TW201434827A - Pyrimidine compound, and organic electroluminescent element containing same - Google Patents

Abstract

The present invention provides: a pyrimidine compound which enables the provision of an element having remarkably superior life properties and electric power efficiency compared with the conventional known electron-transporting materials and an organic electroluminescent element produced using the pyrimidine compound. A pyrimidine compound is used, which is represented by general formula (1) (wherein X represents a single bond or a phenylene group and Y represents an anthracenyl group or a pyrenyl group).

Description

Pyrimidine compound and organic electroluminescent element containing the same

The present invention relates to a useful pyrimidine compound used as a constituent component of an organic electroluminescence device, and an organic electroluminescence device comprising the same.

In the organic electroluminescence device, a light-emitting layer containing a light-emitting material is interposed between the hole transport layer and the electron transport layer, and an anode and a cathode are attached to the outside of the light-emitting layer as a basic structure, and the holes and electrons injected into the light-emitting layer are used. In combination, an element that generates exciton deactivation to derive light release (fluorescence or phosphorescence) is applied to a display or the like. In addition, the hole transport layer is divided into a hole transport layer and a hole injection layer, and the light emitting layer is divided into an electron blocking layer, a light emitting layer and a hole blocking layer, and the electron transport layer is divided into an electron transport layer and an electron injection layer. Case.

Electron transport materials are known to have a ring shape A compound (for example, patent documents 1 and 2).

Patent Document 1 describes a pyrimidine derivative having a specific structure. However, the related art document 1 specifically discloses an organic electroluminescence device in which a compound (electron transport material) is combined with a known luminescent material, and the life of the device cannot sufficiently satisfy the market requirement. Therefore, development of an electron transport material that can further meet the requirements for long life of components is expected.

Patent Document 2 describes three having a specific structure. Compound. However, the related art document 2 specifically discloses an organic electroluminescence device in which a compound (electron transport material) is combined with a known luminescent material, and power efficiency cannot sufficiently satisfy the market demand. Therefore, in order to further improve the power efficiency of components, we are eager to meet the market requirements for material development.

[Advanced technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-84553

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-63584

SUMMARY OF THE INVENTION An object of the present invention is to provide a pyrimidine compound which is excellent in life characteristics or power efficiency of an element compared to conventionally known electron transport materials. Further, an object of the present invention is to provide a long-life, high-power organic light-emitting device comprising the pyrimidine compound.

In order to solve the above problems, the inventors of the present invention have intensively studied, and as a result, an organic electroluminescent device using a pyrimidine compound represented by the following general formula (1) has been used, and a significantly long life has been found as compared with a member using a conventionally known electron transporting material. High power efficiency, and the present invention has been completed.

That is, the present invention relates to a pyrimidine compound represented by the following general formula (1), and an organic electroluminescence device comprising the same.

(wherein X represents a single bond or a phenyl group. Y represents a fluorenyl group or a fluorenyl group.)

The pyrimidine compound of the present invention can provide a ring which is well known in the art. An organic electric field light-emitting element having excellent lifetime and power efficiency under the compound.

1‧‧‧ glass substrate with ITO transparent electrode

2‧‧‧ hole injection layer

3‧‧‧First hole transport layer

4‧‧‧Second hole transport layer

5‧‧‧Lighting layer

6‧‧‧ hole barrier

7‧‧‧Electronic transport layer

8‧‧‧ cathode layer

11‧‧‧Glass substrate with ITO transparent electrode

12‧‧‧ hole injection layer

13‧‧‧First hole transport layer

14‧‧‧Second hole transport layer

15‧‧‧Lighting layer

16‧‧‧Electronic transport layer

17‧‧‧Electronic injection layer

18‧‧‧ cathode layer

Fig. 1 is a cross-sectional view showing a single layer element produced in Example 6 and the like.

Fig. 2 is a cross-sectional view showing a single layer element produced in Example 7 and the like.

Hereinafter, the present invention will be described in detail.

The present invention is a pyrimidine compound represented by the general formula (1):

In the formula, X represents a single bond or a phenyl group. The Y system represents a sulfhydryl group or a fluorenyl group.

In the pyrimidine compound represented by the general formula (1), the X system represents a single bond or a stretch. Phenyl. The above-mentioned stretching phenyl group is not particularly limited, and may, for example, be an exophenyl group, an exophenyl group or a paraphenyl group. Further, the X-based system is preferably a single bond or a pendant phenyl group from the viewpoint of excellent lifetime or power efficiency of the organic electroluminescence device.

In the pyrimidine compound represented by the general formula (1), the Y system represents an anthracenyl group or a fluorenyl group. The above mercapto group is not particularly limited and may, for example, be a 1-fluorenyl group, a 2-fluorenyl group or a 9-fluorenyl group. Among them, from the viewpoint of excellent lifetime of the organic electroluminescent device, a 9-fluorenyl group is preferred. Further, the above mercapto group is not particularly limited, and may, for example, be a 1-fluorenyl group, a 2-fluorenyl group or a 4-fluorenyl group. Among them, from the viewpoint of excellent lifetime or power efficiency of the organic electroluminescent device, a 1-mercapto group is preferred. That is, Y is preferably a 9-fluorenyl group or a 1-fluorenyl group from the viewpoint of excellent lifetime or power efficiency of the organic electroluminescent device.

Specific examples of the pyrimidine compound represented by the general formula (1) are not particularly limited, and can be, for example, shown below:

Among these compounds, in particular, from the viewpoint of excellent lifetime or power efficiency of the organic electroluminescent device, the compounds exemplified below are more preferred:

Hereinafter, an organic electroluminescence device of the present invention will be described.

The light-emitting layer of the organic electroluminescence element, broadly defined, refers to a layer that emits light when a current flows through an electrode composed of a cathode and an anode. Specifically, it means a layer containing a fluorescent compound that emits light when a current flows through an electrode composed of a cathode and an anode. Generally, the organic electroluminescent element adopts a structure in which a light-emitting layer is interposed between a pair of electrodes.

The organic electroluminescence device of the present invention may be provided with a hole transport layer, an electron transport layer, an anode buffer layer, a cathode buffer layer, and the like in addition to the light-emitting layer, and has a structure in which a cathode and an anode are sandwiched. Specifically, it can be constructed, for example, as follows:

(i) anode / luminescent layer / cathode

(ii) anode/hole transport layer/light-emitting layer/cathode

(iii) anode/light emitting layer/electron transport layer/cathode

(iv) anode/hole transport layer/light-emitting layer/electron transport layer/cathode

(v) anode/anode buffer layer/hole transport layer/light-emitting layer/electron transport layer/cathode buffer layer/cathode

As the light-emitting layer in the organic electroluminescence device of the present invention, a conventionally known light-emitting material can be used. The method of forming the light-emitting layer is a method of forming a thin film by a known method such as a vapor deposition method, a spin coating method, a casting method, or an LB method.

In addition, the light-emitting layer is obtained by dissolving a binder such as a resin together with a light-emitting material in a solvent to form a solution, and then applying the film by spin coating or the like to form a film.

The film thickness of the light-emitting layer to be formed in this manner is not particularly limited, and may be appropriately selected depending on the state of the film, and is usually in the range of 5 nm to 1 μm.

Next, other layers which constitute an organic electroluminescence element in combination with a light-emitting layer, such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer, will be described.

The hole injection layer and the hole transport layer have a function of transferring a hole injected from the anode to the light-emitting layer, and the hole injection layer and the hole transport layer are interposed between the anode and the light-emitting layer, and The lower electric field injects more holes into the luminescent layer.

Furthermore, electrons that are injected from the cathode and transported to the light-emitting layer by the electron injecting layer and/or the electron transporting layer may have an electron barrier at the interface between the light emitting layer and the hole injection layer or the hole transport layer, and may not The interface which is accumulated in the light-emitting layer and leaks in the hole injection layer or the hole transport layer is an element excellent in light-emitting performance such as improvement in luminous efficiency.

The material of the hole injection layer and the hole transport layer (hereinafter referred to as "hole injection material" and "hole transport material") is provided before the function of transferring the hole injected from the anode to the light-emitting layer. The rest is not particularly limited, and may be selected from known sources such as a charge injection transport material for a hole conventionally used in a conventional light guide material, or a hole injection layer or a hole transport layer of an organic electric field light-emitting element. use.

The hole injection material and the hole transporting material have any of the characteristics of hole injection, transport, and electron shielding, and may be either organic or inorganic. The hole injection material and the hole transporting material may be, for example, a triazole derivative, Diazole derivatives, imidazole derivatives, polyaralkyl hydrocarbon derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, and amine-substituted chalcone derivatives Object, An azole derivative, a styryl hydrazine derivative, an anthrone derivative, an anthracene derivative, an anthracene derivative, a decazane derivative, an aniline copolymer, and a conductive polymer oligomer, particularly a thiophene oligomer Wait. As the hole injecting material and the hole transporting material, the above may be used, and a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound are preferably used, and an aromatic tertiary amine compound is more preferably used.

Representative examples of the above aromatic tertiary amine compound and styrylamine compound are, for example, N,N,N',N'-tetraphenyl-4,4'-diaminobenzene, N,N'- Diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine (TPD), 2,2-bis (4-pair) Toluidine phenyl)propane, 1,1-bis(4-di-p-toluidine phenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diamine linkage Benzene, 1,1-bis(4-di-p-toluidine phenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, double (4 -di-p-toluidine phenyl)phenylmethane, N,N'-diphenyl-N,N'-di (4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4 '-bis(diphenylamino)biphenyl, N,N,N-tris(p-tolyl)amine, 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)benzene Vinyl]anthracene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbene, N-phenyl Carbazole, 4,4'-bis[N-(1-naphthyl)-N-anilino]biphenyl (NPD), 4,4',4"-tris[N-(3-methylphenyl) -N-anilino]triphenylamine (MTDATA) and the like.

Further, an inorganic compound such as p-type Si or p-type SiC may be used as a hole injecting material or a hole transporting material. In the hole injection layer and the hole transport layer, the hole injection material and the hole transport material are formed by thinning the film by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. The film thickness of the relevant hole injection layer and the hole transport layer is not particularly limited, and is usually about 5 nm to 1 μm. The hole injection layer and the hole transport layer may have a single layer structure composed of one or more of the above materials, or may have a laminated structure composed of a plurality of layers of the same composition or different compositions.

In the organic electroluminescence device of the present invention, the electron transport layer contains the pyrimidine compound represented by the above general formula (1).

In the electron transport layer, the pyrimidine compound represented by the above formula (1) can be formed by a known film formation method such as a vacuum deposition method, a spin coating method, a casting method or an LB method. The film thickness of the electron transport layer is not particularly limited, and is usually selected in the range of 5 nm to 1 μm. The electron transporting layer contains a pyrimidine compound represented by the general formula (1), and may also contain a conventionally known electron transporting material, and may have a single layer structure of one type or two or more types, or may be the same composition or a different composition. A laminated structure composed of a plurality of layers.

Further, in the present invention, the light-emitting material is not limited to the light-emitting layer, and one type of the hole transport layer or the electron transport layer adjacent to the light-emitting layer may be included, whereby the light emission of the organic electric field light-emitting element can be further improved. effectiveness.

The substrate-based glass, plastic, and the like which are preferably used in the organic electroluminescence device of the present invention are not particularly limited as long as they are transparent, and are not particularly limited. The substrate to be preferably used in the organic electroluminescence device of the present invention may be, for example, glass, quartz or a translucent plastic film.

The light transmissive plastic film can be, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether oxime (PES), polyether phthalimide, polyether ether ketone. A film composed of polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), or the like.

A preferred example of producing the organic electroluminescent device of the present invention will be described. For example, a method of fabricating an organic electroluminescence element composed of an anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode will be described.

First, a desired film material (for example, an anode material) is formed on a suitable substrate by a method such as vapor deposition or sputtering to form a film having a film thickness of 1 μm or less, preferably 10 to 200 nm, to form an anode. Next, a film composed of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer/electron injection layer belonging to the element material is formed thereon.

Further, a buffer layer (electrode interface layer) may be present between the anode and the light-emitting layer or the hole injection layer, and between the cathode and the light-emitting layer or the electron injection layer.

Furthermore, in addition to the above basic constituent layers, layers may be laminated as needed. The layer having other functions may also be provided with a functional layer such as a hole blocking layer or an electron blocking layer.

Next, an electrode of the organic electroluminescence device of the present invention will be described. The anode of the organic electroluminescence device preferably uses a metal having a large work function (4 eV or more), an alloy, a conductive compound, and the like as an electrode material. Specific examples of such an electrode material include, for example, a conductive transparent material such as a metal such as Au, CuI, indium tin oxide (ITO), SnO ₂ or ZnO.

The anode may be formed into a thin film of the electrode material by a method such as vapor deposition or sputtering, and then formed into a desired shape pattern by an optical lithography method, or may be formed by a mask of a desired shape during vapor deposition or sputtering. pattern.

On the other hand, the cathode preferably uses a metal having a small work function (4 eV or less) (referred to as "electron injectable metal"), an alloy, a conductive compound, and the like as an electrode material. Specific examples of such electrode materials may be, for example, sodium, sodium-potassium alloys, magnesium, lithium, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum/alumina (Al ₂ O). ₃ ) Mixtures, indium, lithium/aluminum mixtures, rare earth metals, and the like. Among these, from the viewpoints of electron injectability and durability against oxidation, etc., a mixture of an electron injecting metal and a second metal having a work function value larger than that of a stabilizer metal is preferable, and is preferably, for example, magnesium/ Silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, aluminum/alumina (Al ₂ O ₃ ) mixture, lithium/aluminum mixture, and the like. The cathode system can be produced by forming the electrode material by a method such as vapor deposition or sputtering.

As described above, a desired electrode material (for example, an anode material) is formed on a suitable substrate by a method such as vapor deposition or sputtering to form a film having a film thickness of 1 μm or less, preferably 10 to 200 nm, to form an anode, and then On the anode The film of each layer formed of the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer/electron injection layer is formed thereon, and then formed of a cathode material by a method such as vapor deposition or sputtering. Hereinafter, a film having a film thickness in the range of 50 to 200 nm is preferably provided, and a cathode is provided to obtain a desired organic electric field light-emitting element.

The organic electroluminescence device of the present invention can be used as one type of lamp for illumination, an exposure light source, or the like, and can be used as a projection device of a video projection type or a display device (display) that directly views a still image or a moving image. The driving method when using the display device for animation reproduction may be a simple matrix (passive matrix) method or an active matrix method. Further, by using two or more organic light-emitting elements of the present invention having different luminescent colors, a full-color display device can be produced.

[Examples]

Hereinafter, the present invention will be described in more detail based on the embodiments, but the present invention is not limited to the embodiments.

¹ H-NMR and ¹³ C-NMR measurement were carried out using Gemini 200 (manufactured by Varian Co., Ltd.).

The light-emitting characteristics of the organic electroluminescent device were evaluated by applying a direct current to the produced element at room temperature, and using a luminance meter of LUMINANCEMETER (BM-9) (manufactured by TOPCON Co., Ltd.).

Synthesis Example-1

2-(3-Bromo-5-chlorophenyl)-4,6-diphenyl-pyrimidine (7.0 g), 1-indoleboronic acid (4.5 g), bis(triphenylphosphine) II under a stream of argon Palladium chloride (117 mg) and a 4N-aqueous sodium hydroxide solution (17 mL) were suspended in THF (75 mL) and heated to reflux for 1 hour. After cooling, water and methanol were added to the reaction. The precipitated solid was washed with water and methanol to obtain the desired pale yellow powder of 4,6-diphenyl-2-[3-chloro-5-(1-indolyl)phenyl]pyrimidine (yield 12.4 g). , yield 99%).

¹ H-NMR (CDCl ₃ ): δ 7.54 - 7.58 (m, 6H), 7.79 (s, 1H), 8.07 (t, J = 7.6 Hz, 1H), 8.09-8.12 (m, 3H), 8.17 ( s, 2H), 8.22-8.32 (m, 8H), 8.86 (s, 1H), 8.89 (s, 1H).

Synthesis Example-2

2-Bromopyridine (2.84 g) was dissolved in THF (75 mL) under argon flow and stirred at -78 °C. A 1.61 M-t-butyllithium pentane solution (23.3 mL) was added dropwise to the solution, and the mixture was stirred at -78 ° C for 30 minutes. Then, zinc chloride-N,N,N',N'-tetramethylethylenediamine complex (6.8 g) was added to the reaction mixture, and the mixture was heated to room temperature while stirring. 2-(3-Bromo-5-chlorophenyl)-4,6-diphenyl-pyrimidine (6.3 g) and tetrakis(triphenylphosphine)palladium (347 mg) were added to the reaction mixture. After the pentane was distilled off from the reaction mixture, the mixture was stirred under reflux for 3 hours. After the reaction mixture was allowed to cool, a saturated aqueous solution of ammonium chloride was added and extracted with chloroform. The organic layer was purified by a silica gel column chromatography to obtain the target 4,6-diphenyl-2-[3-chloro-5-(2-pyridyl) Pale yellow powder of phenyl]pyrimidine (yield 5.5 g, yield 87%).

¹ H-NMR (CDCl ₃ ): δ 7.34 (dd, J = 7.4, 4.8 Hz, 1H), 7.57-7.64 (m, 6H), 7.87 (t, J = 7.7 Hz, 1H), 7.94 (d, J=8.0 Hz, 1H), 8.10 (s, 1H), 8.25 (s, 1H), 8.31-8.35 (m, 4H), 8.78-8.80 (m, 2H), 9.18 (s, 1H).

Synthesis Example-3

2-(3-Bromo-5-chlorophenyl)-4,6-diphenyl-pyrimidine (8.4 g), 4-(2-pyridyl)phenylboronic acid (4.4 g), under a stream of argon, Tetrakis(triphenylphosphine)palladium (328 mg) and 4N-aqueous sodium hydroxide solution (7.5 mL) were suspended in THF (100 mL) and then refluxed for 24 hours. After allowing to cool, water was added to the reaction, and extraction was carried out using chloroform. The organic layer was purified by a silica gel column chromatography (developing solvent: chloroform) to obtain the desired 4,6-diphenyl-2-[5-chloro-4'-(2-pyridyl)biphenyl. A white powder of -3-yl]pyrimidine (yield 8.3 g, yield 83%).

¹ H-NMR (CDCl ₃ ): δ 7.28-7.32 (m, 1H), 7.59-7.64 (m, 6H), 7.80-7.85 (m, 3H), 7.87 (d, J = 8.5 Hz, 2H), 8.11(s,1H), 8.18(d,J=8.5Hz,2H), 8.32-8.35(m,4H),8.74(s,1H),8.77(d,J=4.8Hz,1H),8.93(s , 1H).

Example-1

2-(3,5-Dibromophenyl)-4,6-diphenyl-pyrimidine (10.0 g), 1-indoleboronic acid (5.3 g), tetrakis(triphenylphosphine)palladium under argon flow 248 mg) and 1 M potassium carbonate aqueous solution (32 mL) were suspended in a mixed solvent of toluene (500 mL) and ethanol (100 mL), and stirred at 50 ° C for 9 hours.

Then, 4-(2-pyridyl)phenylboronic acid (6.4 g) and 1M-potassium carbonate aqueous solution (32 mL) were added, and the mixture was stirred at 65 ° C for 12 hours. After the reaction mixture was allowed to cool, the solvent was evaporated under reduced pressure. The solid precipitated by the filtration was washed with water and methanol, dissolved in chloroform, and purified by a silica gel column chromatography (developing solvent chloroform) to obtain the desired 4,6-diphenyl group. Yellow powder of -2-[5-(1-indolyl)-4'-(2-pyridyl)biphenyl-3-yl]pyrimidine (A-1) (yield: 8.65 g, yield 61%).

¹ H-NMR (CDCl ₃ ): δ 7.26-7.30 (m, 1H), 7.55-7.60 (m, 6H), 7.80 (t, J = 7.6 Hz, 1H), 7.85 (d, J = 7.0 Hz, 1H), 8.01 (d, J = 8.5 Hz, 2H), 8.06 (t, J = 7.6 Hz, 1H), 8.09-8.11 (m, 3H), 8.17-8.23 (m, 6H), 8.25 (d, J) = 7.6 Hz, 1H), 8.31-8.38 (m, 6H), 8. 76 (d, J = 4.8 Hz, 1H), 9.02 (s, 1H), 9.19 (s, 1H).

Example-2

4,6-Diphenyl-2-[3-chloro-5-(1-indolyl)phenyl]pyrimidine (6.5 g), 4-(2-pyridyl)phenylboronic acid under argon flow 2.9 g), palladium acetate (26.9 mg), 2-dicyclohexylphosphine-2', 4',6'-triisopropylbiphenyl (171 mg), and 3M-potassium carbonate aqueous solution (9.6 mL), suspended in A mixed solvent of toluene (54 mL) and 1-butanol (6.0 mL) was stirred at 100 ° C for 3 hours. After the reaction is allowed to cool, water and methanol are added. The solid precipitated by the filtration is washed with water and methanol to obtain the target 4,6-diphenyl-2-[5-(1-indenyl)-4'-(2-pyridyl) group. Yellow powder of phenyl-3-yl]pyrimidine (A-1) (yield 7.53 g, yield 98%).

Example-3

4,6-Diphenyl-2-[3-chloro-5-(2-pyridyl)phenyl]pyrimidine (1.0 g), 1-indoleboronic acid (645 mg), palladium acetate (10.7) under a stream of argon Mg), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (68 mg), and aqueous 3M-potassium phosphate solution (1.6 mL) was suspended in a mixed solvent of toluene (9.5 mL) and 1-butanol (2.4 mL), and stirred at 100 ° C for 19 hours. After the reaction is allowed to cool, water and methanol are added. The solid precipitated by the filtration was purified by using water and methanol to obtain the desired 4,6-diphenyl-2-[5-(1-indolyl)-3-(2-pyridyl)phenyl] Yellow powder of pyrimidine (A-2) (yield 1.35 g, yield 97%).

¹ H-NMR (CDCl ₃ ): δ 7.34 (dd, J = 7.6, 4.8 Hz, 1H), 7.54-7.60 (m, 6H), 7.88 (t, J = 7.6 Hz, 1H), 8.03 - 8.11 ( m, 4H), 8.15-8.23 (m, 4H), 8.25 (d, J = 7.6 Hz, 1H), 8.32 - 8.35 (m, 6H), 8.49 (s, 1H), 8.81 (d, J = 4.8 Hz) , 1H), 9.07 (s, 1H), 9.44 (s, 1H).

Example-4

4,6-diphenyl-2-[5-chloro-4'-(2-pyridyl)biphenyl-3-yl]pyrimidine (600 mg), 9-indoleboronic acid (403 mg), under a stream of argon, Palladium acetate (5.4 mg), 2-dicyclohexylphosphine-2', 4',6'-triisopropylbiphenyl (34.2 mg), and 3M-potassium potassium phosphate solution (1.2 mL), suspended in toluene (4.8) In a mixed solvent of mL) and 1-butanol (1.2 mL), the mixture was stirred at 100 ° C for 2 hours. After the reaction mixture was allowed to cool, water was added and extraction was carried out using chloroform. The organic layer was distilled off under reduced pressure to give the desired 4,6-diphenyl-2-[5-(9-fluorenyl)-4'-(2-pyridyl)biphenyl-3-yl]pyrimidine ( Yellow powder of A-3) (yield 584 g, yield 76%).

¹ H-NMR (CDCl ₃ ): δ 7.27 (t, J = 6.2 Hz, 1H), 7.41 (d, J = 6.5 Hz, 1H), 7.44 (d, J = 6.6 Hz, 1H), 7.51 - 7.60 (m, 8H), 7.80 (t, J = 7.5 Hz, 1H), 7.83 (d, J = 7.7 Hz, 1H), 7.90 (d, J = 8.8 Hz, 2H), 7.94 (s, 1H), 7.99 (d, J = 8.5 Hz, 2H), 8.11 (s, 1H), 8.14 (d, J = 8.5 Hz, 2H), 8.18 (d, J = 8.5 Hz, 2H), 8.29-8.32 (m, 4H) , 8.62 (s, 1H), 8.76 (d, J = 4.8 Hz, 1H), 8.85 (s, 1H), 9.28 (s, 1H).

Example-5

4,6-Diphenyl-2-[3-chloro-5-(2-pyridyl)phenyl]pyrimidine (840 mg), 9-indoleboronic acid (533 mg), palladium acetate (9.0 mg) under a stream of argon , 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (57.2 mg), and a 3 M-potassium carbonate aqueous solution (1.6 mL), a mixed solvent suspended in THF (10.0 mL) The mixture was stirred at 70 ° C for 24 hours. After the reaction mixture was allowed to cool, water was added and extraction was carried out using chloroform. The organic layer was purified by a silica gel column chromatography (developing solvent chloroform) to obtain the desired 4,6-diphenyl-2-[5-(9-fluorenyl)-3-(2-pyridyl group). a yellow powder of phenyl]pyrimidine (A-4) (yield 1.05 g, yield 94%).

¹ H-NMR (CDCl ₃ ): δ 7.34 (dd, J = 7.6, 4.8 Hz, 1H), 7.38 (d, J = 6.8 Hz, 1H), 7.40 (d, J = 6.8 Hz, 1H), 7.50 (d, J = 6.8 Hz, 1H), 7.52 (d, J = 6.8 Hz, 1H), 7.53 - 7.58 (m, 6H), 7.84 (t, J = 7.6 Hz, 1H), 7.86 (d, J = 8.8 Hz, 2H), 8.00 (d, J = 8.0 Hz, 1H), 8.09 (s, 1H), 8.12 (d, J = 8.4 Hz, 2H), 8.28-8.32 (m, 5H), 8.60 (s, 1H), 8.77 (d, J = 4.8 Hz, 1H), 8.89 (s, 1H), 9.54 (s, 1H).

Synthesis Example-4

2-(3,5-Dibromophenyl)-4,6-diphenylpyrimidine (10.0 g), 4-(2-pyridyl)phenylboronic acid (11.1 g), palladium acetate under a stream of argon (96.3 mg), a toluene solution of tri-tert-butylphosphine (1.29 mL), and a 4N-aqueous sodium hydroxide solution (21.5 mL) were suspended in THF (190 mL), and heated under reflux for 9 hours. After the reaction is allowed to cool, water is added. The solid precipitated by filtration was washed with water and methanol to obtain the target 2-[4,4"-bis(2-pyridyl)-1,1':3',1"-terphenyl-5 White powder of '-yl]-4,6-diphenylpyrimidine (ETL-1) (yield 9.2 g, yield 70%).

¹ H-NMR (CDCl ₃ ): δ 7.19-7.23 (m, 2H), 7.53-7.60 (m, 6H), 7.70-7.79 (m, 4H), 7.88 (d, J = 8.5 Hz, 4H), 8.01-8.02 (m, 2H), 8.11 (d, J = 8.3 Hz, 4H), 8.25-8.29 (m, 4H), 8.68 (d, J = 4.5 Hz, 2H), 8.95 (d, J = 1.8 Hz) , 2H).

The structure and abbreviation of the compound used in the evaluation of the element are exemplified below.

Example-6 Component Evaluation

The substrate was a glass substrate patterned with a strip of ITO transparent electrode using a 2 mm indium oxide-tin (ITO) film. The substrate was washed with isopropyl alcohol, and then subjected to surface treatment by washing with oxygen plasma. The washed substrate was subjected to vacuum deposition by vacuum deposition to obtain an organic electroluminescent device having a laminated structure as shown in Fig. 1 and having a light-emitting area of 4 mm ² .

First, the glass substrate was introduced into a vacuum deposition tank, and the pressure was reduced to 1.0 × 10 ^-4 Pa. Then, on the glass substrate with the ITO transparent electrode shown in FIG. 1, the hole injection layer 2, the first hole transport layer 3, the second hole transport layer 4, and the light-emitting layer 5 of the organic compound layer are sequentially formed. The hole blocking layer 6 and the electron transport layer 7 are then formed into a cathode layer 8. The hole injection layer 1 was vacuum-deposited by HTL-1 to have a film thickness of 45 nm. The first hole transport layer 3 was vacuum-deposited by HAT-CN to have a film thickness of 5 nm. The second hole transport layer 4 was vacuum-deposited by HTL-2 to have a film thickness of 30 nm. The light-emitting layer 5 was formed into a film thickness of 25 nm by vacuum evaporation in a 95:5 ratio (weight ratio) of EML-1 and EML-2. The hole barrier layer 6 was vacuum-deposited by EML-1 to have a film thickness of 3 nm. The electron transport layer 7 was made of A-1 synthesized in Example 1 of the present invention, and was subjected to vacuum evaporation to have a film thickness of 30 nm. Further, each of the organic materials was subjected to film formation by resistance heating, and the heated compound was subjected to vacuum deposition at a deposition rate of 0.3 to 0.5 nm/second. Finally, a metal mask is disposed in a manner orthogonal to the ITO pattern to form a cathode layer 8. The cathode layer 8 was formed into a three-layer structure by sequentially depositing a film thickness of 0.4 nm, 80 nm, and 20 nm by vacuum deposition of Liq, magnesium/silver, and silver. Each film thickness was measured by a stylus type film thickness meter (DEKTAK). Further, the element was sealed in a nitrogen atmosphere hand-held work box having an oxygen and a water concentration of 1 ppm or less. For the sealing, a glass sealing cover and the above-mentioned film-forming substrate epoxy-type ultraviolet curable resin (manufactured by Nagase ChemteX Co., Ltd.) were used.

The luminescent properties of the organic electroluminescent element produced by the investigation were investigated. The elemental lifetime (h) was evaluated by setting the initial luminance to 100% and the elapsed time (h) at the time when the luminance was reduced to 70% as "the luminance was reduced by 30%". The evaluation results are shown in Table 1.

Reference example-1

Except that in Example -6, the compound A-1 was replaced, and the same procedure as in Example -6 was carried out except that the ETL-1 synthesized in Synthesis Example-5 was used instead, and an organic electroluminescent element was produced. Luminous properties. The evaluation results of the component life (h) are shown in Table 1.

It is known from Table 1 that the present invention is used in comparison to the compound of Reference Example-1. The life of the organic electroluminescent device of the pyrimidine compound is remarkably excellent.

Example-7

The substrate was a glass substrate patterned with a strip of ITO transparent electrode using a 2 mm indium oxide-tin (ITO) film. The substrate was washed with isopropyl alcohol, and then subjected to surface treatment by washing with oxygen plasma. The washed substrate was subjected to vacuum deposition by vacuum deposition to obtain an organic electroluminescent device having a laminated structure as shown in Fig. 1 and having a light-emitting area of 4 mm ² .

First, the glass substrate was introduced into a vacuum deposition tank, and the pressure was reduced to 1.0 × 10 ^-4 Pa. Then, on the glass substrate having the ITO transparent electrode shown in FIG. 1, the hole injection layer 12, the first hole transport layer 13, the second hole transport layer 14, and the light-emitting layer 15 of the organic compound layer are sequentially formed. The electron transport layer 16, and the electron injection layer 17, and then the cathode layer 18 is formed. The hole injection layer 12 was vacuum-deposited by HTL-1 to have a film thickness of 45 nm. The first hole transport layer 13 was vacuum-deposited by HAT-CN to have a film thickness of 5 nm. The second hole transport layer 14 was vacuum-deposited by HTL-2 to have a film thickness of 30 nm. The light-emitting layer 15 was formed into a film thickness of 20 nm by vacuum evaporation in a ratio of 93:7 (weight ratio) of EML-1 and EML-2. The hole blocking layer 16 was subjected to vacuum evaporation at a thickness of 30 nm from the compound A-2 synthesized in Example 3 of the present invention. The electron transport layer 17 was vacuum-deposited by Liq to have a film thickness of 0.45 nm. Further, each of the organic materials was subjected to film formation by resistance heating, and the heated compound was subjected to vacuum deposition at a deposition rate of 0.3 to 0.5 nm/second. Finally, a metal mask is disposed in a manner orthogonal to the ITO pattern to form a cathode layer 8. The cathode layer 8 was formed by forming a film thickness of 80 nm and 20 nm by vacuum evaporation of magnesium, silver, and silver in this order to form a two-layer structure. Each film thickness was measured by a stylus type film thickness meter (DEKTAK). Further, the element is sealed in a nitrogen environment hand-held work box having an oxygen and water concentration of 1 ppm or less. For the sealing, a glass sealing cover and the above-mentioned film-forming substrate epoxy-type ultraviolet curable resin (manufactured by Nagase ChemteX Co., Ltd.) were used.

A direct current was applied to the produced organic electroluminescent device, and the current-voltage characteristics were investigated. The power efficiency when the current flows at a density of 10 mA/cm ² in the device is shown in Table 2.

Example-8

An organic electroluminescent device was produced by the same operation as in Example -7 except that the compound A-2 was used instead of the compound A-2 synthesized in the synthesis example-4. Current-voltage characteristics of the component. The evaluation results are shown in Table 2.

Example -9

An organic electroluminescent device was produced by the same operation as in Example -7 except that the compound A-2 was used instead of the compound A-2 and the compound A-4 synthesized in Synthesis Example-5 was used instead. Current-voltage characteristics of the component. The evaluation results are shown in Table 2.

Reference example-2

In the same manner as in Example-7 except that the compound A-2 was used instead of the compound A-2, the same operation as in Example -7 was carried out to prepare an organic electroluminescent device, and the current-voltage characteristics of the device were investigated. The evaluation results are shown in Table 2.

As is apparent from Table 2, the power efficiency of the organic electroluminescence device using the pyrimidine compound of the present invention was remarkably excellent as compared with Reference Example-2.

Industrial availability

The organic electroluminescent device using the pyrimidine compound of the present invention is very effective in use for materials for display and illumination applications requiring long life and high efficiency because of excellent life and power efficiency.

1‧‧‧ glass substrate with ITO transparent electrode

2‧‧‧ hole injection layer

3‧‧‧First hole transport layer

4‧‧‧Second hole transport layer

5‧‧‧Lighting layer

6‧‧‧ hole barrier

7‧‧‧Electronic transport layer

8‧‧‧ cathode layer

Claims (5)

A pyrimidine compound, represented by the general formula (1): In the formula, X represents a single bond or a phenyl group; and Y represents a fluorenyl group or a fluorenyl group. A pyrimidine compound according to claim 1, wherein X is a single bond or a pendant phenyl group. A pyrimidine compound according to claim 1 or 2, wherein Y is a 9-fluorenyl group or a 1-fluorenyl group. The pyrimidine compound of claim 1 is represented by the following formula (2), (3), (4), or (5): An organic electroluminescent device comprising a pyrimidine compound represented by the general formula (1) in an electron transport layer: In the formula, X represents a single bond or a phenyl group; and Y represents a fluorenyl group or a fluorenyl group.