WO2013179645A1 - Organic-electroluminescent-element material, and organic electroluminescent element using same - Google Patents

Description

Material for organic electroluminescence device and organic electroluminescence device using the same

The present invention relates to a material for an organic electroluminescence element and an organic electroluminescence element using the same.

Organic electroluminescence (EL) elements include a fluorescent type and a phosphorescent type, and an optimum element design has been studied according to each light emission mechanism. With respect to phosphorescent organic EL elements, it is known from their light emission characteristics that high-performance elements cannot be obtained by simple diversion of fluorescent element technology. The reason is generally considered as follows.
First, since phosphorescence emission is emission using triplet excitons, the energy gap of the compound used for the light emitting layer must be large. This is because the value of the energy gap (hereinafter also referred to as singlet energy) of a compound usually refers to the triplet energy of the compound (in the present invention, the energy difference between the lowest excited triplet state and the ground state). This is because it is larger than the value of).

Therefore, in order to efficiently confine the triplet energy of the phosphorescent dopant material in the light emitting layer, a host material having a triplet energy larger than the triplet energy of the phosphorescent dopant material must first be used for the light emitting layer. I must. Furthermore, an electron transport layer and a hole transport layer adjacent to the light emitting layer are provided, and a compound having a triplet energy higher than that of the phosphorescent dopant material must be used for the electron transport layer and the hole transport layer.
Thus, when based on the element design concept of the conventional organic EL element, a compound having a larger energy gap than the compound used for the fluorescent organic EL element is used for the phosphorescent organic EL element. The drive voltage of the entire element increases.

In addition, hydrocarbon compounds having high oxidation resistance and reduction resistance useful for fluorescent elements have a large energy gap due to the large spread of π electron clouds. Therefore, in a phosphorescent organic EL element, it is difficult to select such a hydrocarbon compound, and an organic compound containing a heteroatom such as oxygen or nitrogen is selected. As a result, the phosphorescent organic EL element is There is a problem that the lifetime is shorter than that of a fluorescent organic EL element.

Furthermore, the fact that the exciton relaxation rate of the triplet exciton of the phosphorescent dopant material is much longer than that of the singlet exciton also greatly affects the device performance. That is, since light emitted from singlet excitons has a high relaxation rate that leads to light emission, it is difficult for excitons to diffuse into the peripheral layer of the light emitting layer (for example, a hole transport layer or an electron transport layer). Light emission is expected. On the other hand, light emission from triplet excitons is spin-forbidden and has a slow relaxation rate, so that excitons are likely to diffuse into the peripheral layer, and thermal energy deactivation occurs from other than specific phosphorescent compounds. End up. That is, control of the recombination region of electrons and holes is more important than the fluorescent organic EL element.

For the above reasons, in order to improve the performance of phosphorescent organic EL elements, material selection and element design different from those of fluorescent organic EL elements are required.
In particular, in the case of a phosphorescent organic EL element that emits blue light, it is necessary to use a compound having a large triplet energy in the light emitting layer and its peripheral layer as compared with a phosphorescent organic EL element that emits green to red light. Specifically, in order to obtain blue phosphorescence without loss of efficiency, the triplet energy of the host material used for the light-emitting layer needs to be approximately 3.0 eV or more. In order to obtain a compound satisfying the performance required as an organic EL material while having such a high triplet energy, not simply combining molecular parts having a high triplet energy such as a heterocyclic compound, Molecular design based on a new concept that considers the electronic state of π electrons is required.

Under such circumstances, as a material of a phosphorescent organic EL element, for example, in Patent Document 1, two benzene rings are bonded to a central benzene ring so as to form a condensed ring, and another condensed group is connected to the terminal. A polycyclic compound having a structure in which rings are bonded is disclosed.
Patent Document 2 discloses a polycyclic compound having a π-conjugated heteroacene skeleton bridged by a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom.

International Publication No. 2009/148062 International Publication No. 2009/148015

An object of the present invention is to provide a material for an organic electroluminescence element capable of extending the life and lowering the driving voltage of the organic electroluminescence element.

（式（１）中、ｎは、１～４の整数である。
　Ｘは、酸素（Ｏ）原子又は硫黄（Ｓ）原子であり、ｎが２以上の場合、複数のＸはそれぞれ同一でも異なっていてもよい。
　Ｌ_１及びＬ_２は、それぞれ、単結合、置換基Ｒを有してもよい環形成炭素数６～１８のアリーレン基、又は置換基Ｒを有してもよい環形成原子数５～１８のヘテロアリーレン基であり、ｎが２以上の場合、複数のＬ_１及び複数のＬ_２はそれぞれ同一でも異なっていてもよい。
　Ｌ_３は、置換基Ｒを有してもよい炭素数１～２０のｎ＋ｑ価の飽和脂肪族炭化水素基、置換基Ｒを有してもよいｎ＋ｑ価のケイ素含有基、置換基Ｒを有してもよい環形成炭素数６～１８のｎ＋ｑ価の芳香族炭化水素基、又は置換基Ｒを有してもよい環形成原子数５～１８のｎ＋ｑ価の不飽和複素環基である。
　Ｒ^１１及びＲ^１２は、それぞれ、置換基Ｒを有してもよい炭素数１～２０のアルキル基、置換基Ｒを有してもよい環形成炭素数３～１８のシクロアルキル基、置換基Ｒを有してもよい炭素数１～２０のアルコキシ基、置換基Ｒを有してもよい環形成炭素数３～２０のシクロアルコキシ基、置換基Ｒを有してもよい環形成炭素数６～１８のアリールオキシ基、置換基Ｒを有してもよいシリル基、フルオロ基、シアノ基、置換基Ｒを有してもよい環形成炭素数６～１８のアリール基、又は置換基Ｒを有してもよい環形成原子数５～１８のヘテロアリール基であり、Ｒ^１１が複数存在する場合、それぞれ同一でも異なっていてもよく、Ｒ^１２が複数存在する場合、それぞれ同一でも異なっていてもよい。
　ｐは、０～３の整数であり、ｎが２以上の場合、複数のｐはそれぞれ同一でも異なっていてもよい。
　ｑは、０～３の整数である。
　置換基Ｒは、炭素数１～２０のアルキル基、環形成炭素数３～１８のシクロアルキル基、炭素数１～２０のアルコキシ基、環形成炭素数３～２０のシクロアルコキシ基、環形成炭素数６～１８のアリールオキシ基、シリル基、フルオロ基、シアノ基、環形成炭素数６～１８のアリール基、又は環形成原子数５～１８のヘテロアリール基であり、Ｒが複数存在する場合、それぞれ同一でも異なっていてもよい。
　Ｃｚは、下記式（２－１）、（２－２）、（３－１）、（３－２）、（４－１）、（４－２）、（５－１）、（５－２）、（６－１）、（６－２）、（７－１）、（７－２）、（８－１）、及び（８－２）からなる群より選ばれる一つの基であり、ｎが２以上の場合、複数のＣｚはそれぞれ同一でも異なっていてもよい。

（式（２－１）、（２－２）、（３－１）、（３－２）、（４－１）、（４－２）、（５－１）、（５－２）、（６－１）、（６－２）、（７－１）、（７－２）、（８－１）、（８－２）中、＊は、Ｌ_１との結合位置を表し、
　Ｙは、酸素（Ｏ）原子又は硫黄（Ｓ）原子であり、ｎが２以上の場合、複数のＹはそれぞれ同一でも異なっていてもよく、
　ｍ^１及びｍ^２は、それぞれ独立に、０～４の整数であり、
　ｍ^３は、０～３の整数であり、
　ｍ^４は、０～２の整数であり、
　ｍ^５は、０～４の整数であり、
　Ｒ^０、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、置換基Ｒを有してもよい炭素数１～２０のアルキル基、置換基Ｒを有してもよい環形成炭素数３～１８のシクロアルキル基、置換基Ｒを有してもよい炭素数１～２０のアルコキシ基、置換基Ｒを有してもよい環形成炭素数３～２０のシクロアルコキシ基、置換基Ｒを有してもよい環形成炭素数６～１８のアリールオキシ基、置換基Ｒを有してもよいシリル基、フルオロ基、シアノ基、置換基Ｒを有してもよい環形成炭素数６～１８のアリール基、又は置換基Ｒを有してもよい環形成原子数５～１８のヘテロアリール基であり、Ｒ^０が複数存在する場合、それぞれ同一でも異なっていてもよく、Ｒ^１が複数存在する場合、それぞれ同一でも異なっていてもよく、Ｒ^２が複数存在する場合、それぞれ同一でも異なっていてもよく、Ｒ^３が複数存在する場合、それぞれ同一でも異なっていてもよい。））
２．下記式（３）で表される１に記載の有機エレクトロルミネッセンス素子用材料。

（式（３）中、ｎ、Ｘ、Ｌ^１、Ｌ^２、Ｌ^３、Ｒ^１１、Ｒ^１２、ｐ、ｑ及びＣｚは、それぞれ、前記式（１）と同じである。）
３．前記Ｃｚが、式（２－１）で表される基である１又は２に記載の有機エレクトロルミネッセンス素子用材料。
４．前記Ｃｚが、式（２－２）で表される基である１又は２に記載の有機エレクトロルミネッセンス素子用材料。
５．前記ｎが、１又は２である１～４のいずれかに記載の有機エレクトロルミネッセンス素子用材料。
６．陰極と陽極の間に、発光層を含む１層以上の有機薄膜層を有し、前記有機薄膜層の少なくとも１層が、１～５のいずれかに記載の有機エレクトロルミネッセンス素子用材料を含有する有機エレクトロルミネッセンス素子。
７．前記発光層が、前記有機エレクトロルミネッセンス素子用材料を含有する６に記載の有機エレクトロルミネッセンス素子。
８．前記陽極と前記発光層の間に正孔輸送帯域を有し、前記正孔輸送帯域が前記有機エレクトロルミネッセンス素子用材料を含有する６に記載の有機エレクトロルミネッセンス素子。
９．前記陰極と前記発光層の間に電子輸送帯域を有し、前記電子輸送帯域が前記有機エレクトロルミネッセンス素子用材料を含有する６に記載の有機エレクトロルミネッセンス素子。
１０．前記発光層が、燐光発光材料を含有し、前記燐光発光材料がイリジウム（Ｉｒ）、オスミウム（Ｏｓ）及び白金（Ｐｔ）から選択される金属原子のオルトメタル化錯体である６～９のいずれかに記載の有機エレクトロルミネッセンス素子。 According to the present invention, the following materials for organic electroluminescence elements are provided.
1. The material for organic electroluminescent elements represented by following formula (1).

(In the formula (1), n is an integer of 1 to 4.
X is an oxygen (O) atom or a sulfur (S) atom. When n is 2 or more, the plurality of X may be the same or different.
L ₁ and L ₂ are each a single bond, an arylene group having 6 to 18 ring carbon atoms which may have a substituent R, or an arylene group having 5 to 18 ring atoms which may have a substituent R. When it is a heteroarylene group and n is 2 or more, the plurality of L ₁ and the plurality of L ₂ may be the same or different.
L ₃ has an n + q valent saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent R, an n + q valent silicon-containing group which may have a substituent R, and a substituent R. And an n + q valent aromatic hydrocarbon group having 6 to 18 ring carbon atoms, or an n + q valent unsaturated heterocyclic group having 5 to 18 ring atoms which may have a substituent R.
R ¹¹ and R ¹² are each an alkyl group having 1 to 20 carbon atoms that may have a substituent R, a cycloalkyl group having 3 to 18 ring carbon atoms that may have a substituent R, and a substituent. An alkoxy group having 1 to 20 carbon atoms which may have R, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a ring forming carbon number which may have a substituent R 6-18 aryloxy group, silyl group optionally having substituent R, fluoro group, cyano group, aryl group having 6-18 ring forming carbon atoms optionally having substituent R, or substituent R A heteroaryl group having 5 to 18 ring atoms that may have a ring structure, and when there are a plurality of R ^{11 s} , they may be the same or different, and when there are a plurality of R ^{12 s} , they may be the same or different from each other. May be.
p is an integer of 0 to 3, and when n is 2 or more, the plurality of p may be the same or different.
q is an integer of 0 to 3.
The substituent R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 18 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms, or a ring forming carbon. An aryloxy group having 6 to 18 atoms, a silyl group, a fluoro group, a cyano group, an aryl group having 6 to 18 ring carbon atoms, or a heteroaryl group having 5 to 18 ring atoms, and when there are a plurality of R These may be the same or different.
Cz is represented by the following formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5- 2) one group selected from the group consisting of (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2) , N is 2 or more, the plurality of Cz may be the same or different.

(Formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5-2), In (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2), * represents a bonding position with L ₁ .
Y is an oxygen (O) atom or a sulfur (S) atom, and when n is 2 or more, the plurality of Y may be the same or different,
m ¹ and m ² are each independently an integer of 0 to 4,
m ³ is an integer from 0 to 3,
m ⁴ is an integer from 0 to 2,
m ⁵ is an integer from 0 to 4,
R ⁰ , R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 20 carbon atoms which may have a substituent R, or a ring having 3 to 3 carbon atoms which may have a substituent R. An cycloalkyl group having 18 carbon atoms which may have a substituent R, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a substituent R; An aryloxy group having 6 to 18 ring carbon atoms, a silyl group optionally having substituent R, a fluoro group, a cyano group, and 6 to 18 ring carbon atoms optionally having substituent R Or a heteroaryl group having 5 to 18 ring atoms that may have a substituent R, and when a plurality of R ⁰ are present, they may be the same or different, and a plurality of R ¹ are present. If you, or different and each identical, if R ² there are a plurality, Re may be the same or different, respectively, when the R ³ there are a plurality may each be the same or different. ))
2. The material for organic electroluminescence elements according to 1, which is represented by the following formula (3).

(In the formula (3), n, X, L ¹ , L ² , L ³ , R ¹¹ , R ¹² , p, q and Cz are the same as those in the formula (1).)
3. 3. The material for an organic electroluminescent element according to 1 or 2, wherein Cz is a group represented by the formula (2-1).
4). 3. The material for an organic electroluminescence element according to 1 or 2, wherein Cz is a group represented by the formula (2-2).
5. 5. The material for an organic electroluminescent element according to any one of 1 to 4, wherein n is 1 or 2.
6). One or more organic thin film layers including a light emitting layer are provided between the cathode and the anode, and at least one of the organic thin film layers contains the material for an organic electroluminescent element according to any one of 1 to 5 Organic electroluminescence device.
7). 7. The organic electroluminescence device according to 6, wherein the light emitting layer contains the material for an organic electroluminescence device.
8). 7. The organic electroluminescence device according to 6, wherein the organic electroluminescence device has a hole transport zone between the anode and the light emitting layer, and the hole transport zone contains the material for an organic electroluminescence device.
9. 7. The organic electroluminescence device according to 6, wherein the organic electroluminescence device has an electron transport zone between the cathode and the light emitting layer, and the electron transport zone contains the material for an organic electroluminescence device.
10. Any of 6 to 9, wherein the light emitting layer contains a phosphorescent material, and the phosphorescent material is an orthometalated complex of a metal atom selected from iridium (Ir), osmium (Os), and platinum (Pt). The organic electroluminescent element of description.

According to the present invention, it is possible to provide a material for an organic electroluminescence element capable of extending the life of the organic electroluminescence element and reducing the driving voltage.

It is a figure which shows one Embodiment of the organic EL element of this invention. It is a figure which shows other embodiment of the organic EL element of this invention.

The material for organic EL elements of the present invention is represented by the following formula (1).

In the formula (1), n is an integer of 1 to 4 (1, 2, 3 or 4). n is 1 or 2, for example.
X is an oxygen (O) atom or a sulfur (S) atom. When n is 2 or more, the plurality of X may be the same or different.
L ₁ and L ₂ are each a single bond, an arylene group having 6 to 18 ring carbon atoms which may have a substituent R, or an arylene group having 5 to 18 ring atoms which may have a substituent R. When it is a heteroarylene group and n is 2 or more, the plurality of L ₁ and the plurality of L ₂ may be the same or different. Here, “ring-forming carbon” means a carbon atom constituting a saturated ring, unsaturated ring or aromatic ring, and “ring-forming atom” means an atom constituting a saturated ring, unsaturated ring or aromatic ring. Means.
In the present invention, the hydrogen atom includes isotopes having different numbers of neutrons, that is, light hydrogen (protium), deuterium (deuterium), and tritium (tritium).

L ₃ has an n + q valent saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent R, an n + q valent silicon-containing group which may have a substituent R, and a substituent R. And an n + q valent aromatic hydrocarbon group having 6 to 18 ring carbon atoms, or an n + q valent unsaturated heterocyclic group having 5 to 18 ring atoms which may have a substituent R.
R ¹¹ and R ¹² are each an alkyl group having 1 to 20 carbon atoms that may have a substituent R, a cycloalkyl group having 3 to 18 ring carbon atoms that may have a substituent R, and a substituent. An alkoxy group having 1 to 20 carbon atoms which may have R, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a ring forming carbon number which may have a substituent R 6-18 aryloxy group, silyl group optionally having substituent R, fluoro group, cyano group, aryl group having 6-18 ring forming carbon atoms optionally having substituent R, or substituent R A heteroaryl group having 5 to 18 ring atoms that may have a ring structure, and when there are a plurality of R ^{11 s} , they may be the same or different, and when there are a plurality of R ^{12 s} , they may be the same or different from each other. May be.

p is an integer of 0 to 3 (0, 1, 2, or 3). When n is 2 or more, the plurality of p may be the same or different. p is, for example, 0.
q is an integer of 0 to 3 (0, 1, 2, or 3), for example, 0.
The substituent R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 18 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms, or a ring forming carbon. An aryloxy group having 6 to 18 atoms, a silyl group, a fluoro group, a cyano group, an aryl group having 6 to 18 ring carbon atoms, or a heteroaryl group having 5 to 18 ring atoms, and when there are a plurality of R These may be the same or different.

Cz is represented by the following formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5- 2) one group selected from the group consisting of (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2) , N is 2 or more, the plurality of Cz may be the same or different.

Formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5-2), ( In (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2), * represents a bonding position with L ₁ .
Y is an oxygen (O) atom or sulfur (S) atom. When n is 2 or more, the plurality of Y may be the same or different.

m ¹ and m ² are each independently an integer of 0 to 4 (0, 1, 2, 3, or 4). m ¹ and m ² are, for example, 0 or 1, and (m ¹ + m ² ) is preferably 2 or less.
m ³ is an integer of 0 to 3 (0, 1, 2, or 3). m ³ is 0, for example.
m ⁴ is an integer of 0 to 2 (0, 1 or 2). m ⁴ is 0, for example.
m ⁵ is an integer of 0 to 4 (0, 1, 2, 3 or 4). m ⁵ is, for example, 0.

R ⁰ , R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 20 carbon atoms which may have a substituent R, or a ring having 3 to 3 carbon atoms which may have a substituent R. An cycloalkyl group having 18 carbon atoms which may have a substituent R, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a substituent R; An aryloxy group having 6 to 18 ring carbon atoms, a silyl group optionally having substituent R, a fluoro group, a cyano group, and 6 to 18 ring carbon atoms optionally having substituent R Or a heteroaryl group having 5 to 18 ring atoms that may have a substituent R, and when a plurality of R ⁰ are present, they may be the same or different, and a plurality of R ¹ are present. If you, or different and each identical, if R ² there are a plurality, Re may be the same or different, respectively, when the R ³ there are a plurality may each be the same or different.

The organic EL device material of the present invention is particularly preferable as a material for a light emitting layer of an organic EL device that emits phosphorescence or a layer adjacent to the light emitting layer, for example, a hole barrier layer or an electron barrier layer.

　式（３）中、ｎ、Ｘ、Ｌ^１、Ｌ^２、Ｌ^３、Ｒ^１１、Ｒ^１２、ｐ、ｑ及びＣｚは、それぞれ、前記式（１）と同じである。 The material for an organic EL device of the present invention is preferably represented by the following formula (3).

In the formula (3), n, X, L ¹ , L ² , L ³ , R ¹¹ , R ¹² , p, q and Cz are the same as those in the formula (1).

In the organic EL device material of the present invention, Cz in the formula (1) has a carbazole skeleton or a ring structure having a carbazole skeleton as a partial structure. Since both the ring structure represented by Cz in the formula (4) and D surrounded by the broken line in the formula (4) have a carbazole skeleton as a partial structure, good affinity between these ring structures And a good film having a high glass transition point and a high carrier transport ability can be formed.

Moreover, the organic EL device material of the present invention has no substituent on the benzene rings A and B in the ring structure represented by D surrounded by the broken line in the above formula (4).
Thereby, a good aggregation state or molecular orientation state is formed between the molecules of the material or between the material molecule and the dopant molecule, and a good film having a high glass transition point and a high carrier transporting ability is formed. be able to. This is thought to be because the aspect ratio tends to be high as the molecular shape.
By using the organic EL device material of the present invention, the obtained organic EL device has a long life. The material for an organic EL element of the present invention is particularly suitable as a host material, an electron barrier layer, and a hole barrier layer of a light emitting layer of the organic EL element.

When Cz in Formula (1) is a group represented by Formula (2-1), that is, when the carbazole skeleton of Cz is bonded to L ₁ at the 9-position, the host material of the light-emitting layer, or It is further suitable as a hole blocking layer.
When Cz in formula (1) is a group represented by formula (2-2), that is, when the carbazole skeleton of Cz is bonded to L ₁ at positions other than 9-position, hole transportability is improved. Therefore, it is more suitable as a material for the electron barrier layer.

Hereinafter, examples of each group of the above-described formula (1) will be described.
Examples of the alkyl group having 1 to 20 carbon atoms include linear or branched alkyl groups, and specifically include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec- Examples include butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like, preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl Group, isobutyl group, sec-butyl group and tert-butyl group, preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group.
Examples of the n + q-valent saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms include the n + q-valent groups of the above-described groups.

Examples of the cycloalkyl group having 3 to 18 ring carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-norbornyl group, and a 2-norbornyl group. Preferred are a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group.
The alkoxy group having 1 to 20 carbon atoms is represented as —OY ₁ and examples of Y ₁ include the above alkyl examples. The alkoxy group is, for example, a methoxy group or an ethoxy group. The alkoxy group may be substituted with a fluorine atom, and in this case, a trifluoromethoxy group or the like is preferable.

A cycloalkoxy group having 3 to 20 ring carbon atoms is represented by —OY _2, and examples of Y ₂ include the above-described cycloalkyl groups. The cycloalkoxy group is, for example, a cyclopentyloxy group or a cyclohexyloxy group.

The aryl group having 6 to 18 ring carbon atoms is preferably an aryl group having 6 to 12 ring carbon atoms.
Specific examples of the monovalent aryl group include phenyl group, biphenyl group, terphenyl group, tolyl group, xylyl group, naphthyl group, anthryl group, phenanthryl group, naphthacenyl group, pyrenyl group, chrysenyl group, triphenylenyl group, fluorenyl group. , Biphenylyl group, terphenyl group, fluoranthenyl group and the like, preferably phenyl group, biphenyl group, terphenyl group, tolyl group, xylyl group, naphthyl group, phenanthryl group and triphenylenyl group.

Examples of the n + q valent aromatic hydrocarbon group having 6 to 18 ring carbon atoms include the n + q valent groups of the aforementioned groups.
Examples of the arylene group having 6 to 18 ring carbon atoms include the divalent groups described above.
An aryloxy group having 6 to 18 ring carbon atoms is represented by —OY _3, and examples of Y ₃ include the above aryl groups. The aryloxy group is, for example, a phenoxy group.

The heteroaryl group having 5 to 18 ring atoms is preferably a heteroaryl group having 5 to 10 ring atoms.
Specific examples of the monovalent heteroaryl group include pyrrolyl group, pyrazinyl group, pyridinyl group, pyrimidinyl group, triazinyl group, indolyl group, isoindolyl group, imidazolyl group, furyl group, benzofuranyl group, isobenzofuranyl group, dibenzofuranyl group. Nyl group, dibenzothiophenyl group, azadibenzofuranyl group, azadibenzothiophenyl group, diazadibenzofuranyl group, diazadibenzothiophenyl group, quinolyl group, isoquinolyl group, quinoxalinyl group, carbazolyl group, phenanthridinyl Group, acridinyl group, phenanthrolinyl group, phenazinyl group, phenothiazinyl group, phenoxazinyl group, oxazolyl group, oxadiazolyl group, furanyl group, thienyl group, benzothiophenyl group, dihydroacridinyl group, azacarbazolyl group And diazacarbazolyl group, quinazolinyl group, etc., preferably pyridinyl group, pyrimidinyl group, triazinyl group, dibenzofuranyl group, dibenzothiophenyl group, azadibenzofuranyl group, azadibenzothiophenyl group, diaza A dibenzofuranyl group, a diazadibenzothiophenyl group, a carbazolyl group, an azacarbazolyl group, and a diazacarbazolyl group;

Examples of the n + q valent unsaturated heterocyclic group having 5 to 18 ring atoms include the n + q valent group described above.
Examples of the heteroarylene group having 5 to 18 ring atoms include the divalent groups described above.

Examples of the n + q-valent silicon-containing group include a silyl group.
Examples of the silicon-containing group substituted by R include an alkylsilyl group having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), and 6 to 18 ring carbon atoms (preferably Is an arylsilyl group having 6 to 12 ring carbon atoms.
Specific examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, and a propyldimethylsilyl group.
Specific examples of the arylsilyl group include a triphenylsilyl group, a phenyldimethylsilyl group, a t-butyldiphenylsilyl group, a tolylsilylsilyl group, a trixylsilyl group, a trinaphthylsilyl group, and the like.
Specific examples of the compound represented by the above formula (1) are shown below.

The compounds of the present invention can be synthesized by the methods described in the synthesis examples of the examples or methods known to those skilled in the art.
Next, the organic EL element of the present invention will be described.
The organic EL device of the present invention has one or more organic thin film layers including a light emitting layer between an anode and a cathode. And at least 1 layer of an organic thin film layer contains the organic EL element material of this invention.

FIG. 1 is a schematic view showing a layer structure of an embodiment of the organic EL device of the present invention.
The organic EL element 1 has a configuration in which an anode 20, a hole transport zone 30, a phosphorescent light emitting layer 40, an electron transport zone 50, and a cathode 60 are laminated on a substrate 10 in this order. The hole transport zone 30 means a hole transport layer or a hole injection layer. Similarly, the electron transport zone 50 means an electron transport layer, an electron injection layer, or the like. These need not be formed, but preferably one or more layers are formed. In this element, the organic thin film layer is each organic layer provided in the hole transport zone 30, each phosphor layer and the organic layer provided in the electron transport zone 50. Among these organic thin film layers, at least one layer contains the organic EL element material of the present invention. Thereby, the drive voltage of an organic EL element can be lowered.
The content of this material with respect to the organic thin film layer containing the organic EL device material of the present invention is preferably 1 to 100% by weight.

In the organic EL device of the present invention, the phosphorescent light emitting layer 40 preferably contains the material for the organic EL device of the present invention, and particularly preferably used as a host material for the light emitting layer. Since the triplet energy of the material of the present invention is sufficiently large, even when a blue phosphorescent dopant material is used, the triplet energy of the phosphorescent dopant material can be efficiently confined in the light emitting layer. In addition, it can be used not only for the blue light emitting layer but also for a light emitting layer of longer wavelength light (such as green to red).

The phosphorescent light emitting layer contains a phosphorescent material (phosphorescent dopant). Examples of phosphorescent dopants include metal complex compounds, preferably selected from iridium (Ir), platinum (Pt), osmium (Os), gold (Au), copper (Cu), rhenium (Re), and ruthenium (Ru). A compound having a metal atom and a ligand. The ligand preferably has an ortho metal bond.
The phosphorescent dopant is preferably a compound containing a metal atom selected from Ir, Os and Pt in that the phosphorescent quantum yield is high and the external quantum efficiency of the light-emitting element can be further improved, and an iridium complex, It is more preferable that it is a metal complex such as an osmium complex and a platinum complex, among which an iridium complex and a platinum complex are more preferable, and an orthometalated iridium complex is most preferable. The dopant may be a single type or a mixture of two or more types.

The addition concentration of the phosphorescent dopant in the phosphorescent light emitting layer is not particularly limited, but is preferably 0.1 to 30% by weight (wt%), more preferably 0.1 to 20% by weight (wt%).

It is also preferable to use the material of the present invention in a layer adjacent to the phosphorescent light emitting layer 40. For example, when a layer containing the material of the present invention (an anode side adjacent layer) is formed between the hole transport zone 30 and the phosphorescent light emitting layer 40 of the device of FIG. 1, the layer functions as an electron barrier layer. It functions as an exciton blocking layer.
On the other hand, when a layer (cathode side adjacent layer) containing the material of the present invention is formed between the phosphorescent light emitting layer 40 and the electron transport zone 50, the layer functions as a hole blocking layer or as an exciton blocking layer. It has a function.

The barrier layer (blocking layer) is a layer having a function of a carrier movement barrier or an exciton diffusion barrier. The organic layer for preventing electrons from leaking from the light-emitting layer to the hole transport zone is mainly defined as an electron barrier layer, and the organic layer for preventing holes from leaking from the light-emitting layer to the electron transport zone is defined as a hole barrier. Sometimes defined as a layer. In addition, an exciton blocking layer (triplet barrier layer) is an organic layer for preventing triplet excitons generated in the light emitting layer from diffusing into a peripheral layer having triplet energy lower than that of the light emitting layer. It may be defined as
Further, the material of the present invention can be used for a layer adjacent to the phosphorescent light emitting layer 40 and further used for another organic thin film layer bonded to the adjacent layer.

Furthermore, when two or more light emitting layers are formed, it is also suitable as a space layer formed between the light emitting layers.
FIG. 2 is a schematic view showing the layer structure of another embodiment of the organic EL device of the present invention.
The organic EL element 2 is an example of a hybrid type organic EL element in which a phosphorescent light emitting layer and a fluorescent light emitting layer are laminated.
The organic EL element 2 has the same configuration as the organic EL element 1 except that a space layer 42 and a fluorescent light emitting layer 44 are formed between the phosphorescent light emitting layer 40 and the electron transport zone 50. In the configuration in which the phosphorescent light emitting layer 40 and the fluorescent light emitting layer 44 are laminated, the excitons formed in the phosphorescent light emitting layer 40 are not diffused into the fluorescent light emitting layer 44, so that a space layer 42 is provided between the fluorescent light emitting layer 44 and the phosphorescent light emitting layer 40. May be provided. Since the material of the present invention has a large triplet energy, it can function as a space layer.

In the organic EL element 2, for example, a white light emitting organic EL element can be obtained by setting the phosphorescent light emitting layer to emit yellow light and the fluorescent light emitting layer to blue light emitting layer. In this embodiment, the phosphorescent light-emitting layer and the fluorescent light-emitting layer are formed one by one. However, the present invention is not limited to this, and two or more layers may be formed, and can be appropriately set according to the application such as lighting and display device. For example, when a full color light emitting device is formed using a white light emitting element and a color filter, a plurality of wavelength regions such as red, green, blue (RGB), red, green, blue, yellow (RGBY) are used from the viewpoint of color rendering. In some cases, it may be preferable to include luminescence.

In addition to the above-described embodiments, the organic EL element of the present invention can employ various known configurations. Further, light emission of the light emitting layer can be taken out from the anode side, the cathode side, or both sides.

The organic EL device of the present invention preferably has at least one of an electron donating dopant and an organometallic complex in an interface region between the cathode and the organic thin film layer.
According to such a configuration, it is possible to improve the light emission luminance and extend the life of the organic EL element.
Examples of the electron donating dopant include at least one selected from alkali metals, alkali metal compounds, alkaline earth metals, alkaline earth metal compounds, rare earth metals, rare earth metal compounds, and the like.
Examples of the organometallic complex include at least one selected from an organometallic complex containing an alkali metal, an organometallic complex containing an alkaline earth metal, an organometallic complex containing a rare earth metal, and the like.

Examples of the alkali metal include lithium (Li) (work function: 2.93 eV), sodium (Na) (work function: 2.36 eV), potassium (K) (work function: 2.28 eV), rubidium (Rb) (work Function: 2.16 eV), cesium (Cs) (work function: 1.95 eV) and the like, and those having a work function of 2.9 eV or less are particularly preferable. Of these, K, Rb, and Cs are preferred, Rb and Cs are more preferred, and Cs is most preferred.
Examples of the alkaline earth metal include calcium (Ca) (work function: 2.9 eV), strontium (Sr) (work function: 2.0 eV to 2.5 eV), barium (Ba) (work function: 2.52 eV). A work function of 2.9 eV or less is particularly preferable.
Examples of the rare earth metal include scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb) and the like, and those having a work function of 2.9 eV or less are particularly preferable.
Among the above metals, preferred metals are particularly high in reducing ability, and by adding a relatively small amount to the electron injection region, it is possible to improve the light emission luminance and extend the life of the organic EL element.

Examples of the alkali metal compound include lithium oxide (Li ₂ O), cesium oxide (Cs ₂ O), alkali oxides such as potassium oxide (K ₂ O), lithium fluoride (LiF), sodium fluoride (NaF), fluorine. Examples thereof include alkali halides such as cesium fluoride (CsF) and potassium fluoride (KF), and lithium fluoride (LiF), lithium oxide (Li ₂ O), and sodium fluoride (NaF) are preferable.
Examples of the alkaline earth metal compound include barium oxide (BaO), strontium oxide (SrO), calcium oxide (CaO), and barium strontium oxide (Ba _x Sr _1-x O) (0 <x <1), Examples thereof include barium calcium oxide (Ba _x Ca _1-x O) (0 <x <1), and BaO, SrO, and CaO are preferable.
The rare earth metal compound, ytterbium fluoride _(YbF 3), scandium fluoride _(ScF 3), scandium oxide _(ScO 3), yttrium oxide _{(Y 2 O} 3), cerium oxide _{(Ce 2 O} 3), gadolinium fluoride _(GdF 3), include such terbium fluoride (TbF _{3) is, YbF 3, ScF 3, TbF} 3 are preferable.

The organometallic complex is not particularly limited as long as it contains at least one of an alkali metal ion, an alkaline earth metal ion, and a rare earth metal ion as a metal ion as described above. The ligands include quinolinol, benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxydiaryloxadiazole, hydroxydiarylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, Hydroxyfulborane, bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene, β-diketones, azomethines, and derivatives thereof are preferred, but are not limited thereto.

As the addition form of the electron donating dopant and the organometallic complex, it is preferable to form a layer or an island in the interface region. As a forming method, while depositing at least one of an electron donating dopant and an organometallic complex by a resistance heating vapor deposition method, an organic material as a light emitting material or an electron injection material for forming an interface region is simultaneously deposited, and an electron is deposited in the organic material. A method of dispersing at least one of the donor dopant and the organometallic complex is preferable. The dispersion concentration is usually organic substance: electron donating dopant and / or organometallic complex in a molar ratio of 100: 1 to 1: 100, preferably 5: 1 to 1: 5.

In the case where at least one of the electron donating dopant and the organometallic complex is formed in a layered form, after forming the light emitting material or the electron injecting material that is the organic layer at the interface in a layered form, at least one of the electron donating dopant and the organometallic complex is formed. These are vapor-deposited by a resistance heating vapor deposition method alone, preferably with a layer thickness of 0.1 nm to 15 nm.

In the case where at least one of an electron donating dopant and an organometallic complex is formed in an island shape, a light emitting material or an electron injecting material which is an organic layer at the interface is formed in an island shape, and then the electron donating dopant and the organometallic complex are formed. At least one of them is vapor-deposited by a resistance heating vapor deposition method, preferably with an island thickness of 0.05 nm to 1 nm.

In the organic EL device of the present invention, the ratio of at least one of the main component and the electron donating dopant and the organometallic complex is, as a molar ratio, the main component: the electron donating dopant and / or the organometallic complex = 5. It is preferably 1 to 1: 5, and more preferably 2: 1 to 1: 2.

In the organic EL element of the present invention, the configuration other than the layer using the organic EL element material of the present invention described above is not particularly limited, and a known material or the like can be used. Hereinafter, although the layer of the element of Embodiment 1 is demonstrated easily, the material applied to the organic EL element of this invention is not limited to the following.

[substrate]
As the substrate, a glass plate, a polymer plate or the like can be used.
Examples of the glass plate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfone, and polysulfone.

[anode]
The anode is made of, for example, a conductive material, and a conductive material having a work function larger than 4 eV is suitable.
Examples of the conductive material include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, and their alloys, ITO substrate, tin oxide used for NESA substrate, indium oxide, and the like. Examples thereof include metal oxides and organic conductive resins such as polythiophene and polypyrrole.
The anode may be formed with a layer structure of two or more layers if necessary.

[cathode]
The cathode is made of, for example, a conductive material, and a conductive material having a work function smaller than 4 eV is suitable.
Examples of the conductive material include, but are not limited to, magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum, lithium fluoride, and alloys thereof.
Examples of the alloy include magnesium / silver, magnesium / indium, lithium / aluminum, and the like, but are not limited thereto. The ratio of the alloy is controlled by the temperature of the vapor deposition source, the atmosphere, the degree of vacuum, etc., and is selected to an appropriate ratio.
If necessary, the cathode may be formed with a layer structure of two or more layers, and the cathode can be produced by forming a thin film from the conductive material by a method such as vapor deposition or sputtering.

When light emitted from the light emitting layer is taken out from the cathode, the transmittance of the cathode for light emission is preferably greater than 10%.
The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

[Light emitting layer]
When the phosphorescent light emitting layer is formed of a material other than the organic EL element layer material of the present invention, a known material can be used as the material of the phosphorescent light emitting layer. Specifically, International Publication No. 2005/079118 (Japanese Patent Application No. 2005-517938) may be referred to.
The organic EL device of the present invention may have a fluorescent light emitting layer like the device shown in FIG. A known material can be used for the fluorescent light emitting layer.

The light emitting layer may be a double host (also referred to as a host / cohost). Specifically, the carrier balance in the light emitting layer may be adjusted by combining an electron transporting host and a hole transporting host in the light emitting layer.
Moreover, it is good also as a double dopant. In the light emitting layer, each dopant emits light by adding two or more dopant materials having a high quantum yield. For example, a yellow light emitting layer may be realized by co-evaporating a host, a red dopant, and a green dopant.
The light emitting layer may be a single layer or a laminated structure. When the light emitting layer is stacked, the recombination region can be concentrated on the light emitting layer interface by accumulating electrons and holes at the light emitting layer interface. This improves the quantum efficiency.

[Hole injection layer and hole transport layer]
The hole injection / transport layer is a layer that assists hole injection into the light emitting layer and transports it to the light emitting region, and has a high hole mobility and a small ionization energy of usually 5.6 eV or less.
As the material for the hole injection / transport layer, a material that transports holes to the light emitting layer with lower electric field strength is preferable. Further, when an electric field is applied with a hole mobility of, for example, 10 ⁴ to 10 ⁶ V / cm, At least 10 ⁻⁴ cm ² / V · sec is preferable.

Specific examples of the material for the hole injection / transport layer include triazole derivatives (see US Pat. No. 3,112,197) and oxadiazole derivatives (US Pat. No. 3,189,447). ), Imidazole derivatives (see Japanese Patent Publication No. 37-16096, etc.), polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989, 3, No. 542,544, JP-B-45-555, JP-A-51-10983, JP-A-51-93224, JP-A-55-17105, JP-A-56-4148, JP-A-55-108667. Gazette, 55-156953 gazette, 56-36656 gazette, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. No. 3,180,729, 4,278,746, JP-A-55-88064, 55-88065, 49-105537, 55-51086, 56-80051, 56 -88141, 57-45545, 54-11126, 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404, JP-B 51-10105) No. 46-3712, No. 47-25336, No. 54-1119925, etc.), arylamine derivatives (US Pat. No. 3,567,450, No. 3,240,597) No. 3,658,520, No. 4,232,103, No. 4,175,961, No. 4,012, No. 76, JP-B-49-35702, JP-A-39-27577, JP-A-55-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,110, 518), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501 etc.), oxazole derivatives (disclosed in US Pat. No. 3,257,203 etc.), styryl Anthracene derivatives (see JP-A-56-46234, etc.), fluorenone derivatives (see JP-A-54-110837, etc.), hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54- 59143, 55-52063, 55-52064, 55-46760, 57-11350, 57-148749, JP-A-2-311591, etc.), stilbene derivatives (JP-A 61-210363, 61-228451, 61-14642, 61-72255, 62-47646, 62-36674, 62-10652, 62-30255, 60-93455, 60-94462, 60-174749, 60-175052, etc.), silazane derivatives (US Pat. No. 4,950,950), polysilanes (JP-A-2-204996), aniline copolymers (JP-A-2-282263) And the like.
In addition, inorganic compounds such as p-type Si and p-type SiC can also be used as the hole injection material.

As the material of the hole injection / transport layer, a cross-linkable material can be used. As the cross-linkable hole injection / transport layer, for example, Chem. Mater. 2008, 20, 413-422, Chem. Mater. 2011, 23 (3), 658-681, International Publication No. 2008/108430, International Publication No. 2009/102027, International Publication No. 2009/123269, International Publication No. 2010/016555, International Publication No. 2010/018813. And a layer obtained by insolubilizing a cross-linking material such as heat or light.

[Electron injection layer and electron transport layer]
The electron injection / transport layer is a layer that assists the injection of electrons into the light emitting layer and transports it to the light emitting region, and has a high electron mobility.
In the organic EL element, since emitted light is reflected by an electrode (for example, a cathode), it is known that light emitted directly from the anode interferes with light emitted via reflection by the electrode. In order to efficiently use this interference effect, the electron injecting / transporting layer is appropriately selected with a film thickness of several nm to several μm. However, particularly when the film thickness is large, in order to avoid a voltage increase, 10 ⁴ to 10 ^6. The electron mobility is preferably at least 10 ⁻⁵ cm ² / Vs or more when an electric field of V / cm is applied.

As the electron transporting material used for the electron injection / transport layer, an aromatic heterocyclic compound containing one or more heteroatoms in the molecule is preferably used, and a nitrogen-containing ring derivative is particularly preferable. The nitrogen-containing ring derivative is preferably an aromatic ring having a nitrogen-containing 6-membered ring or 5-membered ring skeleton, or a condensed aromatic ring compound having a nitrogen-containing 6-membered ring or 5-membered ring skeleton, such as a pyridine ring. , Pyrimidine ring, triazine ring, benzimidazole ring, phenanthroline ring, quinazoline ring and the like.

In addition, an organic layer having semiconductivity may be formed by doping (n) with a donor material and doping (p) with an acceptor material. A typical example of N doping is to dope an electron transporting material with a metal such as Li or Cs, and a typical example of P doping is F4TCNQ (2,3,5,6-tetrafluoro) to a hole transporting material. -7,7,8,8-tetracyanoquinodimethane) or the like (see, for example, Japanese Patent No. 3695714).

For the formation of each layer of the organic EL device of the present invention, a known method such as a dry film forming method such as vacuum deposition, sputtering, plasma, or ion plating, or a wet film forming method such as spin coating, dipping, or flow coating is applied. be able to.
The thickness of each layer is not particularly limited, but must be set to an appropriate thickness. If the film thickness is too thick, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. If the film thickness is too thin, pinholes and the like are generated, and sufficient light emission luminance cannot be obtained even when an electric field is applied. The normal film thickness is suitably in the range of 5 nm to 10 μm, but more preferably in the range of 10 nm to 0.2 μm.

Next, the present invention will be described in further detail using synthesis examples and examples. However, the present invention is not limited to the following synthesis examples and examples.

In addition, the evaluation method of a compound is as follows.
(1) Triplet energy (E ^T )
The measurement was performed using a commercially available apparatus F-4500 (manufactured by Hitachi). The conversion formula of triplet energy (E ^T ) is as follows.
E ^T (eV) = 1239.85 / λ _ph
In the formula, “λ _ph ” (unit: nm) draws a tangent line to the rising edge of the phosphorescence spectrum on the short wavelength side when the phosphorescence spectrum is represented with the phosphorescence intensity on the vertical axis and the wavelength on the horizontal axis. , The wavelength value of the intersection of the tangent and the horizontal axis.

Each compound was dissolved in an EPA solvent (diethyl ether: isopentane: ethanol = 5: 5: 5 (volume ratio), each solvent was a spectroscopic grade) (sample 10 μmol / liter) to prepare a sample for phosphorescence measurement. The phosphorescence measurement sample placed in the quartz cell was cooled to 77 (K), and the phosphorescence measurement sample was irradiated with excitation light, and the phosphorescence intensity was measured while changing the wavelength. In the phosphorescence spectrum, the vertical axis represents phosphorescence intensity and the horizontal axis represents wavelength.
A tangent line was drawn with respect to the rising edge of the phosphorescence spectrum on the short wavelength side, and the wavelength value λ _ph (nm) at the intersection of the tangent line and the horizontal axis was obtained.

The tangent to the rising edge on the short wavelength side of the phosphorescence spectrum is drawn as follows. When moving on the spectrum curve from the short wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side among the maximum values of the spectrum, tangents at each point on the curve are considered toward the long wavelength side. The slope of this tangent increases as the curve rises (that is, as the vertical axis increases). The tangent drawn at the point where the slope value takes the maximum value is taken as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side.
In addition, the maximum point having a peak intensity of 10% or less of the maximum peak intensity of the spectrum is not included in the above-mentioned maximum value on the shortest wavelength side, and has the maximum slope value closest to the maximum value on the shortest wavelength side. The tangent drawn at the point where the value is taken is taken as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side.

(2) Glass transition point (° C)
The glass transition point is about 3 mg of sample, DSC8500 manufactured by Perkin Elmer is used, and the following two steps of (i) to (vi) are performed for the temperature rising and falling processes, and the DSC curve at the time of temperature increase in (vi) This is defined by the rising temperature of the inflection point where the baseline of the curve changes stepwise.

(I) Hold at 30 ° C. for 1 minute.
(Ii) Heat from 30 ° C. to a constant temperature below the thermal decomposition temperature of the sample at a heating rate of 10 ° C./min.
(Iii) Hold at the constant temperature for 3 minutes.
(Iv) Cool from the constant temperature to 0 ° C. at 200 ° C./min.
(V) Hold at 0 ° C. for 10 minutes.
(Vi) Heat from 0 ° C. to 200 ° C. at a heating rate of 10 ° C./min.

Moreover, the evaluation method of an organic EL element is as follows.
(1) External quantum efficiency (%)
The external quantum efficiency at a luminance of 1000 cd / m ² under a dry nitrogen gas atmosphere at 23 ° C. was measured using a luminance meter (Spectral Luminance Radiometer CS-1000 manufactured by Minolta).

(2) Half life (hours)
A continuous energization test (DC) was performed at an initial luminance of 1000 cd / m ² and the time until the initial luminance was reduced by half was measured.

(3) Voltage (V)
Using a KEITLY 236 SOURCE MEASURE UNIT under a dry nitrogen gas atmosphere at 23 ° C., voltage was applied to the electrically wired element to emit light, and the voltage applied to the wiring resistance other than the element was subtracted to measure the element applied voltage. .
At the same time as the voltage application / measurement, the luminance was also measured using a luminance meter (Spectral Luminance Radiometer CS-1000 manufactured by Minolta Co., Ltd.), and the voltage when the element luminance was 1000 cd / m ² was read from these measurement results.

Synthesis Example 1 [Synthesis of Compound (1)]
(1) Synthesis of intermediate (1-1)

In a three-neck flask, 4-bromo-2-chloro-1-fluorobenzene (75.4 g, 360 mmol), carbazole (72.23 g, 432 mmol), K ₃ PO ₄ (152.83 g, 720 mmol), CuI (13.71 g, 72 mmol), trans-1,2-cyclohexanediamine (DACyHx) (26.0 ml, 216 mmol) and 1,4-dioxane (360 ml) were added and refluxed for 24 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated and then concentrated through a silica gel short column. The resulting crude product was purified by silica gel column chromatography (developing solvent hexane: toluene = 1: 1) to obtain an intermediate (1-1). The compound was identified by FD-MS (field desorption mass spectrometry) and ¹ H-NMR (proton nuclear magnetic resonance method). The yield was 73.9 g, and the yield was 69%.

(2) Synthesis of intermediate (1-2)

In a three-necked flask, intermediate (1-1) (70.98 g, 240 mmol), 4-hydroxycarbazole (48.37 g, 264 mmol), K ₂ CO ₃ (66.34 g, 480 mmol), N-methylpyrrolidone (NMP) ( 120 ml) and stirred at 160 ° C. for 9 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature, and then toluene (1 L) was added, followed by filtration using celite. The filtrate was transferred to a separatory funnel and washed several times with water. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated, and the resulting crude product was purified by silica gel column chromatography (developing solvent hexane: dichloromethane = 1: 1), then recrystallized from hexane to give an intermediate (1 -2) was obtained. The compound was identified by FD-MS and ¹ H-NMR. The yield was 47.5 g, and the yield was 43%.

(3) Synthesis of intermediate (1-3)

A three-necked flask equipped with a Dean-Stark trap was charged with intermediate (1-2) (47.3 g, 103 mmol), K ₂ CO ₃ (28.47 g, 206 mmol), Pd (OAc) ₂ ( 2.31 g, 10.3 mmol), 20 wt% toluene solution (29 ml) of tricyclohexylphosphine (P (Cy) ₃ ), N, N-dimethylacetamide (DMAc) (206 ml), toluene (103 ml), nitrogen atmosphere Under reflux using a Dean Stark trap, the mixture was refluxed for 8 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and then toluene (1 L) was added, followed by filtration using celite. The filtrate was transferred to a separatory funnel and washed several times with water. The organic layer was dried over anhydrous magnesium sulfate and filtered, and then the origin impurity component was removed through a silica gel short column. After concentration, recrystallization from toluene twice gave intermediate (1-3). The compound was identified by FD-MS and ¹ H-NMR. The yield was 25.95 g, and the yield was 60%.

(4) Synthesis of compound (1)

A three-necked flask was charged with intermediate (1-3) (3.38 g, 8 mmol), iodobenzene (1.80 g, 8.8 mmol), tert-butoxy sodium (tert-BuONa) (1.53 g, 16 mmol), Benzylideneacetone) dipalladium (0) (Pd ₂ (dba) ₃ ) (147 mg, 0.16 mmol), tri-tert-butylphosphine (P (t-Bu) ₃ ) (0.64 mmol), toluene (40 ml) And refluxed for 8 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated and then concentrated through a silica gel short column. The resulting crude product was purified by silica gel column chromatography (developing solvent hexane: toluene = 6: 4) to obtain compound (1). The compound was identified by FD-MS and ¹ H-NMR. The yield was 3.79 g, and the yield was 95%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.26-7.34 (m, 2H), 7.36-7.72 (m, 14H), 7.95 (t, 2H), 8.14 (d, 1H), 8.19 (d, 2H), 8.59 (d, 1H)
FD-MS measurement data Theoretical value: 498 Actual value: 498

Synthesis Example 2 [Synthesis of Compound (36)]

Compound (36) was synthesized in the same manner as in Synthesis Example 1 (4) except that 9- (3-bromophenyl) carbazole was used in place of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 5.26 g, and the yield was 99%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.24-7.34 (m, 4H), 7.36-7.67 (m, 13H), 7.73-7.82 (m , 2H), 7.86-8.00 (m, 4H), 8.10-8.22 (m, 5H), 8.60 (d, 1H)
FD-MS measurement data Theoretical value: 663 Actual value: 663

Synthesis Example 3 [Synthesis of Compound (39)]

Compound (39) was synthesized in the same manner as in Synthesis Example 1 (4) except that 2-bromodibenzofuran was used in place of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 4.61 g and the yield was 98%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.25-7.34 (m, 2H), 7.36-7.73 (m, 13H), 7.83 (d, 1H), 7.91-8.03 (m, 3H), 8.12-8.23 (m, 4H), 8.62 (d, 1H)
FD-MS measurement data Theoretical value: 588 Actual value: 588

Synthesis Example 4 [Synthesis of Compound (45)]

Compound (45) was synthesized in the same manner as in Synthesis Example 1 (4) except that 3-bromo-9-phenylcarbazole was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 5.10 g, and the yield was 96%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.25-7.34 (m, 3H), 7.36-7.72 (m, 18H), 7.88-8.00 (m , 2H), 8.10-8.15 (m, 2H), 8.18 (d, 2H), 8.36 (d, 1H), 8.62 (d, 1H)
FD-MS measurement data Theoretical value: 663 Actual value: 663

Synthesis Example 5 [Synthesis of Compound (86)]
(1) Synthesis of intermediate (5-1)

A three-necked flask was charged with 4-bromo-2-chloro-1-fluorobenzene (144.9 g, 692 mmol), 4-hydroxycarbazole (126.7 g, 692 mmol), K ₂ CO ₃ (191.3 g, 1.38 mol), NMP. (138 ml) was added and stirred at 160 ° C. for 36 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature, then dichloromethane (1 L) was added, and the mixture was filtered through celite. The filtrate was transferred to a separatory funnel and washed several times with brine. The organic layer was dried over anhydrous magnesium sulfate, filtered, passed through a silica gel short column and concentrated. This was recrystallized from toluene to obtain an intermediate (5-1). The compound was identified by FD-MS and ¹ H-NMR. The yield was 116 g, and the yield was 45%.

(2) Synthesis of intermediate (5-2)

A three-necked flask was charged with intermediate (5-1) (37.26 g, 100 mmol), 3- (9-carbazolyl) phenylboronic acid (110 g, 31.58 mmol), 2M aqueous solution of Na ₂ CO ₃ (100 ml), tetrakis (tri Phenylphosphine) palladium (0) (Pd (PPh ₃ ) ₄ ) (2.31 g, 2 mmol) and 1,2-dimethoxyethane (DME) (200 ml) were added, and the mixture was refluxed for 10 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature, 200 ml of toluene was added, and the mixture was filtered using celite. The filtrate was transferred to a separatory funnel and washed twice with water. The organic layer was dried over anhydrous magnesium sulfate, filtered, passed through a silica gel short column, and concentrated. This was recrystallized from a toluene: hexane mixed solvent to obtain an intermediate (5-2). The compound was identified by FD-MS and ¹ H-NMR. The yield was 39.8 g and the yield was 74%.

(3) Synthesis of intermediate (5-3)

Intermediate (5-3) was synthesized in the same manner as Synthesis Example 1 (3), except that intermediate (5-2) was used instead of intermediate (1-2). The compound was identified by FD-MS and ¹ H-NMR. The yield was 21.71 g, and the yield was 59%.

(4) Synthesis of compound (86)

Compound (86) was synthesized in the same manner as in Synthesis Example 1 (4) except that Intermediate (5-3) was used instead of Intermediate (1-3). The compound was identified by FD-MS and ¹ H-NMR. The yield was 5.51 g and the yield was 96%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.29 (t, 2H), 7.34-7.68 (m, 14H), 7.69-7.76 (m, 2H), 7.77-7.86 (m, 2H), 7.92-7.97 (m, 2H), 8.17 (d, 2H), 8.23 (d, 1H), 8.52 (d, 1H)
FD-MS measurement data Theoretical value: 574 Actual value: 574

Synthesis Example 6 [Synthesis of Compound (121)]

Synthetic Example 5 [compound (86) except that 2- (9-carbazolyl) dibenzofuran-8-boronic acid was used in place of 3- (9-carbazolyl) phenylboronic acid used as a starting material for intermediate (5-2). Compound (121) was synthesized in the same manner as in the above. The compound was identified by FD-MS and ¹ H-NMR. The yield was 4.08 g and the yield was 85%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.27-7.34 (m, 2H), 7.37-7.57 (m, 9H), 7.59-7.69 (m 5H), 7.73-7.78 (m, 2H), 7.79-7.83 (m, 2H), 7.90 (dd, 1H), 8.00 (d, 1H), 8. 15-8.32 (m, 5H), 8.53 (d, 1H)
FD-MS measurement data Theoretical value: 664 Actual value: 664

Synthesis Example 7 [Synthesis of Compound (139)]
(1) Synthesis of intermediate (6-1)

Intermediate (6-1) was synthesized in the same manner as in Synthesis Example 5 (2) except that 9-phenylcarbazole-3-boronic acid was used in place of 3- (9-carbazolyl) phenylboronic acid as a raw material.
(2) Synthesis of intermediate (6-2)

Intermediate (6-2) was synthesized in the same manner as Synthesis Example 1 (3) Intermediate (1-3) except that Intermediate (6-1) was used instead of Intermediate (1-2).
(3) Synthesis of compound (139)

Compound (139) was synthesized in the same manner as in Synthesis Example 1 (4), except that Intermediate (6-2) was used instead of Intermediate (1-3). The compound was identified by FD-MS and ¹ H-NMR. The yield was 4.10 g, and the yield was 76%.

¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.28-7.37 (m, 1H), 7.40-7.58 (m, 9H), 7.59-7.72 (m , 8H), 7.78-7.88 (m, 3H), 8.07 (d, 1H), 8.25 (d, 1H), 8.33 (t, 1H), 8.50 (t, 1H), 8.58 (d, 1H)
FD-MS measurement data Theoretical value: 574 Actual value: 574

Synthesis Example 8 [Synthesis of Compound (48)]

Compound (48) was synthesized in the same manner as in Synthesis Example 1 (4) except that 2-bromo-8- (9-carbazolyl) dibenzofuran was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 1.36 g, and the yield was 65%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.24-7.34 (m, 4H), 7.36-7.55 (m, 12H), 7.60 (dd, 1H), 7.72 (dd, 1H), 7.77 (dd, 1H), 7.87-7.98 (m, 4H), 8.10-8.23 (m, 7H), 8.60 (d, 1H)
FD-MS measurement data Theoretical value: 753 Actual value: 753

Synthesis Example 9 [Synthesis of Compound (76)]

In a three-necked flask, intermediate (1-3) (2.11 g, 5 mmol), 3-bromo-5- (9-carbazolyl) pyridine (1.78 g, 5.5 mmol), K ₃ PO ₄ (2.12 g, 10 mmol) ), CuI (95 mg, 0.5 mmol), trans-1,2-cyclohexanediamine (DACyHx) (0.18 ml, 1.5 mmol), 1,4-dioxane (5 ml), and refluxed for 24 hours under a nitrogen atmosphere I let you. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated and then concentrated through a silica gel short column. The obtained crude product was recrystallized from ethyl acetate to obtain the desired product. The compound was identified by FD-MS and ¹ H-NMR. The yield was 1.72 g and the yield was 52%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.26-7.66 (m, 17H), 7.95-8.05 (m, 2H), 8.13-8.22 (m , 5H), 8.29 (t, 1H), 8.63 (d, 1H), 9.07 (t, 2H)
FD-MS measurement data Theoretical value: 664 Actual value: 664

Synthesis Example 10 [Synthesis of Compound (41)]

Compound (41) was synthesized in the same manner as in Synthesis Example 1 (4) except that 2- (3-bromophenyl) dibenzofuran was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 0.65 g, and the yield was 35%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.25-7.67 (m, 16H), 7.73-7.82 (m, 2H), 7.83-7.90 (m , 1H), 7.92-8.04 (m, 4H), 8.13-8.21 (m, 3H), 8.27 (d, 1H), 8.62 (d, 1H)
FD-MS measurement data Theoretical value: 664 Actual value: 664

Synthesis Example 11 [Synthesis of Compound (49)]

Compound (49) was synthesized in the same manner as in Synthesis Example 1 (4) except that 2- (2-bromodibenzofuran-8-yl) dibenzofuran was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 1.82 g, and the yield was 70%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.25-7.68 (m, 15H), 7.70-7.80 (m, 3H), 7.84-7.91 (m , 2H), 7.93-8.05 (m, 3H), 8.13-8.21 (m, 3H), 8.23-8.32 (m, 3H), 8.62 (d, 1H) )
FD-MS measurement data Theoretical value: 754 Actual value: 754

Synthesis Example 12 [Synthesis of Compound (87)]

Compound (87) was synthesized in the same manner as in Synthesis Example 1 (4) except that Intermediate (5-3) was used instead of Intermediate (1-3) and 2-bromodibenzofuran was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 2.50 g, and the yield was 83%.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 7.28-7.57 (13H, m), 7.62-7.72 (4H, m), 7.78-7.82 (3H, m ), 7.92-7.94 (3H, m), 8.14-8.20 (4H, m), 8.58-8.60 (1H, m)
FD-MS measurement data Theoretical value: Measured value:

Synthesis Example 13 [Synthesis of Compound (141)]

Compound (141) was synthesized in the same manner as in Synthesis Example 1 (4) except that 2-bromodibenzofuran was used instead of iodobenzene. The compound was identified by FD-MS and ¹ H-NMR. The yield was 2.22 g and the yield was 79%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.28-7.36 (m, 1H), 7.37-7.58 (m, 10H), 7.60-7.73 (m 6H), 7.77-7.88 (m, 4H), 8.00 (d, 1H), 8.07 (d, 1H), 8.19-8.27 (m, 2H), 8. 33 (d, 1H), 8.50 (d, 1H), 8.59 (d, 1H)
FD-MS measurement data Theoretical value: 664 Actual value: 664

Synthesis Example 14 [Synthesis of Compound (163)]
(1) Synthesis of intermediate (7-1)

In a three-necked flask, intermediate (5-1) (136.0 g, 365 mmol), iodobenzene (148.9 g, 730 mmol), K ₃ PO ₄ (116.2 g, 547.5 mmol), CuI (3.48 g, 18. 25 mmol), trans-1,2-cyclohexanediamine (6.6 ml, 54.8 mmol) and 1,4-dioxane (365 ml) were added, and the mixture was refluxed for 24 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated and then concentrated through a silica gel short column. The resulting crude product was purified by silica gel column chromatography (developing solvent hexane: toluene = 9: 1) to obtain an intermediate (7-1). The compound was identified by FD-MS and ¹ H-NMR. The yield was 127.7 g, and the yield was 78%.

(2) Synthesis of intermediate (7-2)

Intermediate (7-1) (4.49 g, 10 mmol), 3- (9-phenylcarbazol-3-yl) carbazole (4.49 g, 11 mmol), K ₃ PO ₄ (4.25 g, 20 mmol) was added to a three-necked flask. , CuI (0.95 g, 5 mmol), trans-1,2-cyclohexanediamine (1.8 ml, 15 mmol) and 1,4-dioxane (20 ml) were added and refluxed for 24 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated and then concentrated through a silica gel short column. The obtained crude product was purified by silica gel column chromatography (developing solvent hexane: toluene = 7: 3) to obtain an intermediate (7-2). The compound was identified by FD-MS and ¹ H-NMR. The yield was 7.5 g, and the yield was 97%.

(3) Synthesis of compound (163)

Compound (163) was synthesized in the same manner as in Synthesis Example 1 (3) except that Intermediate (7-2) was used instead of Intermediate (1-2). The compound was identified by FD-MS and ¹ H-NMR. The yield was 1.05 g and the yield was 45%.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 7.31-7.55 (m, 13H), 7.61-7.81 (m, 10H), 7.80 (dt, 2H), 7. 94 (dd, 2H), 8.16 (d, 1H), 8.26 (dd, 2H), 8.49 (dd, 2H), 8.64 (dt, 1H)
FD-MS measurement data Theoretical value: 739 Actual value: 739

Synthesis Example 15 [Synthesis of Compound (501)]
(1) Synthesis of intermediate (8-1)

Intermediate (8-1) was prepared in the same manner as in Synthesis Example 14 (2) except that 5H-benzofuro [3,2-c] carbazole was used instead of 3- (9-phenylcarbazol-3-yl) carbazole. Synthesized.

(2) Synthesis of compound (501)

Compound (501) was synthesized in the same manner as in Synthesis Example 1 (3) except that Intermediate (8-1) was used instead of Intermediate (1-2). The compound was identified by FD-MS and ¹ H-NMR. The yield was 2.16 g, and the yield was 62%.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.35-7.57 (m, 11H), 7.58-7.70 (m, 5H), 7.77 (d, 1H), 7.78-8.02 (m, 4H), 8.18 (d, 1H), 8.53-8.62 (m, 2H)
FD-MS measurement data Theoretical value: 588 Actual value: 588

Example 1
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum deposition apparatus, and the compound (HI1) is first thickened so as to cover the ITO electrode line on the surface on which the ITO electrode line is formed. The compound (HT1) was deposited by resistance heating at a thickness of 60 nm at a thickness of 20 nm, and thin films were sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a hole transport layer, respectively.

Next, on the hole transport layer, the compound (1) and the compound (BD1) were simultaneously deposited by resistance heating to form a thin film having a thickness of 50 nm. At this time, the compound (BD1) was deposited so as to have a mass ratio of 20% with respect to the total mass of the compound (A1) and the compound (BD1). The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, in which the compound (1) functions as a host and the compound (BD1) functions as a light emitting dopant. Table 1 shows triplet energy (eV) and glass transition point (° C.) of the compound (BD1).
Next, a compound (B1) was deposited by resistance heating vapor deposition on this phosphorescent light emitting layer to form a thin film having a thickness of 10 nm (hole blocking layer). The film formation rate was 1.2 liter / s.

Next, a thin film having a thickness of 10 nm was formed on the hole barrier layer by resistance heating evaporation of the compound (ET1). The film formation rate was 1 Å / s. This film functions as an electron injection layer.
Next, LiF having a film thickness of 1.0 nm was deposited on the electron injection layer at a film formation rate of 0.1 Å / s.
Next, metallic aluminum was vapor-deposited on the LiF film at a deposition rate of 8.0 Å / s to form a metal cathode with a film thickness of 80 nm to obtain an organic EL element.
Moreover, the voltage and half-life were calculated | required by said method. The results are shown in Table 2.

Examples 2 to 14 and Comparative Examples 1 to 2
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that the compound shown in Table 1 was used as the host of the phosphorescent light emitting layer instead of the compound (1). Table 1 shows the triplet energy and glass transition point of the compound used, and Table 2 shows the results. The “half life (relative%)” is a relative ratio when the half life of the element of Comparative Example 1 is 100%.

From Table 2, it can be seen that when the compound of the present invention is used as a host of the phosphorescent light emitting layer, an organic EL device having a long life and being driven at a lower voltage than the compound of the comparative example can be provided.

Example 15
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum deposition apparatus, and the compound (HI1) is first thickened so as to cover the ITO electrode line on the surface on which the ITO electrode line is formed. At 20 nm, the compound (HT1) was then vapor deposited by resistance heating at a thickness of 50 nm, and thin films were sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a hole transport layer, respectively.
Next, the compound (39) was deposited by resistance heating vapor deposition on the hole transport layer to form a thin film (electronic barrier layer) having a thickness of 10 nm. The film formation rate was 1 Å / s.

Next, on this electron barrier layer, the compound (B1) and the compound (BD1) were simultaneously deposited by resistance heating to form a thin film having a thickness of 50 nm. At this time, the compound (BD1) was deposited so as to have a mass ratio of 20% with respect to the total mass of the compound (B1) and the compound (BD1). The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, and in this thin film, the compound (B1) functions as a host and the compound (BD1) functions as a light emitting dopant.
Next, a compound (B1) was deposited by resistance heating vapor deposition on this phosphorescent light emitting layer to form a thin film having a thickness of 10 nm (hole blocking layer). The film formation rate was 1.2 liter / s.

Next, a thin film having a thickness of 10 nm was formed on the hole barrier layer by resistance heating evaporation of the compound (ET1). The film formation rate was 1 Å / s. This film functions as an electron injection layer.
Next, LiF having a film thickness of 1.0 nm was deposited on the electron injection layer at a film formation rate of 0.1 Å / s.
Next, metallic aluminum was vapor-deposited on the LiF film at a deposition rate of 8.0 Å / s to form a metal cathode with a film thickness of 80 nm to obtain an organic EL element.
Further, the voltage, external quantum efficiency, and half life were determined by the above methods. The results are shown in Table 3.

Examples 16 to 18 and Comparative Examples 3 to 4
An organic EL device was prepared and evaluated in the same manner as in Example 15 except that the compound shown in Table 3 was used as the electron barrier layer instead of the compound (39). The results are shown in Table 3.

From Table 3, it can be seen that when the compound of the present invention is used as an electron barrier layer, it is possible to provide an organic EL device which has a longer life than the compound of the comparative example and can be driven at a low voltage and high efficiency.

Example 19
Organic EL in the same manner as in Example 1 except that compound (B1) was used instead of compound (1) as the host of the phosphorescent layer, and compound (1) was used instead of compound (B1) as the hole barrier layer. A device was fabricated and evaluated. The results are shown in Table 4.
Examples 20 to 27 and Comparative Example 5
An organic EL device was prepared and evaluated in the same manner as in Example 11 except that the compounds listed in Table 4 were used as the hole blocking layer instead of the compound (1). The results are shown in Tables 4 and 5.

Table 4 shows that when the compound of the present invention is used as a hole blocking layer, an organic EL device having a longer life than the compound of the comparative example can be provided.

Table 5 shows that when the compound of the present invention is used as a hole blocking layer, an organic EL device having a lower voltage and higher efficiency than the compound of the comparative example can be provided.

The compound of the present invention can be used as a material for an organic EL device. When the organic EL element material of the present invention is used, an organic EL element having a long life and low power consumption for low voltage driving can be obtained. The organic EL element of the present invention is extremely useful as a display, a light source and the like for various electronic devices.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
The contents of the documents described in this specification and the specification of the Japanese application that is the basis of Paris priority of the present application are all incorporated herein.

DESCRIPTION OF SYMBOLS 1, 2 Organic EL element 10 Substrate 20 Anode 30 Hole transport zone 40 Phosphorescence layer 42 Space layer 44 Fluorescence layer 50 Electron transport zone 60 Cathode

Claims (10)

The material for organic electroluminescent elements represented by following formula (1).

(In the formula (1), n is an integer of 1 to 4.
X is an oxygen (O) atom or a sulfur (S) atom. When n is 2 or more, the plurality of X may be the same or different.
L ₁ and L ₂ are each a single bond, an arylene group having 6 to 18 ring carbon atoms which may have a substituent R, or an arylene group having 5 to 18 ring atoms which may have a substituent R. When it is a heteroarylene group and n is 2 or more, the plurality of L ₁ and the plurality of L ₂ may be the same or different.
L ₃ has an n + q valent saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent R, an n + q valent silicon-containing group which may have a substituent R, and a substituent R. And an n + q valent aromatic hydrocarbon group having 6 to 18 ring carbon atoms, or an n + q valent unsaturated heterocyclic group having 5 to 18 ring atoms which may have a substituent R.
R ¹¹ and R ¹² are each an alkyl group having 1 to 20 carbon atoms that may have a substituent R, a cycloalkyl group having 3 to 18 ring carbon atoms that may have a substituent R, and a substituent. An alkoxy group having 1 to 20 carbon atoms which may have R, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a ring forming carbon number which may have a substituent R 6-18 aryloxy group, silyl group optionally having substituent R, fluoro group, cyano group, aryl group having 6-18 ring forming carbon atoms optionally having substituent R, or substituent R A heteroaryl group having 5 to 18 ring atoms that may have a ring structure, and when there are a plurality of R ^{11 s} , they may be the same or different, and when there are a plurality of R ^{12 s} , they may be the same or different from each other. May be.
p is an integer of 0 to 3, and when n is 2 or more, the plurality of p may be the same or different.
q is an integer of 0 to 3.
The substituent R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 18 ring carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms, or a ring forming carbon. An aryloxy group having 6 to 18 atoms, a silyl group, a fluoro group, a cyano group, an aryl group having 6 to 18 ring carbon atoms, or a heteroaryl group having 5 to 18 ring atoms, and when there are a plurality of R These may be the same or different.
Cz is represented by the following formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5- 2) one group selected from the group consisting of (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2) , N is 2 or more, the plurality of Cz may be the same or different.

(Formulas (2-1), (2-2), (3-1), (3-2), (4-1), (4-2), (5-1), (5-2), In (6-1), (6-2), (7-1), (7-2), (8-1), and (8-2), * represents a bonding position with L ₁ .
Y is an oxygen (O) atom or a sulfur (S) atom, and when n is 2 or more, the plurality of Y may be the same or different,
m ¹ and m ² are each independently an integer of 0 to 4,
m ³ is an integer from 0 to 3,
m ⁴ is an integer from 0 to 2,
m ⁵ is an integer from 0 to 4,
R ⁰ , R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 20 carbon atoms which may have a substituent R, or a ring having 3 to 3 carbon atoms which may have a substituent R. An cycloalkyl group having 18 carbon atoms which may have a substituent R, an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 ring carbon atoms which may have a substituent R, and a substituent R; An aryloxy group having 6 to 18 ring carbon atoms, a silyl group optionally having substituent R, a fluoro group, a cyano group, and 6 to 18 ring carbon atoms optionally having substituent R Or a heteroaryl group having 5 to 18 ring atoms that may have a substituent R, and when a plurality of R ⁰ are present, they may be the same or different, and a plurality of R ¹ are present. If you, or different and each identical, if R ² there are a plurality, Re may be the same or different, respectively, when the R ³ there are a plurality may each be the same or different. )) The material for organic electroluminescent elements according to claim 1 represented by the following formula (3).

(In the formula (3), n, X, L ¹ , L ² , L ³ , R ¹¹ , R ¹² , p, q and Cz are the same as those in the formula (1).) 3. The material for an organic electroluminescence element according to claim 1, wherein the Cz is a group represented by the formula (2-1). 3. The material for an organic electroluminescent element according to claim 1, wherein the Cz is a group represented by the formula (2-2). 5. The material for an organic electroluminescent element according to claim 1, wherein n is 1 or 2. 6. The organic electroluminescent element material according to claim 1, wherein the organic electroluminescent element material according to claim 1 has at least one organic thin film layer including a light emitting layer between a cathode and an anode. An organic electroluminescence element to be contained. The organic electroluminescent element according to claim 6, wherein the light emitting layer contains the material for an organic electroluminescent element. The organic electroluminescence device according to claim 6, wherein the organic electroluminescence device has a hole transport zone between the anode and the light emitting layer, and the hole transport zone contains the material for the organic electroluminescence device. The organic electroluminescence device according to claim 6, wherein the organic electroluminescence device has an electron transport zone between the cathode and the light emitting layer, and the electron transport zone contains the material for the organic electroluminescence device. The light-emitting layer contains a phosphorescent material, and the phosphorescent material is an orthometalated complex of a metal atom selected from iridium (Ir), osmium (Os), and platinum (Pt). The organic electroluminescent element in any one.

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