JP7359545B2 - Compound, composition containing the same, and organic electroluminescent device containing the composition - Google Patents

Description

The present invention relates to a compound, a composition containing the same, and an organic electroluminescent device containing the composition.

It is generally known that forming a stacked structure such as a hole transport layer/light emitting layer is important for producing a high performance organic electroluminescent device. However, it is not easy to form such a laminated structure using a wet method. In order to stack the light emitting layer on the hole transport layer, it is necessary that the hole transport layer film is insoluble in the light emitting layer solution. In the prior art, a method is used in which a crosslinkable compound is used in the hole transport layer and made insolubilized by post-treatment such as heating. However, when a crosslinking compound is used, impurities and structural defects are often generated as a result of the crosslinking reaction. This has led to problems such as a decrease in efficiency and a deterioration in the life of the element. For this reason, it is expected that a hole-transporting compound that achieves stacking properties without using a crosslinking reaction will be realized.

Examples of hole-transporting compounds that do not use such a crosslinking reaction include compounds described in Patent Documents 1 and 2.

Japanese Patent Application Publication No. 2000-186066 US Patent Application Publication No. 2006/0232198

However, when a hole transporting layer is formed by a wet method, the performance (eg, efficiency, lifespan) is not sufficient.

Therefore, an object of the present invention is to provide an organic electroluminescent device that has sufficient performance (for example, efficiency and life) even when a hole transporting layer is formed by a wet method.

The present invention is characterized by a compound represented by general formula (1).

According to the present invention, it is possible to provide an organic electroluminescent device with sufficient performance (for example, efficiency and life) even when a hole transporting layer is formed by a wet method.

FIG. 1 is a conceptual diagram showing the state of the compound of the present invention in a state in which it is dissolved in a solution (A) and in a film state after film formation (B). FIG. 1(C) is a conceptual diagram showing energy coordinates in each state. FIG. 2 is a schematic diagram showing an organic electroluminescent device according to a fourth embodiment.

Embodiments of the present invention will be described below with reference to the attached drawings. In addition, in the description of the drawings, the same elements are given the same reference numerals, and redundant description will be omitted. Furthermore, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

A first embodiment of the present invention is a compound represented by the following formula (1) (hereinafter also referred to as the present compound).

In the above formula (1),
Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group,
l represents an integer from 0 to 2,
G ₁ represents a linking group containing N (nitrogen atom), Si (silicon atom), a substituted or unsubstituted divalent aromatic hydrocarbon group, or a substituted or unsubstituted divalent aromatic heterocyclic group; ,
L ₁ is represented by the following formula (2),

In the above formula (2),
E ₁ is a group selected from the group consisting of the following formulas (3a) to (3f);

In formulas (3a) to (3f),
* represents a bond,
Y is each independently =C(R ₁ )- or =N-,
R ₁ is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon A group selected from the group consisting of a group-substituted silyl group, an alkoxy group and a halogen atom,
T is -O-, -S- or -Se-,
X is a group selected from the group consisting of -C(=O)-, -C(R ₂ )(R ₃ )-, -N(R ₄ )-, -O-, -S- and -Se- and
R ₂ and R ₃ each independently represent a hydrogen atom (including deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, A group selected from the group consisting of an aromatic heterocyclic group, a hydrocarbon group-substituted silyl group, an alkoxy group, and a halogen atom, in which R ₂ and R ₃ may be bonded to each other to form a ring, _R4 is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon A group selected from the group consisting of a group-substituted silyl group, an alkoxy group, and a halogen atom;
*1 and *2 represent bonds,
m ₁ is an integer of 2 or more, and in this case, if all E ₁ in the compound is composed only of the above formulas (3a) to (3c), at least one m ₁ is an integer of 4 or more. otherwise, it is an integer of 3 or more, in which case each _E1 may be the same or different,
_G2 includes a single bond, N (nitrogen atom), Si (silicon atom), substituted or unsubstituted divalent aromatic hydrocarbon group, or substituted or unsubstituted divalent aromatic heterocyclic group represents a linking group,
L ₂ each independently represents the above formula (2) or a single bond,
A is the following formula (4);

In formula (4),
*5 represents a bond,
Ar ₂ is a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, or a substituted or unsubstituted monovalent aromatic hydrocarbon group; A substituent in combination with a substituted monovalent aromatic heterocyclic group,
_E2 is the following formula;

Here, in the formula,
* represents a bond,
Z is each independently =C(R ₉ )- or =N-,
_R9 is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon A group selected from the group consisting of a group-substituted silyl group, an alkoxy group and a halogen atom,
Different adjacent E ₂ may form a ring via R ₉ ,
At this time, N, Ar ₂ and E ₂ may each be bonded to each other to form a ring,
a is an integer of 2 or more, in this case, each E ₂ may be the same or different,
Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, or a substituted or unsubstituted monovalent aromatic heterocyclic group; A substituent that is a combination of an aromatic hydrocarbon group and a substituted or unsubstituted monovalent aromatic heterocyclic group,
At this time, E ₂ , N, and Ar ₃ may each be bonded to each other to form a ring;
represented by, the plural A's may be the same or different, and at least one A has a total number of carbon atoms of the alkyl group contained in A of 6 or more,
n ₁ is an integer of 2 or more and 8 or less, and n ₂ is 1 or 2.

According to the present compound, an organic electroluminescent device with sufficient performance (eg, efficiency, lifespan) can be provided even when a hole transporting layer is formed by a wet method.

The mechanism by which the present invention produces such effects is estimated as follows. Note that the technical scope of the present invention is not limited in any way by the estimation mechanism described below.

Organic electroluminescent devices are currently manufactured by vapor deposition methods or wet methods. Among these methods, the vapor deposition method allows lamination of multiple layers by vapor deposition, and it is easy to optimize the energy diagram by lamination. Therefore, it is possible to improve luminous efficiency and lifetime, and to reduce driving voltage. However, on the other hand, low productivity and low yield have become major challenges. On the other hand, in manufacturing an organic electroluminescent device using a wet method, a printing process is possible, so a large area and high productivity can be expected. However, on the other hand, designing materials that can be laminated has become a major challenge.

Therefore, the present inventors conducted extensive research into designing a compound with excellent lamination properties. As a result, it has been found that the use of the compound represented by the above formula (1) significantly improves lamination properties.

FIG. 1 is a conceptual diagram showing the state of the compound of the present invention in a state in which it is dissolved in a solution (A) and in a film state after film formation (B). Note that this figure is a conceptual diagram to facilitate understanding of the invention, and the state of implementation is not limited to this.

This compound has an alkyl group as a soluble group in the molecule (for example, the alkyl group present in substituent A). Such an alkyl group prevents intermolecular access and stabilizes the state of dissolution in the ink solution used in the wet method (FIG. 1A). On the other hand, this compound has a structure in which a plurality of aromatic groups are connected as insoluble groups in the molecule (eg, connecting groups L ₁ and L ₂ ). In the film state after film formation, the agglomerated state is stabilized by rigid aromatic groups (insoluble groups). These two stable phases (the dissolved state and the film state) exist through a large activation barrier energy (Fig. 1C).

This compound has an appropriate quantitative balance and intramolecular arrangement of a rigid aromatic group that plays an insoluble role and an alkyl group that plays a soluble role in the molecule. Therefore, it has high solubility in the solvent used in the wet method. In addition, even if a hole transport layer is formed by a wet method when producing an organic electroluminescent device, it is difficult to dissolve in the solvent used when forming an upper layer (for example, forming a light emitting layer). Therefore, excellent lamination properties are achieved.

Furthermore, in the case of conventionally used polymer compounds, impurities are easily incorporated into the polymer during the polymerization reaction and crosslinking reaction process, making it difficult to identify and remove impurities. Unlike conventional polymer compounds, the present compound has a small molecular weight and is a monodisperse structural compound, so it does not involve a polymerization reaction or a crosslinking reaction during the synthesis process. Therefore, even if impurity molecules with impurities incorporated into the molecules are generated during the synthesis process, such impurity molecules can be easily identified and removed. Therefore, according to the present compound, impurities can be easily identified and the purification process and quality control are convenient.

Furthermore, this compound has an arylamine structure. Therefore, in the organic film formed using this compound, hole transport paths are efficiently formed and exhibit good hole transport properties.

As described above, the excellent stacking properties, impurity removability, and hole transport properties of this compound make it possible to achieve high performance (e.g., high efficiency and/or long life) of the resulting organic electroluminescent device. sell.

Embodiments of the present invention will be described below. Note that the present invention is not limited only to the following embodiments. Further, unless otherwise specified, operations and measurements of physical properties, etc. are performed under conditions of room temperature (20° C. or higher and 25° C. or lower)/relative humidity of 40% RH or higher and 50% RH or lower.

<Compound represented by formula (1)>
(Ar ₁ )
In the above formula (1), Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group.

In this specification, an "aromatic hydrocarbon group" is a group derived from a hydrocarbon (aromatic hydrocarbon) having a carbon ring containing one or more aromatic rings. Furthermore, when the aromatic hydrocarbon group includes two or more rings, the two or more rings may be connected or condensed with each other.

Aromatic hydrocarbons constituting the aromatic hydrocarbon group include, but are not limited to, benzene, pentalene, indene, naphthalene, anthracene, azulene, heptalene, acenaphthalene, phenalene, fluorene, anthraquinone, phenanthrene, biphenyl, and terphenyl. , quarterphenyl, quinphenyl, sexiphenyl, triphenylene, pyrene, chrysene, picene, perylene, pentaphene, pentacene, tetraphene, hexaphene, hexacene, rubicene, trinaphthylene, heptafen, pyrantrene, and the like.

The monovalent aromatic hydrocarbon group is preferably a monovalent aromatic hydrocarbon group having 6 to 24 carbon atoms, such as phenyl group, naphthyl group, biphenyl group, fluorenyl group, anthryl group, pyrenyl group. group, azulenyl group, acenaphthylenyl group, terphenyl group, phenanthryl group, etc. Among these, phenyl group, biphenyl group, and fluorenyl group are preferable, phenyl group and biphenyl group are more preferable, and biphenyl group is even more preferable.

The substituents that can be introduced into the monovalent aromatic hydrocarbon group are not particularly limited. Examples of such substituents include halogen atoms, alkyl groups, alkoxy groups, cycloalkyl groups, cycloalkoxy groups, aryloxy groups, aralkyl groups, alkylamino groups, arylamino groups, and aromatic heterocyclic groups, and Examples include combinations. In addition, in the said substituent, the said substituent and the same type of substituent are not substituted with the said substituent. For example, when the substituent is an alkyl group, the alkyl group is not further substituted with an alkyl group (the same applies hereinafter).

The halogen atom is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group is not particularly limited, but may be a linear or branched alkyl group having 1 to 24 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, Neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, 1,3-dimethylbutyl group, 1-isopropylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4- Dimethylpentyl group, 3-ethylpentyl group, 2-methyl-1-isopropylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group, 3-methyl-1-isopropylbutyl group, 2 -Methyl-1-isopropyl group, 1-tert-butyl-2-methylpropyl group, n-nonyl group, 3,5,5-trimethylhexyl group, n-decyl group, isodecyl group, n-undecyl group, 1- Methyldecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, n- Examples include heneicosyl group, n-docosyl group, n-tricosyl group, and n-tetracosyl group.

The alkoxy group is not particularly limited, but may be a linear or branched alkoxy group having 1 to 24 carbon atoms. Specifically, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group group, tridecyloxy group, tetradecyloxy group, pentadecyloxy group, hexadecyloxy group, heptadecyloxy group, octadecyloxy group, 2-ethylhexyloxy group, 3-ethylpentyloxy group and the like.

The cycloalkyl group is not particularly limited, but may be a cycloalkyl group having 3 or more and 16 or less carbon atoms. Specific examples include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

The cycloalkoxy group is not particularly limited, but may be a cycloalkoxy group having 3 or more and 16 or less carbon atoms. Specific examples include a cyclopentyloxy group and a cyclohexyloxy group.

The above aryloxy group is not particularly limited, but may be an aryloxy group having 6 or more and 30 or less carbon atoms. Specific examples include phenoxy group and naphthyloxy group.

The aralkyl group is not particularly limited, but may be an aralkyl group having 7 or more and 40 or less carbon atoms. Specific examples include benzyl group, phenethyl group, diphenylmethyl group, and the like.

The alkylamino group is not particularly limited, but may be an alkylamino group having 1 or more and 20 or less carbon atoms. Specifically, methylamino group, ethylamino group, n-propylamino group, isopropylamino group, n-butylamino group, n-hexylamino group, dimethylamino group, diethylamino group, di-n-propylamino group, etc. Can be mentioned.

The above arylamino group is not particularly limited, but may be an arylamino group having 6 or more and 30 or less carbon atoms. Specific examples include a phenylamino group, a biphenylamino group, a naphthylamino group, an anthrylamino group, and a phenanthrylamino group.

The aromatic heterocyclic group has one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S)), and the remaining ring atoms are It is a group derived from a ring (aromatic heterocycle) containing one or more aromatic rings that are carbon atoms (C). Furthermore, when the aromatic heterocyclic group includes two or more rings, the two or more rings may be fused to each other. Examples of the aromatic heterocycle constituting the aromatic heterocyclic group include, but are not limited to, pyrazole, imidazole, oxazole, thiazole, triazole, tetrazole, oxadiazole, pyridine, pyridazine, pyrimidine, triazine, carbazole, indole, and quinoline. , isoquinoline, benzimidazole, imidazopyridine, imidazopyrimidine and the like. Examples of the monovalent aromatic heterocyclic group include groups obtained by removing any one hydrogen atom from among the hydrogen atoms of the above-mentioned aromatic heterocycles.

In Ar ₁ , the substituent that may be present in the monovalent aromatic hydrocarbon group is preferably an alkyl group, more preferably a linear or branched alkyl group having 1 to 12 carbon atoms. , more preferably a linear or branched alkyl group having 1 to 8 carbon atoms, even more preferably a linear or branched alkyl group having 1 to 4 carbon atoms, Particularly preferred is a linear alkyl group of 1 or more and 4 or less. Further, in Ar ₁ , the number of substituents that can be present in the monovalent aromatic hydrocarbon group is not particularly limited, but it is preferably 1 or 2, and more preferably 1.

(l)
l represents an integer from 0 to 2. When l is 2, the plurality of Ar ₁ 's may have the same structure or different structures, but preferably have the same structure.

( _G1 )
G ₁ represents a linking group containing N (nitrogen atom), Si (silicon atom), a substituted or unsubstituted divalent aromatic hydrocarbon group, or a substituted or unsubstituted divalent aromatic heterocyclic group .

Examples of the aromatic hydrocarbon group include groups obtained by removing any hydrogen atoms from among the hydrogen atoms of the aromatic hydrocarbons described in the Ar ₁ column. Furthermore, one or more hydrogen atoms present in these aromatic hydrocarbon groups may be substituted with a substituent.

Examples of the aromatic heterocyclic group include a group obtained by removing any hydrogen atom from among the hydrogen atoms of the aromatic heterocycle described in the column of substituents for _Ar1 . Furthermore, one or more hydrogen atoms present in these aromatic heterocyclic groups may be substituted with a substituent.

The substituents that may exist in N (nitrogen atom), Si (silicon atom), aromatic hydrocarbon group, or aromatic heterocyclic group include the monovalent aromatic hydrocarbon group described in Ar ₁ above, the monovalent This is the same as a substituent (for example, an alkyl group) that can be introduced into an aromatic heterocyclic group and a monovalent aromatic hydrocarbon group.

The bond in G ₁ is n ₁ +l. Therefore, the number of bonds in _G1 is 2 or more and 8 or less, preferably 2 or more and 4 or less.

Specifically, _G1 preferably has the following structure.

Here, R ₅ , R ₆ , and R ₇ each independently represent a straight chain or branched alkyl group having 1 to 8 carbon atoms, preferably a straight chain or branched alkyl group having 1 to 6 carbon atoms. It is a chain alkyl group, and more preferably a straight chain alkyl group having 1 or more and 6 or less carbon atoms. p is an integer of 1 or more and 4 or less, preferably 1 or 2. When p=2, the two R ₅ 's may be different or the same. q is an integer of 2 or more and 5 or less, preferably an integer of 2 or more and 4 or less, and particularly preferably 3. If q is 2 or more, multiple

may be different or the same.

In addition, in the above, X' consists of -C(=O)-, -C(R ₂ )(R ₃ )-, -N(R ₄ )-, -O-, -S- and -Se- A group selected from the group. Among these, -O- or -S- is preferable, and -O- is more preferable.

More specifically, _G1 preferably has the following structure.

In the above formula, * represents a bond with an adjacent group.

(n ₁ )
n ₁ is an integer of 2 or more and 8 or less. n ₁ is G ₁ and the following substituent (I);

Refers to the number of bonds. n ₁ is preferably an integer of 2 or more and 6 or less, more preferably 2, 3 or 4. The plurality of substituents (I) may be the same or different.

Furthermore, the bonding position between substituent (I) and -Ar ₁ and G ₁ is not particularly limited.

For example, if l = 2, n ₁ = 2, and G ₁ is the following formula,

The bonding position between substituent (I) and -Ar ₁ and G ₁ may be in any of the following forms.

In the above formula, * represents a bond with an adjacent group.

(L ₁ )
L ₁ is represented by the following formula (2).

*1 and *2 represent a bond with G ₁ or G ₂ .

In the above formula (2), E ₁ is represented by the following formulas (3a) to (3f).

In formulas (3a) to (3f), * represents a bond with an adjacent group.

Each Y is independently =C(R ₁ )- or =N-. Considering the effects of the present invention, Y is preferably =C(R ₁ )-.

R ₁ is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon It is a group selected from the group consisting of a group-substituted silyl group, an alkoxy group, and a halogen atom. Examples of each substituent are as described in the Ar ₁ column above. Furthermore, the substituents that may exist in the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group include the monovalent aromatic hydrocarbon group described in Ar ₁ above, and the monovalent aromatic heterocyclic group. This is the same as a substituent (eg, an alkyl group) that can be introduced into a ring group. Examples of the hydrocarbon-substituted silyl group include hydrocarbon-substituted silyl groups having 1 to 20 carbon atoms, specifically trimethylsilyl, triethylsilyl, triisopropylsilyl, tert-butyldimethylsilyl, Examples include tert-butyldiphenylsilyl group. R ₁ is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. It is even more preferable.

T is -O-, -S- or -Se-. Among these, -O- or -S- is preferable, and -S- is more preferable.

X is a group selected from the group consisting of -C(=O)-, -C(R ₂ )(R ₃ )-, -N(R ₄ )-, -O-, -S- and -Se- It is. Among these, -O- or -S- is preferable, and -S- is more preferable.

R ₂ and R ₃ each independently represent a hydrogen atom (including deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, It is a group selected from the group consisting of an aromatic heterocyclic group, a hydrocarbon group-substituted silyl group, an alkoxy group, and a halogen atom. At this time, R ₂ and R ₃ may be combined with each other to form a ring. Among these, R ₂ and R ₃ are each independently more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. More preferred. Further, the substituent that may exist in the aromatic hydrocarbon group or the aromatic heterocyclic group can be introduced into the monovalent aromatic hydrocarbon group and the monovalent aromatic heterocyclic group described in Ar ₁ above. The same applies to substituents (eg, alkyl groups).

_R4 is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon It is a group selected from the group consisting of a group-substituted silyl group, an alkoxy group, and a halogen atom. Among these, R ₄ may be a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a monovalent aromatic hydrocarbon group, a monovalent aromatic heterocyclic group, or a hydrocarbon-substituted silyl group. It is preferably a hydrogen atom or an alkyl group having 1 or more and 8 or less carbon atoms, and even more preferably a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms. Furthermore, the substituents that may exist in the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group include the monovalent aromatic hydrocarbon group described in Ar ₁ above, and the monovalent aromatic heterocyclic group. This is the same as a substituent (eg, an alkyl group) that can be introduced into a ring group.

A plurality of E ₁ 's may have the same structure or different structures.

Among these, E ₁ is more preferably a group selected from Group 1 below. By selecting such a group, the rigidity of the skeleton represented by L ₁ can be further enhanced while exhibiting desired hole transport properties. Therefore, it is possible to achieve a higher degree of both stackability and improvement in device performance.

* represents a bond with an adjacent group.

In Group 1, R ₈ is each independently a linear or branched alkyl group having 1 to 3 carbon atoms, preferably a methyl group or an ethyl group, and more preferably a methyl group. r is an integer of 1 or more and 4 or less, and is preferably 1 or 2. When r=2, the positions of the two R ₈ substituents are not particularly limited, but are preferably at the para position. In Group 1 above, T is preferably O or S, more preferably S. In Group 1, X is preferably -C(R ₂ )(R ₃ )-, O or S, more preferably -C(R ₂ )(R ₃ )-, S.

m ₁ is an integer of 2 or more. Since the molecular weight can be controlled to be low, it is preferably an integer of 2 or more and 10 or less, and more preferably an integer of 2 or more and 8 or less. By controlling the molecular weight to be low, the compounds can be tightly aggregated and there are fewer voids within the layer. Therefore, when forming another layer (e.g., a light-emitting layer) on the hole-transport layer, the intrusion of components of the other layer (e.g., the light-emitting layer) into the hole-transport layer is reduced, resulting in high efficiency and/or long life. . Furthermore, by controlling the molecular weight to be low, the entanglement effect is small and the ink viscosity can be reduced. Therefore, it is possible to eject extremely small droplets, and it can be applied to high-definition inkjet.

Furthermore, in consideration of stackability, at least one m ₁ among the m _1s present in the plurality of L _1s is preferably an integer of 3 or more, and more preferably an integer of 5 or more.

In this case, if all E ₁ in the compound is composed only of the above formulas (3a) to (3c), at least one m ₁ is an integer of 4 or more, otherwise, an integer of 3 or more It is.

From the viewpoint of stackability, it is preferable that at least one of the plurality of L _{1 's} has an alkyl group having a total number of carbon atoms (0 or more) and 5 or less. By setting the total number of carbon atoms in the alkyl group to such a value, the rigidity of the skeleton represented by L ₁ can be further increased, and therefore, it is possible to achieve both stackability and improvement in device performance to a higher degree. Here, the total number of carbon atoms in the alkyl group refers to the total number of carbon atoms in the alkyl group present in L ₁ (the total number of carbon atoms when at least one of R ₁ , R ₂ , R ₃ , and R ₄ is an alkyl group) It does not matter whether it is the number of carbon atoms in one alkyl group or the total number of carbon atoms in multiple alkyl groups.

( _G2 )
_G2 includes a single bond, N (nitrogen atom), Si (silicon atom), substituted or unsubstituted divalent aromatic hydrocarbon group, or substituted or unsubstituted divalent aromatic heterocyclic group Represents a linking group. Specific examples of the substituted or unsubstituted divalent aromatic hydrocarbon group or the substituted or unsubstituted divalent aromatic heterocyclic group are the same as those described in the _G1 column.

_G2 is a single bond or, from the viewpoint of molecular weight reduction and hole transportability,

It is preferable that

* represents a bond with an adjacent group.
( _n2 )
n ₂ is 1 or 2.

n ₂ is G ₂ and the following substituent (II);

Refers to the number of bonds.

When n ₂ is 2, the plurality of substituents (II) may be the same or different.

( _L2 )
L ₂ represents the above formula (2) or a single bond. Examples or preferred examples when L ₂ is represented by the above formula (2) are the same as those described in the column for L ₁ above.

When L ₂ is represented by the above formula (2), E ₁ is particularly preferably a group selected from Group 1' below.

In the above formula, R ₈ and r have the same meanings as in the formula in Group 1.

When L ₂ is represented by the above formula (2), m ₁ is similarly an integer of 2 or more. Since the molecular weight can be controlled to be low, it is preferably an integer of 2 or more and 10 or less, and more preferably an integer of 2 or more and 8 or less. By controlling the molecular weight to be low, the compounds can be tightly aggregated and there are fewer voids within the layer. Therefore, when forming another layer (e.g., a light-emitting layer) on the hole-transport layer, the intrusion of components of the other layer (e.g., the light-emitting layer) into the hole-transport layer is reduced, resulting in high efficiency and/or long life. . Furthermore, by controlling the molecular weight to be low, the entanglement effect is small and the ink viscosity can be reduced. Therefore, it is possible to eject extremely small droplets, and it can be applied to high-definition inkjet.

(A)
A is a group represented by the following formula (4).

In formula (4), *5 represents a bond.

The plural A's may be the same or different.

At least one A has a total of 6 or more carbon atoms in the alkyl groups contained in A. When the total number of carbon atoms in the alkyl group is 6 or more, solvent solubility is improved when a wet method is used. Here, the total number of carbon atoms in the alkyl group refers to the total number of carbon atoms in the alkyl groups present in substituent A, and even if it is the number of carbon atoms in one alkyl group, it is the total number of carbon atoms in multiple alkyl groups. Either is fine. However, from the viewpoint of steric hindrance, the total carbon number of the plurality of alkyl groups is preferable. That is, preferred is a form in which Ar ₂ , E ₂ , Ar ₃ or Ar ₄ is substituted with a plurality of alkyl groups. At least one A preferably has a total carbon number of 6 or more and 40 or less in the alkyl group contained in A, and more preferably has a total carbon number of 6 or more and 30 or less.

Ar ₂ is a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, or a substituted or unsubstituted monovalent aromatic hydrocarbon group; It is a substituent in combination with a substituted monovalent aromatic heterocyclic group.

Examples of the monovalent aromatic hydrocarbon group include those described in the Ar ₁ column above. Among these, as the monovalent aromatic hydrocarbon group, phenyl group, biphenyl group, and fluorenyl group are preferable.

Examples of the monovalent aromatic heterocyclic group include those described in the Ar ₁ column above.

Examples of substituents that can be introduced into the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group include those described in the Ar ₁ column above. The substituent that can be introduced into the monovalent aromatic hydrocarbon group is preferably an alkyl group, more preferably a linear or branched alkyl group having 1 to 12 carbon atoms, and 1 to 12 carbon atoms. It is more preferably a linear or branched alkyl group having 8 or more carbon atoms, even more preferably a linear or branched alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. A straight-chain alkyl group is particularly preferred. The number of substituents on the alkyl group is not particularly limited, but is preferably 1 or 2.

_Ar2 is preferably an unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic hydrocarbon group substituted with an alkyl group.

Note that N, Ar ₂ and E ₂ (adjacent to N) may be bonded to each other to form a ring. For example, Ar ₂ may be a phenyl group and E ₂ may be a phenylene group, forming a ring as shown below.

The * above represents a bonding site with an adjacent atom.

E ₂ is represented by the following formula (5).

Here, in formula (5), * represents a bond.

Z is =C(R ₉ )- or =N-, preferably =C(R ₉ )-.

_R9 is a hydrogen atom (including a deuterium atom), an alkyl group, a cyano group, a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, a hydrocarbon It is a group selected from the group consisting of a group-substituted silyl group, an alkoxy group, and a halogen atom. Examples of each substituent are as described in the R ₁ column above. Furthermore, the substituents that may exist in the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group include the monovalent aromatic hydrocarbon group described in Ar ₁ above, and the monovalent aromatic heterocyclic group. This is the same as a substituent (eg, an alkyl group) that can be introduced into a ring group. R ₉ is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. More preferred.

A plurality of R ₉ 's may be different from each other or may be the same.

Moreover, mutually different adjacent E ₂ may form a ring via R ₉ . For example, the following form;

Also includes the following form (fluorenylene group) in which the group forms a ring via a carbon atom.

a is an integer of 2 or more. Considering solvent solubility, a is preferably an integer of 2 or more and 8 or less, more preferably an integer of 2 or more and 6 or less, even more preferably an integer of 2 or more and 4 or less, 2 or 3 is particularly preferred. At this time, each E ₂ may be the same or different.

In the above formula (4),

Specific examples of the linking group represented by include groups selected from Group 2 below. Note that in Group 2 below, * represents a bonding site with an adjacent atom. Therefore, in the groups shown in Group 2 below, at least one of the two * is bonded to the N atom in the above formula (4).

R each independently represents a hydrogen atom or a straight-chain or branched alkyl group having 1 to 8 carbon atoms, preferably a straight-chain or branched alkyl group having 1 to 6 carbon atoms, and more Preferably, it is a straight chain alkyl group having 1 or more and 6 or less carbon atoms.

In the above formula (4),

Further specific examples of the linking group represented by include Group 2-1 below.

Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted monovalent aromatic hydrocarbon group, a substituted or unsubstituted monovalent aromatic heterocyclic group, or a substituted or unsubstituted monovalent aromatic heterocyclic group; It is a substituent that is a combination of an aromatic hydrocarbon group and a substituted or unsubstituted monovalent aromatic heterocyclic group.

Here, the monovalent aromatic heterocyclic group or the monovalent aromatic heterocyclic group is the same as described in the _Ar2 column. Furthermore, the substituent that can be introduced into the monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group as Ar ₃ and Ar ₄ is the monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group as Ar ₂ . It has the same meaning as a substituent that can be introduced into an aromatic heterocyclic group.

From the viewpoint of further improving hole transport properties, Ar ₃ and Ar ₄ are more preferably groups selected from Group 3 below.

In Group 3, each R is independently a hydrogen atom, a deuterium atom, or an alkyl group. In this case, the alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 3 to 8 carbon atoms. In Group 3 above, * represents a bonding site with the N atom.

Note that E ₂ , N, and Ar ₃ (adjacent to N) may be bonded to each other to form a ring. For example, E ₂ may be a phenylene group and Ar ₃ may be a phenyl group, forming a ring as shown below.

The * above represents a bonding site with an adjacent atom.

Specific examples of A in the above formula (1) include groups represented by the following chemical formula. In addition, in the following chemical formula, * represents a bonding site with an adjacent atom of the above formula (1). Note that Group A1 is a group containing an alkyl group having a total number of carbon atoms of 6 or more, and Group A2 is a group not containing an alkyl group having a total number of carbon atoms of 6 or more.

Specific examples of the compounds of the present invention include the following.

[Production method of this compound]
This compound can be synthesized using a known organic synthesis method. A specific method for synthesizing the present compound can be easily understood by those skilled in the art with reference to the Examples described below.

For example, in the present compound, when G ₂ and L ₂ are single bonds and n ₂ is 1, a compound represented by the following formula (6) and a compound represented by the following formula (7) may be reacted. You can get it at

In the above formula (6), Ar ₁ , l, G ₁ , E ₁ , and n ₁ have the same definitions as in the above formula (1). In formulas (6) and (7), k is an integer from 1 to (m ₁ -1). Q ₁ is a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, especially bromine atom).

In the above formula (7), E ₁ and m ₁ have the same definitions as in the above formula (1). In formula (7), R _A to R _D are each independently an alkyl group having 1 to 3 carbon atoms. Even when G ₂ and L ₂ are not single bonds, the compound can be obtained by the same reaction. be able to.

[Physical properties of this compound]
The molecular weight of the present compound is preferably 2,000 or more and 20,000 or less. The molecular weight is more preferably 3,000 or more and 10,000 or less. If the molecular weight is at least the above lower limit, the lamination properties will be further improved. On the other hand, if the molecular weight is below the above upper limit, it will be advantageous in improving solubility and lowering the viscosity of the ink. By controlling the molecular weight to be low, the entanglement effect is small and the ink viscosity can be reduced. Therefore, it is possible to eject extremely small droplets, and it can be applied to high-definition inkjet.

<Composition>
The second embodiment is a composition containing the present compound and a low molecular weight compound having a molecular weight of less than 2,000. Hereinafter, the composition will also be referred to as the composition of the second embodiment. It becomes possible for the low-molecular-weight compound to fill the voids when forming the hole transport layer. Therefore, by combining low-molecular-weight compounds, it is possible to prevent the solvent from penetrating into the voids of the lower hole transport layer and deteriorating device performance when a light-emitting layer or the like is formed on the upper layer using a wet method. . Therefore, since the composition has excellent hole transport properties, it can be suitably used for hole transport layers of organic electroluminescent devices.

[Low molecular compound]
The low molecular weight compound having a molecular weight of less than 2,000 (hereinafter also simply referred to as "low molecular weight compound") contained in the charge transport material of the present invention includes at least one of the compounds represented by the following formulas (J1) to (J3). Preferably it is a seed.

In the above formula (J1), Ar _a and Ar _b each independently represent an optionally substituted monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group. Preferably, Ar _a and Ar _b are optionally substituted phenyl or m-terphenyl groups. The substituents that can be introduced into the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group as Ar _a and Ar _b are not particularly limited. Examples of the substituent include the substituents exemplified in the explanations for Ar ₁ and Ar ₂ . Furthermore, Ar _a and Ar _b may be combined with adjacent aromatic rings to form a ring.

In the above formula (J1), J is =C(R _a )- or =N-, preferably =C(R _a )-. In this case, R _a is a hydrogen atom, an alkyl group, a cyano group, a monovalent aromatic hydrocarbon group, a monovalent aromatic heterocyclic group, a hydrocarbon group-substituted silyl group, an alkoxy group, or a halogen group. A plurality of R _a may be bonded to each other to form a ring.

As the compound represented by the above formula (J1), a compound represented by the following chemical formula (J1-1) is preferable.

In the above formula (J1-1), Ar _a' and Ar _b' are groups selected from the group consisting of Group 5 below. Note that each group in Group 5 below may be substituted. At this time, the substituents that can be introduced are not particularly limited, and include the substituents exemplified in the explanations for Ar ₁ and Ar ₂ . Furthermore, in Group 5 below, * represents a bond with the benzene ring carbon of the above formula (J1-1). Furthermore, in the above formula (J1-1 ₎ , R _a is each independently a linear alkyl group having preferably 1 to 12 carbon atoms, more preferably 3 to 8 carbon atoms. is a straight-chain alkyl group.

Specific examples of the low molecular weight compound represented by the above formula (J1) include compounds represented by the following formula. These may be used alone or in combination of two or more.

In the above formula (J2), Ar _c to Ar _e each independently represent an optionally substituted monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group. Preferably, Ar _c to Ar _e are each independently an optionally substituted phenyl group, biphenyl group, fluorenyl group or dibenzofuranyl group. The substituents that can be introduced into the monovalent aromatic hydrocarbon group or the monovalent aromatic heterocyclic group as Ar _c to Ar _e are not particularly limited. Examples of the substituent include the substituents exemplified in the explanations for Ar ₁ and Ar ₂ . Although A _c to A _e may be the same or different, it is preferable that at least two of A _c to A _e are the same.

Specific examples of the low molecular weight compound represented by the above formula (J2) include compounds represented by the following formula. These may be used alone or in combination of two or more.

In the above formula (J3), Ar _f , Ar _g , Ar _i and Ar _j are each independently an optionally substituted monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group. be. Preferably, Ar _f , Ar _g , Ar _i and Ar _j are each independently an optionally substituted phenyl group, biphenyl group or fluorenyl group. The substituents that can be introduced into the monovalent aromatic hydrocarbon group or monovalent aromatic heterocyclic group as Ar _f , Ar _g , Ar _i and Ar _j are not particularly limited. Examples of the substituent include the substituents exemplified in the explanations for Ar ₁ and Ar ₂ . Furthermore, Ar _f , Ar _g , Ar _i and Ar _j may be bonded to each other to form a ring.

In the above formula (J3), Ar _h is an optionally substituted divalent aromatic hydrocarbon group or divalent aromatic heterocyclic group. Preferably Ar _h is a phenylene group. The substituent that can be introduced into the divalent aromatic hydrocarbon group or the divalent aromatic heterocyclic group as Ar _h is not particularly limited. Examples of the substituent include the substituents exemplified in the explanations for Ar ₁ and Ar ₂ . Furthermore, Ar _h may be combined with Ar _f , Ar _g , Ar _i and Ar _j to form a ring.

In the above formula (J3), q is an integer of 1 or more and 10 or less, preferably an integer of 2 or more and 5 or less.

Specific examples of the low molecular weight compound represented by the above formula (J3) include compounds represented by the following formula. These may be used alone or in combination of two or more.

In the charge transport material of the present invention, the mass ratio of the present compound and the low molecular weight compound is preferably in the range of 20:80 to 90:10.

<Composition>
The present invention also provides a composition (hereinafter also referred to as a composition of the third embodiment) containing the present compound or the composition of the second embodiment and a solvent. The composition can be applied to a solution coating method (wet method). Furthermore, since the composition has a low viscosity, it can be suitably used for inkjet printing to obtain high-definition EL elements.

[solvent]
The solvent is preferably a solvent having a boiling point of 100°C or more and 350°C or less at normal pressure (hereinafter also simply referred to as "solvent"), and is not particularly limited as long as it can be used in a wet method. Specific examples include toluene, xylene, N,N-dimethylformamide, dimethyl sulfoxide, anisole, hexamethylphosphoric triamide, methyl benzoate, ethyl benzoate, phenylcyclohexane, and tetrahydronaphthalene.

The content of the solvent in the composition of the third embodiment is not particularly limited. For example, it is preferable that the content of the present compound in the composition is within the following range.

The content of the present compound in the composition of the third embodiment is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less.

The composition of the third embodiment preferably has a viscosity at 25° C. of 5 mPa·s or less (lower limit: 0.1 mPa·s, for example). Within the above range, it can be suitably used in inkjet printing for obtaining high-definition organic electroluminescent elements. In this specification, the value measured by an Ostwald viscometer is used as the viscosity.

<Organic layer>
The present invention also provides an organic layer formed from the present compound, the composition of the second embodiment, or the composition of the third embodiment.

The organic layer according to the present invention is formed by a coating method (solution coating method). Specifically, spin coat method, casting method, micro gravure coat method, gravure coat method, bar coat method, roll coat method ) method, wire bar coat method, dip coat method, spray coat method, screen printing method, flexographic printing method, offset printing method, The film is formed using a solution coating method such as an ink jet printing method.

When forming an organic layer by a solution coating method, heat treatment may be performed to remove the solvent. At this time, the heating temperature is not particularly limited, but is, for example, 100° C. or higher and 250° C. or lower. Further, the heating time is also not particularly limited, but is, for example, 5 minutes or more and 300 minutes or less.

<Organic electroluminescent device>
The present invention also provides an organic electroluminescent device having the above organic layer.

Hereinafter, with reference to FIG. 2, the organic electroluminescent device according to this embodiment will be described in detail. FIG. 2 is a schematic diagram showing an organic electroluminescent device according to a fourth embodiment.

As shown in FIG. 2, the organic electroluminescent device 100 according to the present embodiment includes a substrate 110, a first electrode 120 disposed on the substrate 110, and a hole injection layer 130 disposed on the first electrode 120. , a hole transport layer 140 disposed on the hole injection layer 130, a light emitting layer 150 disposed on the hole transport layer 140, an electron transport layer 160 disposed on the light emitting layer 150, and an electron transport layer 140 disposed on the hole injection layer 130; It includes an electron injection layer 170 disposed on the layer 160 and a second electrode 180 disposed on the electron injection layer 170.

Here, the present compound is contained, for example, in any organic layer disposed between the first electrode 120 and the second electrode 180. Specifically, the present compound is preferably included in the hole injection layer 130 as a hole injection material or in the hole transport layer 140 as a hole transport material. Among these, it is particularly preferable to include it in the hole transport layer 140 as a hole transport material.

The method for forming the organic layer containing the present compound is as described above. Furthermore, there are no particular limitations on the method for forming layers other than the organic layer containing the present compound (hereinafter also referred to as other layers). The other layers may be formed by, for example, a vacuum evaporation method or a solution coating method.

As the substrate 110, a substrate used in a general organic electroluminescent device can be used. For example, the substrate 110 may be a glass substrate, a semiconductor substrate such as a silicon substrate, a plastic substrate, or the like.

A first electrode 120 is formed on the substrate 110 . Specifically, the first electrode 120 is an anode, and is made of a metal, an alloy, a conductive compound, etc. that has a large work function (minimum energy required to extract one electron from a substance). It is formed. For example, the first electrode 120 may be made of indium tin oxide (In ₂ O ₃ -SnO ₂ :ITO), indium zinc oxide (In ₂ O ₃ -ZnO), tin oxide (SnO ₂ ), or The transmission electrode may be formed of zinc (ZnO) or the like. Further, the first electrode 120 may be formed as a reflective electrode by laminating magnesium (Mg), aluminum (Al), or the like on the transparent conductive film.

A hole injection layer 130 is formed on the first electrode 120 . The hole injection layer 130 is a layer that facilitates the injection of holes from the first electrode 120, and specifically, the hole injection layer 130 is a layer that facilitates the injection of holes from the first electrode 120. It may be formed with a thickness.

The hole injection layer 130 can be formed of a known hole injection material. Known hole injection materials forming the hole injection layer 130 include, for example, poly(ether ketone)-containing triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis, (pentafluorophenyl)borate (4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate: PPBI), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino) -phenyl]-biphenyl-4,4'-diamine (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'- diamine:DNTPD), copper phthalocyanine, 4,4',4''-tris(3-methylphenylphenylamino)triphenylamine e :m-MTDATA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine:NPB), 4, 4',4''-tris(diphenylamino)triphenylamine (TDATA), 4,4',4''-tris(N,N-2 -naphthylphenylamino)triphenylamine (4,4',4''-tris(N,N-2-naphthylphenylamino)triphenylamine:2-TNATA), polyaniline/dodecylbenzenesulfonic acid honic acid), poly( poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate): PEDOT/PSS), and polyaniline/10-camphorsulfonic acid (polyaniline/ 10-camphorsulfonic acid).

A hole transport layer 140 is formed on the hole injection layer 130. The hole transport layer 140 is a layer having a function of transporting holes, and may be formed to have a thickness (dry film thickness) of, for example, about 10 nm or more and about 150 nm or less. The hole transport layer 140 is preferably formed using the present compound by a solution coating method. According to this method, a compound that can improve the performance of the organic electroluminescent device 100 can be efficiently formed into a film over a large area.

However, if any other organic layer of the organic electroluminescent device 100 contains the present compound, it goes without saying that the hole transport layer 140 may be formed of a known hole transport material. Known hole transport materials include, for example, 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N- Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4 , 4'-diamine (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine: TPD), 4,4',4' '-tris(N-carbazolyl)triphenylamine (TCTA), and N,N'-di(1-naphthyl)-N,N'- Examples include diphenylbenzidine (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine: NPB).

A light emitting layer 150 is formed on the hole transport layer 140. The light emitting layer 150 is a layer that emits light using fluorescence, phosphorescence, or the like. The light emitting layer 150 may have a thickness of, for example, about 10 nm or more and about 60 nm or less. As the light-emitting material of the light-emitting layer 150, a known light-emitting material can be used. However, the luminescent material contained in the luminescent layer 150 is preferably a luminescent material capable of emitting light from triplet excitons (that is, phosphorescence). In such a case, the current efficiency and luminescence lifetime of the organic electroluminescent device 100 can be further improved.

The light-emitting layer 150 uses, for example, tris(8-quinolinato)aluminum (Alq ₃ ), 4,4'-bis(carbazol-9-yl)biphenyl(4,4') as a host material. -bis(carbazol-9-yl)biphenyl:CBP), poly(n-vinyl carbazole)(PVK), 9,10-di(naphthalen-2-yl)anthracene(9,10) -di (naphthalene) anthracene: ADN), 4,4',4''-tris (N-carbazolyl) triphenylamine (TCTA), 1 , 3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI), 3-tert-butyl-9, 10-di(naphth-2-yl)anthracene (3-tert-butyl-9,10-di(naphth-2-yl)anthracene: TBADN), distyrylarylene (DSA), 4,4'-bis (9-carbazole)-2,2'-dimethyl-bipheny (4,4'-bis(9-carbazole)2,2'-dimethyl-bipheny: dmCBP), the following compound h-1, the following compound h-2, etc. May include.

In addition, the light emitting layer 150 may contain, for example, perylene and its derivatives, rubrene and its derivatives, coumarin and its derivatives, 4-dicyanomethylene-2-(p-dimethylaminostyryl) as a dopant material. )-6-Methyl-4H-pyran (4-dicyanomethylene-2-(pdimethylaminostyryl)-6-methyl-4H-pyran: DCM) and its derivatives, bis[2-(4,6-difluorophenyl)pyridinate]picolinate Iridium(III) (bis[2-(4,6-difluorophenyl)pyridinate]picolinate iridium(III): FIrpic), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) quinoline) (acetylacetonate)iridium(III):Ir(piq) ₂ (acac)), tris(2-phenylpyridine)iridium(III)(tris(2-phenylpyridine)iridium(III):Ir(ppy) ₃ ), tris( 2-(3-p-xyyl)phenyl)pyridine May contain iridium (Ir) complexes such as iridium (III), osmium (Os) complexes, platinum complexes, and the like.

Further, the light-emitting layer 150 may include nanoparticles such as quantum dots as a light-emitting material. Quantum dots are nanoparticles composed of semiconductors of the I-VI series, III-V series, or IV-IV series. Examples of the semiconductors include, but are not limited to, CdS, CdSe, CdTe, ZnSe, ZnS, PbS, PbSe, HgS, HgSe, HgTe, CdHgTe, CdSe _X Te _1-X , GaAs, InAs, and InP. It's not something you can do.

Further, the diameter of the nanoparticles is not particularly limited, but may be, for example, 1 nm or more and 20 nm or less. Further, nanoparticles such as quantum dots may have a single core structure, or may have a so-called core/shell structure in which a shell is coated on the surface of the core.

An electron transport layer 160 is formed on the light emitting layer 150. The electron transport layer 160 is a layer with a function of transporting electrons. The electron transport layer 160 may have a thickness of, for example, about 15 nm or more and about 50 nm or less.

The electron transport layer 160 may be formed of a known electron transport material. Known electron transport materials include, for example, (8-quinolinato)lithium (Liq), tris(8-quinolinato)aluminum (Alq ₃ ), and nitrogen-containing Examples include compounds having an aromatic ring. Specific examples of compounds having a nitrogen-containing aromatic ring include 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-tri[(3-pyridyl) -phen-3-yl]benzene), 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3, Compounds containing a triazine ring, such as 5-triazine (2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine), 2 -(4-(N-phenylbenzoimidazolyl-1-yl-phenyl)-9,10-dinaphthylanthracene) Examples include compounds containing an imidazole ring.

An electron injection layer 170 is formed on the electron transport layer 160. The electron injection layer 170 is a layer that has a function of facilitating injection of electrons from the second electrode 180. The electron injection layer 170 may be formed with a thickness of 0.3 nm or more and 20 nm or less. The electron injection layer 170 is not particularly limited, and a known material can be used for forming the electron injection layer 170. For example, the electron injection layer 170 may include lithium compounds such as (8-quinolinato)lithium (Liq) and lithium fluoride (LiF), sodium chloride (NaCl), and cesium fluoride (CsF). ), lithium oxide (Li ₂ O), barium oxide (BaO), or the like.

A second electrode 180 is formed on the electron injection layer 170. Specifically, the second electrode 180 is a cathode, and is formed of a metal, an alloy, a conductive compound, or the like with a small work function. For example, the second electrode 180 is made of metal such as lithium (Li), magnesium (Mg), aluminum (Al), calcium (Ca), or aluminum-lithium (Al-Li), magnesium-indium (Mg-In), The reflective electrode may be formed of an alloy such as magnesium-silver (Mg-Ag). The second electrode 180 is a transparent conductive electrode made of a thin film of 20 nm or less of the above metal material, a transparent conductive film such as indium tin oxide (In ₂ O ₃ -SnO ₂ ), and indium zinc oxide (In ₂ O ₃ -ZnO). It may be formed as

The organic electroluminescent device 100 according to the present embodiment has an organic layer containing the present compound, and thus has excellent current efficiency and luminous lifetime. Note that the organic electroluminescent device 100 according to this embodiment is an example of an organic electroluminescent device according to the present invention.

Note that the stacked structure of the organic electroluminescent device 100 according to this embodiment is not limited to the above example. The organic electroluminescent device 100 according to this embodiment may be formed with other known laminated structures. For example, in the organic electroluminescent device 100, one or more of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170 may be omitted, or other layers may be omitted. may be provided. Furthermore, each layer of the organic electroluminescent device 100 may be formed of a single layer, or may be formed of multiple layers.

For example, the organic electroluminescent device 100 may further include a hole blocking layer between the light emitting layer 150 and the electron transport layer 160 to prevent excitons or holes from diffusing into the electron transport layer 160. Good too. Note that the hole blocking layer can be formed of, for example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or the like.

The effects of the present invention will be explained using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In addition, in the following examples, unless otherwise specified, operations were performed at room temperature (25° C.). Furthermore, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

(Example 1)
<Synthesis of compound 1>

Under a nitrogen atmosphere, bis(4-bromophenyl)amine (581.0 mmol, 190.0 g), (4-propylphenyl)boronic acid (1162 mmol, 190.6 g), and tetrahydrofuran (2905 ml) were placed in a 4-necked flask and dissolved. Ta. 1162 ml of a 2M aqueous potassium carbonate solution was added, and then palladium acetate (34.9 mmol, 7.83 g) and tri(o-tolyl)phosphine (52.3 mmol, 15.92 g) were added and the mixture was refluxed for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with toluene, and extracted. After drying over anhydrous magnesium sulfate, it was filtered using a silica gel pad, recrystallized twice with methanol, and dried in vacuum (50° C., 16 hours) to obtain Compound 1a as a white solid. Yield 200.3g, yield 85%.

Under nitrogen atmosphere, amine body 1a (246.6 mmol, 100 g), 1-bromo-4-iodo-2-methylbenzene (1.05 eq. 258.9 mmol, 76.87 g), tert-BuONa (2 eq. 493.2 mmol) , 47.4 g), 1,4-dioxane (493 ml) and stirred to disperse, and CuI (3 mol%, 7.4 mmol, 1.41 g), trans-1,2-diaminocyclohexane (15 mol%, 37.0 mmol, 4.4 ml) was added and refluxed for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with toluene, and filtered using celite. After concentration, the residue was purified by silica gel chromatography (hexane:toluene=7:3), and then recrystallized from acetone to obtain Compound 1b as a white solid. Yield: 99.2 g, yield: 70%.

Under a nitrogen atmosphere, compound 1b (200 mmol, 114.9 g), bispinacolate diboron (1.05 eq. 210 mmol, 53.3 g), potassium acetate (2 eq. 400 mmol, 39.3 g), N,N-dimethylformamide ( 800 ml), stir to disperse, and add 1,1'-(diphenylphosphino)ferrocene] palladium (II) dichloride/Dichloromethane Adduct (2 mol%, 4 mmol, 3.27 g). The mixture was refluxed for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with toluene (1 L), and filtered using celite. The filtrate was washed with water three times using a separating funnel, dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated. This was purified by silica gel chromatography (developing solvent: dichloromethane:hexane=1:2), and then recrystallized from toluene:ethanol (200ml:1000ml) to obtain Compound 1c as a white solid. Yield 94.5g, yield 76%.

Under nitrogen atmosphere, N-(4-bromophenyl)-[1,1'-biphenyl]-4-amine (160 mmol, 51.9 g), 4-chlorophenylboronic acid (1.05 eq. 168 mmol, 26.3 g), Toluene (640 ml) and ethanol (160 ml) were placed in a 4-necked flask and dissolved. 160 ml of a 2M aqueous potassium carbonate solution was added, and then tetrakis(triphenylphosphine)palladium (4.8 mmol, 5.55 g) was added and the mixture was heated and stirred at 70° C. for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with methanol, and the precipitated solid was collected by filtration and rinsed with methanol. After vacuum drying (50°C, 16 hours), it was dissolved in tetrahydrofuran (1 L), filtered using a silica gel pad, and concentrated. This was recrystallized twice with 20 ml of toluene per 1 g of purified raw material to obtain Compound 1d as a gray solid. Yield 40.4g, yield 71%.

Under nitrogen atmosphere, compound 1d (110 mmol, 39.1 g), 1-bromo-4-iodobenzene (1.2 eq. 132 mmol, 37.3 g), tert-BuONa (1.5 eq. 165 mmol, 15.9 g), toluene (550 ml) was placed in a three-neck flask, and after purging the inside of the flask with nitrogen, 1,1'-(diphenylphosphino)ferrocene] palladium (II) dichloride (4 mol%, 4.4 mmol, 3.22 g) was added and the mixture was heated to 100°C. The mixture was heated and stirred for 4 hours. After the reaction was completed, the mixture was diluted with toluene (500 ml) and filtered using celite. This was further filtered using a silica gel pad and concentrated. This was purified by silica gel chromatography (hexane:toluene=1:1), and then recrystallized twice from a mixed solvent of toluene:hexane=4 ml:10 ml per 1 g of purified raw material to obtain a white solid compound 1e . Yield 37.7g, yield 67%.

Under a nitrogen atmosphere, Compound 1e (70 mmol, 35.8 g), Compound 1c (1.05 eq. 73.5 mmol, 45.7 g), toluene (350 ml), and ethanol (70 ml) were placed in a 3-necked flask and dissolved. 70 ml of 2M aqueous potassium carbonate solution was added, and then tetrakis(triphenylphosphine)palladium (3.5 mmol, 4.04 g) was added and the mixture was heated and stirred at 70° C. for 12 hours. After the reaction was completed, the mixture was diluted with toluene (1 L), washed with water three times using a separating funnel, dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated. This was purified by silica gel chromatography (hexane: toluene = 1:1), and then recrystallized twice from a mixed solvent of toluene: ethyl acetate = 4 ml: 10 ml per 1 g of purified raw material to obtain compound 1f as a white solid. . Yield 47.3g, yield 73%.

Under nitrogen atmosphere, compound 1f (50 mmol, 46.3 g), bispinacolate diboron (1.05 eq. 52.5 mmol, 13.3 g), potassium acetate (2 eq. 100 mmol, 9.81 g), 1,4-dioxane (250 ml) and stirred to disperse, palladium acetate (2 mol%, 1 mmol, 225 mg) and Xphos (4 mol%, 2 mmol, 953 mg) were added thereto, and the mixture was heated and stirred at 100° C. for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with toluene (1 L), and filtered using celite. The filtrate was washed with water three times using a separating funnel, dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated. This was purified by silica gel chromatography (developing solvent: dichloromethane:hexane=1:2), and then recrystallized from toluene:hexane (200ml:1000ml) to obtain 1 g of a pale yellow solid compound. Yield 40.7g, yield 80%.

4-Bromo-4'-chloro-1,1'-biphenyl (374 mmol, 100.2 g), bispinacholate diboron (1.05 eq. 392.7 mmol, 99.7 g), potassium acetate (2 eq. 748 mmol, 73 .4g), N,N-dimethylformamide (1496ml) was added and stirred to disperse, and 1'-(diphenylphosphino)ferrocene]palladium(II) dichloride/Dichloromethane Adduct (2mol%, 7 .5 mmol, 6 .10g) was added and refluxed for 10 hours. After the reaction was completed, the mixture was diluted with toluene (1.5 L) and filtered using celite. The filtrate was washed with water three times using a separating funnel, dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated. This was recrystallized twice with a mixed solvent of toluene:hexane (2 ml: 10 ml) for 1 g of the purified raw material to obtain Compound 1h as a white solid. Yield 84.7g, yield 72%.

Tris(4-bromophenyl)amine (20 mmol, 9.64 g), compound 1h (3.3 eq. 66 mmol, 20.8 g), toluene (100 ml), and ethanol (20 ml) were placed in a 3-necked flask and dissolved. 40 ml of a 2M aqueous solution of potassium carbonate was added, and then tetrakis(triphenylphosphine)palladium (0.6 mmol, 0.69 g) was added and the mixture was heated and stirred at 70° C. for 24 hours. After the reaction was completed, the mixture was diluted with methanol (200 ml), and the precipitated solid was collected by filtration and dried in vacuum (50° C., 16 hours). This crude material was heated and dissolved in toluene (300 ml), filtered using a silica gel pad, and concentrated. This was recrystallized twice from 20 ml of toluene per 1 g of purified raw material to obtain Compound 1i as a pale yellow solid. Yield 10.5g, yield 65%.

Compound 1i (5 mmol, 4.03 g), compound 1 g (3.3 eq. 16.5 mmol, 16.78 g), toluene (100 ml), and ethanol (10 ml) are placed in a 3-necked flask and dispersed. 15 ml of a 2M aqueous potassium carbonate solution was added, and then palladium acetate (5 mol%, 0.25 mmol, 56 mg) and Sphos (8 mol%, 0.4 mmol, 164 mg) were added, and the mixture was heated and stirred at 70° C. for 24 hours. After the reaction was completed, the mixture was diluted with methanol (200 ml), and the precipitated solid was collected by filtration and dried in vacuum (50° C., 16 hours). This crude material was heated and dissolved in toluene (300 ml), filtered using a silica gel pad, and concentrated.

This was purified by silica gel chromatography (developing solvent: toluene) and preparative GPC (developing solvent: tetrahydrofuran) to obtain compound 3' as a pale yellow solid. Yield 11.46g, yield 68%.

(Comparative Examples 1 to 4)

<Solubility evaluation>
The solubility of Compound 1 obtained by synthesis or Comparative Compounds C1 to C4 in anisole was evaluated. Specifically, each compound was added to anisole so that the solid content concentration was 1% by mass, and heated at 80° C. for 10 minutes. Thereafter, the state of dissolution was visually confirmed.

○: No residue is visible visually.
△: Some residual material can be seen visually.
×: Many residual substances are visually observed.

<Viscosity measurement>
The viscosity (mPa·s) at 25° C. was measured using an Ostwald viscometer using an ink for a hole transport layer prepared by the same method as used for solubility evaluation. If it is 5 mPa·s or less, it can be said that it is suitable for inkjet printing for obtaining high-definition organic EL elements.

<Evaluation of stackability>
(1) Evaluation of residual film rate (evaluation of dissolution resistance to upper layer coating solvent)
Using an ink for a hole transport layer prepared by the same method as used for solubility evaluation, the following two types of thin films were produced through the following steps.

[Thin film 1] (Preparation of base thin film)
(A) Film Formation Step A film was formed on a quartz substrate to a thickness of 100 nm by spin coating.
(B) Drying step Heating was performed at 230° C. for 1 hour under a vacuum of 10 ⁻¹ Pa or less.
(C) Annealing step Cooled to room temperature (25° C.) under a vacuum of 10 ⁻¹ Pa or less.
[Thin film 2] (Evaluation of dissolution resistance of base thin film by upper layer coating solvent)
(D) The quartz substrate with the thin film obtained in (C) was placed in a spin coater, and a solvent used in the upper layer coating process (hereinafter referred to as upper layer solvent) was dropped onto the thin film. In this example, methyl benzoate was used as an example. The thin film was kept on standby for 10 seconds with the upper layer solvent on it, and then spun.
(E) The same steps as in (B) and (C) above were performed.

UV-Vis absorbance was measured using [Thin Film 1] and [Thin Film 2] obtained above, and the remaining film rate was evaluated using the following formula. Further, this calculation method is based on Beer-Lambert's law.

Judgment was made according to the following criteria:
◎: Remaining film rate is 99-100%
○: Remaining film rate is 98-99%
△: Remaining film rate is 90-98%
×: Remaining film rate is 90% or less.

(2) Evaluation of interfacial miscibility with the applied and laminated upper layer A light emitting layer was applied on the hole transport layer according to the method disclosed in patent document (International Publication No. 2015/089304) (hereinafter referred to as PL (Photo Luminescence) method). The interfacial miscibility of the laminated two-layer thin film was evaluated.

○: No interfacial mixing observed. △: Slight interfacial mixing observed. ×: Strong interfacial mixing observed.

<Production of organic EL element>
First, as a first electrode (anode), a glass substrate with ITO on which striped indium tin oxide (ITO) is formed to a thickness of 150 nm is prepared. On this glass substrate, poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate):PEDOT/PSS) (Sigma -Aldrich) was applied by spin coating to a dry film thickness of 30 nm to form a hole injection layer.

Next, each ink for the hole transport layer prepared above was applied onto the hole injection layer using a spin coating method so that the dry film thickness was 100 nm, and the mixture was heated at 230° C. under a vacuum of 10 ⁻¹ Pa or less. The mixture was heated for 1 hour and then cooled to room temperature under a vacuum of 10 ⁻¹ Pa or less to form a hole transport layer.

Next, on the hole transport layer, a light-emitting layer ink (compound h-1 and compound h-2 having the following structure as a host material, and a compound TEG (Tris(2-(3- A methyl benzoate solution containing p-xyl)phenyl)pyridineiridium) was applied by spin coating to form a light-emitting layer on the hole transport layer so that the dry film thickness was 30 nm.

The composition of the ink for the light emitting layer is as follows: the solid content concentration of the following compound h-1 is 1.2% by mass, the solid content concentration of the following compound h-2 is 2.8% by mass, and the solid content concentration of the following compound h-2 is 2.8% by mass, based on the solvent methyl benzoate. The solid content concentration of compound TEG was adjusted to 0.4% by mass.

Next, (8-quinolinolato)lithium (Liq) and KLET-03 (manufactured by ChemiPro Kasei Co., Ltd.) were co-evaporated onto the light emitting layer at a mass ratio of 2:8 using a vacuum evaporation device, and the film thickness was A 30 nm electron transport layer was formed.

Furthermore, lithium fluoride (LiF) was deposited on the electron transport layer using a vacuum deposition apparatus to form an electron injection layer with a thickness of 1 nm.

Furthermore, aluminum (Al) was deposited on the electron injection layer using a vacuum evaporation apparatus to form a second electrode (cathode) with a thickness of 100 nm.

Thereafter, in a nitrogen atmosphere glove box with a moisture concentration of 1 ppm or less and an oxygen concentration of 1 ppm or less, the organic EL element was sealed using a glass sealing tube with a desiccant and an ultraviolet curing resin.

<Evaluation of organic EL elements>
The driving voltage, current efficiency, and luminescence life (durability) were evaluated according to the following methods.

Using a DC constant voltage power supply (manufactured by Keyence Corporation, source meter), the voltage applied to the organic EL element was continuously changed from 0 V to 20 V, and the organic EL element was energized to emit light. The brightness at this time was measured using a brightness measuring device (manufactured by Topcom, SR-3).

Here, the current value per unit area (current density) is calculated from the area of the organic EL element, and the current efficiency (cd/m ² ) is divided by the current density (A/m ² ). /A) was calculated. Note that current efficiency indicates the efficiency of converting current into luminescent energy (conversion efficiency), and the higher the current efficiency, the higher the performance of the organic EL element.

In addition, the luminescence life (durability) is determined by continuous driving at a current value that gives an initial luminance of 6,000 cd/ ^m2 , and the time required until the luminance, which decays over time, reaches 80% of the initial luminance. h)".

The results are shown in Table 2 below. Note that in Table 2, the current efficiency is expressed as a relative value when the current efficiency of the organic EL element of Comparative Example 1 is set to 100. Further, the luminescence life (durability) is expressed as a relative value when the element life of the organic EL element of Comparative Example 1 is set to 100. Moreover, "*1" indicates that the comparative example compound was not dissolved and therefore could not be measured. Furthermore, "*2" indicates that measurement was not possible because the EL element could not be manufactured.

From the results in Table 2, it can be seen that Compound 1 of the present invention is excellent in solubility, viscosity, lamination properties, driving voltage, current efficiency, and luminescence life.

On the other hand, Comparative Example Compound C1, which is a low-molecular-weight amine compound that does not have the characteristics of the present invention, had high viscosity and was inferior to the Examples in terms of driving voltage, current efficiency, and luminescence life. Furthermore, it can be seen that Comparative Compounds C2, 3, and 4, which are low-molecular-weight amine compounds that do not have the characteristics of the present invention, do not satisfy the solubility and lamination properties, and are unsuitable for forming a thin film laminated structure by coating.

(Example 2)
Evaluation was performed in the same manner as in Example 1, except that the following Compound I was added as a low molecular compound to the hole transport layer ink at 20% by mass based on Compound 1.

(Comparative example 5)
Evaluation was performed in the same manner as in Comparative Example 1, except that Compound I was added as a low-molecular compound to the hole transport layer ink at 20% by mass based on Compound 1.

The results are shown in Table 3 below. Note that in Table 3, the current efficiency is expressed as a relative value when the current efficiency of the organic EL element of Comparative Example 1 is set to 100. Further, the luminescence life (durability) is expressed as a relative value when the element life of the organic EL element of Comparative Example 1 is set to 100.

From the results in Table 3, Example 2 in which a low-molecular compound was added as an additive to the hole transport layer had even better lamination properties than Example 1 in which no low-molecular compound was added. It can be seen that the luminescence life is excellent.

100 organic electroluminescent device,
110 substrate,
120 first electrode,
130 hole injection layer,
140 hole transport layer,
150 light emitting layer,
160 electron transport layer,
170 electron injection layer,
180 Second electrode.

Claims (11)

Compound represented by the following formula (1):

In the above formula (1),
Ar ₁ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group,
l represents 0 ,
_G1 has one of the following structures,

At this time, in the formula, R ₅ represents a straight chain or branched alkyl group having 1 to 8 carbon atoms,
p is an integer from 1 to 4, and when p = 2 to 4, R ₅ may be different from each other or the same,
q is an integer between 2 and 5, and when q is 2 or more, multiple

may be different or the same,
In the above, * represents a bond with an adjacent group,
L ₁ is represented by the following formula (2),

In the above formula (2),
E ₁ is a group represented by the following formula (3a) ;

In formula (3a) ,
* represents a bond,
Y is = C(R ₁ ) - ,
R ₁ is a hydrogen atom (including a deuterium atom ) ,
* 1 and *2 represent bonds,
m ₁ is an integer of 2 or more and 6 or less , at least one m ₁ is an integer of 4 or more , in this case, each E ₁ may be the same or different,
_G2 represents a single bond or N (nitrogen atom ) ,
L ₂ each independently represents the above formula (2) or a single bond,
A is the following formula (4);

In formula (4),
*5 represents a bond,
Ar ₂ is a substituted or unsubstituted monovalent aromatic hydrocarbon group ,
_E2 is the following formula;

Here, in the formula,
* represents a bond,
Z is each independently =C(R ₉ ) - ,
R ₉ is a hydrogen atom (including a deuterium atom) or an alkyl group having 1 to 6 carbon atoms ,
a is 2 or 3 , in which case each E ₂ may be the same or different,
Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group ;
represented by, the plural A's may be the same or different, and at least one A has a total number of carbon atoms of the alkyl group contained in A of 6 or more,
n ₁ is G ₁

3 when the structure is represented by , and G ₁ is

4 when the structure is represented by
n ₂ is 1 or 2,
When G ₂ is a single bond, n ₂ is 1,
When G ₂ is N (nitrogen atom), n ₂ is 2. G in the above formula (1) ₁ has one of the following structures,

At this time, in the formula, p is 1 or 2, and when p=2, two R ₅ may be different or the same,
m in the above formula (2) ₁ is an integer between 4 and 6,
L in the above formula (1) ₂ 2. The compound according to claim 1, wherein is a single bond. The compound according to claim 1 or 2 , having a molecular weight of 2,000 or more and 20,000 or less. The compound according to any one of claims 1 to 3 , which has a molecular weight of 3,000 or more and 10,000 or less. G in the above formula (1) ₁ has the following structure, the compound according to any one of claims 1 to 4.
Any one of claims 1, 3 and 4, which is one of the compounds represented by the following chemical formula 1, chemical formula 3, chemical formula 3', chemical formula 5, chemical formula 8, chemical formula 11, chemical formula 21 or chemical formula 22. Compounds described in.



7. The compound according to claim 6, which is one of the compounds represented by the chemical formula 1, chemical formula 3, or chemical formula 3'. The compound according to any one of claims 1 to 7 , wherein in L ₁ in formula (1), at least one m ₁ is an integer of 5 or more. A composition for an organic electroluminescent device, comprising the compound according to any one of claims 1 to 8 and a low molecular weight compound having a molecular weight of less than 2000. A composition comprising the compound according to any one of claims 1 to 8 or the composition according to claim 9 , and a solvent. An organic electroluminescent device comprising the compound according to any one of claims 1 to 8 or the composition according to claim 9 between a pair of anode and cathode.