon (registered trademark) stopcock, and phosphorescence spectrum was measured at room temperature after nitrogen bubbling for 20 minutes or more. The wavelength showing the maximum value of the intensity of the obtained phosphorescence spectrum was taken as the maximum emission wavelength. Further, the width of the spectrum intensity at half of the maximum emission wavelength was taken as the half-value width. The half-value width expressed in cm －1 was read from the data of the spectrum normalized to a conversion height of 1, and the shorter wavelength exceeding a height of 0.5 and the longer wavelength below a height of 0.5 were converted to cm -1 and the difference was taken as the half-value width in cm -1 .

[0634] It should be noted that the measurement of the emission spectrum used the following instrument.

[0635] Apparatus: Organic EL Quantum Yield Measurement Apparatus C9920-02 manufactured by Hamamatsu Photonics K.K. Light source: Monochromatic light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380 nm

[0636] [Measurement of PL Quantum Yield]

[0637] As the emission efficiency, the PL quantum yield was measured. The PL quantum yield is an index indicating to what extent emission can be obtained with what efficiency from light (energy) absorbed by the material, and was measured using the following instrument as well.

[0638] Apparatus: Organic EL Quantum Yield Measurement Apparatus C9920-02 manufactured by Hamamatsu Photonics K.K. Light source: Monochromatic light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380 nm

[0639] The half-value width and the maximum wavelength and the PL quantum yield were also measured in the same manner with respect to the compounds D-1, D-3 to D-5, D-8 and D-9, and the comparative compounds D-C1 and D-C2.

[0640] [Table 2]

[0641]

[0642] It can be considered that the values of the PL quantum yield are almost equal except for the compound D-4. It can be considered that the compound D-4 exhibits a slightly lower value of the quantum yield according to the so-called energy gap rule because the wavelength is longer than that of the other compounds. With respect to the values of the half-value width, it can be known that the compounds D-1, D-3 to D-5, D-8 and D-9 are equal to or smaller than the value of the comparative compound D-C1, and are much smaller than the value of the comparative compound D-C2.

[0643] [Example 1]

[0644] An organic electroluminescent element was produced by the following method.

[0645] As an anode, a film deposition product (Geomatec Co., Ltd., sputtering film deposition product) for depositing an indium-tin oxide (ITO) transparent conductive film having a thickness of 50 nm on a glass substrate was patterned into a stripe having a width of 2 mm using a general photolithography technique and hydrochloric acid etching. The substrate on which the ITO had been patterned was sequentially washed by ultrasonic cleaning based on a surfactant aqueous solution, water washing based on ultrapure water, ultrasonic cleaning based on ultrapure water, and water washing based on ultrapure water, and then dried with compressed air, and finally subjected to ultraviolet ozone cleaning.

[0646] As a composition for forming a hole injection layer, a composition in which a hole-transporting high-molecular compound 3.0% by weight having a repeating structure of the following formula (P-1) and an oxidizing agent (HI-1) 0.6% by weight were dissolved in ethyl benzoate was prepared.

[0647]

[0648] The solution was spin-coated on the above substrate in the atmosphere, and dried at 240°C for 30 minutes using a hot plate in the atmosphere to form a uniform thin film having a film thickness of 39 nm as a hole injection layer.

[0649] Next, a charge-transporting high-molecular compound 100 parts by mass having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 3.0% by weight solution.

[0650] The solution was spin-coated on the substrate on which the above hole injection layer was formed into a film 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 having a film thickness of 42 nm as a hole transport layer.

[0651]

[0652] Subsequently, as a material for a light-emitting layer, 50 parts by mass of the following structural formula (H-1), 50 parts by mass of the following structural formula (H-2), 15 parts by mass of the following structural formula (D-A1), and 15 parts by mass of the following structural formula (D-2) were weighed, respectively, and dissolved in cyclohexylbenzene to prepare a 5.0% by weight solution.

[0653]

[0654] The solution was spin-coated on the substrate on which the above hole transport layer was formed into a film 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 having a film thickness of 60 nm as a light-emitting layer.

[0655] A substrate on which a light-emitting layer was formed was set in a vacuum deposition apparatus, and the inside of the apparatus was evacuated to a degree of vacuum of 2 x 10 － 4 Pa or less.

[0656] Next, the following structural formula (ET-1) and 8-hydroxyquinolinol lithium were co-deposited on the light-emitting layer by a vacuum deposition method at a film thickness ratio of 2:3 to form a hole-blocking layer having a film thickness of 30 nm.

[0657]

[0658] Next, a 2 mm wide stripe-shaped shadow mask was attached to the substrate as a mask for cathode deposition in a manner orthogonal to the ITO stripe of the anode, and aluminum was deposited using a molybdenum boat to form an aluminum layer having a film thickness of 80 nm to form a cathode. Thus, an organic electroluminescent element having a light-emitting area portion of 2 mm x 2 mm was obtained.

[0659] (Evaluation of the element)

[0660] The obtained organic electroluminescent element was energized to emit light, and the peak wavelength and half-value width of the emission spectrum were measured.

[0661] In addition, the external quantum efficiency (EQE (%)) when the element was caused to emit light at a luminance of 1000 cd / m 2 was calculated.

[0662] Further, as an evaluation of the driving life of the element, the element was continuously energized at a current density of 60 mA / cm 2 , the time (LT95 (hr)) until the luminance of the element decreased to 95% of the initial luminance was measured, and the life of the LT95 of Examples 1 to 5 when the LT95 of Comparative Example 1 was taken as 1 was recorded as the relative life in Table 4.

[0663] [Example 2]

[0664] The composition of the light-emitting layer was changed to the following structural formula (D-3) instead of the above-described structural formula (D-2), and an organic electroluminescent element was produced in the same manner as in Example 1 except for this.

[0665]

[0666] [Example 3]

[0667] The composition of the light-emitting layer was changed to the following structural formula (D-4) instead of the above-described structural formula (D-2), and an organic electroluminescent element was produced in the same manner as in Example 1 except for this.

[0668]

[0669] [Example 4]

[0670] An organic electroluminescent device was produced in the same manner as in Example 1, except that the composition of the light-emitting layer was changed to Structural Formula (D-5) below instead of the above Structural Formula (D-2).

[0671]

[0672] [Example 5]

[0673] An organic electroluminescent device was produced in the same manner as in Example 1, except that the composition of the light-emitting layer was changed to Structural Formula (D-6) below instead of the above Structural Formula (D-2).

[0674]

[0675] [Example 6]

[0676] An organic electroluminescent device was produced in the same manner as in Example 1, except that the composition of the light-emitting layer was changed to Structural Formula (D-7) below instead of the above Structural Formula (D-2).

[0677]

[0678] [Comparative Example 1]

[0679] An organic electroluminescent device was produced in the same manner as in Example 1, except that the composition of the light-emitting layer was changed to Structural Formula (D-C1) below instead of the above Structural Formula (D-2).

[0680]

[0681] [Solution spectrum]

[0682] The maximum emission wavelength was determined from the solution spectrum of each light-emitting material.

[0683] A solution in which the compound was dissolved in toluene at a concentration of 1 x 10 －5 mol / L was prepared at room temperature, and after nitrogen bubbling was performed for 20 minutes or more, photoluminescence spectrum was measured using a spectrophotometer (Organic EL Quantum Yield Measurement Device C9920-02 manufactured by Hamamatsu Photonics K.K.). The wavelength at which the maximum value of the obtained spectrum intensity was shown was shown as the maximum emission wavelength in Table 3.

[0684] [Table 3]

[0685]

[0686] [Evaluation of the device]

[0687] According to the results in Table 4, in the organic electroluminescent device of the present embodiment, the emission efficiency was equivalent to that of the past, and the half-value width was narrow and good.

[0688] In addition, the element using the light-emitting material including the organic electroluminescent element of the present embodiment has a long and good driving life.

[0689] [Table 4]

[0690]

[0691] [Comparative Example 2]

[0692] The organic electroluminescent element was produced in the same manner as in Example 1, except that the composition of the light-emitting layer was changed to Structural Formula (D-C2) described below instead of the above Structural Formula (D-2).

[0693]

[0694] The peak wavelength and the half-value width of the emission spectrum when the element emitted light were 617 nm and 61 nm, respectively, and the half-value width was wide and not good.

[0695] It was confirmed that the iridium complex compound represented by Formula (1) can narrow the half-value width. In addition, it was confirmed that the half-value width was narrowed and the life was further improved in Structural Formulas (D-2), (D-3), (D-5), (D-6) in which fluorene has a substituent group, and (D-4) in which fluorene is condensed.

[0696] Although the present application has been described in detail with reference to particular embodiments, it is apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present application. This application is based on Japanese Patent Application (Japanese Patent Application No. 2020-021319) filed on February 12, 2020, and the content of this application is incorporated herein by reference in its entirety.

[0697] Explanation of Symbols

[0698] 1 substrate 2 anode 3 hole injection layer 4 hole transport layer 5 light-emitting layer 6 hole blocking layer 7 electron transport layer 8 electron injection layer 9 cathode 10 organic electroluminescent element

Claims

1. An iridium complex compound represented by the following formula (1), In formula (1), Ir represents an iridium atom, R 5 ~R 14 , R 21 and R 22 are each independently selected from a hydrogen atom, a straight chain or branched alkyl group having 1 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, and an aralkyl group having 5 to 60 carbon atoms, wherein, R 12 and any one of R 13 is a substituent represented by the following formula (2), In formula (2), the dotted line indicates the bonding site with formula (1), R 31 represents a linear or branched alkyl group having 1 to 30 carbon atoms, R 32 represents a linear or branched alkyl group having 1 to 30 carbon atoms, or a carbon number 6 to 30 aromatic group which can have a linear or branched alkyl group having 7 or less carbon atoms, or a carbon number 6 to 30 aromatic group which can have an aralkyl group having 7 to 30 carbon atoms.

2. The iridium coordination compound of claim 1, wherein, R in the formula (2) is a tertiary butyl group. 31 is a tertiary butyl group.

3. The iridium coordination compound of claim 1, wherein, R in the formula (2) 32 is phenyl, naphthyl, phenanthrenyl, biphenyl, terphenyl, fluorenyl or spirobifluorenyl.

4. The iridium coordination compound of claim 1, wherein, at least one of R 21 and R 22 is a linear or branched alkyl group having 1 to 30 carbon atoms.

5. The iridium coordination compound of claim 1, wherein, R in the formula (1) is the same as R 21 and R 22 in the formula (1) R 21 and R 22 is methyl, ethyl, n-propyl, i-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, or i-butyl.

6. The iridium coordination compound of claim 1, wherein, R in the formula (1) is a substituent represented by the formula (2). 13 is a substituent represented by the formula (2).

7. The iridium coordination compound of claim 1, wherein, at least any one of R 6 ~R 9 is a linear or branched alkyl group having 1 to 30 carbon atoms, an aromatic group having 5 to 60 carbon atoms, or an aralkyl group having 5 to 60 carbon atoms.

8. The iridium coordination compound of claim 1, wherein, R in the formula (1) 6 ~R 9 mutually adjacent groups in the formula (1) are bonded to each other to form a ring.

9. An iridium complex compound-containing composition comprising the iridium complex compound according to any one of claims 1 to 8 and an organic solvent.

10. The composition containing iridium coordination compound according to claim 9, wherein, further comprising a compound represented by the following formula (3) having a shorter maximum emission wavelength than the iridium complex compound, In the formula (3), R 35 is an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 30 carbon atoms, which groups can further have substituents, R 35 when a plurality of R exists, they can be the same or different, c is an integer of 0 to 4, ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, a oxazole ring, a thiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a benzo-phenanthrene ring, a carboline ring, a benzothiazole ring, a benzoxazole ring, a the ring A can have a substituent which is F, Cl, Br, an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 2 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 20 carbon atoms, and further, adjacent substituents bonded to the ring A can be bonded to each other to further form a ring, and when a plurality of the ring A exists, they can be the same or different, L 2 represents an organic ligand, and n is an integer of 1 to 3.

11. The composition containing iridium coordination compound according to claim 10, wherein, the compound represented by the formula (3) is a compound represented by the following formula (3-1), In the formula (3-1), ring A, L 2 , n have the same meanings as ring A, L 2 , n in the formula (3), respectively, R 36 an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 30 carbon atoms, which groups can further have substituents, R 36 when a plurality of R exists, they can be the same or different, f is an integer of 0 to 5.

12. The composition containing iridium coordination compound according to claim 10 or 11, wherein, the ring A is a pyridine ring or a quinoline ring.

13. The composition containing iridium coordination compound according to claim 10 or 11, wherein, n is 3.

14. The composition containing iridium coordination compound according to claim 9, wherein, further comprising a compound represented by the following formula (20), in the formula (20), W each independently represents CH or N, at least one of 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 can have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, Xa 2 , Ya 2 and Za 2 each independently represent a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, g11, h11 and j11 each independently represent an integer of 0 to 6, at least one of g11, h11 and j11 is an integer of 1 or more, when g11 is 2 or more, there are multiple Xa 1 may be the same or different, h11 is 2 or more, there are multiple Ya 1 may be the same or different, j11 is 2 or more, and multiple Za exist 1 may be the same or different, R 23 represents a hydrogen atom or a substituent, 4 R 23 may be the same or different, wherein g11, h11or j11is 0, the corresponding Xa 2 , Ya 2 or Za 2 is not a hydrogen atom.

15. The composition containing iridium coordination compound according to claim 14, wherein, all of W in the formula (20) are N.

16. The composition containing iridium coordination compound according to claim 14, wherein, Xa 1 , Ya 1 and Za 1 each independently is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, an aromatic hydrocarbon ring of which is a benzene ring, a naphthalene ring or a fluorene ring.

17. A composition containing an iridium coordination compound according to claim 16, wherein, Xa 2 Ya 2 and Za 2 each independently is an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, an aromatic hydrocarbon ring of the aromatic hydrocarbon group is a benzene ring, a naphthalene ring or a fluorene ring, and an aromatic heterocyclic ring of the aromatic heterocyclic group is a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring.

18. A production method of an organic electroluminescent element having an anode, a cathode, and at least one organic layer between the anode and the cathode on a substrate, at least one of the organic layers is formed using the iridium complex compound-containing composition according to any one of claims 9 to 17 by a wet film formation method.

19. An organic electroluminescent element having an anode, a cathode, and at least one organic layer between the anode and the cathode on a substrate, at least one of the organic layers is a light-emitting layer containing the iridium complex compound according to any one of claims 1 to 8.

20. The organic electroluminescent element according to claim 19, wherein further comprising a compound represented by the following formula (3) having a shorter maximum emission wavelength than the iridium complex compound, In the formula (3), R 35 is an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 30 carbon atoms, which groups can further have substituents, R 35 when a plurality of R exists, they can be the same or different, c is an integer of 0 to 4, Ring A is a pyridine ring, a pyrazine ring, a pyrimidine ring, an imidazole ring, Azole ring, thiazole ring, quinoline ring, isoquinoline ring, quinazoline ring, quinoxaline ring, azatriphenylene ring, carboline ring, benzothiazole ring, benzo Any one of the azole rings, the ring A can have a substituent which is F, Cl, Br, an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 2 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 20 carbon atoms, and further, adjacent substituents bonded to the ring A can be bonded to each other to further form a ring, and when a plurality of the ring A exists, they can be the same or different, L 2 represents an organic ligand, and n is an integer of 1 to 3.

21. The organic electroluminescent device according to claim 20, wherein The compound represented by the formula (3) is a compound represented by the following formula (3-1), In the formula (3-1), ring A, L 2 , n have the same meanings as ring A, L 2 , n in the formula (3), respectively, R 36 an alkyl group having 1 to 20 carbon atoms, an aralkyl or heteroaralkyl group having 7 to 40 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy or heteroaryloxy group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 2 to 20 carbon atoms, an arylcarbonyl group having 7 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an aryl or heteroaryl group having 3 to 30 carbon atoms, which groups can further have substituent (s), R 36 when a plurality of R exists, they can be the same or different, f is an integer of 0 to 5.

22. The organic electroluminescent element according to claim 20 or 21, wherein Ring A is a pyridine ring or a quinoline ring.

23. The organic electroluminescent device according to claim 20 or 21, wherein n is 3.

24. The organic electroluminescent device according to claim 19, wherein The light-emitting layer further comprises a compound represented by the following formula (20), in the formula (20), 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 can have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, Xa 2 , Ya 2 and Za 2 each independently represent a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, g11, h11, and j11 each independently represent an integer of 0 to 6, at least one of g11, h11, and j11 is an integer of 1 or more, when g11 is 2 or more, there are multiple Xa 1 may be the same or different, h11 is 2 or more, there are multiple Ya 1 may be the same or different, j11 is 2 or more, and multiple Za exist 1 may be the same or different, R 23 represents a hydrogen atom or a substituent, 4 R 23 may be the same or different, wherein g11, h11or j11is 0, the corresponding Xa 2 , Ya 2 or Za 2 is not a hydrogen atom.

25. The organic electroluminescent device according to claim 24, wherein all of W in the formula (20) are N.

26. The organic electroluminescent device according to claim 24, wherein Xa 1 , Ya 1 , and Za 1 are each independently a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent, the aromatic hydrocarbon ring of the aromatic hydrocarbon group being a benzene ring, a naphthalene ring, or a fluorene ring.

27. The organic electroluminescent device according to claim 26, wherein Xa 2 Ya 2 and Za 2 each independently is an aromatic hydrocarbon group having 6 to 30 carbon atoms which can have a substituent or an aromatic heterocyclic group having 3 to 30 carbon atoms which can have a substituent, an aromatic hydrocarbon ring of the aromatic hydrocarbon group is a benzene ring, a naphthalene ring or a fluorene ring, and an aromatic heterocyclic ring of the aromatic heterocyclic group is a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring.

28. An organic EL display device comprising the organic electroluminescent element according to any one of claims 19 to 27.

29. An organic EL illuminating device comprising the organic electroluminescent element according to any one of claims 19 to 27.

Images