JP2011108953A - Organic electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element using a compound having a high triplet level as an organic EL element, especially, an EL element using phosphorescent material. <P>SOLUTION: An amine derivative, which has a partial skeleton represented by general formula (1), is used. (In the formula, a curve represents an aliphatic hydrocarbon group which may have a heteroatom other than a nitrogen atom, and constitutes a cyclic structure with the nitrogen atom. Ar<SB>1</SB>and Ar<SB>2</SB>are each independently an aryl group with 6 to 40 in carbon numbers which may have a substituent, or a heteroaryl group with 5 to 40 in carbon numbers which may have a substituent, and Ar' is a divalent arylene group). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence (EL) device using an amine derivative having an alicyclic amine skeleton. The amine derivative in the present invention may be used as a photosensitive material or an organic photoconductive material. Specifically, the amine derivative may be a flat light source, a hole transport material such as an organic EL device or an electrophotographic photoreceptor used for display, Use as a hole injection material and a light emitting material is expected.

  Organic EL devices are currently being actively researched as next-generation thin flat displays, and have already been put into practical use in mobile phone displays and televisions. However, in order to further spread the organic EL element, it is required to further improve the light emission efficiency of the element.

  The general light emission mechanism of an organic EL device is that when electrons and holes are injected from both electrodes, they go to the counter electrode and recombine in the light emitting layer to generate excitons. Light emission occurs when returning to the ground state. In this excited state, there are a singlet excited state in which the direction of electron spin is antiparallel and a triplet excited state in which the direction of electron spin is parallel. Fluorescence emission involving only the excited state is the mainstream. However, from the simple quantum mechanical reasoning, the ratio of singlet excited state and triplet excited state generated by recombination of electrons and holes is 1: 3. Therefore, in the case of an organic EL device using fluorescence, The maximum value of the internal quantum efficiency is 25%. That is, 75% of the excited state is not used for light emission. In addition, since the light extraction efficiency to the outside of the organic EL element is about 20% at most, in the organic EL element using fluorescence, the external quantum efficiency is 25% × 20%, which is estimated to be about 5% at the maximum. .

  For this reason, in order to further improve the external quantum efficiency, it is necessary to use light emission from a triplet excited state that occupies 75% of the excited state, that is, phosphorescence. If this utilization becomes possible, the external quantum efficiency can be improved up to 20%. Against this background, in recent years, development of devices using phosphorescent materials has become active.

  By the way, in the organic EL element using a phosphorescent material, the material used for the layer adjacent to the light emitting layer is required to have a higher triplet level (T1) than the fluorescent material. On the other hand, it is difficult to say that triplet levels of known materials conventionally used in organic EL elements utilizing fluorescence are sufficient. For example, the triplet level of 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD), which is well known as a hole transport material, is as low as about 2.3 eV. Therefore, when combined with a phosphorescent material having a triplet level of 2.3 eV or higher, the excitation energy is not sufficiently confined, leading to a decrease in efficiency.

  Furthermore, in order to improve the triplet level, a method of introducing a skeleton such as a carbazole group into the material has been attempted. For example, a compound having a carbazole skeleton includes 4,4′-bis (N-carbazolyl) biphenyl (CBP) (see, for example, Non-Patent Document 1), and the triplet level is about 2.6 eV. It's hard to say that the level is sufficient.

R. Holms et. al. , Appl. Phys. Lett. , 2003, 82, 2422

  An object of the present invention is to provide a novel organic EL device using a material that is highly useful in an organic EL material that exhibits higher efficiency than conventional materials, particularly an organic EL device using a phosphorescent material. .

  As a result of intensive studies, the present inventors have found that the specific amine derivative represented by the general formula (1) has a higher triplet level than conventionally known materials. That is, the present invention relates to an electroluminescence device using an amine derivative having a partial skeleton represented by the general formula (1).

（式中、曲線は窒素原子以外のヘテロ原子を含んでいてもよい脂肪族の炭化水素基を表し、窒素原子と共に環状構造を構成する。Ａｒ_１及びＡｒ_２は各々独立して置換基を有していてもよい炭素数６〜４０のアリール基、または置換基を有していてもよい炭素数５〜４０のヘテロアリール基を表す。Ａｒ’は２価のアリーレン基を表す。）
以下、本発明を詳細に説明する。

(In the formula, the curve represents an aliphatic hydrocarbon group which may contain a heteroatom other than a nitrogen atom, and constitutes a cyclic structure together with the nitrogen atom. Ar ₁ and Ar ₂ each independently have a substituent. An optionally substituted aryl group having 6 to 40 carbon atoms, or an optionally substituted heteroaryl group having 5 to 40 carbon atoms, Ar ′ represents a divalent arylene group.
Hereinafter, the present invention will be described in detail.

  In the amine derivative represented by the general formula (1) of the present invention, the curve represents an aliphatic hydrocarbon group which may contain a hetero atom other than a nitrogen atom. Specific examples include an alkylene group which may have a substituent and an alkenylene group which may have a substituent. The amine derivative represented by the general formula (1) of the present invention forms a cyclic structure together with an aliphatic hydrocarbon group which may contain a hetero atom other than these nitrogen atoms, and becomes an alicyclic amine derivative. In addition, the aliphatic hydrocarbon group that may contain a hetero atom other than the nitrogen atom represented by a curve may have a crosslinked structure bonded to each other at an arbitrary position.

In the amine derivative represented by the general formula (1) of the present invention, Ar ₁ and Ar ₂ each independently have an optionally substituted aryl group having 6 to 40 carbon atoms, or a substituent. Represents a heteroaryl group having 5 to 40 carbon atoms which may be present. Examples of the aryl group having 6 to 40 carbon atoms that may have a substituent include, but are not limited to, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-anthryl group, 9-anthryl group, 2-fluorenyl group, phenanthryl group, pyrenyl group, chrysenyl group, perylenyl group, picenyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 4-ethylphenyl group, 3 -Ethylphenyl group, 2-ethylphenyl group, 4-n-propylphenyl group, 4-isopropylphenyl group, 2-isopropylphenyl group, 4-n-butylphenyl group, 4-isobutylphenyl group, 4-sec-butyl Phenyl group, 2-sec-butylphenyl group, 4-tert-butylphenyl group, 3-tert-butylphenyl group, 2- ert-butylphenyl group, 4-n-pentylphenyl group, 4-isopentylphenyl group, 2-neopentylphenyl group, 4-tert-pentylphenyl group, 4-n-hexylphenyl group, 4- (2′- Ethylbutyl) phenyl group, 4-n-heptylphenyl group, 4-n-octylphenyl group, 4- (2′-ethylhexyl) phenyl group, 4-tert-octylphenyl group, 4-n-decylphenyl group, 4- n-dodecylphenyl group, 4-n-tetradecylphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl group, 4- (4'-methylcyclohexyl) phenyl group, 4- (4'-tert-butylcyclohexyl) Phenyl group, 3-cyclohexylphenyl group, 2-cyclohexylphenyl group, 4-ethyl-1-naphthyl Group, 6-n-butyl-2-naphthyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,6-dimethyl Phenyl group, 2,4-diethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group, 3,4,5-trimethylphenyl group, 2,6-diethylphenyl group, 2 , 5-diisopropylphenyl group, 2,6-diisobutylphenyl group, 2,4-di-tert-butylphenyl group, 2,5-di-tert-butylphenyl group, 4,6-di-tert-butyl-2 -Methylphenyl group, 5-tert-butyl-2-methylphenyl group, 4-tert-butyl-2,6-dimethylphenyl group, 9-methyl-2-fluorenyl group, 9-ethyl Ru-2-fluorenyl group, 9-n-hexyl-2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 9,9-diethyl-2-fluorenyl group, 9,9-di-n-propyl- 2-fluorenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 3-ethoxyphenyl group, 2-ethoxyphenyl group, 4-n-propoxyphenyl group, 3 -N-propoxyphenyl group, 4-isopropoxyphenyl group, 2-isopropoxyphenyl group, 4-n-butoxyphenyl group, 4-isobutoxyphenyl group, 2-sec-butoxyphenyl group, 4-n-pentyloxy Phenyl group, 4-isopentyloxyphenyl group, 2-isopentyloxyphenyl group, 4-neopentyloxypheny Group, 2-neopentyloxyphenyl group, 4-n-hexyloxyphenyl group, 2- (2′-ethylbutyl) oxyphenyl group, 4-n-octyloxyphenyl group, 4-n-decyloxyphenyl group, 4-n-dodecyloxyphenyl group, 4-n-tetradecyloxyphenyl group, 4-cyclohexyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-methoxy-1-naphthyl group, 4-methoxy-1-naphthyl group 4-n-butoxy-1-naphthyl group, 5-ethoxy-1-naphthyl group, 6-methoxy-2-naphthyl group, 6-ethoxy-2-naphthyl group, 6-n-butoxy-2-naphthyl group, 6-n-hexyloxy-2-naphthyl group, 7-methoxy-2-naphthyl group, 7-n-butoxy-2-naphthyl group, 2-methyl-4-methyl Toxiphenyl group, 2-methyl-5-methoxyphenyl group, 3-methyl-4-methoxyphenyl group, 3-methyl-5-methoxyphenyl group, 3-ethyl-5-methoxyphenyl group, 2-methoxy-4- Methylphenyl group, 3-methoxy-4-methylphenyl group, 2,4-dimethoxyphenyl group, 2,5-dimethoxyphenyl group, 2,6-dimethoxyphenyl group, 3,4-dimethoxyphenyl group, 3,5- Dimethoxyphenyl group, 3,5-diethoxyphenyl group, 3,5-di-n-butoxyphenyl group, 2-methoxy-4-ethoxyphenyl group, 2-methoxy-6-ethoxyphenyl group, 3,4,5 -Trimethoxyphenyl group, 4-biphenylyl group, 3-biphenylyl group, 2-biphenylyl group, 4- (4'-methylphenyl) phenyl group, 4- ( 3′-methylphenyl) phenyl group, 4- (4′-methoxyphenyl) phenyl group, 4- (4′-n-butoxyphenyl) phenyl group, 2- (2′-methoxyphenyl) phenyl group, 4- ( 4'-chlorophenyl) phenyl group, 3-methyl-4-phenylphenyl group, 3-methoxy-4-phenylphenyl group, terphenyl group, 3,5-diphenylphenyl group, 10-phenylanthryl group, 10- ( 3,5-diphenylphenyl) -9-anthryl group, 9-phenyl-2-fluorenyl group, 4-fluorophenyl group, 3-fluorophenyl group, 2-fluorophenyl group, 4-chlorophenyl group, 3-chlorophenyl group, 2-chlorophenyl group, 4-bromophenyl group, 2-bromophenyl group, 4-chloro-1-naphthyl group, 4-chloro-2-naphth Group, 6-bromo-2-naphthyl group, 2,3-difluorophenyl group, 2,4-difluorophenyl group, 2,5-difluorophenyl group, 2,6-difluorophenyl group, 3,4-difluorophenyl Group, 3,5-difluorophenyl group, 2,3-dichlorophenyl group, 2,4-dichlorophenyl group, 2,5-dichlorophenyl group, 3,4-dichlorophenyl group, 3,5-dichlorophenyl group, 2,5-dibromo Phenyl group, 2,4,6-trichlorophenyl group, 2,4-dichloro-1-naphthyl group, 1,6-dichloro-2-naphthyl group, 2-fluoro-4-methylphenyl group, 2-fluoro-5 -Methylphenyl group, 3-fluoro-2-methylphenyl group, 3-fluoro-4-methylphenyl group, 2-methyl-4-fluorophenyl group, 2 -Methyl-5-fluorophenyl group, 3-methyl-4-fluorophenyl group, 2-chloro-4-methylphenyl group, 2-chloro-5-methylphenyl group, 2-chloro-6-methylphenyl group, 2 -Methyl-3-chlorophenyl group, 2-methyl-4-chlorophenyl group, 3-chloro-4-methylphenyl group, 3-methyl-4-chlorophenyl group, 2-chloro-4,6-dimethylphenyl group, 2- Methoxy-4-fluorophenyl group, 2-fluoro-4-methoxyphenyl group, 2-fluoro-4-ethoxyphenyl group, 2-fluoro-6-methoxyphenyl group, 3-fluoro-4-ethoxyphenyl group, 3- Chloro-4-methoxyphenyl group, 2-methoxy-5-chlorophenyl group, 3-methoxy-6-chlorophenyl group, 5-chloro-2,4- Such as methoxyphenyl group can be mentioned. Further, the heteroaryl group having 5 to 40 carbon atoms which may have a substituent is not limited to the following, but includes at least one heteroatom selected from an oxygen atom, a nitrogen atom and a sulfur atom. For example, 4-quinolyl group, 4-pyridyl group, 3-pyridyl group, 2-pyridyl group, 3-furyl group, 2-furyl group, 3-thienyl group, 2-thienyl group, Examples thereof include heterocyclic groups such as 2-oxazolyl group, 2-thiazolyl group, 2-benzoxazolyl group, 2-benzothiazolyl group and 2-benzimidazolyl group. Ar ₁ and Ar ₂ may be bonded to each other to form a ring. Examples of the ring formed by Ar ₁ and Ar ₂ include a carbazole ring, a phenothiazine ring, and a phenoxazine ring.

  In the formula, Ar ′ represents a divalent arylene group. Although not limited to the following, for example, a phenylene group, a biphenylene group, a naphthylene group, an anthranyl group, or a fluorenyl group which may have a substituent can be exemplified.

  Furthermore, the following general formula (2) and (3) can be mentioned as a preferable specific example of the said General formula (1).

（式中、Ａｒ_１及びＡｒ_２は各々独立して置換基を有していてもよい炭素数６〜４０のアリール基、または置換基を有していてもよい炭素数５〜４０のヘテロアリール基を表す。Ａｒ’は２価のアリーレン基を表す。Ｒは水素原子、炭素数１〜１８の直鎖、分岐若しくは環状のアルキル基、炭素数１〜１８の直鎖、分岐若しくは環状のアルコキシ基、置換基を有していてもよいアリール基、置換基を有していてもよいアリールオキシ基、または置換基を有していてもよいアリールアミノ基を表し、任意のＲ同士が互いに結合して架橋基を形成してもよい。）
炭素数１〜１８の直鎖、分岐若しくは環状のアルキル基としては、具体的には、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ステアリル基、トリクロロメチル基、トリフルオロメチル基、シクロプロピル基、シクロヘキシル基、１，３−シクロヘキサジエニル基、２−シクロペンテン−１−イル基等を挙げることができる。

(In the formula, Ar ₁ and Ar ₂ are each independently an aryl group having 6 to 40 carbon atoms which may have a substituent, or a heteroaryl having 5 to 40 carbon atoms which may have a substituent) Ar ′ represents a divalent arylene group, R represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 18 carbon atoms. Represents a group, an aryl group which may have a substituent, an aryloxy group which may have a substituent, or an arylamino group which may have a substituent, and arbitrary Rs are bonded to each other To form a crosslinking group.)
Specific examples of the linear, branched or cyclic alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, and a pentyl group. Hexyl group, heptyl group, octyl group, stearyl group, trichloromethyl group, trifluoromethyl group, cyclopropyl group, cyclohexyl group, 1,3-cyclohexadienyl group, 2-cyclopenten-1-yl group, etc. Can do.

  Specific examples of the linear, branched or cyclic alkoxy group having 1 to 18 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a tert-butoxy group. Pentyloxy group, hexyloxy group, stearyloxy group, trifluoromethoxy group and the like.

  The aryl group which may have a substituent is specifically an aromatic group having 6 to 24 carbon atoms which may have a substituent, and more specifically, a phenyl group, 4- Methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 4-ethylphenyl group, 3-ethylphenyl group, 2-ethylphenyl group, 4-n-propylphenyl group, 4-n-butylphenyl group, 4-isobutylphenyl group, 4-tert-butylphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl group, 2,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3,4-dimethylphenyl group, 1-biphenyl group, 1-naphthyl group, 2-naphthyl group, 9-phenanthryl group, 9,9-dialkyl-fluoren-2-yl group, 9,9-di-trifluoromethyl Le - can be exemplified a fluorene-2-yl group.

  The aryloxy group which may have a substituent is specifically an aromatic oxy group having 6 to 24 carbon atoms which may have a substituent, more specifically, a phenoxy group, p. Examples include -tert-butylphenoxy group, 3-fluorophenoxy group, 4-fluorophenoxy group and the like.

  Moreover, the arylamino group which may have a substituent is a group represented by the following general formula (A),

（式中、Ｒ_１及びＲ_２は置換基を有していてもよいアリール基を表す。）
Ｒ_１及びＲ_２において、置換基を有していてもよいアリール基の具体例としては、上記一般式（２）及び（３）におけるＲで例示した置換基を有していてもよいアリール基と同じ基を挙げることができる。なお、Ｒ_１とＲ_２は互いに結合して窒素原子と共に環を形成してもよい。

(In the formula, R ₁ and R ₂ represent an aryl group which may have a substituent.)
Specific examples of the aryl group which may have a substituent in R ₁ and R ₂ include an aryl group which may have a substituent exemplified by R in the general formulas (2) and (3). The same group can be mentioned. R ₁ and R ₂ may be bonded to each other to form a ring together with the nitrogen atom.

  Arbitrary Rs may be bonded to each other to have a crosslinked structure.

  Next, although the preferable specific example of the amine derivative which has a partial skeleton represented by the said General formula (1) is shown, it is not limited to these.

本発明の一般式（１）で表されるアミン誘導体は、公知の方法によって合成することができる（例えば、非特許文献２参照）。

The amine derivative represented by the general formula (1) of the present invention can be synthesized by a known method (for example, see Non-Patent Document 2).

Tetrahedron Letters (Tetrahedron Letters), 1998, 39, 2367 (amination reaction)

  Since the amine derivative represented by the general formula (1) according to the present invention has a triplet level higher than that of the conventional material, it can exhibit high efficiency in an organic EL element, particularly an EL element using a phosphorescent material. It becomes possible.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples at all.

  The analytical instruments and measurement methods used in this example are listed below.

[Elemental analysis]
Element analyzer: Perkin Elmer fully automatic element analyzer 2400II
Oxygen flask combustion-IC measurement method: Tosoh ion chromatography IC-2001
[Mass spectrometry]
Mass spectrometer: M-80B manufactured by Hitachi, Ltd.
Measuring method: FD-MS analysis [HPLC analysis]
Measuring device: Tosoh Multi Station LC-8020
Measuring method: Column Inertsil ODS-3V (4.6 mmΦ × 250 mm)
Detector UV detection (wavelength 254nm)
Eluent Methanol / Tetrahydrofuran = 9/1 (v / v ratio)
[Phosphorescence spectrum measurement]
Measuring device: Streak camera (C4334) manufactured by Hamamatsu Photonics
[NMR measurement]
Measuring device: Gemini200 manufactured by Varian
[Light emission characteristics of organic EL element]
Measuring device: Luminance meter LUMINANCE METER (BM-9) manufactured by TOPCON
Synthesis Example 1 Synthesis of Precursor (N-Phenyl-N- (4- (2,2,6,6-tetramethylpiperidinyl) phenyl) amine) of Compound (1-3) N- (4-Bromophenyl) ) -2,2,6,6-tetramethylpiperidine (BPTMP) was synthesized by the route shown below according to the method described in JP-A-2006-73241 and used as a raw material.

窒素雰囲気下、攪拌装置を備えた５０ｍＬの三つ口フラスコ中に、ＢＰＴＭＰ ５．０ｇ（１６．９ｍｍｏｌ）、アニリン ３．１４ｇ（３３．８ｍｍｏｌ）、ナトリウム−ｔｅｒｔ−ブトキシド ２．２７ｇ（２３．６ｍｍｏｌ）、ｏ−キシレン ３０ｍＬを加え、スラリー状の反応液に酢酸パラジウム ３７ｍｇ（０．１６ｍｍｏｌ）、トリ（ｔｅｒｔ−ブチル）ホスフィン １１９ｍｇ（０．５９ｍｍｏｌ）を添加して１３０℃で２４時間攪拌した。室温まで冷却後、水 １０ｍＬを加え、有機層を分離した。有機層を水、飽和食塩水で洗浄した後、無水硫酸マグネシウムで乾燥し、減圧下に濃縮した。残渣をシリカゲルカラムクロマトグラフィー（トルエンとヘキサンの混合溶媒）で精製し、Ｎ−フェニル−Ｎ−（４−（２，２，６，６−テトラメチルピペリジニル）フェニル）アミンの針状結晶を１．８ｇ（５．８ｍｍｏｌ、ＨＰＬＣ純度 ９８．８％）単離した（収率 ３４％）。化合物の同定は、ＦＤＭＳ測定、^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲ測定により行った。

Under a nitrogen atmosphere, in a 50 mL three-necked flask equipped with a stirrer, 5.0 g (16.9 mmol) of BPTMP, 3.14 g (33.8 mmol) of aniline, 2.27 g (23.6 mmol) of sodium-tert-butoxide ), 30 mL of o-xylene was added, and 37 mg (0.16 mmol) of palladium acetate and 119 mg (0.59 mmol) of tri (tert-butyl) phosphine were added to the slurry-like reaction solution, followed by stirring at 130 ° C. for 24 hours. After cooling to room temperature, 10 mL of water was added and the organic layer was separated. The organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (a mixed solvent of toluene and hexane), and needle-like crystals of N-phenyl-N- (4- (2,2,6,6-tetramethylpiperidinyl) phenyl) amine were obtained. Isolated 1.8 g (5.8 mmol, HPLC purity 98.8%) (yield 34%). The compound was identified by FDMS measurement, ¹ H-NMR and ¹³ C-NMR measurement.

Mass Spectrometry (FDMS) = 308 (M ⁺ )
¹ H-NMR (CDCl ₃ ) δ (ppm) = 7.36 (d, 2H), 7.06 (d, 2H), 1.64-1.72 (m, 2H), 1.55 (t, 4H), 0.99 (s, 12H)
¹³ C-NMR (CDCl ₃ ) δ (ppm) = 145.80, 135.69, 130.69, 119.10, 54.11, 42.23, 29.70, 18.37
Example 1 Synthesis of Compound (1-3) N-phenyl-N- (4- (2,2,6) synthesized in Synthesis Example 1 was placed in a 50 mL three-necked flask equipped with a stirrer under a nitrogen atmosphere. , 6-tetramethylpiperidinyl) phenyl) amine 1.5 g (4.86 mmol), 3,3′-dichlorobiphenyl 490 mg (2.2 mmol), sodium tert-butoxide 594 mg (6.1 mmol), o-xylene 5 mL was added, 9 mg (0.04 mmol) of palladium acetate and 31 mg (0.15 mmol) of tri (tert-butyl) phosphine were added to the slurry reaction solution, and the mixture was stirred at 130 ° C. for 24 hours. After cooling to room temperature, 5 mL of water was added and the organic layer was separated. The organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (a mixed solvent of toluene and hexane), and 430 mg (0.56 mmol) of the target product was isolated as a slightly yellow powder (yield 25%, HPLC purity 99.0%). The compound was identified by FDMS measurement, ¹ H-NMR and ¹³ C-NMR measurement.

Mass Spectrometry (FDMS) = 766 (M ⁺ )
¹ H-NMR (CDCl ₃ ) δ (ppm) = 7.18-7.26 (m, 6H), 6.94-7.10 (m, 20H), 1.64-1.76 (m, 4H) ), 1.52-1.56 (m, 8H), 1.03 (s, 24H)
¹³ C-NMR (CDCl ₃ ) δ (ppm) = 148.32, 147.83, 144.74, 141.92, 134.61, 129.30, 129.08, 123.75, 123.70, 122 .54, 122.32, 122.21, 120.95, 54.15, 42.32, 29.83, 18.48
Example 2 Measurement of triplet level (measurement of phosphorescence spectrum)
On the silicon substrate, the compound (1-3) synthesized in Example 1 was formed into a film with a thickness of 50 nm by vacuum deposition. Next, this substrate was cooled to 5K using a cryostat under vacuum, and the substrate was irradiated with light having a wavelength of 337 nm using a nitrogen gas laser as an excitation light source. The triplet level of the compound (1-3) calculated from the obtained phosphorescence spectrum was 2.69 eV.

Example 3 Device Evaluation of Compound (1-3) A glass substrate on which an ITO transparent electrode having a thickness of 200 nm was laminated was subjected to ultrasonic cleaning with acetone and pure water, boiling cleaning with isopropyl alcohol, and then dried. Further, UV / ozone treatment was performed, and after evacuation with a vacuum pump until it was 1 × 10 ⁻⁴ Pa after installation in a vacuum deposition apparatus. First, α-NPD was deposited on the ITO transparent electrode at a deposition rate of 0.3 nm / second to form a 20 nm hole injection layer. Subsequently, after depositing compound (1-3) at a deposition rate of 0.3 nm / second for 30 nm, phosphorous dopant material Tris (2-phenylpyridine) iridium (Ir (ppy) ₃ ) and host material 4,4 '-Bis (N-carbazolyl) biphenyl (CBP) was co-evaporated at a deposition rate of 0.25 nm / second so that the weight ratio was 1: 11.5, to obtain a 20 nm light emitting layer. Next, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was vapor-deposited at a vapor deposition rate of 0.3 nm / second to form an excitocin block layer having a thickness of 10 nm. A quinolinolato) aluminum complex was deposited at 0.3 nm / second to form a 30 nm electron transport layer. Subsequently, lithium fluoride was deposited as an electron injection layer at a deposition rate of 0.01 nm / second to 0.5 nm, and aluminum was deposited at a deposition rate of 0.25 nm / second to 100 nm to form a cathode. In a nitrogen atmosphere, a sealing glass plate was bonded with a UV curable resin to obtain an organic EL element for evaluation. A current of 20 mA / cm ² was applied to the device thus obtained, and driving voltage and external quantum efficiency were measured. The results are shown in Table 1.

Comparative Example 1 Element Evaluation of α-NPD An organic EL element was produced in the same manner as in Example 3 except that the compound (1-3) was changed to α-NPD. Table 1 shows the results of driving voltage and external quantum efficiency when driven under a constant current density condition of 20 mA / cm ² .

  The amine derivative of the present invention can be used as a hole injection material, a hole transport material or a host material for a light emitting layer of an organic EL device, and can be expected to be extremely useful particularly in an EL device using a phosphorescent material. Furthermore, not only as a hole injection material, a hole transport material, or a light emitting material such as an organic EL element or an electrophotographic photosensitive member, but also in a field of organic photoconductive materials such as a photoelectric conversion element, a solar cell, and an image sensor. Applicable.

Claims (2)

An organic electroluminescence device comprising an amine derivative having a partial skeleton represented by the general formula (1) in any one or more of a light emitting layer, a hole transport layer and a hole injection layer.

(In the formula, the curve represents an aliphatic hydrocarbon group which may contain a heteroatom other than a nitrogen atom, and constitutes a cyclic structure together with the nitrogen atom. Ar ₁ and Ar ₂ each independently have a substituent. An optionally substituted aryl group having 6 to 40 carbon atoms, or an optionally substituted heteroaryl group having 5 to 40 carbon atoms, Ar ′ represents a divalent arylene group. The organic electroluminescent device according to claim 1, wherein an amine derivative having a partial skeleton represented by the general formula (2) or (3) is used.

(In the formula, Ar ₁ and Ar ₂ are each independently an aryl group having 6 to 40 carbon atoms which may have a substituent, or a heteroaryl having 5 to 40 carbon atoms which may have a substituent) Ar ′ represents a divalent arylene group, R represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 18 carbon atoms. Represents a group, an aryl group which may have a substituent, an aryloxy group which may have a substituent, or an arylamino group which may have a substituent, and arbitrary Rs are bonded to each other To form a crosslinking group.)