JP6237786B2 - ORGANIC ELECTROLUMINESCENT ELEMENT MATERIAL, ORGANIC ELECTROLUMINESCENT ELEMENT AND LIGHTING DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element material having a carbazole skeleton, an organic luminescence element containing the organic electroluminescence element material, an illumination device, and a display element.

In an organic electroluminescence element (hereinafter, electroluminescence may be abbreviated as EL), a light emitting material emits light by recombination energy of holes injected from an anode and electrons injected from a cathode by applying an electric field. It is a self-luminous element utilizing the principle.
In a light emitting layer of an organic electroluminescence element, a doping method is generally used in which a host is doped with a light emitting material as a dopant. As the host, it is necessary to efficiently generate excitons from the charge injected from the carrier transport layer, transfer the excitons to the dopant, and as the dopant, convert the excitons to emission energy with high efficiency. It is done. In recent years, phosphorescent dopants have been actively developed from the viewpoint of high-efficiency light emission, and search for host materials suitable for phosphorescent dopants has continued.
As a host material, there is a carbazole skeleton as a typical skeleton that has been used for a long time. For example, Patent Document 1 is cited. In recent years, Patent Document 2, Patent Document 3, and Patent Document have been proposed to improve carrier balance and durability. Dimerization or the like has been studied as disclosed in FIG.

  On the other hand, in order to increase the size and cost of organic EL elements and to develop flexible displays, a method for manufacturing organic EL elements by a printing method (printed electronics) has been studied. In order to form an element by making an organic EL material into an ink and applying it instead of a conventional vapor deposition method, good solvent solubility is required.

JP 2001-313178 A JP 2003-133075 A JP 2007-194241 A WO2011 / 132683 Publication

The 3,3′-biscarbazole derivatives described in Patent Document 2, Patent Document 3, and Patent Document 4 are known as phosphorescent hosts, but have a large molecular planarity, resulting in a large conjugate length and triplet energy. The level of becomes low. Therefore, the triplet energy is transferred from the dopant to the host in reverse energy and can be deactivated non-radiatively from the host. Therefore, good emission characteristics cannot be obtained. Furthermore, since the symmetry of the molecule is high, the solvent solubility is poor and it is difficult to apply to the printing method.
Accordingly, an object of the present invention is to provide an organic EL material that is excellent in solvent solubility and suitable for production by a printing method, and that can emit light with high efficiency because of high triplet energy. It is another object of the present invention to provide an organic EL element, a display element, and a lighting device using the organic EL material.

  As a result of intensive studies, the present inventors have found that the above-described problems can be solved by providing an organic EL device material having a structure represented by the following formula (1).

(In formula (1), R ₁ and R ₂ are each independently a hydrogen atom; an optionally substituted alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group; or polymerizable reactive group. Represents a group having

  Furthermore, the organic EL element characterized by using the said organic EL material is provided.

  Furthermore, the display element and lighting device which have the said organic EL element are provided.

  Since the organic EL device material represented by the above formula (1) has a twist between carbazoles, the triplet energy is increased, and the reverse energy transfer from the dopant to the host is suppressed, so that highly efficient light emission is possible. Furthermore, since it is excellent in solvent solubility, it can be suitably used for the production of an organic EL device by a printing method.

[Materials for organic EL elements]
The organic EL device material of the present invention has a structure represented by the following formula (1).

(In formula (1), R ₁ and R ₂ are each independently a hydrogen atom; an optionally substituted alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group; or polymerizable reactive group. Represents a group having

  The organic EL device material of the present invention may have a 1,3′-biscarbazole structure represented by the above formula (1), and the structure represented by the above formula (1) may be one or plural. Absent.

  Since the organic EL device material of the present invention has a 1,3′-biscarbazole structure having a twist between two carbazoles, the conjugate length is reduced and the triplet energy is high. Therefore, reverse energy transfer does not occur from the dopant to the host, and good light emission characteristics can be obtained. Since the material for an organic EL device of the present invention has a high triplet energy level, not only green and red phosphorescent materials but also blue phosphorescent materials are effective as host materials. Moreover, since the solubility in a solvent is excellent due to the twisted structure of the molecule, the organic EL element can be produced by a printing method using an ink for an organic EL element. Moreover, since Tg is high, it is excellent in heat resistance.

As the 1,3′-biscarbazole structure represented by the formula (1), in the formula (1), R ₁ and R ₂ are each independently a hydrogen atom; an alkyl group which may have a substituent, An alkenyl group, an alkynyl group, an aryl group, a heteroaryl group; or a group having a polymerizable reactive group.

  In this specification, the term “hydrogen” includes deuterium.

  Examples of the alkyl group that may have a substituent include a methyl group, an ethyl group, a propyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, Linear alkyl groups such as n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl Further, branched alkyl groups such as isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group, cyclic alkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group, etc. Can be mentioned. An alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, cyclopentyl group, cyclohexyl group, cyclohexane A heptyl group etc. are mentioned.

  Examples of the alkenyl group which may have a substituent include, for example, vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, decenyl group, dodecenyl group, tetradecenyl group, hexadecenyl group, octadecenyl group And straight-chain alkenyl groups such as a group, and further branched alkenyl groups such as a methylpentenyl group, cyclic alkenyl groups such as a cyclohexenyl group, a cycloheptenyl group, and a 4-methylcyclohexene group.

  Examples of the alkynyl group which may have a substituent include, for example, an ethenyl group, a 1-propenyl group, a 2-propenyl group, a 1-butenyl group, a 1-pentenyl group, a 1-hexenyl group, a 1-heptenyl group, 1- Octenyl group, 1-nonenyl group, 1-decenyl group, 1-undecenyl group, 1-dodecenyl group, 1-tridecenyl group, 1-tetradecenyl group, 1-pentadecenyl group, 1-hexadecenyl group, 1-heptadecenyl group, 1- Examples include an octadecenyl group and a 1-nonadecenyl group.

  Examples of the aryl group which may have a substituent include, for example, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, a pyrenyl group, a chrysenyl group, a fluorenyl group, and 9,9-dimethylfluorenyl. Group, spirofluorenyl group, and fluoranthenyl group, and when having a substituent, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a halogeno group, and a cyano group are preferable.

  As the heteroaryl group which may have a substituent, for example, thiophene, thiazole, furan, oxazole, pyran, pyrrole, imidazole, pyrazole, isothiazole, isoxazole, furazane, triazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine , Benzothiophene, benzothiazole, thianthrene, isobenzofuran, benzoxazole, chromene, xanthene, phenoxathiin, indolizine, isoindole, indole, benzimidazole, indazole, benzotriazole, purine, quinolidine, isoquinoline, quinoline, phthalazine, naphthyridine , Quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, perimidine Examples include monovalent groups formed by removing one hydrogen atom from phenanthroline, phenazine, phenothiazine, phenoxazine, and dibenzodioxin, and more preferably, one hydrogen atom can be removed from pyridine, pyrazine, pyrimidine, pyridazine, and triazine. A monovalent group etc. are mentioned. When the heteroaryl group has a substituent, preferred substituents include an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a halogeno group, a cyano group, a substituted amino group, a phenyl group, a biphenyl group, and a terphenyl group. And a naphthyl group.

  Examples of the polymerizable reactive group include a cationic polymerizable reactive group and a radical polymerizable reactive group. Examples of the cationic polymerizable reactive group include a cyclic ether group such as an epoxy group and an oxetanyl group, and a radical polymerizable reaction. Examples of the functional group include ethylenically unsaturated groups such as a vinyl group, a (meth) acryloyl group, an allyl group, a styryl group, and a maleimide group. These polymerizable groups may have a linking group such as an alkylene group, an alkyleneoxy group, an arylene group, or a heteroarylene group between 1,3′-biscarbazole. When it has a polymerizable reactive group, the organic EL device material of the present invention becomes a curable material and can be cured with active energy rays or the like, so that a coating film with improved solvent resistance and durability can be provided.

  The structure represented by the above formula (1) may be a low molecular compound or a high molecular compound. When it has a polymerizable reactive group, it may be reacted with another monomer to form a copolymer. Among the above-mentioned substituents, an aryl group that may have a substituent, a heteroaryl group that may have a substituent, and an alkyl group that may have a substituent are preferable, and luminous efficiency is increased. An aryl group which may have a substituent and a heteroaryl group which may have a substituent are more preferable.

  The structure represented by the above formula (1) is obtained by heating and stirring 1,2,3,4-tetrahydrocarbazole in activated carbon, or by a coupling reaction of a 1-position halogenated carbazole derivative and a 3-position boronic acid carbazole derivative. Can be synthesized.

  The structure represented by the above formula (1) includes a portion other than the 1-position and 3′-position of the carbazole ring (2,3,4,5,6,1 ′, 2 ′, 4 ′, 5 ′, 6 ′). Each independently has a hydrogen atom; an optionally substituted alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, alkoxy group; or a group having a polymerizable reactive group. be able to.

The definition of an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group which may have a substituent; or a group having a polymerizable reactive group is the same as the above definition.

  The structure represented by the above formula (1) includes a portion other than the 1-position and 3′-position of the carbazole ring (2,3,4,5,6,1 ′, 2 ′, 4 ′, 5 ′, 6 ′). When the substituent is modified at the position), the portion (2, 3, 4, 5, 6, 1 ′, 2 ′, 4 ′, 5 ′, 6 ′ position) excluding the 1-position and 3′-position of the carbazole ring Substituents can be easily modified by halogenation. From the viewpoint of ease of synthesis, the 4-position, 6-position and 6'-position are preferred as the position for modifying the substituent.

  Specific examples of the structure represented by the above formula (1) are shown below, but are not limited thereto.

  The material for organic EL elements of the present invention can be used as an active layer material for organic EL elements. The active layer means a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a hole block layer, an electron transport layer, an electron injection layer, or the like of the organic EL element. Especially, since the organic EL element material of this invention has a high triplet level, it is effective for a positive hole transport layer or a light emitting layer, Especially preferably, it is a light emitting layer.

  Moreover, the organic EL device material of the present invention can be used in fields such as an electrophotographic photosensitive member, a transistor, and a solar cell in addition to the active layer material of the organic EL device.

  When the organic EL device material of the present invention is used for a light emitting layer, it can be particularly suitably used as a host material. At this time, a known and commonly used material can be used as the light emitter, but it is preferably used as a host material of a phosphorescent light emitting material because of its large triplet level.

As the phosphorescent light-emitting material, an organometallic complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold can be used.

Preferred phosphorescent light emitting materials include complexes such as Ir (ppy) ₃ having a noble metal element such as Ir as a central metal, complexes such as Ir (bt) ₂ .acac ₃ , and complexes such as PtOEt _3. . Specific examples of these complexes are shown below, but are not limited to the following compounds.

  The amount of the phosphorescent light emitting material contained in the light emitting layer is 1 to 25% by weight, preferably 5 to 20% by weight. In this case, as the host material, the organic EL device material of the present invention is 50% by weight or more, preferably 80 to 95% by weight.

[Ink for organic EL elements]
The organic EL device material of the present invention can be used as a vapor deposition material as it is, but since it is excellent in solvent solubility, it is preferably dissolved in a solvent and used as an organic EL device ink.

  Any organic solvent may be used, or two or more organic solvents may be mixed and used. Specifically, aliphatic solvents such as n-hexane, n-octane, n-decane and n-dodecane; alicyclic solvents such as cyclohexane; benzene, toluene, cumene, o-xylene, m-xylene, p-xylene, p-cymene, mesitylene, anisole, 2-methylanisole, 3-methylanisole, 4-methylanisole, 2,5-dimethylanisole, 3,5-dimethoxytoluene, 2,4-dimethylanisole, phenetole, Methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, 1,5-dimethyltetralin, n-propylbenzene, n-butylbenzene, n-pentylbenzene, n-hexylbenzene, cyclohexylbenzene, 1,3, 5-triethylbenzene, 1,3-dimethoxybenzene, chlorobenzene Aromatic solvents such as o-dichlorobenzene and trichlorobenzene; ether solvents such as tetrahydrofuran, dioxane, ethylene glycol diethyl ether, anisole, benzyl ethyl ether, ethyl phenyl ether, diphenyl ether, methyl diphenyl ether, and methyl-t-butyl ether; acetic acid Ester solvents such as methyl, ethyl acetate, ethyl cellosolve, propylene glycol methyl ether acetate; alcohol solvents such as methanol, ethanol, isopropanol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, 2-hexanone, 2-heptanone, 3-heptanone System solvents; other examples include, but are not limited to, dimethylformamide, dimethylsulfoxide, and diethylformamide. It is not.

  The organic EL element ink may contain other compounding materials in addition to the organic EL element material as long as the organic EL element characteristics are not impaired. It may contain a transport material, an electron injection material, an electron transport material, a light emitting material, a binder polymer and the like.

  When the ink for organic EL elements is used for the light emitting layer, the ink can contain a light emitting material in addition to the present material. Although a well-known and usual material can be used as a light-emitting body, since the organic EL element material of this invention has a large triplet level, it is preferable to use it for a phosphorescent light-emitting material.

  The amount of the phosphorescent light-emitting material contained in the organic EL element ink is 1 to 30% by weight, preferably 5 to 25% by weight, based on the organic EL element material of the present invention. In this case, as the host material, the organic EL device material of the present invention is preferably 50% by weight or more, preferably 75 to 95% by weight.

  In the organic EL element ink, the blending amount of the organic EL element material of the present invention may be 0.1 wt% to 10 wt% in the organic EL element ink, preferably 0.1 wt% to 5.0% by weight.

[Organic EL device]
The structure of the organic EL element is not particularly limited, but generally an electroluminescent layer (light emitting layer) is included between a cathode (cathode) and an anode (anode) in which at least one of the electrodes is transparent. It is a waste. Furthermore, one or more electron injection layers and / or electron transport layers are inserted between the electroluminescent layer (light emitting layer) and the cathode, one or more hole injection layers and / or hole transport In some cases, a layer is inserted between the electroluminescent layer (light emitting layer) and the anode.

  The anode plays a role of hole injection into the hole injection layer and is usually made of metal such as aluminum, gold, silver, nickel, palladium, platinum, indium and / or tin oxide (ITO), etc. It is composed of a metal oxide, a metal halide such as copper iodide, carbon black, or a conductive polymer such as poly (3-methylthiophene, polypyrrole, polyaniline).

  The cathode serves to inject electrons into the light emitting layer through the electron transport layer / or electron injection layer. The material used as the cathode is preferably a metal having a low work function in order to efficiently inject electrons, and an appropriate metal such as tin, magnesium, indium, calcium, cesium, aluminum, silver, or an alloy thereof is used. . Specific examples include a magnesium-silver alloy, a magnesium-indium alloy, and an aluminum-lithium alloy.

  The hole injection layer, hole transport layer, and electron transport layer can be any organic layer, but the hole injection layer is used for the purpose of increasing the efficiency of injecting holes from the anode into the hole transport layer. The hole transport layer and the electron transport layer serve to move holes and electrons to the light emitting layer, respectively. Further, an electron injection layer can be provided between the cathode and the electron transport layer.

  Examples of the hole injection material include phthalocyanine compounds such as copper phthalocyanine (CuPc), organic compounds such as polyaniline and polythiophene, and metal oxides such as vanadium oxide, ruthenium oxide, and molybdenum oxide.

  Examples of hole transport materials include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives such as NPB, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene Derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, particularly thiophene oligomers, and the like can be given.

As the electron transporting material, a metal complex such as Alq _3, 10- hydroxy-benzo [h] quinoline metal complexes, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3- or 5-hydroxyflavone metal complexes, benzoxazole Metal complex, benzothiazole metal complex, trisbenzimidazolylbenzenequinoxaline compound, phenanthroline derivative, 2-t-butyl-9,10-N, N′-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide, n-type Examples thereof include zinc sulfide and n-type zinc selenide.

  Examples of the electron injection layer include alkali metals, alkali metal complexes, alkali metal compounds, alkaline earth metals, alkaline earth metal complexes, alkaline earth metal complex compounds, rare earth metals, rare earth metal complexes, and rare earth metal compounds. .

  When the organic EL element material of the present invention is an organic EL element, a publicly known vapor deposition method may be used, but a coating method such as a printing method is preferably used. Examples of the coating method used include a dipping method, a spray coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a roll coating method, a bar coating method, a die coating method, and a liquid dropping method such as an inkjet method. Can be mentioned.

[Display elements, lighting devices]
Since the organic EL element having the organic EL element material of the present invention is excellent in heat resistance, it can be suitably used as a display device or a lighting device. The display element can be applied to both a display element having a structure arranged in an array and a display element having an anode and a cathode arranged in an XY matrix, and is applied to a full-color or multi-color panel. be able to. The lighting device can be applied to a monochromatic or dimmable lighting device.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

[Synthesis Example 1] Synthesis of Compound 1

  To a 250 mL four-necked flask, 1,2,3,4-tetrahydrocarbazole (12 g, 72 mmol), activated carbon (12 g), 120 mL of 1,2-dichlorobenzene were sequentially added, and air was added at 500 mL / min. The reaction was stirred for hours. After cooling the reaction solution to room temperature, the reaction solution was filtered, the organic solvent was removed under reduced pressure, and the residue was purified by column chromatography. After removing the organic solvent under reduced pressure, 3.2 g (yield: 10%) of a yellow solid (Intermediate 1) was obtained.

In a 200 mL three-neck flask under an argon atmosphere, Intermediate 1 (0.836 g, 2.52 mmol), 4-bromo-N, N′-diphenylaniline (1.95 g, 6.04 mmol), tris (dibenzylidene) di Palladium (0.130 g, 0.13 mmol), tri-t-butylphosphine (0.076 g, 0.38 mmol), sodium-t-butoxide (0.725 g, 7.55 mmol), and toluene (50 mL) were sequentially added for 8 hours. Heated to reflux. After cooling the reaction solution to room temperature, water was added and the organic layer was recovered with a separatory funnel. After removing the organic solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain 1.03 g (yield 50%) of a white solid (Compound 1).
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.42 (s, 1H), 8.12 (d, 1H), 7.75 (d, 1H), 7.62-7.22 (m, 34H), 7 .10 (t, 4H), 6.94 (t, 1H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 819

[Synthesis Example 2] Synthesis of Compound 2

Intermediate 1 (6.0 g, 18.0 mmol), bromoethane (4.9 g, 45.1 mmol), potassium hydroxide 3.3 g, and acetone 40 mL were sequentially added to a 100 ml eggplant flask and heated to reflux for 5 hours. After cooling the reaction solution to room temperature, water and toluene were added, and the organic layer was recovered with a separatory funnel. After removing the organic solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain 3.1 g (yield 44%) of a white solid (Compound 2).
¹ HNMR (CDCl ₃ ): δ 8.35 (s, 1H), 8.08 (d, 1H), 7.67-7.16 (m, 11H), 6.84 (t, 1H), 4.41 (M, 4H), 1.46 (m, 6H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: water = 8: 2): m / z: 389

[Synthesis Example 3] Synthesis of Compound 3

0.9 g (yield 40%) of a white solid was obtained in the same manner as in Synthesis Example 2, except that 1-bromopropane (5.5 g, 45.1 mmol) was used instead of bromoethane. m / z was 416, and the production of the target product was confirmed.
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.35 (s, 1H), 8.08 (d, 1H), 7.67-7.16 (m, 11H), 6.84 (t, 1H), 4 .27 (m, 4H), 1.56 (m, 4H), 0.94 (m, 6H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: water = 8: 2): m / z: 416

[Synthesis Example 4] Synthesis of Compound 4

Except for using 2-chloro-4,6-di-p-tolyl-1,3,5-triazine (0.745 g, 2.52 mmol) instead of 4-bromo-N, N′-diphenylaniline By the same operation as in Synthesis Example 1, 0.34 g (yield 32%) of a white solid was obtained.
¹ HNMR (CDCl ₃ , 300 MHz): δ 9.31 (d, 1H), 9.20 (m, 2H), 9.12 (d, 1H), 8.67 (d, 8H), 8.27 (s , 1H), 8.04 (d, 1H), 7.80 (m, 2H), 7.48-7.33 (m, 13H), 7.03 (t, 1H), 2.49 (s, 12H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 850

[Synthesis Example 5] Synthesis of Compound 5

  In an argon atmosphere, a 200 mL three-necked flask was charged with intermediate 1 (1.0 g, 3.01 mmol), di-p-tolyl-1,3,5-triazine (0.89 g, 3.01 mmol), tris (dibenzylidene). ) Dipalladium (0.16 g, 0.15 mmol), tri-t-butylphosphine (0.09 g, 0.45 mmol), sodium-t-butoxide (0.87 g, 9.03 mmol), and toluene 50 mL were sequentially added. Heated to reflux for 8 hours. After cooling the reaction solution to room temperature, water was added and the organic layer was recovered with a separatory funnel. The organic solvent was removed under reduced pressure, and the residue was purified by silica gel chromatography to obtain 0.64 g of Intermediate 2 (yield 36%).

In an argon atmosphere, a 200 mL three-necked flask was charged with Intermediate 2 (0.60 g, 1.01 mmol), 1-bromo-4-t-butylbenzene (0.26 g, 1.21 mmol), tris (dibenzylidene) dipalladium ( 0.052 g, 0.05 mmol), tri-t-butylphosphine (0.031 g, 0.15 mmol), sodium-t-butoxide (0.292 g, 3.04 mmol), and toluene 50 mL were sequentially added, and the mixture was heated under reflux for 8 hours. did. After cooling the reaction solution to room temperature, water was added and the organic layer was recovered with a separatory funnel. After removing the organic solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain 0.47 g (yield: 64%) of the target compound 5.
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.68 (d, 4H), 8.34 (s, 1H), 8.05 (d, 1H), 7.82-7.16 (m, 15H), 6 .84 (t, 1H), 2.49 (s, 6H), 1.35 (s, 9H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 724

[Synthesis Example 6] Synthesis of Compound 6

A white solid (Compound 6) was prepared in the same manner as in Synthesis Example 1 except that 1-bromo-4-t-butylbenzene (1.287 g, 6.04 mmol) was used instead of 4-bromo-N, N′-diphenylaniline. ) 0.9 g (yield 60%) was obtained.
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.36 (s, 1H), 8.08 (d, 1H), 7.67-7.16 (m, 19H), 6.84 (t, 1H), 1 .35 (s, 18H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile): m / z: 596

[Synthesis Example 7] Synthesis of Compound 7

The same as Synthesis Example 1 except that 4- (4-bromophenyl) -2,6-diphenylpyrimidine (2.34 g, 6.04 mmol) was used instead of 4-bromo-N, N′-diphenylaniline. Thus, 1.1 g (yield 45%) of the target compound 7 was obtained.
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.79 (m, 4H), 8.60 (t, 4H), 8.47 (s, 1H), 8.35 (m, 4H), 8.15 (m 3H), 7.95 (d, 2H), 7.85 (d, 2H), 7.74-7.51 (m, 19H), 7.39-7.32 (m, 4H), 7. 01 (t, 1H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 946

[Synthesis Example 8] Synthesis of Compound 8

  Under a nitrogen atmosphere, Compound 6 (1.0 g, 3.01 mmol), N-bromosuccinimide (1.63 g, 9.18 mmol) and 100 mL of dichloromethane were sequentially added to a 200 mL three-necked flask, and the mixture was stirred at room temperature for 1 hour. After completion of the reaction, the organic solvent was removed under reduced pressure, and 1.23 g (yield 84%) of a white solid (intermediate 3) was obtained by recrystallization.

In an argon atmosphere, a 200 mL three-necked flask was charged with Intermediate 3 (0.40 g, 0.48 mmol), 9,9′-spirobifluoren-7-yl-boronic acid (0.62 g, 1.73 mmol), sodium carbonate ( 0.20 g, 1.92 mmol), tetrakis (triphenylphosphine) palladium (0.04 g, 0.03 mmol), and 30 mL of toluene were sequentially added, and the mixture was stirred for 15 minutes. Thereafter, 10 mL of Aliquat 336 1.0 wt% aqueous solution was added, and the mixture was refluxed at 80 ° C. for 8 hours. After cooling the reaction solution to room temperature, water was added and the organic layer was recovered with a separatory funnel. After removing the organic solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain 0.33 g (yield 45%) of a white solid (Compound 8).
¹ HNMR (CDCl ₃ , 300 MHz): δ 7.93 (d, 2H), 7.87 (m, 4H), 7.93 (d, 2H), 7.76 (m, 3H), 7.68-7 .55 (m, 12H), 7.42-7.27 (m, 14H), 7.15-6.98 (m, 14H), 6.87 (d, 1H), 6.73 (m, 7H) ), 6.64 (m, 4H), 6.55 (m, 2H), 6.45 (d, 1H), 6.35 (d, 1H), 1.55 (s, 18H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 1539

[Synthesis Reference Example 1] Synthesis of Comparative Compound 1

  Carbazole (10 g, 59.8 mmol), iron (III) chloride (38.8 g, 239.3 mmol) and chloroform (200 mL) were sequentially added to a 400 mL four-necked flask, and the mixture was stirred at room temperature for 30 minutes. After completion of the reaction, the organic solvent was removed under reduced pressure, and the resulting solid was washed with methanol. The solid was recovered by filtration, and then the same methanol washing was repeated twice to obtain Intermediate 3 (16.7 g, yield 84%).

In a 200 mL three-necked flask under an argon atmosphere, Intermediate 3 (0.50 g, 1.50 mmol), 4-bromo-N, N′-diphenylaniline (1.07 g, 3.31 mmol), tris (dibenzylidene) di Palladium (0.08 g, 0.08 mmol), tri-t-butylphosphine (0.05 g, 0.23 mmol), sodium-t-butoxide (0.43 g, 4.51 mmol) and toluene (50 mL) were sequentially added for 8 hours. Heated to reflux. After cooling the reaction solution to room temperature, water was added and the organic layer was recovered with a separatory funnel. After removing the organic solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain 0.47 g (yield 65%) of a white solid (Comparative Compound 1).
¹ HNMR (CDCl ₃ , 300 MHz): δ 8.45 (d, 2H), 8.23 (d, 2H), 7.79 (dd, 2H), 7.55-7.43 (m, 8H), 7 .35-7.21 (m, 26H), 7.11 (t, 4H)
MS spectrum (HPLC-MS (APCI), eluent; acetonitrile: THF: water = 6: 3: 1): m / z: 819

〔Evaluation method〕
(1) Solvent solubility evaluation Using the synthesized compound and comparative compound 1, a 2.0 wt% toluene solution was prepared. The solution was visually confirmed after standing for 1 day. The solution in which the compound was dissolved was marked with ◯, and the solution with insoluble matter was marked with x.

(2) Evaluation of characteristics of organic EL element <Preparation of vapor deposition organic EL element>
After UV-O ₃ was irradiated onto the cleaned ITO substrate, a PEDOT / PSS (CLEVIOS P VP.AI4083) film having a thickness of 45 nm was formed by spin coating as a hole injection layer, and heated in the atmosphere at 180 ° C. for 15 minutes. Thereafter, HT-1 is 10 nm as a hole transport layer under a vacuum of 5 × 10 ⁻³ Pa, and a host material and a dopant material (GD-1) are 30 nm by co-evaporation as a light emitting layer, and ET-1 as an electron transport layer. 45 nm, lithium fluoride 0.5 nm as an electron injection layer, and aluminum 100 nm as a cathode. The content of GD-1 was 10 wt%. After film formation up to the cathode, the substrate was transported to a glove box and sealed with a glass substrate to produce an organic EL device.

<Production of coated organic EL element>
After the irradiated ITO substrate was irradiated with UV / O ₃ , a PEDOT / PSS film having a thickness of 45 nm was formed by spin coating as a hole injection layer and heated in the atmosphere at 180 ° C. for 15 minutes. Subsequently, a 10 nm film was formed by spin coating using a 0.3 wt% xylene solution of HT-2 and dried at 200 ° C. for 30 minutes in a nitrogen atmosphere. Next, as a light emitting layer, a 30 nm film was formed by spin coating using a toluene solution containing a host material and GD-1 at a weight ratio of 9: 1 and having a solid concentration of 0.8% by weight. And dried at 110 ° C. for 15 minutes. Thereafter, under a vacuum of 5 × 10 ⁻³ Pa, ET-1 as an electron transport layer was deposited to 45 nm, lithium fluoride as an electron injection layer was 0.5 nm, and aluminum as a cathode was sequentially deposited to 100 nm. After film formation up to the cathode, the substrate was transported to a glove box and sealed with a glass substrate to produce an organic EL device.

<Evaluation of organic EL element>
Luminance measurement of organic EL element The organic EL element produced as described above was connected to an external power source, a direct current voltage was applied, and light emission from the element was measured with Topcon BM-9. Luminous efficiency was calculated from the value. The table below shows the voltage and luminous efficiency when 10 mA / cm ² current was applied.

[Examples 1-7]
Table 1 shows the results of evaluation of the compounds of the present invention obtained in Examples 1 to 9 by the above evaluation method.

[Comparative Examples 1-2]
Table 1 shows the results of the same evaluation as in Examples using Comparative Compound 1.

  Table 1 shows that the compound of the present invention exhibits high luminous efficiency in both the vapor deposition element and the coating element. It has been found that the compound of the present invention is advantageous in the production of a coating element because it is superior in solvent solubility than the conventional compound.

  The material for an organic EL element of the present invention can be suitably used for an organic EL element.

Claims (6)

A material for an organic electroluminescence device comprising a compound represented by the following general formula (1).

(In Formula (1), R ₁ and R ₂ each independently have a hydrogen atom; an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a substituent. An alkynyl group which may be substituted, an aryl group having a substituent, a heteroaryl group having a substituent; or a group having a polymerizable reactive group.)   Furthermore, the material for organic electroluminescent elements of Claim 1 containing a phosphorescent luminescent material.   The ink for organic electroluminescent elements containing the material of Claim 1 or 2.   An organic electroluminescent element comprising the organic electroluminescent element material according to claim 1.   The display element which has an organic electroluminescent element of Claim 4.   The illuminating device which has an organic electroluminescent element of Claim 4.