JP5349889B2 - Novel terphenyl derivative, electron transport material comprising the same, and organic electroluminescence device including the same - Google Patents

Description

  The present invention relates to a novel terphenyl derivative useful for forming a wide-gap electron transporting layer suitable for a novel phosphorescent material, particularly a blue phosphorescent material, an electron transporting material comprising the same, and organic electroluminescence comprising the same It relates to an element.

  The organic electroluminescence element emits light by the excitation energy generated by the recombination of holes and electrons injected from the electrodes being relaxed to the ground state through the light emission process. However, there are two types of excited states generated by recombination of holes and electrons, a singlet excited state and a triplet excited state in a ratio of 1: 3. In many cases, a fluorescent material that utilizes light emission from a singlet excited state has been used as a light emitting material. Therefore, the internal quantum efficiency is 25% at the maximum. If the extraction efficiency at this time is 20%, the maximum is The external quantum efficiency was 5%, which was the theoretical limit.

  In recent years, improvement in luminous efficiency has been reported by using light emission from a triplet excited state, for example, phosphorescence emission, using complex compounds utilizing heavy atom effects such as iridium and platinum (for example, non-patented) Reference 1). The maximum quantum efficiency can theoretically reach 100% by utilizing light emission from the triplet excited state in addition to the singlet excited state, and phosphorescent materials are attracting attention as light emitting materials (non-patented). Reference 3).

に示されるトリス（２−フェニルピリジナト）イリジウム（III）〔Ｉｒ（ｐｐｙ）_３〕が広く利用されている。 For example, as a green material, the following formula

Tris (2-phenylpyridinato) iridium (III) [Ir (ppy) ₃ ] shown in FIG.

で示すビス〔２−（４，６−ジフルオロフェニル）ピリジネート−Ｎ，Ｃ２′〕イリジウム（III）ピコリネート（ＦＩｒｐｉｃ）が注目を浴びるようになり、それ以降ＦＩｒｐｉｃを用いた有機ＥＬ素子の高効率化検討および新規な青色リン光錯体探索研究が盛んに行われるようになった。 In addition, the following formula, which is a blue phosphorescent material, is disclosed by Non-Patent Document 2 concerning the announcement by Adachi et al.

Bis [2- (4,6-difluorophenyl) pyridinate-N, C2 ′] iridium (III) picolinate (FIrpic) has been attracting attention, and since then, higher efficiency of organic EL devices using FIrpic Studies and new blue phosphorescent complex exploration studies have been actively conducted.

で示すトリス｛１−〔４−（トリフルオロメチル）フェニル〕−１Ｈ−ピラゾラト−Ｎ，Ｃ２′｝イリジウム（III）（Ｉｒｔｆｍｐｐｚ３）やＭ．Ｅ．Ｔｈｏｍｐｓｏｎらによる非特許文献４の下記式

で示すビス〔２−（４′，６′−ジフルオロフェニル）ピリジナト−Ｎ，Ｃ２′〕イリジウム（III）テトラキス（１−ピラゾリル）ボレート（ＦＩｒ６）が開発された。 As a result, recently S.I. R. Non-patent document 1 by Forrest et al.

Tris {1- [4- (trifluoromethyl) phenyl] -1H-pyrazolato-N, C2 ′} iridium (III) (Irtfmpppz3) and M. E. The following formula of Non-Patent Document 4 by Thompson et al.

Bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C2 ′] iridium (III) tetrakis (1-pyrazolyl) borate (FIr6) has been developed.

In order for these light emitting materials to emit light efficiently, it is necessary to adjust the injection balance of holes and electrons and select a hole transport agent or electron transport agent having a wide gap.
Especially for blue phosphorescent materials, since the energy gap is large, hole transport materials and electron transport materials having a wide gap are required. At present, these phosphorescent materials include Alq ₃ [tris (8-hydroxyquinolinolato) aluminum] and BAlq ₂ [bis (2-methyl-8-hydroxyquinolinolato) (which are conventionally used electron transport materials) ( 4-phenylphenoxy) aluminum] and the like are used. However, since it does not have a sufficient energy gap for use in phosphorescent materials, it is necessary to develop a new wide gap electron transport material.

M.M. A. Baldo, S .; Lamansky, P.M. E. Burrows, M .; E. Thompson, S.M. R. Forrest Appl. Phys. Lett 1999 75 (1) 4-7 Appl. Phys. Lett. 79, 2082 (2001) J. et al. Appl. Phys. , 90 5048 (2001) Polyhedron, 23 419 (2004)

  An object of the present invention is to provide a novel terphenyl derivative, an electron transport material comprising the derivative, and an organic electroluminescence device including the material.

（式中、Ｑは

よりなる群から選ばれた基であり、
Ｒ^３〜Ｒ^１８は水素、炭素数１〜６の直鎖または分岐のアルキル基、炭素数１〜６の直鎖または分岐のアルキル基をもつアルコキシ基、および炭素数１〜６の直鎖または分岐のアルキル基をもつアルキルアミノ基よりなる群からそれぞれ独立して選ばれた基であり、Ｒ^１、Ｒ^２、Ｒ^１９〜Ｒ^６５は水素および炭素数１〜６の直鎖または分岐のアルキル基よりなる群からそれぞれ独立して選ばれた基である）
で示されるターフェニル誘導体に関する。
本発明の第２は、請求項１記載のターフェニル誘導体よりなる電子輸送材料に関する。
本発明の第３は、請求項１記載のターフェニル誘導体を用いた有機エレクトロルミネッセンス素子に関する。 The first of the present invention is the following general formula (1)

(Where Q is

A group selected from the group consisting of:
R ^{3 to} R ¹⁸ are hydrogen, a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group having a linear or branched alkyl group having 1 to 6 carbon atoms, and a straight chain having 1 to 6 carbon atoms or R ¹ , R ² , R ^{19 to} R ⁶⁵ are groups independently selected from the group consisting of alkylamino groups having a branched alkyl group, and R ¹ , R ² , R ^{19 to} R ⁶⁵ are hydrogen and a linear or branched alkyl having 1 to 6 carbon atoms. Each group independently selected from the group consisting of groups)
The terphenyl derivative shown by these is related.
The second of the present invention relates to an electron transport material comprising the terphenyl derivative according to claim 1.
3rd of this invention is related with the organic electroluminescent element using the terphenyl derivative of Claim 1.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms in R ^{1 to} R ⁶⁵ of the present invention include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, heptyl, isoheptyl, n- Examples include hexyl.

Examples of the linear or branched alkoxy group having 1 to 6 carbon atoms in R ^{3 to} R ¹⁸ of the present invention include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, t-butoxy, heptoxy, isoheptoxy, n -Hexyloxy etc. can be mentioned.

The linear or branched alkylamino group having 1 to 6 carbon atoms in R ^{3 to} R ¹⁸ in the present invention is a type in which one or all of —NH ₂ hydrogens are substituted with the alkyl group.

なお、（前記式中、Ｑは、

よりなる群から選ばれた基であり、
Ｒ^３〜Ｒ^１８は水素、炭素数１〜６の直鎖または分岐のアルキル基、炭素数１〜６の直鎖または分岐のアルキル基をもつアルコキシ基、および炭素数１〜６の直鎖または分岐のアルキル基をもつアルキルアミノ基よりなる群からそれぞれ独立して選ばれた基であり、Ｒ^１、Ｒ^２、Ｒ^１９〜Ｒ^６５は水素および炭素数１〜６の直鎖または分岐のアルキル基よりなる群からそれぞれ独立して選ばれた基であり、Ｒ^７０、Ｒ^７１は、水素、炭素数１〜６の直鎖または分岐のアルキル基または、これらが結合して環を形成していても構わない基からそれぞれ独立して選ばれた基であり、Ｘ^１〜Ｘ^６はハロゲンである。
反応式中の、Ｐｄ−ｃａｔａｌｙｓｔはパラジウム触媒の、Ｂａｓｉｃ−ｓｏｌｕｔｉｏｎは塩基性水溶液の、ｓｏｌｖｅｎｔは有機溶媒の、それぞれ略称である。 The compound of the present invention can be produced by the following reaction.

In the above formula, Q is

A group selected from the group consisting of:
R ^{3 to} R ¹⁸ are hydrogen, a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group having a linear or branched alkyl group having 1 to 6 carbon atoms, and a straight chain having 1 to 6 carbon atoms or R ¹ , R ² , R ^{19 to} R ⁶⁵ are groups independently selected from the group consisting of alkylamino groups having branched alkyl groups, wherein R ¹ , R ² , R ^{19 to} R ⁶⁵ are hydrogen and linear or branched alkyl having 1 to 6 carbon atoms. R ⁷⁰ and R ⁷¹ are each independently selected from the group consisting of groups, and R ⁷⁰ and R ⁷¹ are hydrogen, a linear or branched alkyl group having 1 to 6 carbon atoms, or a combination thereof to form a ring. And X ^{1 to} X ⁶ are halogens independently selected from groups that may be used.
In the reaction formula, Pd-catalyst is an abbreviation for a palladium catalyst, Basic-solution is a basic aqueous solution, and solvent is an organic solvent.

The first reaction utilizes a reaction usually referred to as a Suzuki coupling reaction, and details are described in Miyaura, N .; Suzuki, A .; Chem. Rev. 1995, 95, 2457, and the like.
The organic solvent to be used is not particularly limited as long as it is a solvent that dissolves the halide and boric acid compound of the reaction substrate, and examples thereof include a mixed solvent of an aromatic hydrocarbon solvent and an alcohol solvent or an ether solvent. The mixed solvent can be used at an arbitrary mixing ratio, but in general, it is preferable to use a mixture of 3 parts of an aromatic hydrocarbon solvent and 1 part of an alcohol solvent. Examples of the aromatic hydrocarbon solvent include toluene, xylene, ethylbenzene, trimethylbenzene and the like. Examples of alcohol solvents include methanol, ethanol, propanol, butanol and the like. Examples of ether solvents include cyclic ethers such as tetrahydrofuran and 1,4-dioxane, aliphatic ethers such as methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether. In this reaction, a mixed solvent of an aromatic hydrocarbon type and an alcohol type is preferable, and a particularly preferable combination is a mixed solvent of toluene and ethanol.
The base that can be used as the 2M basic solution is not particularly limited as long as it contains an alkali or alkaline earth metal. For example, hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, beryllium carbonate , Carbonates such as magnesium carbonate, calcium carbonate, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, cesium bicarbonate, beryllium bicarbonate, magnesium bicarbonate, bicarbonate such as calcium bicarbonate, or these metals And organic bases such as alcoholates and acetates. In this reaction, it is preferable to use a carbonate in view of the reaction rate, and potassium carbonate is more preferable.
Since the palladium catalyst is a coupling reaction between a halogen compound and a boric acid compound, a Pd (0) catalyst can be used. Examples of other palladium catalysts include tetrakis (triphenylphosphine) palladium [Pd (PPh ₃ ) ₄ ], tris (dibenzylideneacetone) dipalladium [Pd ₂ (dba) ₃ ] and palladium dibenzylideneacetone. Is preferably tetrakis (triphenylphosphine) palladium.

で示される（Ａ）のような４，４，５，５−テトラメチル−１，３，２−ジオキサボロランや（Ｂ）のような５，５−ジメチル−１，３，２−ジオキサボリナンも使用することができる。 As the halide used in the first reaction, any of a chloro form, a bromo form, and an iodo form can be used. However, when X ¹ and X ² are the same halogen, the halogen of X ² also reacts with the boric acid compound in the same manner as X ¹ , so that it does not give the desired halide and becomes a high molecular weight polymer as a by-product. There is a risk that. Therefore, when X ¹ is an iodo compound, X ² must be a bromo compound or a chloro compound, and when X ¹ is a bromo compound, X ² must be a chloro compound.
For boric acid compounds that react with halides, boric acid or boric acid esters can be used. Examples of the boric acid ester include methyl ester and ethyl ester. The following general formula modified to two boron-containing cyclic ester structure

4,4,5,5-tetramethyl-1,3,2-dioxaborolane as shown in (A) and 5,5-dimethyl-1,3,2-dioxaborinane as in (B) are also used. be able to.

The second reaction is a reaction in which the halide obtained in the first reaction is converted to a boric acid compound using pinacolatodiborane. As the solvent used here, a solvent capable of dissolving pinacolatodiborane may be selected. Examples thereof include cyclic ethers such as tetrahydrofuran and 1,4-dioxane, and highly polar solvents such as dimethylformamide and dimethylacetamide. Can be listed. Cyclic ether is preferable, and 1,4-dioxane is more preferable.
About the base used by reaction, the base which can be used by the above-mentioned 1st reaction can be illustrated. Here, acetate is preferable, and potassium acetate is more preferable because of the reaction time.
As the palladium catalyst used in this reaction, one showing Pd (0) can be used. Specifically, a complex of an organic ligand and palladium can be exemplified. Preferred are tetrakis (triphenylphosphine) palladium and tris (dibenzylideneacetone) dipalladium, and more preferred is bis (dibenzylideneacetone) palladium [Pd (dba) ₂ ].
As the phosphorus catalyst added to activate palladium, a tertiary alkyl phosphine can be used. For example, trimethylphosphine, triethylphosphine, tri [n- (iso-) propyl] phosphine, tri [n An aliphatic group such as (-(iso-, tert-) butyl) phosphine and an alicyclic group such as tricyclohexylphosphine (PCy ₃ ) can be used. In view of compatibility with the palladium compound to be used, alicyclic tricyclohexylphosphine is preferable here.

  The third reaction is a Suzuki coupling reaction like the first reaction, and the reaction conditions are the same as those of the first reaction. The tetrahalogenated benzene used in the reaction may be any of chloro, bromo or iodo. When reaction time etc. are considered, a bromo body or an iodine body is preferable.

  Specific examples of the compound of the present invention are illustrated below. In the exemplified compound, the methyl group can be replaced with another alkyl group such as an ethyl group or a propyl group.

  The novel terphenyl derivative of the present invention has high electron transport performance. Therefore, it can be used as an electron transport material.

  When the novel terphenyl derivative of the present invention is used for an electron transport layer, the compound of the present invention can be used as an electron transport material. It can also be used in combination with other electron transport materials.

  Next, the organic electroluminescence element (organic EL element) of the present invention will be described. The organic EL device of the present invention is a device in which a plurality of organic compounds are laminated between an anode and a cathode, and contains the terphenyl derivative of the present invention as an electron transport material. The light emitting layer is composed of a light emitting material and a host material. Examples of the configuration of the multilayer organic EL device include, for example, an anode (for example, ITO) / hole transport layer / light emitting layer / electron transport layer / cathode, ITO / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode. ITO / hole transport layer / light-emitting layer / hole block layer / electron transport layer / cathode, ITO / hole transport layer / light-emitting layer / hole block layer / electron transport layer / electron injection layer / cathode, ITO / hole injection layer (positive And a multilayer structure such as hole injection layer) / hole transport layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode. Moreover, you may have a sealing layer on a cathode as needed.

  Each of the hole transport layer, the electron transport layer, and the light-emitting layer preferably has a multilayer structure in which each function is separated. In addition, the hole transport layer and the electron transport layer can be provided separately with a layer responsible for the injection function (hole injection layer and electron injection layer) and a layer responsible for the transport function (hole transport layer and electron transport layer).

  The organic electroluminescent element of the present invention is not limited to the above-described configuration, and various configurations can be adopted. If necessary, a layer in which a hole transport layer component and a light emitting layer component or an electron transport layer component and a light emitting layer component are mixed may be provided.

  Hereinafter, the constituent elements of the organic EL element of the present invention will be described by taking as an example an element structure composed of an anode / hole transport layer / light emitting layer / electron transport layer / cathode. The organic EL element of the present invention is preferably supported on a substrate.

  There is no restriction | limiting in particular about the raw material of a board | substrate, For example, what is conventionally used for the conventional organic EL element can be used, For example, what consists of glass, quartz glass, a transparent plastic etc. can be used.

As an anode of the organic EL device of the present invention, it is preferable to use a single metal having a high work function (4 eV or more), an alloy of metals having a high work function (4 eV or more), a conductive substance, or a mixture thereof as an electrode material. . Specific examples of such electrode materials include metals such as gold, silver, and copper, conductive transparent materials such as ITO (indium-tin oxide), tin oxide (SnO ₂ ), and zinc oxide (ZnO), polypyrrole, and polythiophene. Examples thereof include conductive polymer materials such as For the anode, these electrode materials can be formed by a method such as vapor deposition, sputtering, or coating. The sheet electrical resistance of the anode is preferably several hundred Ω / cm ² or less. The thickness of the anode depends on the material, but is generally about 5 to 1,000 nm, preferably 10 to 500 nm.

As the cathode, an electrode material is preferably a single metal having a low work function (4 eV or less), an alloy of metals having a low work function (4 eV or less), a conductive substance, or a mixture thereof. Specific examples of such electrode materials include lithium, lithium-indium alloy, sodium, sodium-potassium alloy, magnesium, magnesium-silver alloy, magnesium-indium alloy, aluminum, aluminum-lithium alloy, and aluminum-magnesium alloy. Can be mentioned. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet electrical resistance of the cathode is preferably several hundred Ω / cm ² or less. The thickness of the cathode depends on the material, but is generally about 5 to 1,000 nm, preferably 10 to 500 nm. In order to efficiently extract light emitted from the organic EL device of the present invention, at least one of the anode and the cathode is preferably transparent or translucent.

The hole transport layer (hole transport layer) of the organic electroluminescence element of the present invention is made of a hole (hole) transmitting substance and has a function of transmitting holes (holes) injected from the anode to the light emitting layer. doing. When a hole transfer compound is disposed between two electrodes to which an electric field is applied and holes are injected from the anode, a hole transfer material having a hole mobility of at least 10 ⁻⁶ cm ² / V · sec or more is preferable. The hole transfer material used for the hole transport layer of the organic electroluminescence device of the present invention is not particularly limited as long as it has the above-mentioned preferable performance. Any one of materials conventionally used as charge injection materials for holes in photoconductive materials and known materials used for hole transport layers of organic electroluminescence elements can be selected and used.

ホール輸送材料としては、下記化学式に示すＴＰＤ、ＤＴＡＳｉ、α−ＮＰＤなどを挙げることができる。

Examples of the hole transfer material include phthalocyanine derivatives such as copper phthalocyanine, N, N, N ′, N′-tetraphenyl-1,4-phenylenediamine, N, N′-di (m-tolyl) -N, Triarylamines such as N′-diphenyl-4,4-diaminophenyl (TPD) and N, N′-di (1-naphthyl) -N, N′-diphenyl-4,4-diaminophenyl (α-NPD) Derivatives, polyphenylenediamine derivatives, polythiophene derivatives, and water-soluble PEDOT-PSS (polyethylenedioxathiophene-polystyrene sulfonic acid). The hole transport layer may be composed of one or more of these other hole transport compounds, or may be a stack of hole transport layers composed of a compound different from the hole transport material. .
Examples of the hole injection material include PEDOT-PSS (polymer mixture) and DNTPD represented by the following chemical formula.

Examples of the hole transport material include TPD, DTASi, and α-NPD represented by the following chemical formula.

  There is no restriction | limiting in particular about the light emitting material used for the light emitting layer of the organic electroluminescent element of this invention, Arbitrary things can be selected and used.

Examples of the light-emitting material include perylene derivatives, naphthacene derivatives, quinacridone derivatives, coumarin derivatives (eg, coumarin 1, coumarin 540, coumarin 545, etc.), pyran derivatives (eg, DCM-1, DCM-2, DCJTB, etc.), organometallic complexes, such as Fluorescent materials such as tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ) and tris (4-methyl-8-hydroxyquinolinolato) aluminum complex (Almq ₃ ) and bis [2- (4,6-difluoro Phenyl) pyridinate-N, C2 ′] iridium (III) picolylate (FIrpic), tris {1- [4- (trifluoromethyl) phenyl] -1H-pyrazolate-N, C2 ′} iridium (III) (Irtfmpppz3), Bis [2- (4 ′, 6′-difluorophenyl) Phosphorescent materials such as pyridinato-N, C2 ′] iridium (III) tetrakis (1-pyrazolyl) borate (FIr6) and tris (2-phenylpyridinato) iridium (III) [Ir (ppy) ₃ ] be able to.

The light emitting layer is formed of a host material and a light emitting material (dopant) [Appl. Phys. Lett. , 65 3610 (1989)]. In particular, when a phosphorescent material is used for the light emitting layer, it is necessary to use a host material. As the host material used at this time, 4,4′-di (N-carbazolyl) -1,1′-biphenyl ( CBP), 1,4-di (N-carbazolyl) benzene-2,2′-di [4 ″-(N-carbazolyl) phenyl] -1,1′-biphenyl (4CzPBP) and the like.

The light emitting material is preferably 0.01 to 40% by weight, more preferably 0.1 to 20% by weight with respect to the host material. Examples of the light emitting material include conventionally known FIrpic, Ir (ppy) ₃ , and Fir6 shown below.

As a material for the electron transport layer of the organic electroluminescence device of the present invention, the novel terphenyl derivative of the present invention is preferable. Although this compound can be used alone, it may be used in combination Other electron-transporting materials, for example, Alq 3 represented by the following chemical formula, _TAZ, DPB such as.

In the organic electroluminescence device of the present invention, an electron injection layer composed of a conductor may be provided between the cathode and the organic layer (electron transport layer) for the purpose of further improving the electron injection property. As the conductor used here, it is preferable to use at least one metal compound selected from alkali metal halides, alkaline earth metal halides, and alkali metal organic complexes. Examples of the alkali metal halide include lithium fluoride, sodium fluoride, potassium fluoride, cesium fluoride, and lithium chloride. Examples of the alkaline earth metal halide include magnesium fluoride, calcium fluoride, barium fluoride, and strontium fluoride. Examples of the alkali metal organic complex include 8-hydroxyquinolinolatolithium and 8-hydroxyquinolinolatocesium. Also, a phenanthroline derivative lithium complex (LiPB) as described in Japanese Patent Application No. 2006-292032 of the present applicant and a phenoxypyridine lithium complex (LiPP) listed in Japanese Patent Application No. 2007-29695 can be used.

  The method for forming the hole injection layer, the hole transport layer and the light emitting layer of the device containing the novel terphenyl derivative of the present invention is not particularly limited. For example, a dry film forming method (for example, a vacuum vapor deposition method, an ionization vapor deposition method, etc.) or a wet film forming method [a solvent coating method (for example, a spin coating method, a casting method, an ink jet method, etc.)] can be used. The film formation of the electron transport layer is limited to a dry film formation method (for example, a vacuum vapor deposition method, an ionization vapor deposition method, etc.) because the lower layer may be eluted when the wet film formation method is used. For the production of the element, the above film forming method may be used in combination.

When forming each layer such as a hole transport layer, a light emitting layer, and an electron transport layer by a vacuum deposition method, the vacuum deposition conditions are not particularly limited. Usually, under a vacuum of about 10 ⁻⁵ Torr or less, a boat temperature (deposition source temperature) of about 50 to 500 ° C., a substrate temperature of about −50 to 300 ° C., and 0.01 to 50 nm / sec. Vapor deposition is preferred. When forming each layer of a positive hole transport layer, a light emitting layer, and an electron carrying layer using a some compound, it is preferable to co-evaporate the boat which put the compound, respectively controlling temperature.

  When the hole injection layer, the hole transport layer and the light emitting layer are formed by a solvent coating method, the components constituting each layer are dissolved or dispersed in a solvent to obtain a coating solution. Solvents include hydrocarbon solvents (eg, heptane, toluene, xylene, cyclohexane, etc.), ketone solvents (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), halogen solvents (eg, dichloromethane, chloroform, chlorobenzene, dichlorobenzene, etc.) Ester solvents (eg, ethyl acetate, butyl acetate, etc.), alcohol solvents (eg, methanol, ethanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ether solvents (eg, dibutyl ether, tetrahydrofuran, 1,4-dioxane, 1 , 2-dimethoxyethane, etc.), aprotic solvents (eg, N, N′-dimethylacetamide, dimethyl sulfoxide, etc.), water and the like. The solvent may be used alone, or a plurality of solvents may be used in combination.

  The thickness of each layer such as the hole transport layer, the light emitting layer, and the electron transport layer is not particularly limited, but is usually 5 to 5,000 nm.

  The organic electroluminescence device of the present invention can be protected by providing a protective layer (sealing layer) for the purpose of blocking contact with oxygen, moisture, etc., or encapsulating the device in an inert substance. Examples of the inert substance include paraffin, silicon oil, and fluorocarbon. Examples of the material used for the protective layer include fluororesin, epoxy resin, silicone resin, polyester, polycarbonate, and photocurable resin.

  The organic electroluminescence device of the present invention can be used as a normal DC drive device. When a DC voltage is applied, light emission is usually observed when about 1.5 to 20 V is applied with the positive polarity of the anode and the negative polarity of the cathode. The organic EL element of the present invention can also be used as an AC drive element. When an AC voltage is applied, light is emitted when the anode is in a positive state and the cathode is in a negative state. The organic electroluminescence device of the present invention includes, for example, a flat light emitter such as an electrophotographic photosensitive member and a flat panel display, a copying machine, a printer, a backlight of a liquid crystal display, a light source such as an instrument, various light emitting devices, various display devices, and various signs. It can be used for various sensors and various accessories.

  The preferable example of the organic electroluminescent element of this invention is shown in FIGS.

  FIG. 12 is a cross-sectional view showing an example of the organic EL element of the present invention. FIG. 12 shows a configuration in which an anode 2, a hole transport layer 5, a light emitting layer 3, and a cathode 4 are sequentially provided on a substrate 1.

  FIG. 13 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 13 shows a configuration in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. This is a separation of the functions of carrier transport and light emission, and the degree of freedom in material selection increases, so that the efficiency of light emission and the degree of freedom in light emission color increase.

  FIG. 14 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 14 shows a structure in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. In this case, the provision of the hole injection layer 7 improves the adhesion between the anode 2 and the hole transport layer 5, improves the injection of holes from the anode, and is effective in lowering the voltage of the light emitting element.

  FIG. 15 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 15 shows a structure in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8 and a cathode 4 are sequentially provided on a substrate 1. In this case, injection of electrons from the cathode 4 is improved, which is effective for lowering the voltage of the light emitting element.

  FIG. 16 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 16 shows a configuration in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8 and a cathode 4 are sequentially provided on a substrate 1. In this case, hole injection from the anode 2 is improved and electron injection from the cathode 4 is improved, which is the most effective for driving at a low voltage.

  17 to 20 are sectional views of the device in which the hole block layer 9 is inserted. The hole blocking layer has an effect of preventing holes injected from the anode or excitons generated by recombination in the light emitting layer 3 from escaping to the cathode 4, and is effective in improving the light emission efficiency of the organic electroluminescence device. is there. The hole blocking layer 9 can be inserted between the light emitting layer 3 and the cathode 4, between the light emitting layer 3 and the electron transport layer 6, or between the light emitting layer 3 and the electron injection layer 8. More preferred is between the light emitting layer 3 and the electron transport layer 6.

  17 to 20, each of the hole transport layer 5, the hole injection layer 7, the electron transport layer 6, the electron injection layer 8, the light emitting layer 3, and the hole blocking layer 9 has a single layer structure or a multilayer structure. May be.

  12 to 20 are basic element configurations to the last, and the configuration of the organic electroluminescence element using the compound of the present invention is not limited thereto.

As can be seen from, for example, Examples 3 and 4, the terphenyl derivative of the present invention has higher luminous efficiency and external quantum efficiency than the similar compounds of Comparative Examples 1 and 2. This is thought to be because the heteroaryl group such as a pyridine ring exhibiting electron transporting properties is connected by a meta bond, so that the electron transport state in the electron transporting layer is good and the device functions well.
Therefore, the compound of the present invention is necessary for increasing the efficiency of the device and is extremely important industrially.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

四つ口フラスコに３−ブロモピリジン（４．８４ｇ，３０．６ｍｍｏｌ）、３−クロロフェニルホウ酸（４．９５ｇ，３１．６ｍｍｏｌ）、テトラキス（トリフェニルホスフィン）パラジウム〔Ｐｄ（ＰＰｈ_３）_４〕（０．７０ｇ，０．６１ｍｍｏｌ）、トルエン／エタノール（３／１，２００ｍＬ）と２Ｍ Ｋ_２ＣＯ_３（９０ｍＬ）を入れて、窒素気流下９０℃で２４時間反応させた。反応終了後、反応溶液を水に注ぎ、トルエンで抽出し、飽和食塩水で洗浄した。無水硫酸マグネシウムで脱水し、溶媒をエバポレーターで除去した。
精製はカラムクロマトグラフィー法（展開溶媒：ｎ−ヘキサン／酢酸エチル＝３／１）で行い、無色の粘体を得た。ｍ−ＣＰｈ３Ｐｙの収率：９２．７％

２）３−（４，４，５，５−テトラメチル−１，３，２−ジオキサボロラン−２−イル）−１−（ピリジン−３−イル）ベンゼン（略称３ＰｙＰｈｍＤＯＢ）の合成

四つ口フラスコにｍ−ＣＰｈ３Ｐｙ（５．４４ｇ，２８．７ｍｍｏｌ）、ビスピナコラートジボラン（８．７５ｇ，３４．４ｍｍｏｌ）、酢酸カリウム（８．４５ｇ，８６．１ｍｍｏｌ）、ビス（ジベンジリデンアセトン）パラジウム（０）〔Ｐｄ（ｄｂａ）_２〕（９９０ｍｇ，１．７２ｍｍｏｌ）、トリシクロヘキシルホスフィン（１．９３ｇ，６．８９ｍｍｏｌ）と無水１，４−ジオキサン（１５０ｍＬ）を入れて、窒素気流下８０℃で７２時間反応させた。その後、反応溶液に水を注ぎ、トルエンで抽出し、飽和食塩水で洗浄した。無水硫酸マグネシウムで脱水し、溶媒をエバポレーターで除去した。
精製はカラムクロマトグラフィー法〔展開溶媒：クロロホルム／酢酸エチル＝６／１（２回）、クロロホルム／酢酸エチル＝４／１〕で行い、薄い黄色の結晶を得た。３ＰｙＰｈｍＤＯＢの収率：８８．０％。

３）２′，５′−ジ〔３−（ピリジン−３−イル）フェニル〕−３，３″−ジ（ピリジン−３−イル）−１，１′：４′，１″−ターフェニル（略称ｔｅｔｒａ−ｍ３ＰｙＰｈＢ）の合成

四つ口フラスコに１，２，４，５−テトラブロモベンゼン（０．９８４ｇ，２．５ｍｍｏｌ）、３ＰｙＰｈｍＤＯＢ（３．０９ｇ，１１．０ｍｍｏｌ）、Ｐｄ（ＰＰｈ_３）_４（２３１ｍｇ，０．２０ｍｍｏｌ）、トルエン／エタノール（３／１，１６０ｍＬ）と２Ｍ Ｋ_２ＣＯ_３（４０ｍＬ）を入れて、窒素気流下９０℃で２４時間反応させた。反応終了後、反応溶液を水に注ぎ、トルエンで抽出し、飽和食塩水で洗浄した。無水硫酸マグネシウムで脱水し、溶媒をエバポレーターで除去した。
精製はカラムクロマトグラフィー法（展開溶媒：酢酸エチルで不純物を除去し、クロロホルム／メタノール混合溶媒を下記の割合で用いて１回づつ洗浄、５０／１，４０／１，２５／１）で行い、アセトンにより再結晶を行い、白色の粉末を得た。ｔｅｔｒａ−ｍ３ＰｙＰｈＢの収率：９３．２％。
得られたｔｅｔｒａ−ｍ３ＰｙＰｈＢの熱特性および電気化学特性について表１に示す。

Ｔｇ（ガラス転移温度）については、ＤＳＣ（Ｄｉｆｆｅｒｅｎｔｉａｌ Ｓｃａｎｎｉｎｇ Ｃａｌｏｒｉｍｅｔｅｒ 示差熱量計）中にサンプルを加え、溶融されたものを急冷し、２〜３回繰返すとガラス点を示すカーブがチャート上に現れるので、そのカーブを接線で結び、その交点の温度をＴｇとして採用する。
Ｔｍ（融点）は、同じくＤＳＣにサンプルを加え、昇温させていくと急熱カーブが現れるのでその極大のところの温度を読んで、その温度をＴｍとする。
Ｔｄ（分解温度）は、ＤＴＡ（Ｄｉｆｆｅｒｅｎｔｉａｌ Ｔｈｅｒｍａｌ Ａｎａｌｙｚｅｒ 示差熱分析装置）にサンプルを加え、加熱していくとサンプルが熱によって分解し、重量が減少しだす。その減少が開始し５％重量減少したところの温度を読んでその点をＴｄとする。
エネルギーギャップ（Ｅｇ）については、蒸着機で作成した薄膜を紫外−可視吸光度計で薄膜の吸収曲線を測定する。その薄膜の短波長側の立ち上がりのところに接線を引き、求まった交点の波長Ｗ（ｎｍ）を次の式に代入し目的の値を求める。それによって得た値がＥｇになる。
Ｅｇ＝１２４０÷Ｗ
例えば接線を引いて求めた値Ｗ（ｎｍ）が４７０ｎｍだったとしたらこの時のＥｇの値は、
Ｅｇ＝１２４０÷４７０＝２．６３（ｅＶ）
と言うことになる。
Ｉｐ（イオン化ポテンシャル）は、イオン化ポテンシャル測定装置（例えば理研計器ＡＣ−３）を使用して測定し、測定するサンプルがイオン化を開始したところの電圧（ｅＶ）の値を読む。
Ｅａ（電子親和力）は、ＩｐからＥｇを引いた値である。
また、薄膜での吸収スペクトルは図１に、励起スペクトルおよび発光スペクトルは図２に示す。 Example 1
2 ', 5'-di [3- (pyridin-3-yl) phenyl] -3,3 "-di (pyridin-3-yl) -1,1': 4 ', 1" -terphenyl (abbreviation tetra) Synthesis of -m3PyPhB) 1) Synthesis of 3- (pyridin-3-yl) chlorobenzene (abbreviation m-CPh3Py)

In a four-necked flask, 3-bromopyridine (4.84 g, 30.6 mmol), 3-chlorophenylboric acid (4.95 g, 31.6 mmol), tetrakis (triphenylphosphine) palladium [Pd (PPh ₃ ) ₄ ] ( 0.70 g, 0.61 mmol), toluene / ethanol (3 / 1,200 mL) and 2M K ₂ CO ₃ (90 mL) were added and reacted at 90 ° C. for 24 hours under a nitrogen stream. After completion of the reaction, the reaction solution was poured into water, extracted with toluene, and washed with saturated brine. It dehydrated with anhydrous magnesium sulfate and the solvent was removed by an evaporator.
Purification was performed by a column chromatography method (developing solvent: n-hexane / ethyl acetate = 3/1) to obtain a colorless viscous body. The yield of m-CPh3Py: 92.7%

2) Synthesis of 3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1- (pyridin-3-yl) benzene (abbreviation 3PyPhmDOB)

In a four-necked flask, m-CPh3Py (5.44 g, 28.7 mmol), bispinacolato diborane (8.75 g, 34.4 mmol), potassium acetate (8.45 g, 86.1 mmol), bis (dibenzylideneacetone) Palladium (0) [Pd (dba) ₂ ] (990 mg, 1.72 mmol), tricyclohexylphosphine (1.93 g, 6.89 mmol) and anhydrous 1,4-dioxane (150 mL) were added, and the mixture was heated at 80 ° C. under a nitrogen stream. For 72 hours. Thereafter, water was poured into the reaction solution, extracted with toluene, and washed with saturated brine. It dehydrated with anhydrous magnesium sulfate and the solvent was removed by an evaporator.
Purification was performed by a column chromatography method [developing solvent: chloroform / ethyl acetate = 6/1 (twice), chloroform / ethyl acetate = 4/1] to obtain pale yellow crystals. Yield of 3PyPhmDOB: 88.0%.

3) 2 ', 5'-di [3- (pyridin-3-yl) phenyl] -3,3 "-di (pyridin-3-yl) -1,1': 4 ', 1" -terphenyl ( Abbreviation tetra-m3PyPhB)

In a four-necked flask, 1,2,4,5-tetrabromobenzene (0.984 g, 2.5 mmol), 3PyPhmDOB (3.09 g, 11.0 mmol), Pd (PPh ₃ ) ₄ (231 mg, 0.20 mmol) Toluene / ethanol (3/1, 160 mL) and 2M K ₂ CO ₃ (40 mL) were added and reacted at 90 ° C. for 24 hours under a nitrogen stream. After completion of the reaction, the reaction solution was poured into water, extracted with toluene, and washed with saturated brine. It dehydrated with anhydrous magnesium sulfate and the solvent was removed by an evaporator.
Purification is performed by column chromatography (developing solvent: ethyl acetate to remove impurities, washing once with chloroform / methanol mixed solvent at the following ratio, 50/1, 40/1, 25/1) Recrystallization with acetone gave a white powder. yield of tetra-m3PyPhB: 93.2%.
Table 1 shows the thermal properties and electrochemical properties of the obtained tetra-m3PyPhB.

About Tg (glass transition temperature), a sample is added to DSC (Differential Scanning Calorimeter), the melted material is rapidly cooled, and a curve showing the glass point appears on the chart when repeated 2 to 3 times. The curves are connected by a tangent line, and the temperature at the intersection is adopted as Tg.
As for Tm (melting point), when a sample is similarly added to DSC and the temperature is raised, a rapid heating curve appears. Therefore, the temperature at the maximum is read, and the temperature is defined as Tm.
As for Td (decomposition temperature), when a sample is added to DTA (Differential Thermal Analyzer differential thermal analyzer) and heated, the sample is decomposed by heat and the weight starts to decrease. The temperature at which the decrease starts and the weight decreased by 5% is read, and that point is defined as Td.
Regarding the energy gap (Eg), an absorption curve of the thin film prepared with a vapor deposition machine is measured with an ultraviolet-visible absorptiometer. A tangent line is drawn at the short-wavelength rising edge of the thin film, and the target wavelength is obtained by substituting the obtained wavelength W (nm) of the intersection into the following equation. The value obtained thereby becomes Eg.
Eg = 1240 ÷ W
For example, if the value W (nm) obtained by drawing the tangent is 470 nm, the value of Eg at this time is
Eg = 1240 ÷ 470 = 2.63 (eV)
It will be said.
Ip (ionization potential) is measured using an ionization potential measuring device (for example, Riken Keiki AC-3), and the value of the voltage (eV) at which the sample to be measured starts ionization is read.
Ea (electron affinity) is a value obtained by subtracting Eg from Ip.
The absorption spectrum in the thin film is shown in FIG. 1, and the excitation spectrum and emission spectrum are shown in FIG.

四つ口フラスコに１，２，４，５−テトラブロモベンゼン（０．９８４ｇ，２．５ｍｍｏｌ）、実施例１に準じて合成した４ＰｙＰｈｍＤＯＢ（３．３７ｇ，１２ｍｍｏｌ）、Ｐｄ（ＰＰｈ_３）_４（２３１ｍｇ，０．２０ｍｍｏｌ）、トルエン／エタノール（３／１，１６０ｍＬ）と２Ｍ Ｋ_２ＣＯ_３（５０ｍＬ）を入れて、窒素気流下９０℃で２４時間反応させた。反応終了後、反応溶液を水に注ぎ、クロロホルムで抽出し、飽和食塩水で洗浄した。無水硫酸マグネシウムで脱水し、溶媒をエバポレーターで除去した。
精製はカラムクロマトグラフィー法（展開溶媒：クロロホルム／酢酸エチル／メタノール＝２０／１０／１，クロロホルム／メタノール＝１００／３）で行い、白色の粉末を得た。ｔｅｔｒａ−ｍ４ＰｙＰｈＢの収率：６２．２％。
得られたｔｅｔｒａ−ｍ４ＰｙＰｈＢの熱特性および電気化学特性について表２に示す。

また、薄膜での吸収スペクトルは図３に、励起スペクトルおよび発光スペクトルは図４に示す。 Example 2
2 ', 5'-di [3- (pyridin-4-yl) phenyl] -3,3 "-di (pyridin-4-yl) -1,1': 4 ', 1" -terphenyl (abbreviation tetra) -M4PyPhB)

In a four-necked flask, 1,2,4,5-tetrabromobenzene (0.984 g, 2.5 mmol), 4PyPhmDOB (3.37 g, 12 mmol) synthesized according to Example 1, Pd (PPh ₃ ) ₄ ( 231 mg, 0.20 mmol), toluene / ethanol (3/1, 160 mL) and 2M K ₂ CO ₃ (50 mL) were added and reacted at 90 ° C. for 24 hours under a nitrogen stream. After completion of the reaction, the reaction solution was poured into water, extracted with chloroform, and washed with saturated brine. It dehydrated with anhydrous magnesium sulfate and the solvent was removed by an evaporator.
Purification was performed by a column chromatography method (developing solvent: chloroform / ethyl acetate / methanol = 20/10/1, chloroform / methanol = 100/3) to obtain a white powder. yield of tetra-m4PyPhB: 62.2%.
Table 2 shows the thermal properties and electrochemical properties of the obtained tetra-m4PyPhB.

The absorption spectrum in the thin film is shown in FIG. 3, and the excitation spectrum and emission spectrum are shown in FIG.

およびその異性体

を同様に合成し、素子評価をおこなった。
作成した素子構成は以下の通りである。
＜素子構造＞
実施例３□：ＩＴＯ／ＴＰＤＰＥＳ（２０ｎｍ）（ホール注入層）／３ＤＴＡＰＢＰ（３０ｎｍ）（ホール輸送層）／４ＣｚＰＢＰ：ＦＩｒｐｉｃ（１３ｗｔ％）（１０ｎｍ）（発光層）／ｔｅｔｒａ−ｍ３ＰｙＰｈＢ（実施例１合成）（５０ｎｍ）（電子輸送層）／ＬｉＦ（０．５ｎｍ）／Ａｌ（１００ｎｍ）；
実施例４△：ＩＴＯ／ＴＰＤＰＥＳ（２０ｎｍ）（ホール注入層）／３ＤＴＡＰＢＰ（３０ｎｍ）（ホール輸送層）／４ＣｚＰＢＰ：ＦＩｒｐｉｃ（１３ｗｔ％）（１０ｎｍ）（発光層）／ｔｅｔｒａ−ｍ４ＰｙＰｈＢ（実施例２合成）（５０ｎｍ）（電子輸送層）／ＬｉＦ（０．５ｎｍ）／Ａｌ（１００ｎｍ）；
比較例１◇：ＩＴＯ／ＴＰＤＰＥＳ（２０ｎｍ）（ホール注入層）／３ＤＴＡＰＢＰ（３０ｎｍ）（ホール輸送層）／４ＣｚＰＢＰ：ＦＩｒｐｉｃ（１３ｗｔ％）（１０ｎｍ）（発光層）／ｔｅｔｒａ−ｐ３ＰｙＰｈＢ（５０ｎｍ）（電子輸送層）／ＬｉＦ（０．５ｎｍ）／Ａｌ（１００ｎｍ）；
比較例２○：ＩＴＯ／ＴＰＤＰＥＳ（２０ｎｍ）（ホール注入層）／３ＤＴＡＰＢＰ（３０ｎｍ）（ホール輸送層）／４ＣｚＰＢＰ：ＦＩｒｐｉｃ（１３ｗｔ％）（１０ｎｍ）（発光層）／ｔｅｔｒａ−ｐ４ＰｙＰｈＢ（５０ｎｍ）（電子輸送層）／ＬｉＦ（０．５ｎｍ）／Ａｌ（１００ｎｍ）

３ＤＴＡＰＢＰ：３，３″′−ジ（Ｎ，Ｎ−ジ−ｐ−トリル）−１，１′：２′，１″：２″，１″′−クォーターフェニル

４ＣｚＰＢＰ：４，４″′−ジ（カルバゾール−９−イル）−１，１′：２′，１″：２″，１″′−クォーターフェニル

ＴＰＤＰＥＳ：ポリ｛オキシ−１，４−フェニレンスルホニル−１，４−フェニレンオキシ−１，４−フェニレン（フェニルイミノ）〔１，１′−ビフェニル〕−４，４′−ジイル（フェニルイミノ）−１，４−フェニレン｝
これらの素子の
電流密度−電圧特性は図５に、
輝度−電圧特性は図６に、
視感効率−電圧特性は図７に、
電流効率−電圧特性は図８に、
視感効率−輝度特性は図９に、
外部量子効率−輝度特性は図１０に、
ＥＬスペクトルは図１１に、
それぞれ示す。
これらの素子の１００ｃｄ／ｍ^２における電圧（Ｖｏｌｔａｇｅ）、電流密度（Ｃｕｒｒｅｎｔ ｄｅｎｓｉｔｙ）、視感効率（Ｐ．Ｅ．）、外部量子効率（Ｑ．Ｅ．）の結果を表３に、１０００ｃｄ／ｍ^２における結果を表４に示す。

表３および表４からわかるように、本発明のｔｅｔｒａ−ｍ３ＰｙＰｈＢやｔｅｔｒａ−ｍ４ＰｙＰｈＢは、構造異性体の比較例の化合物に較べ、視感効率（Ｐ．Ｅ．）や外部量子効率（Ｑ．Ｅ．）が高い。これは電子の輸送性能が比較例の化合物よりも高いことを証明しており、電子輸送材料としての高い特性を示すものである。 Examples 3 and 4 and Comparative Examples 1 and 2
An element using the tetra-m3PyPhB synthesized in Example 1 and the tetra-m4PyPhB synthesized in Example 2 for the electron transport layer was prepared, and the electron transport property was evaluated. For comparison, certain compounds described in US Pat. No. 6,852,249.

And its isomers

Were synthesized in the same manner, and element evaluation was performed.
The created device configuration is as follows.
<Element structure>
Example 3 □: ITO / TPDPES (20 nm) (hole injection layer) / 3DTAPBP (30 nm) (hole transport layer) / 4CzPBP: FIrpic (13 wt%) (10 nm) (light emitting layer) / tetra-m3PyPhB (Example 1 synthesis) ) (50 nm) (electron transport layer) / LiF (0.5 nm) / Al (100 nm);
Example 4 Δ: ITO / TPDPES (20 nm) (hole injection layer) / 3DTAPBP (30 nm) (hole transport layer) / 4CzPBP: FIrpic (13 wt%) (10 nm) (light emitting layer) / tetra-m4PyPhB (Example 2 synthesis) ) (50 nm) (electron transport layer) / LiF (0.5 nm) / Al (100 nm);
Comparative Example 1 ◇: ITO / TPDPES (20 nm) (hole injection layer) / 3DTAPBP (30 nm) (hole transport layer) / 4CzPBP: FIrpic (13 wt%) (10 nm) (light emitting layer) / tetra-p3PyPhB (50 nm) Transport layer) / LiF (0.5 nm) / Al (100 nm);
Comparative Example 2 ○: ITO / TPDPES (20 nm) (hole injection layer) / 3DTAPBP (30 nm) (hole transport layer) / 4CzPBP: FIrpic (13 wt%) (10 nm) (light emitting layer) / tetra-p4PyPhB (50 nm) Transport layer) / LiF (0.5 nm) / Al (100 nm)

3DTAPBP: 3,3 ″ ′-di (N, N-di-p-tolyl) -1,1 ′: 2 ′, 1 ″: 2 ″, 1 ″ ′-quarterphenyl

4CzPBP: 4,4 "'-di (carbazol-9-yl) -1,1': 2 ', 1": 2 ", 1"'-quarterphenyl

TPDPES: poly {oxy-1,4-phenylenesulfonyl-1,4-phenyleneoxy-1,4-phenylene (phenylimino) [1,1'-biphenyl] -4,4'-diyl (phenylimino) -1 , 4-phenylene}
The current density-voltage characteristics of these elements are shown in FIG.
The luminance-voltage characteristics are shown in FIG.
The luminous efficiency vs. voltage characteristics are shown in FIG.
The current efficiency vs. voltage characteristics are shown in FIG.
The luminous efficiency-luminance characteristics are shown in FIG.
The external quantum efficiency-luminance characteristics are shown in FIG.
The EL spectrum is shown in FIG.
Each is shown.
The results of voltage (Voltage), current density (Current density), luminous efficiency (PE), and external quantum efficiency (QE) of these elements at 100 cd / m ² are shown in Table 3, and 1000 cd / m. The results in ² are shown in Table 4.

As can be seen from Tables 3 and 4, the tetra-m3PyPhB and tetra-m4PyPhB of the present invention have a luminous efficiency (PE) and an external quantum efficiency (QE) as compared to the compounds of comparative structural isomers. .) Is high. This proves that the electron transport performance is higher than that of the compound of the comparative example, and shows high characteristics as an electron transport material.

2 ', 5'-di [3- (pyridin-3-yl) phenyl] -3,3 "-di (pyridin-3-yl) -1,1' of Example 1, 4 ', 1" -ter An absorption spectrum of a thin film of phenyl (abbreviation tetra-m3PyPhB) is shown. 2 ', 5'-di [3- (pyridin-3-yl) phenyl] -3,3 "-di (pyridin-3-yl) -1,1' of Example 1, 4 ', 1" -ter An excitation spectrum and an emission spectrum of a thin film of phenyl (abbreviation tetra-m3PyPhB) are shown. 2 ', 5'-di [3- (pyridin-4-yl) phenyl] -3,3 "-di (pyridin-4-yl) -1,1': 4 ', 1" -ter of Example 2 An absorption spectrum of a thin film of phenyl (abbreviation tetra-m4PyPhB) is shown. 2 ', 5'-di [3- (pyridin-4-yl) phenyl] -3,3 "-di (pyridin-4-yl) -1,1': 4 ', 1" -ter of Example 2 An excitation spectrum and an emission spectrum of a thin film of phenyl (abbreviation tetra-m4PyPhB) are shown. The current density-voltage characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The luminance-voltage characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The luminous efficiency-voltage characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The current efficiency-voltage characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The luminous efficiency-luminance characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The external quantum efficiency-luminance characteristics of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. The EL spectra of Examples 3 and 4 and Comparative Examples 1 and 2 are shown. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention. It is sectional drawing which shows another example of the organic electroluminescent element in this invention.

Explanation of symbols

1 Substrate 2 Anode (ITO)
DESCRIPTION OF SYMBOLS 3 Light emitting layer 4 Cathode 5 Hole transport layer 6 Electron transport layer 7 Hole injection layer 8 Electron injection layer 9 Hole block layer

Claims (3)

The following general formula (1)

(Where Q is

A group selected from the group consisting of:
R ^{3 to} R ¹⁸ are hydrogen, a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group having a linear or branched alkyl group having 1 to 6 carbon atoms, and a straight chain having 1 to 6 carbon atoms or R ¹ , R ² , R ^{19 to} R ⁶⁵ are groups independently selected from the group consisting of alkylamino groups having branched alkyl groups, wherein R ¹ , R ² , R ^{19 to} R ⁶⁵ are hydrogen and linear or branched alkyl having 1 to 6 carbon atoms. Each group independently selected from the group consisting of groups)
A terphenyl derivative represented by:   An electron transport material comprising the terphenyl derivative according to claim 1.   An organic electroluminescence device using the terphenyl derivative according to claim 1.

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