WO2012005214A1

WO2012005214A1 - Electron transport material and organic electroluminescent elements using same

Info

Publication number: WO2012005214A1
Application number: PCT/JP2011/065282
Authority: WO
Inventors: 馬場　大輔; 洋平小野; 内田　学
Original assignee: Jnc株式会社
Priority date: 2010-07-05
Filing date: 2011-07-04
Publication date: 2012-01-12
Also published as: TW201202199A; TWI498321B; JPWO2012005214A1; JP5807637B2

Abstract

The compound represented by formula (1) is useful as an electron transport material for organic EL elements. Use of said electron transport material contributes to extension of the life of organic EL elements. In formula (1), Py is a group selected from a set of monovalent groups represented by Formulas (2), (3), (4) and (5); Ar¹ is a naphthalene-1,4-diyl or naphthalene-1,5-diyl group; Ar² is a phenyl or 2-naphthyl group. Optional hydrogens of the Py, Ar¹ and Ar² can be substituted with C_1-6 alkyl groups and/or C_3-6 cycloalkyl groups.

Description

Electron transport material and organic electroluminescent device using the same

The present invention relates to a novel electron transport material having a pyridyl group, an organic electroluminescence device using the electron transport material (hereinafter, sometimes abbreviated as an organic EL device or simply a device), and the like.

In recent years, organic EL elements have attracted attention as next-generation full-color flat panel displays, and active research has been conducted. In order to promote the practical use of organic EL elements, it is indispensable to reduce the drive voltage and extend the life of the elements, and new electron transport materials have been developed to achieve these. In particular, it is essential to lower the driving voltage and extend the life of the blue element. Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-123983) discloses that an organic EL device can be driven at a low voltage by using a 2,2′-bipyridyl compound, which is a phenanthroline derivative or an analog thereof, as an electron transport material. It is stated that it can be done. However, the element characteristics (driving voltage, light emission efficiency, etc.) reported in the examples of this document are only relative values based on comparative examples, and no actual measurement values that can be judged as practical values are described. Alternatively, example of using 2,2'-bipyridyl compound to the electron transport material, non-patent document ^{1 (Proceedings of the 10 th International} Workshop on Inorganic and Organic Electroluminescence), Patent Document 2 (JP 2002-158093 JP ) And Patent Document 3 (International Publication No. 2007/86552 pamphlet). The compound described in Non-Patent Document 1 has a low Tg and is not practical. Although the compounds described in Patent Documents 2 and 3 can drive an organic EL device at a relatively low voltage, longer life is desired for practical use.

JP 2003-123983 A JP 2002-158093 A International Publication 2007/86552 Pamphlet

The present invention has been made in view of the problems of such conventional techniques. It is an object of the present invention to provide an electron transport material that contributes to extending the lifetime of an organic EL element. Furthermore, this invention makes it a subject to provide the organic EL element using this electron transport material.

As a result of intensive studies, the present inventors have found that a compound having pyridyl, bipyridyl, phenylpyridyl, or pyridylphenyl in the naphthyl of 9- (1-naphthyl) anthracene is used for the electron transport layer of the organic EL device, resulting in a long lifetime. The present inventors have found that an organic EL element that can be driven by the method is obtained, and have completed the present invention based on this finding.
Said subject is solved by each item shown below.

[1] A compound represented by the following formula (1).

In equation (1),
Py is one selected from the group of monovalent groups represented by the following formulas (2), (3), (4) and (5), and any hydrogen of these groups has 1 to 6 carbon atoms. Or an alkyl of 3 to 6 carbon atoms may be substituted;

Ar ¹ is naphthalene-1,4-diyl or naphthalene-1,5-diyl, and any hydrogen in these groups is replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons Well;
Ar ² is phenyl or 2-naphthyl, and any hydrogen of these groups may be replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons.

[2] The compound according to item [1], wherein Py is one selected from the group of monovalent groups represented by formulas (2), (3) and (4).

[3] The compound according to item [1], wherein Py is one selected from the group of monovalent groups represented by formula (2).
[4] The compound according to item [1], wherein Py is one selected from the group of monovalent groups represented by formula (3).
[5] The compound according to item [1], wherein Py is one selected from the group of monovalent groups represented by formula (4).
[6] The compound according to item [1], wherein Py is one selected from the group of monovalent groups represented by formula (5).

[7] The compound according to item [1], wherein Py is 2-pyridyl.
[8] The compound according to item [1], wherein Py is 3-pyridyl.
[9] The compound according to [1] above, wherein Py is 4-pyridyl.

[10] The compound according to [1], wherein Py is one selected from the group of monovalent groups below.

[11] The compound according to item [1], wherein Py is one selected from the group of monovalent groups below.

[12] The following formulas (1-2), (1-3), (1-19), (1-20), (1-24), (1-48), (1-51), (1- 104) or (1-1027), the compound according to the above item [1].

[13] An electron transport material containing the compound according to any one of [1] to [12].

[14] A pair of electrodes composed of an anode and a cathode, a light emitting layer disposed between the pair of electrodes, an electron transport material according to the above [13], disposed between the cathode and the light emitting layer. An organic electroluminescent device having an electron transport layer and / or an electron injection layer containing
[15] At least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of a quinolinol-based metal complex, a bipyridine derivative, a phenanthroline derivative, and a borane derivative. The organic electroluminescent element described in the item.
[16] At least one of the electron transport layer and the electron injection layer further includes an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, or an alkaline earth. Containing at least one selected from the group consisting of metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes The organic electroluminescent element as described in the above item [14].

The compound of the present invention is stable even when a voltage is applied in a thin film state and has a feature of high charge transport capability. The compound of the present invention is suitable as a charge transport material in an organic EL device. By using the compound of this invention for the electron carrying layer of an organic EL element, the organic EL element which has a long lifetime can be obtained. By using the organic EL element of the present invention, a high-performance display device such as full-color display can be created.

Hereinafter, the present invention will be described in more detail. In the present specification, for example, the “compound represented by formula (1-1)” may be referred to as “compound (1-1)”. The “compound represented by formula (1-2)” may be referred to as “compound (1-2)”. Other formula symbols and formula numbers are handled in the same manner.

<Description of compound>
The first invention of the present application is a compound having pyridyl, bipyridyl, phenylpyridyl, or pyridylphenyl in the naphthyl of 9- (1-naphthyl) anthracene represented by the following formula (1).

In formula (1), Py is one selected from the group of monovalent groups represented by the following formulas (2), (3), (4) and (5).

Specifically, pyridyl represented by the formula (2) is 2-pyridyl, 3-pyridyl or 4-pyridyl.

Specific examples of bipyridyl represented by the formula (3) include 2,2′-bipyridin-5-yl, 2,2′-bipyridin-6-yl, 2,2′-bipyridin-4-yl, 2, 3'-bipyridin-5-yl, 2,3'-bipyridin-6-yl, 2,3'-bipyridin-4-yl, 2,4'-bipyridin-5-yl, 2,4'-bipyridine-6 -Yl, 2,4'-bipyridin-4-yl, 3,2'-bipyridin-6-yl, 3,2'-bipyridin-5-yl, 3,3'-bipyridin-6-yl, 3,3 '-Bipyridin-5-yl, 3,4'-bipyridin-6-yl, 3,4'-bipyridin-5-yl, 4,2'-bipyridin-3-yl, 4,3'-bipyridine-3- Or 4,4′-bipyridin-3-yl. Among them, 2,2′-bipyridin-5-yl, 2,2′-bipyridin-6-yl, 2,3′-bipyridin-5-yl, 2,3′-bipyridin-6-yl, 2, 4'-bipyridin-5-yl, 2,4'-bipyridin-6-yl, 3,2'-bipyridin-6-yl, 3,2'-bipyridin-5-yl, 3,3'-bipyridine-6 -Yl, 3,3'-bipyridin-5-yl, 3,4'-bipyridin-6-yl, 3,4'-bipyridin-5-yl, 4,2'-bipyridin-3-yl, 4,3 '-Bipyridin-3-yl and 4,4'-bipyridin-3-yl are preferred. 2,2′-bipyridin-5-yl, 2,2′-bipyridin-6-yl, 2,3′-bipyridin-5-yl, 2,3′-bipyridin-6-yl, 2,4 ′ More preferred are -bipyridin-5-yl and 2,4'-bipyridin-6-yl.

Specific examples of the phenylpyridyl represented by the formula (4) include 3-phenylpyridin-2-yl, 4-phenylpyridin-2-yl, 5-phenylpyridin-2-yl, and 6-phenylpyridin-2- Yl, 2-phenylpyridin-3-yl, 4-phenylpyridin-3-yl, 5-phenylpyridin-3-yl, 6-phenylpyridin-3-yl, 2-phenylpyridin-4-yl, and 3- Phenylpyridin-4-yl. Among these, 4-phenylpyridin-2-yl, 5-phenylpyridin-2-yl, 6-phenylpyridin-2-yl, 5-phenylpyridin-3-yl, 6-phenylpyridin-3-yl, -Phenylpyridin-4-yl is preferred. Further, 6-phenylpyridin-2-yl, 6-phenylpyridin-3-yl, and 2-phenylpyridin-4-yl are more preferable.

Specific examples of the pyridylphenyl represented by the formula (5) include 4- (2-pyridyl) phenyl, 4- (3-pyridyl) phenyl, 4- (4-pyridyl) phenyl, and 3- (2-pyridyl). It is phenyl, 3- (3-pyridyl) phenyl, 3- (4-pyridyl) phenyl, 2- (2-pyridyl) phenyl, 2- (3-pyridyl) phenyl, or 2- (4-pyridyl) phenyl. Among these, 4- (2-pyridyl) phenyl, 4- (3-pyridyl) phenyl, 4- (4-pyridyl) phenyl, 3- (2-pyridyl) phenyl, 3- (3-pyridyl) phenyl, and 3- (4-pyridyl) is preferred.

Any hydrogen in the monovalent group represented by the above formulas (2) to (5) may be replaced with alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons. Examples of the alkyl having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, Examples thereof include 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl and 2-ethylbutyl. Among these, methyl, ethyl, isopropyl and t-butyl are preferable. Examples of the cycloalkyl having 3 to 6 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl. The number of substituents that may be bonded to the monovalent group is, for example, the maximum number of substituents, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

Ar ¹ is naphthalene-1,4-diyl or naphthalene-1,5-diyl. Any hydrogen of these groups may be replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons. As examples of the alkyl having 1 to 6 carbon atoms and the cycloalkyl having 3 to 6 carbon atoms, the examples of the substituent of the monovalent group represented by the above formulas (2) to (5) are applied. The number of substituents that may be bonded to naphthalene-1,4-diyl or naphthalene-1,5-diyl is, for example, the maximum number of substituents, preferably 1 to 3, more preferably 1 to 2 More preferably, it is 1.

Ar ² is phenyl or 2-naphthyl. Any hydrogen of these groups may be replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons. Examples of the monovalent group substituents represented by the above formulas (2) to (5) are also applied to the examples of the alkyl having 1 to 6 carbons and the cycloalkyl having 3 to 6 carbons. The number of substituents that may be bonded to phenyl or 2-naphthyl is, for example, the maximum number of substituents, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1. Whether Ar ² is phenyl or 2-naphthyl, the above substituents may be linked at any position, but when linked at any one position, the 4-position in phenyl is 2- In naphthyl, the 6-position is preferred.

<Specific examples of compounds>
Specific examples of the compounds of the present invention are shown by the formulas listed below, but the present invention is not limited by the disclosure of these specific structures.

Specific examples of the compound represented by the formula (1) include the following formulas (1-1) to (1-205), (1-211) to (1-617), and (1-621) to (1-1032). ). Among these, preferred compounds (1-1) to (1-12), (1-19) to (1-24), (1-31) to (1-37), (1-39), (1-40), (1-43), (1-46) to (1-51), (1-103) to (1-114), (1-121) to (1-126), (1 -134) to (1-136), (1-138) to (1-140), (1-142) to (1-144), (1-147), (1-149), (1-150) ), (1-152) to (1-154), and (1-1023) to (1-1032). More preferable compounds are compounds (1-1) to (1-12), (1-19) to (1-24), (1-31) to (1-37), (1-39), (1- 40), (1-43), (1-48), (1-51), (1-103) to (1-114), (1-121) to (1-126), (1-134) To (1-136), (1-138) to (1-140), formulas (1-142) to (1-144), and (1-1023) to (1-1032). In the formula, Me, Et, i-Pr, and t-Bu are abbreviations for methyl, ethyl, isopropyl, and tertiary butyl, respectively.

<Method of synthesizing compounds>
The compounds of the present invention can be synthesized using known synthesis methods. The method for synthesizing the compound of the present invention will be described using the compound (1-2) as an example.

First, 9-phenylanthracene is synthesized in Reaction 1. Bromobenzene is reacted with metallic magnesium in THF to give a Grignard reagent, which is reacted with 9-bromoanthracene in the presence of a catalyst to give 9-phenylanthracene. The coupling of the benzene ring and the anthracene ring is not limited to the above-described method, and it can be performed by the Negishi coupling reaction, the Suzuki coupling reaction, or the like, and these conventional methods can be appropriately used depending on the situation. Further, 9-phenylanthracene may be a commercially available product.

In reaction 2, the 10-position of 9-phenylanthracene is brominated using N-bromosuccinimide. Here too, a commonly used brominating agent other than N-bromosuccinimide can be used.

In Reaction 3, 9-bromo-10-phenylanthracene is lithiated using an organolithium reagent, or converted to a Grignard reagent using magnesium or an organomagnesium reagent, such as trimethyl borate, triethyl borate, or triisopropyl borate. (10-phenylanthracen-9-yl) boronic acid ester can be synthesized by reacting with. Furthermore, (10-phenylanthracen-9-yl) boronic acid can be synthesized by hydrolyzing the boronic ester in Reaction 4.

On the other hand, by synthesizing a zinc chloride complex from 3-bromopyridine in reaction 5, and then reacting the zinc chloride complex of pyridine with 1,4-dibromonaphthalene in the following reaction 6, 3- (4-bromonaphthalene) -1-yl) pyridine can be synthesized. “ZnCl ₂ · TMEDA” in the above reaction formula is a tetramethylethylenediamine complex of zinc chloride. R in RLi or RMgX represents straight-chain or branched alkyl, preferably straight-chain or branched alkyl having 1 to 4 carbon atoms. X is a halogen, and chlorine, bromine and iodine are preferably used.

The compound (1-2) of the present invention can be synthesized by coupling the anthraceneboronic acid and naphthalene bromide in the presence of a palladium catalyst in the reaction 7.

Other compounds of the present invention can be synthesized by appropriately changing the materials used in the above reaction. For example, by using an alkyl-substituted bromobenzene such as 4-bromotoluene instead of bromobenzene in reaction 1, a compound having an alkyl-substituted phenyl can be synthesized.

By using 2-bromopyridine or 4-bromopyridine in place of 3-bromopyridine used in Reaction 5, a compound in which 2-pyridyl or 4-pyridyl is substituted for naphthyl can be synthesized. Also, iodopyridine can be used instead of bromopyridine. By using 1,5-dibromonaphthalene instead of 1,4-dibromonaphthalene used in Reaction 6, a compound in which pyridyl is bonded to the 5-position of naphthyl can be synthesized.

A compound in which bipyridyl, phenylpyridyl or pyridylphenyl is bonded to naphthyl instead of pyridyl can be synthesized by the following procedure by applying the above reaction.

By applying the previous reaction 6, the rings can be coupled to each other as in reactions 8) to c) to synthesize bromobipyridine, phenylbromopyridine or pyridylbromobenzene. By appropriately selecting the raw materials used in these reactions, a compound containing a nitrogen atom at an arbitrary position can be obtained. By applying reaction 5 from the compound obtained above to synthesize a zinc chloride complex, then again reacting the zinc chloride complex with 1,4-dibromonaphthalene or 1,5-dibromonaphthalene according to reaction 6 , Bromonaphthalene to which bipyridyl, phenylpyridyl or pyridylphenyl is bonded can be obtained. By coupling these bromonaphthalenes with anthraceneboronic acid according to Reaction 7, the target compound can be synthesized.

The step of coupling bromobipyridine, phenylbromopyridine or pyridylbromobenzene with 1,4-dibromonaphthalene or 1,5-dibromonaphthalene is not limited to the above Negishi coupling reaction, depending on the types of available raw materials and reagents. The Suzuki coupling reaction used in reactions 3, 4 and 7 can also be used.

In Reactions 3 to 4, the 10-position of 9-phenylanthracene was converted to a boronic acid and subjected to the coupling reaction. However, the boronic acid ester which is the product of Reaction 3 may be used as it is in the coupling reaction. Further, as shown in Reaction 9 below, 9-bromo-10-phenylanthracene is lithiated using an organolithium reagent, or converted to a Grignard reagent using magnesium or an organomagnesium reagent, and bis (pinacolato) diboron or 4 , 4,5,5-Tetramethyl-1,3,2-dioxaborolane, the following (10-phenylanthracen-9-yl) boronic acid ester can be synthesized.

Further, as shown in Reaction 10, 9-bromo-10-phenylanthracene and bis (pinacolato) diboron or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane, a palladium catalyst and a base are used. The same (10-phenylanthracen-9-yl) boronic acid ester can be synthesized also by a coupling reaction.

The (10-phenylanthracen-9-yl) boronic acid ester thus obtained can also be suitably used for the coupling reaction of Reaction 7.

The example of the Suzuki coupling reaction shown in Reaction 7 was taken up as a method for coupling the anthracene part and the naphthalene part, which are the final steps of the synthesis, but the Negishi coupling reaction depends on the types of available raw materials and reagents. May be used. Furthermore, the synthesis of the compound of the present invention is not limited to the method in which the reaction of coupling the anthracene part and the naphthalene part is the final step. When synthesizing a compound of the present invention in which bipyridyl, phenylpyridyl or pyridylphenyl is bonded to naphthalene, first an anthracene part and a dibromonaphthalene part are coupled in advance, and then a zinc chloride complex, a boronic acid ester, a boronic acid, etc. It is also possible to synthesize bipyridyl, phenylpyridyl or pyridylphenyl having the following active groups by coupling with naphthalene bromide.

<Reagent used in reaction>
Specific examples of the palladium catalyst used in the Suzuki coupling reaction include Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd (OAc) ₂ , tris (dibenzylideneacetone) dipalladium (0), tris ( Dibenzylideneacetone) dipalladium (0) chloroform complex, or bis (dibenzylideneacetone) palladium (0).

In order to accelerate the reaction, a phosphine compound may be added to these palladium compounds in some cases. Specific examples of the phosphine compound include tri (t-butyl) phosphine, tricyclohexylphosphine, 1- (N, N-dimethylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (N, N-dibutylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (methoxymethyl) -2- (di-t-butylphosphino) ferrocene, 1,1′-bis (di-t-butylphos Fino) ferrocene, 2,2′-bis (di-t-butylphosphino) -1,1′-binaphthyl, 2-methoxy-2 ′-(di-t-butylphosphino) -1,1′-binaphthyl, or 2-dicyclohexylphosphino-2 ', 6'-dimethoxybiphenyl.

Specific examples of bases used in the Suzuki coupling reaction include sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, sodium t-butoxide, sodium acetate. , Tripotassium phosphate, or potassium fluoride.

Specific examples of the solvent used in the Suzuki coupling reaction include benzene, toluene, xylene, 1,2,4-trimethylbenzene, N, N-dimethylformamide, tetrahydrofuran, diethyl ether, t-butyl methyl ether, 1 1,4-dioxane, methanol, ethanol, cyclopentyl methyl ether or isopropyl alcohol. These solvents can be appropriately selected and may be used alone or as a mixed solvent.

Specific examples of the palladium catalyst used in the Negishi coupling reaction include Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd (OAc) ₂ , tris (dibenzylideneacetone) dipalladium (0), tris ( Dibenzylideneacetone) dipalladium (0) chloroform complex, bis (dibenzylideneacetone) palladium (0), bis (tri-t-butylphosphino) palladium (0), or (1,1′-bis (diphenylphosphino) Ferrocene) dichloropalladium (II).

Specific examples of the solvent used in the Negishi coupling reaction include benzene, toluene, xylene, 1,2,4-trimethylbenzene, N, N-dimethylformamide, tetrahydrofuran, diethyl ether, t-butyl methyl ether, cyclopentyl. Examples include methyl ether or 1,4-dioxane. These solvents can be appropriately selected and may be used alone or as a mixed solvent.

When the compound of the present invention is used for an electron injection layer or an electron transport layer in an organic EL device, it is stable when an electric field is applied. These represent that the compound of the present invention is excellent as an electron injecting material or an electron transporting material for an electroluminescent device. The electron injection layer mentioned here is a layer for receiving electrons from the cathode to the organic layer, and the electron transport layer is a layer for transporting the injected electrons to the light emitting layer. The electron transport layer can also serve as the electron injection layer. The material used for each layer is referred to as an electron injection material and an electron transport material.

<Description of organic EL element>
2nd invention of this application is an organic EL element containing the compound represented by Formula (1) of this invention in an electron injection layer or an electron carrying layer. The organic EL element of the present invention has a low driving voltage and high durability during driving.

Although the structure of the organic EL device of the present invention has various modes, it is basically a multilayer structure in which at least a hole transport layer, a light emitting layer, and an electron transport layer are sandwiched between an anode and a cathode. Examples of the specific configuration of the device are (1) anode / hole transport layer / light emitting layer / electron transport layer / cathode, (2) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer. / Cathode, (3) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode, etc.

Since the compound of the present invention has high electron injecting property and electron transporting property, it can be used for an electron injecting layer or an electron transporting layer alone or in combination with other materials. The organic EL device of the present invention emits blue, green, red and white light by combining a hole injection layer, a hole transport layer, a light emitting layer, etc. using other materials with the electron transport material of the present invention. It can also be obtained.

The light-emitting material or light-emitting dopant that can be used in the organic EL device of the present invention is daylight fluorescence as described in the Polymer Society of Japan, Polymer Functional Materials Series “Optical Functional Materials”, Joint Publication (1991), P236. Materials, fluorescent brighteners, laser dyes, organic scintillators, various fluorescent analysis reagents and other luminescent materials, supervised by Koji Koji, “Organic EL materials and displays” published by CMMC (2001) P155-156 And a light emitting material of a triplet material as described in P170 to 172.

The compounds that can be used as the light emitting material or the light emitting dopant are polycyclic aromatic compounds, heteroaromatic compounds, organometallic complexes, dyes, polymer light emitting materials, styryl derivatives, aromatic amine derivatives, coumarin derivatives, borane derivatives, oxazines. Derivatives, compounds having a spiro ring, oxadiazole derivatives, fluorene derivatives and the like. Examples of the polycyclic aromatic compound are anthracene derivatives, phenanthrene derivatives, naphthacene derivatives, pyrene derivatives, chrysene derivatives, perylene derivatives, coronene derivatives, rubrene derivatives, and the like. Examples of heteroaromatic compounds are oxadiazole derivatives having a dialkylamino group or diarylamino group, pyrazoloquinoline derivatives, pyridine derivatives, pyran derivatives, phenanthroline derivatives, silole derivatives, thiophene derivatives having a triphenylamino group, quinacridone derivatives Etc. Examples of organometallic complexes are zinc, aluminum, beryllium, europium, terbium, dysprosium, iridium, platinum, osmium, gold, etc., quinolinol derivatives, benzoxazole derivatives, benzothiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, A complex with a benzimidazole derivative, a pyrrole derivative, a pyridine derivative, a phenanthroline derivative, or the like. Examples of dyes are xanthene derivatives, polymethine derivatives, porphyrin derivatives, coumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, oxobenzanthracene derivatives, carbostyril derivatives, perylene derivatives, benzoxazole derivatives, benzothiazole derivatives, benzimidazoles And pigments such as derivatives. Examples of the polymer light-emitting material are polyparaphenyl vinylene derivatives, polythiophene derivatives, polyvinyl carbazole derivatives, polysilane derivatives, polyfluorene derivatives, polyparaphenylene derivatives, and the like. Examples of styryl derivatives are amine-containing styryl derivatives, styrylarylene derivatives, and the like.

Other electron transport materials used in the organic EL device of the present invention are arbitrarily selected from compounds that can be used as electron transport compounds in photoconductive materials and compounds that can be used in the electron transport layer and electron injection layer of organic EL devices. Can be used.

Specific examples of such electron transport materials include quinolinol metal complexes, 2,2′-bipyridyl derivatives, phenanthroline derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives, thiophene derivatives, triazole derivatives, thiadiazole derivatives, oxine derivatives. Metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives, imidazopyridine derivatives, borane derivatives, and the like.

Regarding the hole injection material and the hole transport material used in the organic EL device of the present invention, in a photoconductive material, a compound conventionally used as a charge transport material for holes or a hole injection of an organic EL device is used. Any known material used for the layer and the hole transport layer can be selected and used. Specific examples thereof are carbazole derivatives, triarylamine derivatives, phthalocyanine derivatives and the like.

Each layer constituting the organic EL element of the present invention can be formed by forming a material to constitute each layer into a thin film by a method such as a vapor deposition method, a spin coat method, or a cast method. The film thickness of each layer thus formed is not particularly limited and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. Note that it is preferable to adopt a vapor deposition method as a method of thinning the light emitting material from the viewpoint that a homogeneous film can be easily obtained and pinholes are hardly generated. When thinning using the vapor deposition method, the vapor deposition conditions differ depending on the type of the light emitting material of the present invention. Deposition conditions generally include boat heating temperature 50 to 400 ° C., vacuum degree 10 ⁻⁶ to 10 ⁻³ Pa, deposition rate 0.01 to 50 nm / second, substrate temperature −150 to + 300 ° C., film thickness 5 nm to 5 μm. It is preferable to set appropriately within the range.

The organic EL device of the present invention is preferably supported by a substrate in any of the structures described above. The substrate only needs to have mechanical strength, thermal stability, and transparency, and glass, a transparent plastic film, and the like can be used. As the anode material, metals, alloys, electrically conductive compounds and mixtures thereof having a work function larger than 4 eV can be used. Specific examples thereof include metals such as Au, CuI, indium tin oxide (hereinafter abbreviated as ITO), SnO ₂ , ZnO, and the like.

Cathode materials can use metals, alloys, electrically conductive compounds, and mixtures thereof with work functions of less than 4 eV. Specific examples thereof are aluminum, calcium, magnesium, lithium, magnesium alloy, aluminum alloy and the like. Specific examples of the alloy include aluminum / lithium fluoride, aluminum / lithium, magnesium / silver, and magnesium / indium. In order to efficiently extract light emitted from the organic EL element, it is desirable that at least one of the electrodes has a light transmittance of 10% or more. The sheet resistance as the electrode is preferably several hundred Ω / □ or less. Although the film thickness depends on the properties of the electrode material, it is usually set in the range of 10 nm to 1 μm, preferably 10 to 400 nm. Such an electrode can be produced by forming a thin film by a method such as vapor deposition or sputtering using the electrode material described above.

Next, as an example of a method for producing an organic EL device using the light emitting material of the present invention, an organic material comprising the above-mentioned anode / hole injection layer / hole transport layer / light emitting layer / electron transport material of the present invention / cathode is used. A method for creating an EL element will be described. A thin film of an anode material is formed on a suitable substrate by vapor deposition to produce an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A light emitting layer thin film is formed thereon. On this light emitting layer, the electron transport material of this invention is vacuum-deposited, a thin film is formed, and it is set as an electron carrying layer. Furthermore, the target organic EL element is obtained by forming the thin film which consists of a substance for cathodes by a vapor deposition method, and making it a cathode. In the production of the organic EL element described above, the production order can be reversed, and the cathode, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode can be produced in this order.

When a DC voltage is applied to the organic EL device thus obtained, the anode may be applied with a positive polarity and the cathode with a negative polarity. When a voltage of about 2 to 40 V is applied, a transparent or translucent electrode is applied. Luminescence can be observed from the side (anode or cathode and both). The organic EL element also emits light when an alternating voltage is applied. The alternating current waveform to be applied may be arbitrary.

Hereinafter, the present invention will be described in more detail based on examples. First, synthesis examples of the compounds used in the examples are described below.

After putting 22.98 g of 3-bromonaphthalene into the flask and replacing the inside of the flask with nitrogen gas, 160 mL of dry THF was added and cooled in an ice bath. 80 mL of isopropyl magnesium chloride / THF solution (2M) was added dropwise thereto. After completion of the dropwise addition, the mixture was stirred as it was for 1 hour, 40.32 g of zinc chloride / tetramethylethylenediamine complex was added, and after further stirring for 1 hour, 62.40 g of 1,4-dibromonaphthalene and tetrakis (triphenylphosphine) palladium 5. 04g was added and it heated and refluxed for 4 hours. The reaction solution was cooled to room temperature, and an aqueous solution obtained by dissolving 181.60 g of ethylenediaminetetraacetic acid / tetrasodium salt in 200 mL of water was added and stirred. The organic layer and the aqueous layer were separated, and the organic layer was dried over magnesium sulfate. The crude product obtained by distilling off the solvent under reduced pressure was purified by silica gel column chromatography (developing solvent: toluene to toluene / ethyl acetate = 9/1 (volume ratio)). 28.90 g of (4-bromonaphthalen-1-yl) pyridine was obtained.

11.71 g of (10-phenylanthracen-9-yl) boronic acid, 6.96 g of 3- (4-bromonaphthalen-1-yl) pyridine, 0.74 g of tetrakis (triphenylphosphine) palladium, tripotassium phosphate 39 g, pseudocumene 30 mL, isopropyl alcohol 3 mL, and water 3 mL were placed in a flask and stirred at reflux temperature for 15 hours under a nitrogen atmosphere. The (10-phenylanthracen-9-yl) boronic acid was used as it was without purifying a commercially available product. After the heating, the mixture was cooled to room temperature, and the precipitated solid was separated by filtration and washed with pure water and then with ethyl acetate. The solid was dissolved in toluene and purified by silica gel chromatography (developing solution toluene to toluene / ethyl acetate = 9/1 (volume ratio)), and further filtered through activated carbon (solvent toluene). The solvent was distilled off under reduced pressure to obtain 10.00 g of 3- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) pyridine.
¹ H-NMR (CDCl ₃ ): δ = 9.0 (d, 1H), 8.8 (dd, 1H), 8.0 (m, 2H), 7.8 (d, 2H), 7.7 To 7.6 (m, 4H), 7.5 (m, 2H), 7.5 (m, 4H), 7.5 (m, 1H), 7.4 to 7.3 (m, 2H), 7.3 (m, 4H).

236 g of commercially available 1-ethoxynaphthalene and 400 mL of acetonitrile were placed in a flask, and 234 g of N-bromosuccinimide (NBS) was added as a powder while cooling with ice. After stirring for 2 hours, the resulting solid was filtered off. This solid was dissolved in toluene, filtered through silica gel, and then the solvent was removed under reduced pressure to obtain 318 g of 1-bromo-4-ethoxynaphthalene.

In a nitrogen atmosphere, 34 g of magnesium and 500 mL of THF were placed in a flask. A solution of 317 g of 1-bromo-4-ethoxynaphthalene in 500 mL of THF was added dropwise over 2 hours, and the mixture was further heated under reflux for 30 minutes. The Grignard reagent thus obtained was added dropwise to a flask containing 157 g of trimethoxyborane and 500 mL of THF using a cannula. After completion of the dropwise addition, the mixture was stirred for 12 hours, 10% dilute sulfuric acid was added, and the mixture was further stirred for 1 hour, and then extracted with ethyl acetate. The organic layer was washed with pure water, heptane was added to the place where the solvent was distilled off under reduced pressure, and the resulting precipitate was filtered off and dried to obtain 238 g of 4-ethoxynaphthalen-1-ylboronic acid.

40.0 g of commercially available 9-bromo-10-phenylanthracene, 33.7 g of (4-ethoxynaphthalen-1-yl) boronic acid, 0.79 g of tetrakis (triphenylphosphine) palladium (0), barium hydroxide and 8 water A 57.6 g Japanese product, 420 mL dimethoxyethane, and 70 mL water were placed in a flask and refluxed for 4 hours. The reaction solution was cooled to room temperature, water was added and the precipitated solid was filtered off and washed with methanol. This crude product was dissolved in toluene, filtered through silica gel, and then the solvent was distilled off under reduced pressure to obtain 43.4 g of 9- (4-ethoxynaphthalen-1-yl) -10-phenylanthracene.

42.5 g of 9- (4-ethoxynaphthalen-1-yl) -10-phenylanthracene, 116 g of pyridine hydrochloride and 50 mL of N-methyl-2-pyrrolidone were placed in a flask and heated at 200 ° C. for 14 hours. The reaction solution was cooled to room temperature, water was added, and the precipitated solid was separated by filtration. This was washed with methanol and dried to obtain 38.5 g of 4- (10-phenylanthracen-9-yl) naphthalen-1-ol.

4- (10-phenylanthracen-9-yl) naphthalen-1-ol (26.5 g) and anhydrous pyridine (300 mL) were placed in a flask and cooled to 0 ° C. Thereto, 24.6 g of trifluoromethanesulfonic anhydride was added dropwise and stirred for 3 hours. Water was added to the reaction solution returned to room temperature, and the deposited precipitate was separated by filtration, washed with water and methanol, dissolved in toluene, and filtered through silica gel. The solvent was distilled off under reduced pressure, heptane was added, and the resulting precipitate was filtered off and dried to obtain 31.6 g of 4- (10-phenylanthracen-9-yl) naphthalen-1-yl trifluoromethanesulfonate. It was.

4- (10-phenylanthracen-9-yl) naphthalen-1-yl trifluoromethanesulfonate 29.6 g, bispinacholate diboron 17.1 g, [1,1-bis (diphenylphosphino) ferrocene] palladium dichloride dichloromethane complex 1.37g, potassium acetate 10.0g, and cyclopentyl methyl ether 150mL were put into the flask, and it heated and refluxed for 11 hours. After heating, toluene and water were added, and the extracted organic layer was dried, concentrated, and filtered through silica gel. Further, the solvent was distilled off under reduced pressure, and the precipitate obtained by adding heptane was filtered off, dried, and dried to 4,4,5,5-tetramethyl-2- (4- (10-phenylanthracene-9- Yl) 11.7 g of naphthalen-1-yl) -1,3,2-dioxaborolane was obtained.

After putting 1.0 g of 4-iodopyridine into the flask and replacing the inside of the flask with nitrogen gas, 30 mL of dry THF was added and cooled in an ice bath. 2.8 mL of isopropylmagnesium chloride THF solution (2M) was added dropwise thereto. After the dropwise addition, the mixture was stirred for 1 hour, and then 1.4 g of zinc chloride / tetramethylethylenediamine complex was added. After further stirring for 1 hour, 4- (10-phenylanthracen-9-yl) naphthalen-1-yl trifluoromethanesulfonate 2 0.4 g, tetrakis (triphenylphosphine) palladium (0) 0.17 g, and anhydrous xylene 20 mL were added, and the mixture was heated to reflux for 12 hours. The reaction solution was cooled to room temperature, ethylenediaminetetraacetic acid / tetrasodium salt aqueous solution was added, and the organic layer and the aqueous layer were separated. After drying the organic layer with magnesium sulfate, the solvent was distilled off under reduced pressure. This crude product is purified by silica gel column chromatography (developing solution: toluene to toluene / ethyl acetate = 97/3) to give 4- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl. ) 0.95 g of pyridine was obtained.
¹ H-NMR (CDCl ₃ ): δ = 8.8 (d, 2H), 8.0 (d, 1H), 7.8 (d, 2H), 7.6 to 7.5 (m, 12H) 7.3-7.2 (m, 6H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 5-bromo-2, A flask was charged with 1.1 g of 2′-bipyridine, 0.14 g of tetrakis (triphenylphosphine) palladium (0), 1.7 g of tripotassium phosphate, 12 mL of pseudocumene, 2 mL of t-butyl alcohol, and 0.5 mL of water. The mixture was stirred at a reflux temperature for 9 hours under a nitrogen atmosphere. After heating, the mixture was cooled to room temperature, and the precipitated solid was filtered off. The solid material was dissolved in toluene and purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 95/5 (volume ratio)) to give 5- (4- (10-phenylanthracen-9-yl) naphthalene. -1-yl) -2,2′-bipyridine (0.81 g) was obtained. The 5-bromo-2,2′-bipyridine used here was synthesized by applying the above coupling reaction.
¹ H-NMR (CDCl ₃ ): δ = 9.0 (d, 1H), 8.8 (d, 1H), 8.6 (d, 1H), 8.6 to 8.5 (d, 1H) , 8.2 (dd, 1H), 8.1 (d, 1H), 7.9 (dt, 1H), 7.8 (d, 2H), 7.7 to 7.5 (m, 9H), 7.5 (m, 1H), 7.4 to 7.2 (m, 7H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 5-bromo-2, A flask was charged with 1.1 g of 3′-bipyridine, 0.14 g of tetrakis (triphenylphosphine) palladium, 1.7 g of tripotassium phosphate, 12 mL of pseudocumene, 2 mL of t-butyl alcohol, and 0.5 mL of water under a nitrogen atmosphere. And stirred at reflux temperature for 13 hours. After heating, the mixture was cooled to room temperature, and the precipitated solid was filtered off. The solid material was dissolved in toluene and purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 85/15 (volume ratio)) to give 5- (4- (10-phenylanthracen-9-yl) naphthalene. -1-yl) -2,3′-bipyridine (0.95 g) was obtained. The 5-bromo-2,3′-bipyridine used here was synthesized by applying the above coupling reaction.
¹ H-NMR (CDCl ₃ ): δ = 9.4 (dd, 1H), 9.1 (dd, 1H), 8.8 (dd, 1H), 8.5 (dt, 1H), 8.2 (Dd, 1H), 8.1 (d, 1H), 8.0 (d, 1H), 7.8 (d, 2H), 7.7 to 7.5 (m, 11H), 7.4 to 7.3 (m, 6H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 5-bromo-3, A flask was charged with 1.1 g of 4′-bipyridine, 0.14 g of tetrakis (triphenylphosphine) palladium (0), 1.7 g of tripotassium phosphate, 12 mL of pseudocumene, 2 mL of t-butyl alcohol, and 0.5 mL of water. The mixture was stirred at reflux temperature for 3 hours under a nitrogen atmosphere. After heating, the mixture was cooled to room temperature, and the precipitated solid was filtered off. The solid was dissolved in toluene and purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 3/1 (volume ratio)) to give 5- (4- (10-phenylanthracen-9-yl). 1.65 g of naphthalen-1-yl) -3,4'-bipyridine was obtained. Note that 5-bromo-3,4'-bipyridine used here was synthesized by applying the above coupling reaction.
¹ H-NMR (CDCl ₃ ): δ = 9.0 (dd, 2H), 8.8 (dd, 2H), 8.3 (t, 1H), 8.0 (d, 1H), 7.8 (D, 2H), 7.7 to 7.6 (m, 6H), 7.6 (m, 2H), 7.5 (m, 4H), 7.4 to 7.3 (m, 6H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 4- (3-bromo Phenyl) pyridine (1.1 g), tetrakis (triphenylphosphine) palladium (0) (0.14 g), tripotassium phosphate (1.7 g), pseudocumene (12 mL), t-butyl alcohol (2 mL), and water (0.5 mL) were placed in a flask. The mixture was stirred at reflux temperature for 4 hours under an atmosphere. After heating, the mixture was cooled to room temperature, and water and toluene were added to separate the layers. The organic layer was dried and concentrated, and the crude product was purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 95/5 (volume ratio)) to give 4- (3- (4- (10-phenylanthracene). 1.36 g of -9-yl) naphthalen-1-yl) phenyl) pyridine was obtained. The 4- (3-bromophenyl) pyridine used here was synthesized by applying the above coupling reaction.
¹ H-NMR (CDCl ₃ ): δ = 8.7 (d, 2H), 8.1 (d, 1H), 8.0 (t, 1H), 7.8 (m, 4H), 7.7 (M, 2H), 7.7 to 7.6 (m, 5H), 7.6 to 7.5 (m, 5H), 7.5 to 7.4 (m, 1H), 7.4 to 7 .3 (m, 2H), 7.3 to 7.2 (m, 4H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 4- (4-bromo (Phenyl) pyridine (1.1 g), tetrakis (triphenylphosphine) palladium (0.14 g), tripotassium phosphate (1.7 g), pseudocumene (12 mL), t-butyl alcohol (2 mL), and water (0.5 mL) were placed in a flask. Stir at reflux for 3 hours. After heating, the mixture was cooled to room temperature, and water and toluene were added to separate the layers. The organic layer was dried and concentrated, and the crude product was purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 97/3 (volume ratio)) to give 4- (4- (4- (10-phenylanthracene). 0.98 g of -9-yl) naphthalen-1-yl) phenyl) pyridine was obtained. The 4- (4-bromophenyl) pyridine used here was synthesized by applying the above coupling reaction.
¹ H-NMR (CDCl ₃ ): δ = 8.7 (dd, 2H), 8.1 (d, 1H), 7.9 to 7.8 (q, 4H), 7.8 (d, 2H) 7.7-7.5 (m, 11H), 7.5-7.4 (m, 1H), 7.4-7.2 (m, 6H).

<Synthesis Example of Compound (1-104)>
Synthesis of <3- (4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) naphthalen-1-yl) pyridine>

2. 29.84 g of 3- (4-bromonaphthalen-1-yl) pyridine, 5.49 g of bispinacholate diboron, (1,1′-bis (diphenylphosphino) ferrocene) palladium (II) dichloride / dichloromethane complex 15 g, potassium acetate 28.03 g, and cyclopentyl methyl ether 60 mL were placed in a flask, and the mixture was heated and stirred at reflux temperature for 1.5 hours in a nitrogen atmosphere. After completion of heating, the mixture was cooled to room temperature and washed with pure water. After concentration under reduced pressure, purification by activated carbon column chromatography (developing solution: toluene) gave 3- (4- (4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) naphthalene- 30 g of 1-yl) pyridine was obtained. The 3- (4-bromonaphthalen-1-yl) pyridine used here was synthesized by applying the above coupling reaction.

9-Bromo-10- (naphthalen-2-yl) anthracene 2.0 g, 3- (4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) naphthalene-1 -Yl) Pyridine 1.1 g, tetrakis (triphenylphosphine) palladium (0) 0.14 g, tripotassium phosphate 1.7 g, pseudocumene 12 mL, t-butyl alcohol 2 mL, and water 0.5 mL were placed in a flask. The mixture was stirred at reflux temperature for 3 hours under a nitrogen atmosphere. After heating, the mixture was cooled to room temperature, and water and toluene were added to separate the layers. The organic layer was dried and concentrated, and the crude product was purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 97/3 (volume ratio)) to give 4- (4- (4- (10-phenylanthracene). 0.98 g of -9-yl) naphthalen-1-yl) phenyl) pyridine was obtained.
¹ H-NMR (CDCl ₃ ): δ = 9.0 (dd, 1H), 8.8 (dd, 1H), 8.1 to 7.9 (m, 6H), 7.8 (d, 2H) 7.7-7.5 (m, 9H), 7.3-7.2 (m, 6H).

4,4,5,5-tetramethyl-2- (4- (10-phenylanthracen-9-yl) naphthalen-1-yl) -1,3,2-dioxaborolane 2.0 g, 3-bromo-2- 0.72 g of methylpyridine, 0.14 g of tetrakis (triphenylphosphine) palladium, 1.7 g of tripotassium phosphate, 12 mL of pseudocumene, 2 mL of t-butyl alcohol, and 0.5 mL of water are placed in a flask and refluxed under a nitrogen atmosphere. Stir at temperature for 8 hours. After heating, the mixture was cooled to room temperature, and water and toluene were added to separate the layers. The organic layer was dried and concentrated, and the crude product was purified by silica gel chromatography (developing solution: toluene to toluene / ethyl acetate = 9/1 (volume ratio)) to give 2-methyl-3- (4- (10-phenyl). 1.30 g of anthracen-9-yl) naphthalen-1-yl) pyridine was obtained.
¹ H-NMR (CDCl ₃ ): δ = 8.7 (dd, 1H), 7.8 (m, 3H), 7.7 to 7.5 (m, 10H), 7.4 (m, 1H) , 7.4 to 7.3 (m, 3H), 7.3 to 7.2 (m, 4H), 2.5 (s, 3H).

By appropriately changing the raw material compound, other derivative compounds of the present invention can be synthesized by a method according to the synthesis example described above.

Examples will be shown below for illustrating the present invention in more detail, but the present invention is not limited to these examples.

The electroluminescent elements according to Example 1 and Comparative Example 1 were manufactured, and the driving start voltage (V) in the constant current driving test and the time (hr) for maintaining the luminance of 90% or more of the initial luminance were measured. . Hereinafter, examples and comparative examples will be described in detail.

Table 1 below shows the material configuration of each layer in the electroluminescent elements according to the manufactured Example 1 and Comparative Examples 1 and 2.

In Table 1, “CuPc” is copper phthalocyanine, “NPD” is N, N′-diphenyl-N, N′-dinaphthyl-4,4′-diaminobiphenyl, and compound (A) is 9-phenyl-10- [6 -(1,1 ′; 3,1 ″) terphenyl-5′-yl] naphthalen-2-yl] anthracene, compound (B) is N ⁵ , N ⁵ , N ⁹ , N ⁹ -7,7-hexa Phenyl-7H-benzo [c] fluorene-5,9-diamine, compound (C) is 5,5 ′-(2-phenylanthracene-9,10-diyl) di-2,2′-bipyridine, Have the following chemical structure.

A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) obtained by polishing ITO deposited to a thickness of 180 nm by sputtering to 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Vacuum Kiko Co., Ltd.), and a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, and a compound (A) are placed therein. A molybdenum vapor deposition boat, a molybdenum vapor deposition boat containing compound (B), a molybdenum vapor deposition boat containing compound (1-2), a molybdenum vapor deposition boat containing lithium fluoride, and aluminum. A tungsten vapor deposition boat was installed.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5 × 10 ⁻⁴ Pa, and first, a vapor deposition boat containing CuPc was heated and deposited to a film thickness of 40 nm to form a hole injection layer, and then NPD was contained. The vapor deposition boat was heated and vapor-deposited so that it might become a film thickness of 30 nm, and the positive hole transport layer was formed. Next, the vapor deposition boat containing the compound (A) and the vapor deposition boat containing the compound (B) were heated at the same time to form a light emitting layer by vapor deposition to a film thickness of 35 nm. The deposition rate was adjusted so that the weight ratio of compound (A) to compound (B) was approximately 95 to 5. Next, the evaporation boat containing the compound (1-2) was heated and evaporated to a thickness of 15 nm to form an electron transport layer. The deposition rate of each layer was 0.01 to 1 nm / second.

Thereafter, the evaporation boat containing lithium fluoride is heated to deposit at a deposition rate of 0.003 to 0.1 nm / second so as to have a film thickness of 1 nm, and then the evaporation boat containing aluminum is heated to form a film. The cathode was formed by vapor deposition at a vapor deposition rate of 0.01 to 10 nm / second so as to have a thickness of 100 nm, and an organic electroluminescence device was obtained.

When a direct current voltage was applied using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, blue light emission with a wavelength of about 455 nm was obtained. In addition, a constant current driving test was performed at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 4.75 V, and the time for maintaining 90% or more of the initial luminance was 34 hours.

<Comparative Example 1>
An organic EL device was obtained in the same manner as in Example 1 except that the compound (1-2) was changed to the compound (C). A constant current driving test was performed using an ITO electrode as an anode and a lithium fluoride / aluminum electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 4.63 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 23 hours.

The above results are summarized in Table 2.

Further, electroluminescent devices according to Examples 2 to 10, Comparative Example 2 and Comparative Example 3 having configurations different from those of the electroluminescent devices according to Example 1 and Comparative Example 1 were prepared. The drive start voltage (V) and the time (hr) for maintaining the luminance of 90% or more of the initial luminance were measured.

Table 3 below shows the material configuration of each layer in the electroluminescent devices according to Examples 2 to 10, Comparative Example 2 and Comparative Example 3 thus manufactured.

In Table 3, “HI” represents N ⁴ , N ⁴ ′ -diphenyl-N ⁴ , N ⁴ ′ -bis (9-phenyl-9H-carbazol-3-yl)-[1,1′-biphenyl] -4, 4'-diamine, compound (D) is 9-phenyl-10- (4-phenylnaphthalen-1-yl) anthracene, compound (E) is 9,10-bis (4- (pyridin-2-yl) naphthalene- 1-yl) anthracene, compound (F) is 9,10-bis (4- (pyridin-4-yl) naphthalen-1-yl) anthracene. “NPD” and compound (B) are the same compounds as in Table 1. The chemical structure is shown below together with lithium 8-quinolinolato (Liq) used for forming the cathode.

A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) obtained by polishing ITO deposited to a thickness of 180 nm by sputtering to 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Vacuum Kiko Co., Ltd.), and a molybdenum vapor deposition boat containing HI, a molybdenum vapor deposition boat containing NPD, and compound (D) are placed therein. Molybdenum vapor deposition boat, molybdenum vapor deposition boat containing compound (B), molybdenum vapor deposition boat containing compound (1-2), molybdenum vapor deposition boat containing Liq, molybdenum containing silver A vapor deposition boat and a molybdenum vapor deposition boat containing magnesium were installed.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5 × 10 ⁻⁴ Pa, first, a vapor deposition boat containing HI was heated and vapor-deposited to a film thickness of 40 nm to form a hole injection layer, and then NPD was contained. The vapor deposition boat was heated and vapor-deposited to a film thickness of 25 nm to form a hole transport layer. Next, the vapor deposition boat containing the compound (D) and the vapor deposition boat containing the compound (B) were heated at the same time to form a light emitting layer by vapor deposition to a film thickness of 25 nm. Next, the deposition rate was adjusted so that the weight ratio of the compound (D) to the compound (B) was approximately 95 to 5. Next, the evaporation boat containing the compound (1-2) was heated and evaporated to a film thickness of 25 nm to form an electron transport layer. The deposition rate of each layer was 0.01 to 1 nm / second.

Thereafter, the evaporation boat containing Liq is heated to deposit at a deposition rate of 0.003 to 0.1 nm / second so that the film thickness becomes 1 nm, and then the evaporation boat containing silver and magnesium are deposited. The boat was heated at the same time, and the deposition rate was adjusted so that the atomic weight ratio of silver to magnesium was about 1: 9. A cathode was formed by vapor deposition at a vapor deposition rate of 0.01 to 10 nm / second so that the film thickness was 100 nm, and an organic electroluminescent device was obtained.

When a direct current voltage was applied using the ITO electrode as the anode and the Liq / magnesium-silver alloy electrode as the cathode, blue light emission with a wavelength of about 455 nm was obtained. In addition, a constant current driving test was performed at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 4.38 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 106 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-3). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 5.24 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 110 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-19). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 5.55 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 81 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-20). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 4.62 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 75 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-24). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 6.00 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 98 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-48). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 3.70 V, and the time for maintaining 90% or more of the initial luminance was 79 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-51). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 4.90 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 112 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-104). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 3.98 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 118 hours.

An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (1-1027). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test starting voltage was 3.55 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 82 hours.

<Comparative Example 2>
An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (E). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 4.08 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 2 hours.

<Comparative Example 3>
An organic EL device was obtained in the same manner as in Example 2 except that the compound (1-2) was changed to the compound (F). A constant current driving test was performed with an ITO electrode as an anode and a Liq / magnesium-silver alloy electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . The driving test start voltage was 3.87 V, and the time for maintaining the luminance of 90% or more of the initial luminance was 30 hours.

The above results are summarized in Table 4.

According to a preferred aspect of the present invention, it is possible to provide an organic electroluminescent element that improves the lifetime of the light emitting element and has an excellent balance with the driving voltage, a display device including the organic electroluminescent element, and a lighting device including the organic electroluminescent element. it can.

Claims

A compound represented by the following formula (1).

In equation (1),
Py is one selected from the group of monovalent groups represented by the following formulas (2), (3), (4) and (5), and any hydrogen of these groups has 1 to 6 carbon atoms. Or an alkyl of 3 to 6 carbon atoms may be substituted;

Ar 1 is naphthalene-1,4-diyl or naphthalene-1,5-diyl, and any hydrogen in these groups is replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons Well;
Ar 2 is phenyl or 2-naphthyl, and any hydrogen of these groups may be replaced by alkyl having 1 to 6 carbons or cycloalkyl having 3 to 6 carbons.
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups represented by formulas (2), (3) and (4).
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups represented by formula (2).
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups represented by formula (3).
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups represented by formula (4).
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups represented by formula (5).
The compound of claim 1, wherein Py is 2-pyridyl.
The compound of claim 1, wherein Py is 3-pyridyl.
The compound of claim 1, wherein Py is 4-pyridyl.
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups below.
The compound according to claim 1, wherein Py is one selected from the group of monovalent groups below.
The following formulas (1-2), (1-3), (1-19), (1-20), (1-24), (1-48), (1-51), (1-104), Or the compound of Claim 1 represented by (1-1027).
An electron transport material containing the compound according to any one of claims 1 to 12.
The electron transport containing the electron transport material of Claim 13 arrange | positioned between a pair of electrode which consists of an anode and a cathode, the light emitting layer arrange | positioned between this pair of electrodes, and the said cathode and this light emitting layer An organic electroluminescent device having a layer and / or an electron injection layer.
The organic material according to claim 14, wherein at least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of a quinolinol-based metal complex, a bipyridine derivative, a phenanthroline derivative, and a borane derivative. Electroluminescent device.
At least one of the electron transport layer and the electron injection layer is further made of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, or an alkaline earth metal. The material contains at least one selected from the group consisting of halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes. 14. The organic electroluminescent element according to 14.