JP2020105154A - Compound, composition, liquid composition, and organic electroluminescent element - Google Patents

Abstract

To provide a compound which has high solubility and a long solution pot life and can achieve an organic EL element increased in the efficiency and the lifespan.SOLUTION: The invention provides a compound represented by formula (1), a composition, a liquid composition, and an organic electroluminescent element. In the formula, X represents O, S, or Se; Ar1 represents a substituted or unsubstituted phenyl group, naphthyl group, or the like; R each independently represent D, CN, F, a C1-20 alkyl group, or the like; a1, a2 and a5 each independently represent a number from 0 to 4; a3 and a4 each independently represent a number from 0 to 3; and a6 represents a number from 0 to 5.SELECTED DRAWING: Figure 5

Description

The present invention relates to compounds, compositions, liquid compositions and organic electroluminescent devices.

2. Description of the Related Art In recent years, a display device and a lighting device using an organic electroluminescence device (hereinafter, sometimes referred to as an organic electroluminescence device) which is a self-luminous light emitting device have been actively developed. ing. The organic electroluminescence element has an organic layer containing a light emitting material. In the organic layer of the organic EL device, the light emitting material is excited by the recombination of electrons and holes, and light emission occurs when the light emitting material returns to the ground state.

In such an organic EL device, various materials for forming an organic layer have been developed for the purpose of improving device characteristics such as current efficiency and light emission life. Patent Documents 1 to 3 disclose compounds having a carbazole structure, a dibenzofuran structure, a dibenzothiophene structure, and a dibenzoselenophene structure, and organic electroluminescence devices using these compounds. Further, Patent Documents 1 and 2 disclose that these compounds can be used as materials for organic layers, particularly as host materials for light emitting layers.

Further, in the manufacture of an organic EL element, it is general that the organic film forming the organic EL element is formed by a dry film forming method such as a vapor deposition method. However, film formation by a dry film formation method such as a vapor deposition method has a problem that it takes time and cost. Therefore, in place of such a dry film forming method, it has been considered to use a wet film forming method such as a solution coating method (hereinafter, sometimes referred to as a coating method) capable of suppressing time and cost.

JP, 2012-033784, A Chinese Patent Application Publication No. 106318379 JP, 2017-081909, A

However, the above compounds described in Patent Documents 1 to 3 have problems that when used in a wet film formation method, the solubility is low and the pot life of the solution is short. Further, organic EL devices using these compounds have problems of low efficiency and short life.

Therefore, an object of the present invention is to provide a compound which has high solubility, has a long pot life of a solution, and can achieve high efficiency and long life of an organic EL device.

In order to solve the above problems, the present inventors have earnestly accumulated research. As a result, an aromatic hydrocarbon ring assembling group in which a dibenzofuran structure, a dibenzothiophene structure or a dibenzoselenophene structure and two or more benzene rings or naphthalene rings are directly bonded by a single bond (provided that the benzene ring and the naphthalene ring are It was found that the above problems can be solved by a compound having a ring which is not further condensed with the ring), and the present invention has been completed.

That is, the said subject of this invention is solved by the following means;
A compound represented by the following general formula (1):

In the general formula (1),
X represents O, S, or Se,
Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, or two or more substituted or unsubstituted naphthalene rings. , Or a monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, , No further ring is condensed with the benzene ring and the naphthalene ring),
R is independently a deuterium atom, a cyano group, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted Substituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings and substituted Monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, the ring is not further condensed with the benzene ring or the naphthalene ring) ),
a1, a2 and a5 each independently represent 0, 1, 2, 3 or 4.
a3 and a4 each independently represent 0, 1, 2 or 3.
a6 represents 0, 1, 2, 3, 4 or 5.

According to the present invention, it is possible to provide a compound having high solubility, a long pot life of a solution, and a high efficiency and a long life of an organic EL device. Also, compositions and liquid compositions containing the compounds may be provided. Furthermore, in the organic EL device, a means capable of achieving high efficiency and long life can be provided.

FIG. 3 is an explanatory diagram for explaining a preferable energy level relationship between a compound represented by the general formula (1) and a carbazole derivative in a composition according to an embodiment of the present invention. FIG. 3 is an explanatory diagram for explaining a preferable energy level relationship between the compound represented by the general formula (1) and the azine ring derivative in the composition according to the embodiment of the present invention. To explain a preferable energy level relationship among the compound represented by the general formula (1), the azine derivative, and the phosphorescent platinum group complex in the composition according to the embodiment of the present invention. FIG. A preferable energy level relationship among the compound represented by the general formula (1), the azine derivative, the carbazole derivative, and the phosphorescent platinum group complex in the composition according to the embodiment of the present invention. It is an explanatory view for explaining. It is a schematic diagram which shows the organic electroluminescent element which concerns on one Embodiment of this invention.

Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments. Unless otherwise specified, operations and measurements of physical properties are carried out under the conditions of room temperature (20° C. or higher and 25° C. or lower)/relative humidity 40% or higher and 50% or lower.

In the present specification, "X and Y are each independently" means that X and Y may be the same or different.

Further, in the present specification, “substituted or unsubstituted” or “substituted or unsubstituted” means that the compound may have another substituent in place of the hydrogen atom. ..

Further, in the present specification, "a monovalent aromatic hydrocarbon ring-assembling group in which two or more substituted or unsubstituted benzene rings or naphthalene rings are directly bonded by a single bond (provided that the benzene ring and the The ring is not further condensed with the naphthalene ring)" is also simply referred to as "monovalent aromatic hydrocarbon ring assembly group".

<Compound>
One aspect of the present invention relates to a compound represented by the following general formula (1).

In the general formula (1),
X represents O, S, or Se,
Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, or two or more substituted or unsubstituted naphthalene rings. , Or a monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, , No further ring is condensed with the benzene ring and the naphthalene ring),
R is independently a deuterium atom, a cyano group, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted Substituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings and substituted Monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, the ring is not further condensed with the benzene ring or the naphthalene ring) ),
a1, a2 and a5 each independently represent 0, 1, 2, 3 or 4.
a3 and a4 each independently represent 0, 1, 2 or 3.
a6 represents 0, 1, 2, 3, 4 or 5.

Here, when each of a1 to a6 is 0, it represents that the ring structure site of interest has no substituents and may be unsubstituted, and a hydrogen atom is bonded to each bonding position. ..

In the compound according to one embodiment of the present invention, in the monovalent aromatic hydrocarbon ring assembling group, the bonding position of each benzene ring or naphthalene ring is not particularly limited. That is, the group includes those having a structure in which each benzene ring or naphthalene ring is bonded at various bonding positions.

The present inventors presume the mechanism by which the above-mentioned configuration solves the problem as follows.

The compounds described in Patent Documents 1 to 3 have a molecular structure that additionally requires a condensed ring in which three or more rings are condensed, in addition to one dibenzofuran structure, dibenzothiophene structure or dibenzoselenophene structure. It has the characteristics of. Due to this feature, these compounds have a small number of conformations (also referred to as the number of conformation patterns) even if they have the same molecular weight as the molecule of the compound of the present invention. Further, from this characteristic, since the cohesive force between the planes of these compounds is strong, aggregation of molecules is likely to occur and crystallization is likely to occur. As a result, when it is applied to a wet film forming method, it is difficult to cause dispersion in a solvent at the molecular level, and the solubility becomes low. Even if a solution can be prepared, it is likely to crystallize and precipitate from the solution, which shortens the pot life of the solution. Furthermore, these compounds have a high glass transition temperature (Tg) due to the characteristics of the aforementioned molecular structure. As a result, at the time of forming the organic EL device, at least one of the barycentric position and the conformation of the compound molecule is firmly fixed in the film containing these compounds. In addition, in the drying step of removing the solvent, voids through which volatile impurity molecules (for example, solvent, water, oxygen, etc. (hereinafter, also referred to as volatile impurity molecules)) are less likely to form in the film. As a result, the volatile impurity molecules cannot be sufficiently removed, the luminous efficiency of the organic EL element is lowered, and/or the luminous lifetime is shortened. Further, the compound described in Patent Document 3 has physical properties significantly different from those of the compound of the present invention because it contains an azine ring structure. Specifically, at least one of the depth of the LUMO (Lowest Unoccupied Molecular Orbital) level and the carrier mobility of electrons and holes are greatly different in the compound containing an azine ring structure. From this, it is difficult to balance the carrier of the compound containing the azine ring structure. As a result, the recombination of charges and the distribution of excitons generated in the layer containing the compound are concentrated in one place, and the load is also concentrated, so that the emission lifetime of the organic EL element is shortened.

On the other hand, the compound according to one embodiment of the present invention has a large number of conformations that can be obtained, and thus at least one of molecular aggregation and crystallization hardly occurs. Further, a relatively low glass transition temperature is exhibited by not including two or more rigid fused rings such as dibenzofuran in which three or more rings are condensed, which has a large effect on raising the glass transition temperature. As a result, it has a high solubility, is hard to precipitate from the solution, and the pot life of the solution is long. In addition, in the drying step of removing the solvent, the relatively low glass transition temperature makes it relatively easy for the compound molecule to undergo thermal motion in the film containing the compound. As a result, voids through which the volatile impurity molecules pass can easily be formed, facilitating diffusion and removal of the volatile impurity molecules. Therefore, the luminous efficiency and the luminous life of the organic EL element are improved. Furthermore, the compound has a 4,6-di([1,1′-biphenyl]-4-yl)dibenzo[b,d]furan structure, 4,6-di([1,1 It has a'-biphenyl]-4-yl)dibenzo[b,d]thiophene structure or a 4,6-di([1,1'-biphenyl]-4-yl)dibenzo[b,d]selenophene structure. By having these structures, the LUMO level and the carrier mobility of electrons and holes are well balanced. As a result, at least one of the charge recombination distribution and the exciton generation distribution in the layer containing the compound is dispersed, and the load thereof is also dispersed, so that the life of the organic EL element is improved.

By compounding the effects exhibited by these specific partial structures, the compound according to one aspect of the present invention achieves both the low glass transition temperature and the difficulty of crystallization, which have been difficult in the past. The compound also achieves a good LUMO level and carrier mobility balance between electrons and holes. Then, the compound according to one aspect of the present invention has both high solubility and a long pot life of a solution, and can contribute to higher efficiency and longer life of the organic EL device.

The above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

In the general formula (1), the phenyl group, the naphthyl group, or the monovalent aromatic hydrocarbon ring assembling group that can form Ar ₁ is not particularly limited. Specifically, for example, phenyl group, terphenyl group, quaterphenyl group, kink phenyl group, sexiphenyl group, naphthyl group, binaphthyl group, ternaphthyl group, quaternaphthyl group, phenylnaphthyl group, biphenylnaphthyl group, diphenylnaphthyl group. Group, a phenylbiphenylnaphthyl group, and the like.

The ring is not further condensed with the benzene ring and the naphthalene ring forming the aromatic hydrocarbon ring assembly group. That is, the condensed ring that the aromatic hydrocarbon ring assembling group may have is only a naphthalene ring formed by condensing two rings. This is because the glass transition temperature becomes higher when the condensed ring formed by condensing three or more rings is additionally included, and it becomes difficult to remove the volatile impurity molecules as described above.

In the above general formula (1), the alkyl group having 1 to 20 carbon atoms which can constitute R is not particularly limited, and a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms can be used. Can be mentioned. 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 thereof include a heneicosyl group, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group and an adamantyl group. Among these, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms is preferable.

The monovalent aromatic hydrocarbon ring assembling group that can form R is the same as the description for Ar ₁ in the above general formula (1), and thus the description thereof is omitted.

In the above general formula (1), the phenyl group, the naphthyl group, or the monovalent aromatic hydrocarbon ring assembling group that may form Ar ₁ may be substituted with another substituent.

The phenyl group, naphthyl group, or other substituent capable of substituting the monovalent aromatic hydrocarbon ring-assembling group that can form Ar ₁ is a deuterium atom, a cyano group, a fluoro group, or a substituted or An unsubstituted alkyl group having 1 to 20 carbon atoms can be mentioned. Among these, a cyano group, a fluoro group, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms is preferable. However, these other substituents do not include those which are condensed or bonded to each other to form a ring.

In the above general formula (1), an alkyl group having 1 to 20 carbon atoms, a phenyl group, a naphthyl group, or a monovalent aromatic hydrocarbon ring assembling group that may constitute R is substituted with another substituent. May be.

The phenyl group, naphthyl group, or other substituent capable of substituting the monovalent aromatic hydrocarbon ring-assembling group that can constitute R includes a deuterium atom, a cyano group, a fluoro group, or a substituted or non-substituted group. Examples thereof include a substituted alkyl group having 1 to 20 carbon atoms. Among these, a cyano group, a fluoro group, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms is preferable. However, these other substituents do not include those which are condensed or bonded to each other to form a ring.

Examples of other substituents that can constitute R and can substitute the alkyl group having 1 to 20 carbon atoms include a deuterium atom, a deuterium atom, a cyano group, and a fluoro group. Among these, a cyano group and a fluoro group are preferable.

Here, the alkyl group having 1 to 20 carbon atoms, which may form another substituent, is the same as the description of R in the general formula (1), and thus the description thereof is omitted.

Further, the monovalent aromatic hydrocarbon ring-assembling group which may form other substituents is the same as the description in Ar ₁ , and therefore the description thereof is omitted.

In addition, as another substituent which can further substitute the alkyl group having 1 to 20 carbon atoms as another substituent, a deuterium atom, a cyano group, and a fluoro group can be mentioned. Among these, a cyano group and a fluoro group are preferable.

Here, the compound represented by the general formula (1) is preferably a compound represented by the following general formula (2).

In the above general formula (2),
X, Ar ₁ , R, a1, a2, a3, a4 and a5 are the same as in the general formula (1),
Ar ₂ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, substituted or Unsubstituted two or more naphthalene rings, or one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings, which are monovalent and are directly bonded to each other by a single bond. Represents an aromatic hydrocarbon ring assembling group (however, no further ring is condensed with the benzene ring and the naphthalene ring),
a6′ represents 0, 1, 2, 3 or 4.

Here, when a6' is 0, it means that the ring structure site of interest has no substituents and may be unsubstituted, and a hydrogen atom is bonded to each bonding position.

With the structure represented by the general formula (2), the solubility is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. In addition, the luminous efficiency and the luminous life of the organic EL element are improved.

In the above general formula (2), a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted monovalent aromatic hydrocarbon which can form Ar ₂ The ring assembly group is the same as the description of Ar ₁ in the general formula (1) above, and thus the description thereof is omitted.

In the structure represented by the general formula (2), the phenyl group, the naphthyl group, or the monovalent aromatic hydrocarbon ring assembling group that may form Ar ₂ may be substituted with another substituent. .. Since the other substituents are the same as the description of the other substituents in the description of Ar _{1 in} the general formula (1), the description thereof will be omitted.

In the above general formula (2), Ar ₁ and Ar ₂ may be the same group or different groups, but are preferably different groups. By making Ar ₁ and Ar ₂ different from each other, the solubility is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is prolonged. In addition, the luminous efficiency and the luminous life of the organic EL element are improved.

Ar ₁ is preferably a group capable of further increasing the number of conformations of the above compound. Ar ₁ is a substituted or unsubstituted 2 or more benzene ring, a substituted or unsubstituted 2 or more naphthalene ring, or a substituted or unsubstituted 1 or more benzene ring and a substituted Monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, the ring is not further condensed with the benzene ring or the naphthalene ring) ) Group is more preferred. Ar ₁ is a monovalent aromatic hydrocarbon ring assembly group containing at least a substituted or unsubstituted metaphenylene group and a substituted or unsubstituted benzene ring or naphthalene ring (provided that the benzene ring is And a ring is not further condensed with the naphthalene ring).

That is, the compound represented by the general formula (2) is preferably a compound represented by the following general formula (3).

In the above general formula (3),
X, R, a1, a2, a3, a4 and a5 are respectively the same as in the general formula (1),
Ar _{2 and} a6′ are the same as in the general formula (2),
R'is each independently a deuterium atom, a cyano group, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or An unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings, and A monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (provided that a ring is further condensed with the benzene ring and the naphthalene ring. No)
L ₁ and L ₂ are each independently a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or two or more substituted or unsubstituted benzene rings, Two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings directly bonded by a single bond Represents a divalent aromatic hydrocarbon ring assembling group (however, the benzene ring and the naphthalene ring are not further condensed with a ring),
E is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene A ring, or a monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond ( However, no further ring is condensed to the benzene ring and the naphthalene ring),
a7 represents 0, 1, 2, 3 or 4,
n represents an integer of 1 or more.

Here, when a7 is 0, it means that the ring structure site of interest has no substituents and may be unsubstituted, and a hydrogen atom is bonded to each bonding position.

Due to the structure represented by the general formula (3), remarkably high solubility is obtained, precipitation from the solution is less likely to occur, and the pot life of the solution is extremely long. Further, the light emission efficiency and the light emission life of the organic EL element are remarkably improved.

In the general formula (3), the alkyl group, phenyl group, naphthyl group, and monovalent aromatic hydrocarbon ring assembling group that can constitute R′ are the same as those described above for R in the general formula (1). Therefore, the description is omitted.

In the general formula (3), the divalent aromatic hydrocarbon ring assembling group that can form L ₁ and L ₂ is a monovalent aromatic hydrocarbon ring assembling group for Ar ₁ in the general formula (1). More one hydrogen atom is removed. Here, the description of the aromatic hydrocarbon rings constituting these is the same as the description of the monovalent aromatic hydrocarbon ring assembling group of Ar _{1 in} the above general formula (1), and therefore the description thereof is omitted.

In the above general formula (3), an alkyl group having 1 to 20 carbon atoms, a phenyl group, a naphthyl group, or a monovalent aromatic hydrocarbon ring-assembling group which may constitute R′ is substituted with another substituent. It may have been done.

In the structure represented by the general formula (3), the phenylene group, the naphthylene group, or the divalent aromatic hydrocarbon ring assembling group that may form L ₁ , L _2, and E may be substituted with another substituent. It may be substituted by a group.

Since these other substituents are the same as the other substituents in the description of Ar ₁ and R in the general formula (1), the description thereof will be omitted.

In the above general formulas (1) to (3), X is preferably O or S. 4,6-di([1,1'-biphenyl]-4-yl)dibenzo[b,d]furan structure or 4,6-di([1,1'-biphenyl]-4-in the central part of the molecule By having the (yl)dibenzo[b,d]thiophene structure, the LUMO level and the carrier mobility of electrons and holes are better balanced, and the life of the organic EL device is further improved.

In the general formulas (1) and (2), Ar ₁ is preferably an unsubstituted phenyl group, an unsubstituted naphthyl group, or an unsubstituted monovalent aromatic hydrocarbon ring assembly group. Among these, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted 2 or more and 10 or less benzene ring, a substituted or unsubstituted 2 or more naphthalene ring, or a substituted or unsubstituted A monovalent aromatic hydrocarbon ring assembling group in which one or more substituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (provided that the benzene ring and the naphthalene It is more preferable that the ring is not condensed with another ring). Further, an unsubstituted phenyl group, an unsubstituted terphenyl group, an unsubstituted quaterphenyl group, an unsubstituted kink phenyl group, an unsubstituted sexiphenyl group, an unsubstituted naphthyl group, an unsubstituted binaphthyl group, an unsubstituted Is more preferably a ternaphthyl group, an unsubstituted quaternaphthyl group, an unsubstituted phenylnaphthyl group, an unsubstituted biphenylnaphthyl group, an unsubstituted diphenylnaphthyl group, and an unsubstituted phenylbiphenylnaphthyl group. And it is particularly preferable that it is an unsubstituted phenyl group, an unsubstituted biphenyl group, an unsubstituted terphenyl group or an unsubstituted naphthyl group.

As shown in the general formula (3), Ar ₁ in the general formulas (1) and (2) is -L ₁ -[-(substituted or unsubstituted metaphenylene group) -L ₂ -. ] It is preferable that it is a partial structure represented by _n- E. At this time, in the general formula (3), a7 is preferably 0. When a7 is not 0, each R′ is preferably independently a cyano group, a fluoro group or an unsubstituted alkyl group having 1 to 20 carbon atoms.

In the general formulas (1) to (3), a1, a2, a3, a4 and a5 are preferably 0.

As shown in the general formulas (2) and (3), R at the specific position in the general formula (1) is preferably Ar ₂ described above. At this time, in the general formula (1), a6 is preferably 1. Therefore, in the general formulas (2) and (3), a6′ is preferably 0.

In the general formulas (2) and (3), Ar ₂ is preferably an unsubstituted phenyl group, an unsubstituted naphthyl group, or an unsubstituted monovalent aromatic hydrocarbon ring assembly group. Among these, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted 2 to 10 benzene ring, an unsubstituted 2 or more naphthalene ring, or an unsubstituted benzene ring or more And a monovalent aromatic hydrocarbon ring assembling group in which one or more unsubstituted naphthalene rings are directly bonded by a single bond (however, no further ring is condensed with the benzene ring or the naphthalene ring) More preferably. Further, an unsubstituted phenyl group, an unsubstituted terphenyl group, an unsubstituted quaterphenyl group, an unsubstituted kink phenyl group, an unsubstituted sexiphenyl group, an unsubstituted naphthyl group, an unsubstituted binaphthyl group, an unsubstituted Is more preferably a ternaphthyl group, an unsubstituted quaternaphthyl group, an unsubstituted phenylnaphthyl group, an unsubstituted biphenylnaphthyl group, an unsubstituted diphenylnaphthyl group, and an unsubstituted phenylbiphenylnaphthyl group. And it is particularly preferable that it is an unsubstituted phenyl group, an unsubstituted biphenyl group, an unsubstituted terphenyl group or an unsubstituted naphthyl group.

In the general formula (1), when a1, a2, a3, a4, a5, and a6 are not 0, each R is independently a cyano group, a fluoro group, or an unsubstituted carbon number 1 or more 20 The following alkyl groups are preferred.

In the general formula (2), when a1, a2, a3, a4, a5, and a6′ are not 0, each R is independently a cyano group, a fluoro group, or an unsubstituted carbon number 1 or more. It is preferably an alkyl group having 20 or less.

In the general formula (3), when a1, a2, a3, a4, a5, and a6′ are not 0, each R is independently a cyano group, a fluoro group, or an unsubstituted carbon number 1 or more. It is preferably an alkyl group having 20 or less.

In the general formula (3), L ₁ and L ₂ are each independently a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, or two or more unsubstituted benzene rings, an unsubstituted 2 Or more naphthalene rings, or a divalent aromatic hydrocarbon ring assembling group in which one or more unsubstituted benzene rings and one or more unsubstituted naphthalene rings are directly bonded by a single bond (provided that the benzene is The ring and the naphthalene ring are not further condensed with a ring). Among these, a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, or an unsubstituted 2 or more and 10 or less benzene ring, an unsubstituted 2 or more naphthalene ring, or an unsubstituted 1 or more A divalent aromatic hydrocarbon ring assembling group in which the benzene ring and one or more unsubstituted or naphthalene rings are directly bonded by a single bond (provided that the ring is further condensed with the benzene ring and the naphthalene ring). Is more preferable). In addition, a single bond, or an unsubstituted phenylene group, an unsubstituted biphenylene group, an unsubstituted terphenylene group, an unsubstituted quaterphenylene group, an unsubstituted kinkphenylene group, an unsubstituted sexiphenylene group, no It is more preferably a substituted naphthylene group, an unsubstituted binaphthylene group, an unsubstituted ternaphthylene group, an unsubstituted quaternaphthylene group, an unsubstituted phenylenenaphthylene group or an unsubstituted biphenylenenaphthylene group. Further, a single bond or an unsubstituted phenylene group is more preferable, and a single bond or an unsubstituted metaphenylene group is particularly preferable. And it is most preferable that both L ₁ and L ₂ are single bonds.

In the general formula (3), E is an unsubstituted phenyl group, an unsubstituted naphthyl group, or two or more unsubstituted benzene rings, two or more unsubstituted naphthalene rings, or one unsubstituted one. A monovalent aromatic hydrocarbon ring assembling group in which the above benzene ring and one or more unsubstituted naphthalene rings are directly bonded by a single bond (provided that the ring is further condensed with the benzene ring and the naphthalene ring). Is preferably not present). Among these, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted 2 to 10 benzene ring, an unsubstituted 2 or more naphthalene ring, or an unsubstituted benzene ring or more And a monovalent aromatic hydrocarbon ring assembling group in which one or more unsubstituted naphthalene rings are directly bonded by a single bond (however, no further ring is condensed with the benzene ring or the naphthalene ring) More preferably. Further, an unsubstituted phenyl group, an unsubstituted biphenyl group, an unsubstituted terphenyl group, an unsubstituted quaterphenyl group, an unsubstituted naphthyl group, an unsubstituted binaphthyl group, an unsubstituted ternaphthyl group, an unsubstituted phenyl group A quaternaphthyl group, an unsubstituted phenylnaphthyl group, and an unsubstituted biphenylnaphthyl group are more preferable. And it is particularly preferable that it is an unsubstituted phenyl group, an unsubstituted biphenyl group, an unsubstituted terphenyl group or a naphthyl group. Here, it is most preferably an unsubstituted phenyl group or an unsubstituted biphenyl group.

In the general formula (3), n is preferably an integer of 1 or more and 9 or less, and more preferably an integer of 1 or more and 4 or less. Among these, n is more preferably 1 or 2, and particularly preferably 1.

In the general formula (2), Ar ₁ and Ar ₂ are preferably different groups, as described above. Therefore, also in the general formula (3), Ar ₂ and the partial structure represented by -L ₁ -[-(substituted or unsubstituted metaphenylene group) -L ₂ -] _n -E are: It is preferable that the groups are different from each other.

From the above, the compound represented by the general formula (3) is
X represents O or S,
Ar ₂ is an unsubstituted phenyl group, an unsubstituted naphthyl group, or two or more unsubstituted benzene rings, two or more unsubstituted naphthalene rings, or one or more unsubstituted benzene rings and an unsubstituted group. Represents a monovalent aromatic hydrocarbon ring assembling group in which one or more naphthalene rings are directly bonded by a single bond (however, the benzene ring and the naphthalene ring are not further condensed with a ring),
a1, a2, a3, a4, a5, a6′ and a7 all represent 0,
L ₁ and L ₂ are each independently a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, two or more unsubstituted benzene rings, two or more unsubstituted naphthalene rings, or an unsubstituted group. A divalent aromatic hydrocarbon ring assembling group in which one or more substituted benzene rings and one or more unsubstituted naphthalene rings are directly bonded by a single bond (provided that the benzene ring and the naphthalene ring have a ring Does not condense),
E represents an unsubstituted phenyl group or an unsubstituted naphthyl group,
It is preferable that n represents 1.

Hereinafter, the compound represented by the above general formula (1) will be specifically exemplified. However, the present invention is not limited to these specific examples.

Among the compounds of the above general formulas 1 to 24, the above compounds 1, 2 or 11 are particularly preferable.

The compound represented by the general formula (1) is preferably a wide gap material. Here, the wide gap material means a material having a HOMO-LUMO energy gap of 3.0 eV or more. The HOMO-LUMO energy gap is not particularly limited, but is preferably 3.1 eV or more. Further, the HOMO-LUMO energy gap is more preferably 3.2 eV or more. The HOMO-LUMO energy gap is preferably 6.0 eV or less.

The compound represented by the general formula (1) has a low glass transition temperature (Tg). Although the glass transition temperature (Tg) is not particularly limited, it is preferably 140° C. or lower, more preferably 120° C. or lower, and further preferably 105° C. or lower. The glass transition temperature (Tg) is not particularly limited, but is preferably 60°C or higher.

The method for producing the compound represented by the general formula (1) is not particularly limited, and various production methods including known synthesis methods can be used.

The compound represented by the general formula (1) is preferably used as a material for an organic electroluminescence element (also referred to as an organic EL element material in the present specification). From this, it is preferable that the organic EL device material contains the compound represented by the general formula (1).

The compound represented by the general formula (1) can realize high light emission efficiency and light emission life of the organic EL device. The reason for this is speculated that, as mentioned above, the compound has a low glass transition temperature, and a good LUMO level and a well-balanced electron-hole carrier mobility. The organic EL device material containing the compound can be used, for example, as a material for a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Among these, it is preferable to use as a material for the light emitting layer.

Further, the compound represented by the general formula (1) is difficult to precipitate from the solution, and the pot life of the solution is long. The reason for this is presumed to be that, as described above, the compound has a high conformation number and thus has a high degree of amorphousness, and crystallization is unlikely to occur. Therefore, the compound can achieve high emission efficiency and emission life of the organic EL element even when the wet film formation method is used.

<Composition>
Another aspect of the present invention relates to a composition, which further contains another compound in addition to the compound represented by the above general formula (1).

As described above, the compound represented by the general formula (1) can realize high efficiency and life of the organic EL device. And the composition which concerns on one form of this invention contains the said compound. The material for an organic EL device containing the composition can be used, for example, as a material for a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Among these, it is preferable to use as a material for the light emitting layer. Further, the compound represented by the general formula (1) is hard to precipitate from the solution, and the pot life of the solution becomes long. And the composition which concerns on one form of this invention contains the said compound. The composition can achieve high emission efficiency and emission life of an organic EL device even when a wet film formation method is used.

The other compound is not particularly limited, and a known compound as an organic layer forming material of an organic EL device can be appropriately adopted. Among these, a light emitting material, a carbazole derivative or an azine ring derivative is preferable.

Content of the compound represented by the said General formula (1) in the composition which concerns on one form of this invention is 5 mass% or more and 95 mass% or less with respect to 100 mass% of the said composition. Is preferred. Further, the content is more preferably 10% by mass or more and 90% by mass or less, and further preferably 20% by mass or more and 80% by mass or less. Within this range, the solubility is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. In addition, the luminous efficiency and the luminous life of the organic EL element are improved.

Hereinafter, details of the light emitting material, the carbazole derivative, and the azine ring derivative, which are preferable other compounds, will be described.

(Light emitting material)
The composition according to one aspect of the present invention preferably further contains a light emitting material.

The light emitting material is not particularly limited as long as it has a high light emitting function, and is a phosphorescent light emitting material composed of an organic metal complex containing an organic fluorescent molecule and a platinum group metal element (hereinafter, also referred to as a phosphorescent light emitting platinum group metal complex). ), quantum dots, etc. can be used.

From the viewpoint of luminous efficiency, the light emitting material is preferably a phosphorescent platinum group metal complex. The platinum group metal element is a general term for ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt). Among these, a phosphorescent iridium (Ir) complex and a platinum (Pt) complex are more preferable, and a phosphorescent iridium (Ir) complex is more preferable.

The phosphorescent light emitting platinum group metal complex is not particularly limited. For example, it is preferable to have at least one ligand selected from the group consisting of the following general formulas L1 to L26.

In the general formulas L1 to L26,
X ^{1 to} X ¹³ are each independently carbon or nitrogen;
X is, BR ', NR', PR ', O, S, Se, C = O, S = O, SO 2, CR'R'', from the group consisting of SiR'R''andGeR'R''Selected;
R′ and R″ may be fused or combined to form a ring;
R _a , R _b , R _c and R _d may or may not be present up to the maximum possible number of substitutions;
R′, R″, R _a , R _b , R _c and R _d are each independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, Alkoxy group, aryloxy group, amino group, silyl group, alkenyl group, cycloalkenyl group, heteroalkenyl group, alkynyl group, aryl group, heteroaryl group, acyl group, carbonyl group, carboxylic acid group, ester group, nitrite group , An isonitrile group, a sulfanyl group, a sulfinyl group, a sulfonyl group, a phosphino group and combinations thereof;
Two adjacent substituents of R _a , R _b , R _c and R _d may be fused or combined to form a ring or may form a polydentate ligand.

Specific examples of the phosphorescent platinum group metal complex having the ligands represented by the above general formulas L1 to L26 are shown below. However, the phosphorescent light emitting platinum group metal complex is not limited to these specific examples.

Among these phosphorescent platinum group metal complexes, the compound of D1 is preferable.

The phosphorescent platinum group metal complex is not limited to the compounds of the specific examples shown above. For example, known phosphorescence-emitting platinum group metal complexes described in paragraphs 0105 to 0113 of U.S. Patent Application Publication No. 2016/0093808, JP-A-2014-509067 and the like can be incorporated into the present invention by reference. The phosphorescent platinum group metal complexes described in these references can also be used as the basis for correction in the present specification.

The content of the light emitting material in the composition is preferably 0.5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the compound represented by the general formula (1) which functions as a host material. .. The content is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 2 parts by mass or more and 25 parts by mass or less.

The content of the light emitting material in the composition is such that the compound represented by the general formula (1) functions as a host material, the carbazole derivative described later that functions as a host material, and the host material. It is preferably 0.5 parts by mass or more and 50 parts by mass or less based on 100 parts by mass of the total amount of the azine ring derivative described later. The content is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 2 parts by mass or more and 25 parts by mass or less. Within the above range, the solubility of the composition is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. In addition, as described later, the carbazole derivative and the azine ring derivative are host materials that can be used arbitrarily.

(Carbazole derivative)
The composition according to one aspect of the present invention preferably further contains a carbazole derivative. That is, it is preferable that the composition contains the compound represented by the general formula (1) and a carbazole derivative.

By containing the carbazole derivative, the composition according to one embodiment of the present invention can further enhance the effect of suppressing the aggregation of molecules and improve the balance of carrier mobility between electrons and holes. Therefore, the solubility of the composition is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved.

The carbazole derivative has a nitrogen-containing heterocyclic compound structure (carbazole structure) composed of 13 ring-forming atoms containing a nitrogen atom (N). Therefore, the carbazole derivative distributes a shallow HOMO (Highest Occupied Molecular Orbital) in the composition according to one embodiment of the present invention, excluding the light emitting material. Therefore, at least one of the hole injecting property and the hole transporting property is further enhanced while suppressing the aggregation of molecules in the film. Further, at least one of the hole injecting property and the hole transporting property can be easily and continuously modulated by controlling the composition ratio of the carbazole derivative. In particular, it becomes easy to control the amount of holes in the light emitting layer and the hole density profile in the film thickness direction. As a result, the performance of the organic EL device manufactured by the wet film formation method (in particular, at least one of the hole injection property and the hole transport property) by including the carbazole derivative in the composition according to one embodiment of the present invention Will be improved. As a result, the light emission efficiency and the light emission life of the organic EL element are further improved.

The carbazole derivative is preferably a compound represented by the following general formula (C1). The compound represented by the following general formula (C1) has a structure (skeleton structure) in which R ₂₁ is bonded to N at the 9-position of the heterocyclic structure containing a nitrogen atom (N) (nitrogen-containing heterocyclic compound).

In the general formula (C1), R ₂₁ is a group having no azine ring structure, and is derived from an aromatic hydrocarbon ring composed of one or more substituted or unsubstituted aromatic hydrocarbon rings. A monovalent group (hereinafter, also simply referred to as “monovalent aromatic hydrocarbon ring group” in the description of the carbazole derivative), an aromatic heterocycle composed of one or more substituted or unsubstituted aromatic heterocycles. A monovalent group derived from a ring (hereinafter, also simply referred to as a “monovalent aromatic heterocyclic group” in the description of a carbazole derivative) (however, a group having an azine ring structure is excluded), or substituted or unsubstituted A monovalent ring assembly group composed of one or more aromatic hydrocarbon rings and one or more substituted or unsubstituted aromatic heterocycles (hereinafter, in the description of the carbazole derivative, simply referred to as “monovalent Also referred to as "aromatic hydrocarbon ring-aromatic heterocyclic ring group") (however, those having an azine ring structure are excluded).

In the present specification, the “azine ring structure” refers to a 6-membered ring structure such as an azine ring, a diazine ring or a triazine ring, or a condensed ring structure including a part thereof.

The monovalent aromatic hydrocarbon ring group that can form R ₂₁ is not particularly limited. For example, an aromatic hydrocarbon ring group having 6 to 60 carbon atoms, that is, a group derived from a hydrocarbon (aromatic hydrocarbon) ring having a carbon ring containing at least one aromatic ring having 6 to 60 carbon atoms, etc. Are listed. Further, when the aromatic hydrocarbon ring group includes two or more rings, the two or more rings may be bonded or fused with each other by a single bond.

The aromatic hydrocarbon ring constituting the monovalent aromatic hydrocarbon ring group is not particularly limited, but specifically, a benzene ring, a pentalene ring, an indene ring, a naphthalene ring, an anthracene ring, an azulene ring, a heptalene ring, Acenaphthalene ring, phenalene ring, fluorene ring, phenanthrene ring, biphenyl ring, triphenylene ring, pyrene ring, chrysene ring, picene ring, perylene ring, pentaphene ring, pentacene ring, tetraphene ring, hexaphene ring, hexacene ring, rubicene ring, Examples thereof include a trinaphthylene ring, a heptaphene ring, a pyrantrene ring and a fluorene ring.

The monovalent aromatic heterocyclic group that can form R ₂₁ is not particularly limited as long as it does not have an azine ring structure. For example, a monovalent aromatic heterocyclic group having 3 to 60 ring atoms, that is, one or more hetero atoms (eg, nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom) A group derived from a ring (aromatic heterocycle) having 3 to 60 ring-forming atoms, including one or more aromatic rings having (S)) and the remaining ring atoms being carbon atoms (C) (provided that (Excluding groups having an azine ring structure) and the like. Moreover, when the aromatic heterocyclic group includes two or more rings, the two or more rings may be bonded or fused to each other by a single bond.

Here, the number of ring-forming atoms represents the number of atoms constituting the ring itself in a compound having a structure in which atoms are cyclically bonded (for example, a monocycle, a condensed ring, a ring assembly). Atoms that do not form a ring (for example, a hydrogen atom that terminates a bond of an atom that forms a ring) or, when the ring is substituted with a substituent, the atom included in the substituent is not included in the number of ring-forming atoms. .. For example, the carbazolyl group has 13 ring atoms.

The aromatic heterocycle constituting the monovalent aromatic heterocyclic group is not particularly limited, and examples thereof include a π-electron excess aromatic heterocycle, a π-electron deficient aromatic heterocycle and a π-electron excess aromatic heterocycle. Examples of the mixed aromatic heterocycle include a π-electron deficient system and π-electron excess system mixed with a ring.

Specific examples of the π-electron excess aromatic heterocycle include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyrrole ring, an indole ring, a carbazole ring, and an indolocarbazole ring. To be

Specific examples of the π electron deficient system-π electron excess system mixed aromatic heterocycle include an imidazole ring, an indazole ring, an oxazole ring, an isoxazole ring, a benzoxazole ring, a benzisoxazole ring, a thiazole ring, an isothiazole ring, and benzo. Examples thereof include a thiazole ring, a benzisothiazole ring, an imidazolinone ring, a benzimidazolinone ring, a diazadibenzothiophene, a xanthone ring and a thioxanthone ring.

The monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group is not particularly limited. For example, a group in which one or more aromatic hydrocarbon rings having 6 or more and 60 or less carbon atoms and one or more aromatic heterocycles having 3 or more and 60 or less ring-forming atoms are bonded to each other by a single bond, and the like can be mentioned. .. Moreover, one or more hydrogen atoms present in these aromatic hydrocarbon ring groups or aromatic heterocycles may be substituted with other substituents. In addition, the aromatic hydrocarbon ring and the aromatic heterocycle that compose the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group are the monovalent aromatic hydrocarbon ring group and the monovalent aromatic ring, respectively. Since it is the same as the heterocyclic group, description thereof will be omitted.

Y _{1 to} Y ₈ are each independently C(R ₂₂ ). C in C(R ₂₂ ) represents a carbon atom. Furthermore, C (R ₂₂₎ R 22 in each independently, it is not particularly limited as long as it is a hydrogen atom, an organic group having no deuterium or azine ring. Among these, hydrogen atom, deuterium atom, cyano group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group (provided that the azine ring structure A group having a), a substituted or unsubstituted alkylamino group, a substituted or an unsubstituted arylamino group (excluding a group having an azine ring structure), a substituted or unsubstituted monovalent group Aromatic hydrocarbon ring group, substituted or unsubstituted monovalent aromatic heterocyclic group (excluding those having an azine ring structure), or substituted or unsubstituted monovalent aromatic carbon group It is preferably a hydrogen ring-aromatic heterocyclic ring assembling group (excluding those having an azine ring structure).

In Y _{1 to} Y ₈ , the alkyl group that may form R ₂₂ in C(R ₂₂ ) is not particularly limited. For example, it is a linear or branched alkyl group having 1 to 30 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 thereof include a heneicosyl group, an n-docosyl group, an n-tricosyl group and an n-tetracosyl group.

In Y _{1 to} Y ₈ , the alkoxy group that can form R ₂₂ in C(R ₂₂ ) is not particularly limited. For example, it is a linear or branched alkoxy group having 1 to 30 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. Among these, a linear or branched alkoxy group having 1 to 8 carbon atoms is preferable.

In Y _{1 to} Y ₈ , the aryloxy group that can form R ₂₂ in C(R ₂₂ ) is not particularly limited as long as it does not have an azine ring structure. For example, it is an aryloxy group having 6 or more and 30 or less ring-forming atoms (excluding those having an azine ring structure). The aryloxy group may contain a hetero atom. That is, it may be a heteroaryloxy group. Specifically, a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 2-azurenyloxy group, a 2-furanyloxy group, a 2-thienyloxy group, a 2-indolyloxy group, a 3-indolyloxy group, Examples thereof include a 2-benzofuryloxy group and a 2-benzothienyloxy group.

In Y _{1 to} Y ₈ , the arylamino group that can form R ₂₂ in C(R ₂₂ ) is not particularly limited as long as it does not have an azine ring structure. For example, it is an arylamino group having 6 to 60 ring atoms (excluding those having an azine ring structure). The arylphenyl group may contain heteroatoms. That is, it may be a heteroarylamino group. Specific examples thereof include N-arylamino groups such as N-phenylamino group, N-biphenylamino group and N-terphenylamino group. Further, N,N-diphenylamino group, N,N-dibiphenylamino group, N,N-diterphenylamino group, N-biphenyl-N-phenylamino group, N-biphenyl-N-terphenylamino group, Examples thereof include N,N-diphenylamino groups such as N-phenylter-N-phenylamino group.

In Y _{1 to} Y ₈ , the alkylamino group that can form R ₂₂ in C(R ₂₂ ) is not particularly limited. For example, it is a linear or branched alkylamino group having 1 to 30 carbon atoms. Specifically, N-methylamino group, N-ethylamino group, N-propylamino group, N-isopropylamino group, N-butylamino group, N-isobutylamino group, N-sec-butylamino group, N- Examples thereof include N-alkylamino groups such as -tert-butylamino group, N-pentylamino group and N-hexylamino group. Further, N,N,N-dimethylamino group, N-methyl-N-ethylamino group, N,N-diethylamino group, N,N-dipropylamino group, N,N-diisopropylamino group, N,N- Examples thereof include N,N-dialkylamino groups such as dibutylamino group, N,N-diisobutylamino group, N,N-dipentylamino group and N,N-dihexylamino group.

In Y _{1 to} Y ₈ , a monovalent aromatic hydrocarbon ring group, a monovalent aromatic heterocyclic group and a monovalent aromatic hydrocarbon ring-which may form R ₂₂ in C(R ₂₂ )- The aromatic heterocyclic ring group includes a monovalent aromatic hydrocarbon ring group, a monovalent aromatic heterocyclic group, and a monovalent aromatic hydrocarbon ring-aromatic heterocycle, each of which can form R ₂₁ described above. The explanation is omitted because it is similar to the explanation of the aggregation group.

The monovalent aromatic hydrocarbon ring group, monovalent aromatic heterocyclic group, and monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group that may form R ₂₁ are substituted with other substituents. May be.

An alkyl group, an alkoxy group, an aryloxy group (excluding a group having an azine ring structure), an alkylamino group, an arylamino group (excluding a group having an azine ring structure) which can form R ₂₂ , monovalent The aromatic hydrocarbon ring group, the monovalent aromatic heterocyclic group, and the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group may be substituted with other substituents.

These other substituents are not particularly limited as long as they are a deuterium atom or an organic group having no azine ring structure.

Monovalent aromatic hydrocarbon ring group, monovalent aromatic heterocyclic group, or monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring assembly group that can form R ₂₁ and R ₂₂ Examples of the group include a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group (provided that the azine ring structure is And a substituted or unsubstituted alkylamino group, and a substituted or unsubstituted arylamino group (excluding groups having an azine ring structure).

By substituting an alkyl group, an alkoxy group, an aryloxy group (excluding a group having an azine ring structure), an alkylamino group, an arylamino group (excluding a group having an azine ring structure) that may form R ₂₂ Examples of other substituents that can be used include a deuterium atom, a cyano group, an unsubstituted alkyl group, an unsubstituted alkoxy group, an unsubstituted aryloxy group (excluding groups having an azine ring structure), an unsubstituted And an unsubstituted arylamino group (excluding groups having an azine ring structure).

The alkyl group, the alkoxy group, the aryloxy group, and the alkylamino group which may form other substituents for R ₂₁ and R ₂₂ respectively, are the explanations of these groups which may form R ₂₂ in C(R ₂₂ ). Since it is the same as, the description will be omitted.

A monovalent aromatic hydrocarbon ring group, a monovalent aromatic heterocyclic group (excluding those having an azine ring structure), and a monovalent aromatic hydrocarbon ring group which may constitute other substituents for R ₂₁ and R ₂₂ . The description of the aromatic hydrocarbon ring-aromatic heterocyclic ring group is omitted because it is the same as the description of the aromatic hydrocarbon ring group and aromatic heterocyclic group that can form R ₂₁ described above.

Incidentally, a monovalent aromatic hydrocarbon ring group as another substituent, a monovalent aromatic heterocyclic group, another substituent capable of substituting a monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group. Examples of further other substituents that may be further substituted include, for example, a deuterium atom, a cyano group, an unsubstituted alkyl group, an unsubstituted alkoxy group, an unsubstituted aryloxy group (provided that a group having an azine ring structure is And a non-substituted alkylamino group and an arylamino group (excluding a group having an azine ring structure).

The monovalent aromatic hydrocarbon ring group that can form R ₂₁ and R ₂₂ is preferably a monovalent aromatic hydrocarbon ring group having 6 to 60 carbon atoms. Further, it is more preferably a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms.

The monovalent aromatic heterocyclic group that can form R ₂₁ and R ₂₂ is preferably a monovalent aromatic heterocyclic group having 3 to 60 ring atoms. Further, it is more preferably a monovalent aromatic heterocyclic group having 3 to 30 ring atoms.

The monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring assembling group that can form R ₂₁ and R ₂₂ is one or more aromatic hydrocarbon rings having 6 to 60 carbon atoms and one or more ring-forming atoms. It is preferable that the aromatic heterocycles having a number of 3 or more and 60 or less are bonded to each other by a single bond. In addition, it is a group in which one or more aromatic hydrocarbon rings having 6 to 30 carbon atoms and one or more aromatic heterocycles having 3 to 30 ring atoms are bonded to each other by a single bond. preferable.

In addition, R ₂₁ and one or more R ₂₂ or two or more R ₂₂ may each independently be condensed or bonded to each other to form a ring structure.

Further, the compound represented by the general formula (C1) may be a multimer in which the structure represented by the general formula (C1) is bonded via each R ₂₁ or R ₂₂ .

The compound represented by the general formula (C1) is not particularly limited, but a preferable example thereof includes a compound represented by the following general formula (C2). Here, the compound represented by the following general formula (C2) is an example of the compound in the above general formula (C1) in which R ₂₂ 's are bonded to each other to form a ring structure.

In the general formula (C2), Q is a condensed ring bond having a ring structure represented by the following general formula,

R ₂₁ is independently the same as in the general formula (C1),
R ₂₂₁ and R ₂₂₂ are each independently a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group ( Provided that a group having an azine ring structure is excluded), a substituted or unsubstituted alkylamino group, a substituted or unsubstituted arylamino group (excluding a group having an azine ring structure), a substituted or Unsubstituted monovalent aromatic hydrocarbon ring group, substituted or unsubstituted monovalent aromatic heterocyclic group (excluding groups having an azine ring structure), or substituted or unsubstituted monovalent Valent aromatic hydrocarbon ring-representing an aromatic heterocyclic ring group (excluding those having an azine ring structure),
b independently represents 0, 1, 2, 3 or 4,
c represents 0, 1 or 2.

Here, when b and c are 0 respectively, it means that the ring structure site of interest has no substituents and is unsubstituted, and a hydrogen atom is bonded to each bonding position. ..

Here, the description of each substituent that can form R ₂₂₁ and R ₂₂₂ is the same as the description of each substituent that can form R ₂₂ of the above general formula (C1), and thus the description thereof is omitted. ..

The monovalent aromatic hydrocarbon ring group that can form R ₂₂₁ and R ₂₂₂ is preferably a monovalent aromatic hydrocarbon ring group having 6 to 60 carbon atoms. Further, it is more preferably a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms.

The monovalent aromatic heterocyclic group that can form R ₂₂₁ and R ₂₂₂ is preferably a monovalent aromatic heterocyclic group having 3 to 60 ring-forming atoms. Further, it is more preferably a monovalent aromatic heterocyclic group having 3 to 60 ring atoms.

The monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group that may form R ₂₂₁ and R ₂₂₂ is one or more aromatic hydrocarbon rings having 6 to 60 carbon atoms and one or more ring-forming atoms. It is preferable that the aromatic heterocycles having a number of 3 or more and 60 or less are bonded to each other by a single bond. In addition, it is a group in which one or more aromatic hydrocarbon rings having 6 to 30 carbon atoms and one or more aromatic heterocycles having 3 to 30 ring atoms are bonded to each other by a single bond. preferable.

In the above general formula (C2), when b is 0 or b is not 0, R ₂₂₁ is each independently a deuterium atom, a substituted or unsubstituted group having no azine ring structure. A monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms, which does not have an azine ring structure, or A substituted or unsubstituted one or more aromatic hydrocarbon ring having 6 to 30 carbon atoms having no azine ring structure, and one or more substituted or unsubstituted one having no azine ring structure It is preferable that the aromatic heterocycle having 3 to 30 ring-forming atoms is bonded to each other by a single bond.

In the general formula (C2), when c is 0 or c is not 0, R ₂₂₂ is independently a deuterium atom, a azine ring structure-free, substituted or unsubstituted A monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms, which does not have an azine ring structure, Or a substituted or unsubstituted one having no azine ring structure, one or more aromatic hydrocarbon ring having 6 to 30 carbon atoms and a substituted or unsubstituted one having no azine ring structure It is preferable that the aromatic heterocycle having 3 to 30 ring-forming atoms is bonded to each other by a single bond.

Here, in the general formula (C2), it is more preferable that b and c are both 0, and R ₂₁ is an unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms. Further, in the general formula (C2), it is more preferable that both b and c are 0, and R ₂₁ is an unsubstituted terphenyl group.

In the above general formula (C2), at least two groups out of R ₂₁ , one or more R _221, and one or more R ₂₂₂ may be fused or bonded to each other to form a ring structure.

The compound represented by the general formula (C2) can have any of the following five core structures (a) to (e) which do not have the substituents R ₂₁ , R _221, and R ₂₂₂ . Of these, the core structure (a) is preferable.

Hereinafter, the compound represented by the above general formula (C2) will be specifically exemplified. However, the carbazole derivative that can be included in the composition according to one embodiment of the present invention is not limited to these specific examples.

The compound represented by the general formula (C1) is not particularly limited, but a preferable example thereof includes a compound represented by the following general formula (C3). The compound represented by the following general formula (C3) is preferably a compound represented by the following general formula (C4).

In the above general formulas (C3) and (C4),
R ₂₁ is independently the same as in the general formula (C1),
R ₂₂₃ and R ₂₂₄ are each independently a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group ( Provided that a group having an azine ring structure is excluded), a substituted or unsubstituted alkylamino group, a substituted or unsubstituted arylamino group (excluding a group having an azine ring structure), a substituted or Unsubstituted monovalent aromatic hydrocarbon ring group, substituted or unsubstituted monovalent aromatic heterocyclic group (excluding groups having an azine ring structure), or substituted or unsubstituted monovalent Valent aromatic hydrocarbon ring-representing an aromatic heterocyclic ring group (however, excluding those having an azine ring structure),
d independently represents 0, 1, 2, 3 or 4,
e represents 0, 1, 2 or 3.

Here, when d and e are each 0, it means that the ring structure site of interest has no substituents and is unsubstituted, and a hydrogen atom is bonded to each bonding position. ..

Here, the description of each substituent that can form R ₂₂₃ and R ₂₂₄ is the same as the description of each substituent that can form R ₂₂ of the above general formula (C1), and thus the description thereof is omitted. ..

The monovalent aromatic hydrocarbon ring group that can form R ₂₂₃ and R ₂₂₄ is preferably a monovalent aromatic hydrocarbon ring group having 6 to 60 carbon atoms. Further, it is more preferably a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms.

The monovalent aromatic heterocyclic group that can form R ₂₂₃ and R ₂₂₄ is preferably a monovalent aromatic heterocyclic group having 3 to 60 ring atoms. Further, it is preferably a monovalent aromatic heterocyclic group having 3 to 60 ring atoms.

The monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring assembling group that can form R ₂₂₃ and R ₂₂₄ is one or more aromatic hydrocarbon rings having 6 to 60 carbon atoms and one or more ring-forming atoms. It is preferably a group in which aromatic heterocycles having a number of 3 or more and 60 or less are bonded to each other by a single bond. In addition, it is a group in which one or more aromatic hydrocarbon rings having 6 to 30 carbon atoms and one or more aromatic heterocycles having 3 to 30 ring atoms are bonded to each other by a single bond. preferable.

In the general formula (C4), d is preferably 0. When d is not 0, R ₂₂₃ is independently a substituted or unsubstituted monovalent aromatic hydrocarbon ring having 6 to 30 carbon atoms, which does not have a deuterium atom or an azine ring structure. Group, a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms, which does not have an azine ring structure, or a substituted or unsubstituted, which does not have an azine ring structure, A substituted or unsubstituted one or more aromatic hydrocarbon ring having 6 or more and 30 or less carbon atoms and an azine ring structure, or one or more aromatic heterocycle having 3 or more and 30 or less ring-forming atoms, It is preferable that the groups are bonded to each other by a single bond.

Further, in the above general formula (C4), e is preferably 0. When e is not 0, R ₂₂₄ is independently a substituted or unsubstituted monovalent aromatic hydrocarbon ring having 6 to 30 carbon atoms, which does not have a deuterium atom or an azine ring structure. Group, a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms, which does not have an azine ring structure, or a substituted or unsubstituted, which does not have an azine ring structure, A substituted or unsubstituted one or more aromatic hydrocarbon ring having 6 or more and 30 or less carbon atoms and an azine ring structure, or one or more aromatic heterocycle having 3 or more and 30 or less ring-forming atoms, It is preferable that the groups are bonded to each other by a single bond.

Here, in the general formula (C4), it is more preferable that both d and e are 0, and R ₂₁ is an unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms. Further, it is more preferable that both d and e are 0, and R ₂₁ is an unsubstituted biphenyl group.

In the above general formula (C4), at least two groups out of R ₂₁ , one or more R ₂₂₃ and one or more R ₂₂₄ may be fused or bonded to each other to form a ring structure.

Hereinafter, the compound represented by the above general formula (C3) will be specifically exemplified. However, the carbazole derivative is not limited to these specific examples.

Moreover, the following compounds are mentioned as a preferable example of a preferable carbazole derivative other than the above.

Among these carbazole derivatives, the compounds of H1-1, H2-34 or H3-3 are preferable.

The carbazole derivative is not limited to the compounds of the specific examples shown above. For example, known carbazole derivatives described in US2016/009388, paragraphs 0095 to 0104, JP-A-2014-509067 and the like can be incorporated into the present invention by reference. The carbazole derivatives described in these references can also be used as the basis for the amendment in this specification.

The content of the carbazole derivative in the composition is 100 mass% of the total of the carbazole derivative itself which functions as a host material and the compound represented by the above general formula (1) which functions as a host material. It is preferably 5% by mass or more and 90% by mass or less. Further, the content is more preferably 10% by mass or more and 80% by mass or less, further preferably 15% by mass or more and 70% by mass or less.

The content of the carbazole derivative in the composition is such that the carbazole derivative itself which functions as a host material, the compound represented by the above general formula (1) which functions as a host material, and the compound which functions as a host material, It is preferably 5% by mass or more and 90% by mass or less with respect to 100% by mass of the total mass of the azine ring derivative described later. Further, the content is preferably 10% by mass or more and 80% by mass or less, and more preferably 15% by mass or more and 70% by mass or less. Within the above range, the solubility of the composition is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. As described below, the azine ring derivative is a host material that can be used arbitrarily.

When the composition according to one embodiment of the present invention further includes a carbazole derivative, the difference (ΔHOMO) between the HOMO level (HOMO ₀ ) of the compound represented by the above general formula (1) and the HOMO (HOMO _Cz ) of the carbazole derivative. ) (Hole trap depth) is calculated by the following mathematical expression (1). Here, both HOMO ₀ and HOMO _Cz are numerical values in the negative region, that is, negative values.

ΔHOMO is preferably 0.05 eV or more and 1.0 eV or less, more preferably 0.10 eV or more and 0.8 eV or less, and further preferably 0.15 eV or more and 0.7 eV or less. Here, a preferable relationship between HOMO ₀ and HOMO _Cz is shown in FIG. Within the above range, the light emitting efficiency and the light emitting life of the organic EL element are further improved.

(Azine ring derivative)
The composition according to one aspect of the present invention preferably further contains an azine ring derivative. That is, it is preferable that the composition contains the compound represented by the general formula (1) and an azine ring derivative.

In the present specification, the “azine ring derivative” refers to a compound having a nitrogen-containing aromatic ring, which has a 6-membered ring structure such as an azine ring, a diazine ring or a triazine ring, or a condensed ring structure containing a part thereof. ..

By containing the azine ring derivative, the composition according to one embodiment of the present invention can further enhance the effect of suppressing the aggregation of molecules and improve the balance of the carrier mobility of electrons and holes. Therefore, the solubility of the composition is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved.

The azine ring derivative has a 6-membered heterocyclic structure (azine ring structure) containing a nitrogen atom (N) as a ring-forming atom. Therefore, a deep LUMO (Lowest Unoccupied Molecular Orbital) is distributed in the composition according to one aspect of the present invention by the azine ring derivative. Therefore, at least one of the electron injecting property and the electron transporting property is further enhanced while suppressing the aggregation of molecules in the film. Further, continuous modulation can be easily performed by controlling the composition ratio of the electron-injecting and electron-transporting azine ring derivative. In particular, it becomes easy to control the amount of electrons in the light emitting layer and the electron density profile in the film thickness direction. As a result, when the composition according to one embodiment of the present invention contains the azine ring derivative, the performance (in particular, at least one of the electron injection property and the electron transport property) of the organic EL device produced by the wet film formation method is improved. To improve. As a result, at least one of luminous efficiency and luminous lifetime of the organic EL element is further improved.

The azine ring derivative is preferably a compound represented by the following general formula (A1).

In the general formula (A1), Z _{1 to} Z ₆ are each independently C(R ₃₁ ) or a nitrogen atom. Further, at least one of Z _{1 to} Z ₆ is a nitrogen atom. That is, the compound represented by the general formula (A1) is a 6-membered heterocyclic compound containing a nitrogen atom (N) (nitrogen-containing heterocyclic compound).

In Z _{1 to} Z ₆ , C in C(R ₃₁ ) represents a carbon atom.

Here, _{R 31} in the C _{(R 31)} is not particularly limited as long as it is a hydrogen atom, a deuterium atom or an organic group. Among these, a monovalent aromatic hydrocarbon ring derived from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, and one or more substituted or unsubstituted aromatic hydrocarbon rings. Group (hereinafter, also simply referred to as “monovalent aromatic hydrocarbon ring group” in the description of the azine ring derivative), an aromatic heterocycle composed of one or more substituted or unsubstituted aromatic heterocycles. A ring-derived monovalent group (hereinafter, also simply referred to as “monovalent aromatic heterocyclic group” in the description of the azine ring derivative), or a substituted or unsubstituted one or more aromatic hydrocarbon rings and A monovalent ring-assembling group composed of one or more substituted or unsubstituted aromatic heterocycles (hereinafter, in the description of the azine ring derivative, "monovalent aromatic hydrocarbon ring-aromatic heterocycle" It is also referred to as an “assembling group”).

The alkyl group that can form R ₃₁ in C(R ₃₁ ) is the same as the description for R ₂₂ in the general formula (C1), and thus the description is omitted.

The monovalent aromatic hydrocarbon ring group that can form R ₃₁ in C(R ₃₁ ) is the same as the description of R ₂₁ of the above general formula (C1), and thus the description thereof is omitted.

The aromatic heterocyclic monovalent group capable of constituting the R ₃₁ in the C (R ₃₁₎ is not particularly limited. For example, a monovalent aromatic heterocyclic group having 3 to 60 ring atoms, that is, 1 or more hetero atoms (eg, nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom) (S)) and the group derived from a ring (aromatic heterocycle) having 3 to 60 ring-forming atoms including one or more aromatic rings in which the remaining ring atoms are carbon atoms (C). To be The monovalent aromatic heterocyclic group that can form R ₃₁ is preferably a monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms. Moreover, when the aromatic heterocyclic group includes two or more rings, the two or more rings may be bonded or fused to each other by a single bond.

The aromatic heterocycle constituting the monovalent aromatic heterocyclic group is not particularly limited, and examples thereof include a π-electron deficient aromatic heterocycle, a π-electron excess aromatic heterocycle, and a π-electron deficient aromatic heterocycle. An example is a π-electron deficient system-π-electron excess system mixed aromatic heterocycle in which a ring and a π-electron excess system aromatic heterocycle are mixed.

Specific examples of the π-electron-deficient aromatic heterocycle include pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, naphthyridine ring, acridine ring, phenazine ring, Examples thereof include a benzoquinoline ring, a benzisoquinoline ring, a phenanthridine ring, a phenanthroline ring, a benzoquinone ring, a coumarin ring, an anthraquinone ring and a fluorenone ring.

Specific examples of the π-electron excess aromatic heterocycle include furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofura ring, dibenzothiophene ring, pyrrole ring, indole ring, carbazole ring and indolocarbazole ring. Can be mentioned.

Specific examples of the π-electron deficient system-π-electron excess system mixed aromatic heterocycle include an imidazole ring, a benzimidazole ring, a pyrazole ring, an indazole ring, an oxazole ring, an isoxazole ring, a benzoxazole ring, a benzisoxazole ring, and a thiazole. Ring, isothiazole ring, benzothiazole ring, benzisothiazole ring, imidazolinone ring, benzimidazolinone ring, imidazopyridine ring, imidazopyrimidine ring, imidazophenanthridine ring, benzimidazophenanthridine ring, azadibenzofuran ring, aza Examples thereof include a carbazole ring, an azadibenzothiophene ring, a diazadibenzofuran ring, a diazacarbazole ring, a diazadibenzothiophene ring, a xanthone ring and a thioxanthone ring.

The monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group is not particularly limited. For example, a group in which one or more aromatic hydrocarbon rings having 6 or more and 60 or less carbon atoms and one or more aromatic heterocycles having 3 or more and 60 or less ring-forming atoms are bonded to each other by a single bond, and the like can be mentioned. .. Moreover, one or more hydrogen atoms present in these aromatic hydrocarbon ring groups or aromatic heterocycles may be substituted with other substituents. In addition, the aromatic hydrocarbon ring and the aromatic heterocycle that compose the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group are the monovalent aromatic hydrocarbon ring group and the monovalent aromatic ring, respectively. Since it is the same as the heterocyclic group, description thereof will be omitted.

The monovalent aromatic hydrocarbon ring group, the monovalent aromatic heterocyclic group, and the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group which may form R ₃₁ are substituted with another substituent. May be.

The alkyl group that can form R ₃₁ may be substituted with another substituent.

These other substituents are not particularly limited as long as they are a deuterium atom or an organic group.

Examples of other substituents that may substitute the monovalent aromatic hydrocarbon ring group, the monovalent aromatic heterocyclic group, and the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group that may form R ₃₁ , For example, deuterium atom, cyano group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylamino Groups, or substituted or unsubstituted arylamino groups.

Examples of the other substituent capable of substituting the alkyl group that may form R ₃₁ include a deuterium atom, a cyano group, an unsubstituted alkoxy group, an unsubstituted aryloxy group, an unsubstituted alkylamino group, or an unsubstituted group. Substituted arylamino groups are mentioned.

The alkyl group, the alkoxy group, and the alkylamino group which can form the other substituents in R ₃₁ are the same as the description of these groups which can form the R ₂₂ in the general formula (C1), respectively, The description is omitted.

The aryloxy group which may form another substituent in R ₃₁ is not particularly limited. For example, an aryloxy group having 6 to 30 ring-forming atoms and the like can be mentioned. The aryloxy group may contain a hetero atom. That is, it may be a heteroaryloxy group. The aryloxy group is a monocyclic or condensed polycyclic aryloxy group having 6 to 30 ring-forming atoms. Specifically, a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 2-azurenyloxy group, a 2-furanyloxy group, a 2-thienyloxy group, a 2-indolyloxy group, a 3-indolyloxy group, Examples thereof include a 2-benzofuryloxy group and a 2-benzothienyloxy group.

The arylamino group that may form another substituent in R ₃₁ is not particularly limited. For example, it is an arylamino group having 6 to 60 ring atoms (excluding those having an azine ring structure). The arylphenyl group may contain heteroatoms. That is, it may be a heteroarylamino group. Specific examples thereof include N-arylamino groups such as N-phenylamino group, N-biphenylamino group and N-terphenylamino group. Further, N,N-diphenylamino group, N,N-dibiphenylamino group, N,N-diterphenylamino group, N-biphenyl-N-phenylamino group, N-biphenyl-N-terphenylamino group, Examples thereof include N,N-diphenylamino groups such as N-phenylter-N-phenylamino group.

The monovalent aromatic hydrocarbon ring group, the monovalent aromatic heterocyclic group and the monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group which may form the other substituents in R ₃₁ , are respectively: Since it is the same as the description of the monovalent aromatic hydrocarbon ring group, monovalent aromatic heterocyclic group and monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group which can form R ₃₁ described above, The description is omitted.

Incidentally, a monovalent aromatic hydrocarbon ring group as another substituent, a monovalent aromatic heterocyclic group, another substituent capable of substituting a monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group. Examples of further other substituents that may further substitute are, for example, deuterium atom, cyano group, unsubstituted alkyl group, unsubstituted alkoxy group, unsubstituted aryloxy group, unsubstituted alkylamino group, arylamino Groups.

In addition, two or more R _31's may be bonded, fused or bonded to each other with a single bond to form a ring structure.

Further, the compound represented by the general formula (A1) may be a multimer in which the structure represented by the general formula (A1) is bonded via each R ₃₁ .

Preferred examples of the azine ring derivative include compounds represented by the following general formulas (A2-1) to (A2-5). Among these, compounds represented by the following general formula (A2-1) are preferable.

In formulas (A2-1) to (A2-5), Ar is each independently a substituted or unsubstituted monovalent aromatic hydrocarbon ring group, a substituted or unsubstituted monovalent It is an aromatic heterocyclic group or a substituted or unsubstituted monovalent aromatic hydrocarbon ring-aromatic heterocyclic ring group.

A monovalent aromatic hydrocarbon ring group, a monovalent aromatic heterocyclic group, and a monovalent aromatic hydrocarbon ring capable of forming Ar in the general formulas (A2-1) to (A2-5). The aromatic heterocyclic ring group is the same as the description of these groups in C ₃₁ of the general formula (A1), and thus the description thereof is omitted.

In the above general formulas (A2-1) to (A2-5), a monovalent aromatic hydrocarbon ring group in Ar, a monovalent aromatic hydrocarbon ring group, a monovalent aromatic hydrocarbon ring-aromatic group The heterocyclic ring assembly group may be substituted with another substituent. Here, the other substituents in Ar are a monovalent aromatic hydrocarbon ring group, a monovalent aromatic heterocyclic group, and a monovalent aromatic hydrocarbon ring-in R ₃₁ of the general formula (A1). The description is omitted because it is similar to the description of the other substituents that can substitute the aromatic heterocyclic ring assembly group.

In formulas (A2-1) to (A2-5), two or more substituents may be bonded or condensed with each other by a single bond to form a ring structure.

Further, a preferable example of the azine ring derivative is a compound represented by the following general formula (A3).

In the general formula (A3), T is a condensed ring bond having a ring structure represented by the following general formula,

Z ₁ , Z ₃ and Z ₅ are each independently CH or N, provided that at least one of Z ₁ , Z ₃ and Z ₅ is N,
R ₃₁ is independently the same as in the general formula (A1),
R ₃₂ , R ₃₂ ′, R ₃₃ and R ₃₄ are each independently a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or Unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted arylamino group, substituted or unsubstituted monovalent aromatic hydrocarbon ring group, substituted or An unsubstituted monovalent aromatic heterocyclic group, or a substituted or unsubstituted monovalent aromatic hydrocarbon ring-representing an aromatic heterocyclic ring group,
f and g each independently represent 0, 1, 2, 3 or 4,
h represents 0, 1, 2, 3, 4 or 5,
i represents 0, 1 or 2.

Here, when f, h, and i are each 0, the ring structure site of interest has no substituents and is unsubstituted, and a hydrogen atom is bonded to each bonding position. Represents.

Here, each substituent that may form R _32, R ₃₂ ′ _, R ₃₃ and R ₃₄ in the general formula (A3) may form another substituent in R ₃₁ of the general formula (C1). The description is omitted because it is similar to the description of the substituent.

In some embodiments of general formula (A3) above, it is preferable that Z ₁ , Z ₃ and Z ₅ are all N.

In the general formula (A3), f and g are both 0, h is 1, i is 0, and R ₃₁ and R ₃₃ are both unsubstituted monovalent aromatic hydrocarbons. It is preferably a cyclic group. In the general formula (A3), f and g are both 0, h is 1, i is 0, R ₃₁ is an unsubstituted phenyl group, and R ₃₃ is an unsubstituted phenyl group. Is preferably a biphenyl group.

In the general formula (A3), at least two groups out of one or more R ₃₁ , one or more R ₃₂ , one or more R ₃₂ ′, one or more R ₃₃ and one or more R ₃₄ , They may be bonded or fused or bonded to each other with a single bond to form a ring structure.

Examples of the azine ring derivative of one aspect of the present invention include the following compounds.

In the triazine compound represented by the general formula A2-1, it is more preferable that at least two of the three Ars bonded to the triazine ring have different structures from each other. With such a structure, the crystallinity of the compound can be reduced and the solubility of the compound can be increased.

Specific examples of the compounds represented by the general formulas A2-2, A2-3, A2-4, and A2-5 include, in the exemplified compound of the general formula A2-1, a triazine ring, a pyrimidine ring, a pyridazine ring, and a pyrazine ring. , Compounds each substituted with a pyridine ring, and the like.

Specific examples of the quinazoline compound and the quinoline compound include compounds in which the triazine ring in the exemplified compound of the general formula A2-1 is replaced with a quinazoline ring or a quinoline ring.

Among these azine ring derivatives, the above Az1 is preferable.

The azine ring derivative is not limited to the above-exemplified compounds. For example, paragraphs 0078 to 0094 of U.S. Patent Application Publication No. 2016/0093808, Japanese Patent Publication No. 2013-535830, Japanese Patent Publication No. 2018-524797, U.S. Patent Application Publication No. 2017/0346020, U.S. Patent Application Known azine ring derivatives described in Japanese Patent Publication No. 2017/0309829 and the like can also be incorporated into the present invention by reference. In addition, the azine ring derivatives described in these references can also be used as the basis for the amendment in the present specification.

The content of the azine ring derivative in the composition is 100% by mass with respect to the total of the azine ring derivative itself that functions as a host material and the compound represented by the general formula (1) that functions as a host material. Therefore, it is preferably 5% by mass or more and 90% by mass or less. Further, the content is preferably 10% by mass or more and 80% by mass or less, and more preferably 15% by mass or more and 70% by mass or less.

The content of the azine ring derivative in the composition is such that the azine ring derivative itself that functions as a host material, the compound represented by the general formula (1) that functions as a host material, and the compound that functions as a host material. It is preferably 5% by mass or more and 90% by mass or less based on 100% by mass of the total mass of the carbazole ring derivative. Further, the content is preferably 10% by mass or more and 80% by mass or less, and more preferably 15% by mass or more and 70% by mass or less. Within the above range, the solubility of the composition is further improved, precipitation from the solution is less likely to occur, and the pot life of the solution is longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. As described above, the carbazole derivative is a host material that can be used arbitrarily.

When the composition according to one embodiment of the present invention further contains an azine ring derivative described below, the LUMO level (LUMO ₀ ) of the compound represented by the general formula (1) and the LUMO (LUMO _Azine ) of the azine ring derivative The difference (ΔLUMO) (electron trap depth) is calculated by the following mathematical expression (2). Here, both LUMO ₀ and LUMO _azine are numerical values in the negative region, that is, negative values.

ΔLUMO is preferably 0.05 eV or more and 1.0 eV or less, more preferably 0.05 eV or more and 0.5 eV or less, and further preferably 0.05 eV or more and 0.3 eV or less. Here, the preferable relationship between LUMO ₀ and LUMO _azine is shown in FIG. Within the above range, the light emitting efficiency and the light emitting life of the organic EL element are further improved.

(Example of preferred composition)
The composition according to one aspect of the present invention preferably contains the compound represented by the general formula (1), and at least one of the carbazole derivative and the azine ring derivative. Further, the composition according to one aspect of the present invention more preferably contains the compound represented by the general formula (1), the carbazole derivative, and the azine ring derivative.

As described above, the composition according to one aspect of the present invention preferably contains the compound represented by the general formula (1) and the carbazole derivative. Among these, it is more preferable to contain the compound represented by the general formula (1) and the compound represented by the general formula (C1). At this time, it is particularly preferable that the compound 1, 2 or 11 and the carbazole derivative H1-1, H2-34 or H3-3 are contained. The solubility is further improved by using the composition containing the compound represented by the general formula (1) and the carbazole derivative. Then, precipitation from the solution becomes more difficult to occur, and the pot life of the solution becomes longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. Here, it is more preferable that these compositions further include the above-mentioned phosphorescent platinum group metal complex. The phosphorescence-emitting platinum group metal complex can further improve the emission efficiency and emission life of the organic EL device. In this case, it is extremely preferable to include the compound 1, 2 or 11, the carbazole derivative H1-1, H2-34 or H3-3, and the phosphorescent platinum group metal complex D1. In addition, it is most preferable to include Compound 1, 2 or 11, a carbazole derivative H2-34, and a phosphorescent platinum group metal complex D1.

Further, the composition according to one aspect of the present invention preferably contains the compound represented by the general formula (1) and the azine ring derivative. Among these, it is more preferable to include the compound represented by the general formula (1) and the compound represented by the general formula (A1). Among these, it is more preferable to include the compound represented by the general formula (3) and the compound represented by the general formula (A3). At this time, it is more preferable that the compound 1, 2 or 11 and the azine ring derivative Az1 are contained. The solubility is further improved by using the composition containing the compound represented by the general formula (1) and the azine ring derivative. Then, precipitation from the solution becomes more difficult to occur, and the pot life of the solution becomes longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. Here, it is particularly preferable that these compositions further include the above phosphorescent platinum group metal complex. The phosphorescence-emitting platinum group metal complex can further improve the emission efficiency and emission life of the organic EL device. In this case, it is extremely preferable to include the compound 1, 2 or 11, the azine ring derivative Az1, and the phosphorescent platinum group metal complex D1.

The present inventors have found that the composition containing the compound represented by the general formula (1), the azine ring derivative, and the phosphorescent platinum group metal complex improves the emission efficiency and the emission lifetime of the organic EL device. The mechanism of improvement is estimated as follows.

Generally, an organic layer in which a hole-transporting host material typified by a conventional carbazole derivative, an electron-transporting host material typified by a conventional azine ring derivative, and a phosphorescent platinum group metal complex are combined. In the case of (light emitting layer), it is difficult to adjust the charge distribution (carrier profile) of holes and electrons in the organic layer. This is because the hole transporting property and the electron transporting property of the carbazole derivative and the azine ring derivative are too strong. For this reason, at least one of the recombination distribution (profile) and the exciton generation distribution (profile) in the organic layer is locally concentrated, so that the lifetime tends to be shortened.

On the other hand, as shown in Figure 3, LUMO (LUMO ₀₎ of the compound represented by the general formula (1) is generally shallower than the LUMO of the azine ring derivatives _{(LUMO AZINE).} Further, as shown in FIG. 3, the HOMO (HOMO ₀ ) of the compound represented by the general formula (1) is usually deeper than the HOMO (HOMO _Cz ) of the carbazole derivative. The hole mobility of the compound represented by the general formula (1) is usually lower than that of the carbazole derivative.

Therefore, the compound represented by the general formula (1) is used instead of the hole-transporting host material such as a carbazole derivative, the compound, the electron-transporting host material such as an azine ring derivative, and the phosphorescent platinum. In the case of a light emitting layer in which a group metal complex is combined, it is presumed that the following mechanism appears.

First, in the organic layer composed of the above composition, electrons are once trapped in LUMO (LUMO _azine ) of the deepest azine ring derivative. However, the trapped electrons are detrapped in LUMO (LUMO ₀ ) of the compound represented by the above general formula (1) and restart the movement. Therefore, in the organic layer, the electrons move by repeating trap- _detrap between LUMO _azine and LUMO ₀ , and the electron mobility decreases. Further, in the organic layer composed of the above composition, holes are trapped by HOMO (HOMO _MC ) of the phosphorescent platinum group metal complex. Then, the trapped holes are detrapped in HOMO (HOMO ₀ ) of the compound represented by the above general formula (1) and restart the movement. At this time, due to at least one of a large trap depth (HOMO ₀ −HOMO _MC ) and a very low detrapping probability and a low hole mobility of the compound represented by the general formula (1), Within the organic layer, hole mobility is significantly reduced. As a result, the electrons are accumulated in a high concentration on the side close to the anode (for example, the side close to the electron transport layer) in the organic layer. On the other hand, holes are accumulated in high concentration on the side close to the cathode (for example, the side close to the hole transport layer) in the organic layer. As a result, carrier recombination gradually occurs in the intermediate region between them. Then, at least one of the recombination distribution (profile) and the exciton generation profile in the organic layer (light emitting layer) is dispersed very well. As a result, the light emission efficiency and the light emission life of the organic EL element are further improved.

The above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

The composition according to one aspect of the present invention preferably contains the compound represented by the general formula (1), the carbazole derivative, and the azine ring derivative. Among these, it is more preferable to include the compound represented by the general formula (1), the compound represented by the general formula (C1), and the compound represented by the general formula (A1). Among these, it is more preferable to include the compound represented by the general formula (3), the compound represented by the general formula (C1), and the compound represented by the general formula (A3). .. At this time, it is particularly preferable that the compound 1, 2 or 11 be included, the carbazole derivative H1-1, H2-34 or H3-3, and the azine ring derivative Az1. The solubility is further improved by using the composition containing the compound represented by the general formula (1), the carbazole derivative, and the azine ring derivative. Then, precipitation from the solution becomes more difficult to occur, and the pot life of the solution becomes longer. Further, the light emission efficiency and the light emission life of the organic EL element are further improved. In particular, since the driving voltage of the organic EL element is further reduced and the power consumption is further reduced, the effect of improving the luminous efficiency becomes remarkable. Here, it is particularly preferable that these compositions further include the above phosphorescent platinum group metal complex. The phosphorescence-emitting platinum group metal complex can further improve the emission efficiency and emission life of the organic EL device. In this case, it is extremely preferable to include the compound 1, 2 or 11, the carbazole derivative H1-1, H2-34 or H3-3, the azine ring derivative Az1, and the phosphorescent platinum group metal complex D1.

The inventors of the present invention emitted light of an organic EL device using a composition containing the compound represented by the general formula (1), the carbazole derivative, the azine ring derivative, and the phosphorescent platinum group metal complex. The mechanism for improving efficiency and emission lifetime is estimated as follows.

As described in the explanation of the presumed mechanism of the composition containing the compound represented by the general formula (1), the azine ring derivative, and the phosphorescent platinum group metal complex, the conventional carbazole derivative, etc. In the case of an organic layer (light-emitting layer) in which the hole-transporting host material (1), a conventional electron-transporting host material such as an azine ring derivative, and a phosphorescent platinum group metal complex are combined, the Local concentration of at least one of the coupling distribution (profile) and the exciton generation distribution (profile) tends to shorten the lifetime.

Also, as shown in FIG. 4, LUMO ₀ is usually shallower than LUMO _azine . HOMO ₀ is usually deeper than HOMO _Cz . The hole mobility of the compound represented by the general formula (1) is usually lower than that of the carbazole ring derivative.

Therefore, a compound represented by the general formula (1) is prepared by using a hole-transporting host material such as a carbazole derivative, an electron-transporting host material such as an azine ring derivative, and the above phosphorescent platinum group metal complex. It is presumed that the following mechanism will appear when additional addition is made to the combined light emitting layer.

First, in the organic layer composed of the above composition, the electron is once trapped in the deepest LUMO _azine . However, the trapped electrons are detrapped in LUMO ₀ and restart the movement. Therefore, in the organic layer, the electrons move by repeating trap- _detrap between LUMO _azine and LUMO ₀ , and the electron mobility decreases. These points are related to the composition containing the compound represented by the general formula (1), the azine ring derivative, and the phosphorescent platinum group metal complex described with reference to FIG. It is similar to the estimation mechanism.

In addition, in this embodiment, holes are trapped in the HOMO _MC . Then, the trapped holes are detrapped in the HOMO _Cz and restart the movement. Further, in the organic layer, the compound represented by the general formula (1) is present in a certain amount or more. Here, as shown in FIG. 4, the compound represented by the general formula (1) has a deeper HOMO ₀ and lower hole mobility as compared with the carbazole derivative. From this, the hole mobility in the organic layer is obtained when the compound represented by the general formula (1) does not exist, that is, the hole transporting host material such as the carbazole derivative or the like and the azine ring derivative or the like. This is lower than in the case of the conventional organic layer (light emitting layer) in which the electron transporting host material (1) and the above phosphorescent light emitting platinum group metal complex are combined.

As a result, the electrons are accumulated in a high concentration on the side close to the anode (for example, the side close to the electron transport layer) in the organic layer. On the other hand, holes are accumulated in high concentration on the side close to the cathode (for example, the side close to the hole transport layer) in the organic layer. As a result, carrier recombination gradually occurs in the intermediate region between them. Then, at least one of the recombination distribution (profile) and the exciton generation distribution (profile) in the organic layer (light emitting layer) is dispersed extremely well. As a result, the light emission efficiency and the light emission life of the organic EL element are further improved.

In addition, as described above, an embodiment of the composition using only the compound represented by the general formula (1) and the azine ring derivative as the host material and using the phosphorescent platinum group metal complex as the light emitting material When adopted, the high effect of the present invention is exhibited. However, an embodiment relating to a composition using the compound represented by the general formula (1), the carbazole derivative and the azine ring derivative as a host material and the phosphorescent platinum group metal complex as a light emitting material is adopted. In that case, the effect of the present invention is further enhanced. This is because the hole mobility is reduced to a suitable degree, and in addition to the effect of improving the light emission life, the lowering of the driving voltage (lowering of power consumption) is satisfied.

The above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

In each composition described above, the compound represented by the general formula (1) is preferably a wide gap material. By using the material, the light emission efficiency and the light emission life of the organic EL element are further improved.

The method for preparing each composition described above is not particularly limited. For example, these compositions can be prepared by mixing the compound represented by the general formula (1) with another compound optionally used. The order of mixing is not particularly limited, the mixing method and the mixing conditions are not particularly limited, and various preparation methods including known preparation methods can be used.

The composition according to one aspect of the present invention is preferably used as a material for an organic electroluminescence device (also referred to as a material for an organic EL device in the present specification). That is, the organic EL device material preferably contains the composition according to one embodiment of the present invention.

<Liquid composition>
Another aspect of the present invention relates to a liquid composition containing a compound represented by the general formula (1) or a composition containing the compound and another compound, and a solvent. As the liquid composition, it is preferable to include the composition described in the example of the preferable composition and a solvent.

The solvent is not particularly limited, but a solvent having a boiling point of 100° C. or higher and 350° C. or lower at atmospheric pressure (101.3 kPa, 1 atm) is preferable. That is, a preferred embodiment of the present invention comprises a compound represented by the general formula (1) or a composition containing the compound and another compound, and a solvent having a boiling point at atmospheric pressure of 100° C. or higher and 350° C. or lower. It is a liquid composition containing. The boiling point of the solvent at atmospheric pressure is more preferably 150° C. or higher and 320° C. or lower, and further preferably 180° C. or higher and 300° C. or lower. When the boiling point of the solvent at atmospheric pressure is in the above range, the film forming property and processability in the wet film forming method, particularly the inkjet (ink jet) printing method are improved. As a result, at least one of the effect that the light emission efficiency and the light emission life of the organic EL element are further improved and that the convenience (work efficiency or yield) in the manufacturing process is improved is obtained.

The solvent having a boiling point of 100° C. or higher and 350° C. or lower at atmospheric pressure is not particularly limited, and a known solvent can be appropriately adopted. Specific examples of the solvent having a boiling point of 100° C. or higher and 350° C. or lower at atmospheric pressure are shown below, but the present invention is not limited to these specific examples.

Examples of the hydrocarbon solvent include octane, nonane, decane, undecane, dodecane and the like. Examples of the aromatic hydrocarbon solvent include toluene, xylene, ethylbenzene, n-propylbenzene, iso-propylbenzene (isopropylbenzene), and mesitylene. (Mesitylene), n-butylbenzene (n-butylbenzene), sec-butylbenzene (sec-butylbenzene), 1-phenylpentane (1-phenylpentane), 2-phenylpentane (2-phenylpentane), 3-phenylpentane (3) Examples thereof include -phenylpentane), phenylcyclopentane, phenylcyclohexane, 2-ethylbiphenyl, 3-ethylbiphenyl, and 3-ethylbiphenyl. -Dioxane (1,4-dioxane), 1,2-diethoxyethane (1,2-diethoxyethane), diethylene glycol dimethyl ether (diethylene glycol diethylether), 3 diethylene ethereal ethene (ethoxy), anisole (anisole), anisole (anisole). -Methylanisole, m-dimethoxybenzene, etc. As the ketone solvent, 2-hexanone (2-hexanone), 3-hexanone (3-hexanone), cyclohexanone (cyclohexanone). ), 2-heptanone (2-heptanone), 3-heptanone (3-heptanone), 4-heptanone (4-heptanone), cycloheptanone (cycloheptanone), etc. Butyl acetate (butylacetate) is used as the ester solvent. ), butyl propionate (butylpropionate), butyl butyrate (heptylbutyrate), propylene carbonate (propyrenecarbonate), methyl benzoate (methyl benzoate) (methyl) Benzoate), ethyl benzoate, 1-propyl benzoate, 1-butyl benzoate, and the like. Examples of the nitrile solvent include benzonitrile, 3-methylbenzonitrile, and the like. Examples of the amide solvent include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like. Among these, ester solvents are preferable, and methylbenzoate is more preferable. You may use these solvent individually by 1 type or in combination of 2 or more types.

When the liquid composition contains only the compound represented by the general formula (1) and the solvent, the concentration of the compound in the liquid composition is not particularly limited and can be appropriately adjusted depending on the application. However, from the viewpoint of ease of application and the like, the content of the compound in the liquid composition is adjusted to preferably 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the solvent. Further, the concentration of the compound is adjusted to be more preferably 0.1 part by mass or more and 6 parts by mass or less with respect to 100 parts by mass of the solvent. Within the above range, it becomes easy to secure the required film thickness of the organic thin film when the film is formed by the coating method, and the precipitation from the solution is less likely to occur, the pot life of the solution becomes longer, and the organic EL element Luminous efficiency and luminous lifetime are further improved.

When the liquid composition contains a composition containing the compound represented by the general formula (1) and another compound and a solvent, the content of the composition in the liquid composition is not particularly limited, It can be adjusted accordingly. However, from the viewpoint of ease of coating and the like, the concentration of the composition in the liquid composition is preferably adjusted to 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the solvent. Further, the concentration of the composition is adjusted to more preferably 0.1 part by mass or more and 6 parts by mass or less with respect to 100 parts by mass of the solvent. Within the above range, precipitation from the solution is less likely to occur, the pot life of the solution becomes longer, and the light emission efficiency and light emission life of the organic EL element are further improved.

The method for preparing the liquid composition is not particularly limited. For example, the liquid composition can be prepared by mixing the compound represented by the general formula (1), another compound optionally used, and a solvent. The order of mixing is not particularly limited, the mixing method and the mixing conditions are not particularly limited, and various preparation methods including known preparation methods can be used.

<Organic electroluminescence device>
Yet another embodiment of the present invention relates to an organic electroluminescence device containing the compound represented by the general formula (1). More specifically, the embodiment has a pair of electrodes, and an organic electroluminescent device provided with an organic layer disposed between the pair of electrodes and containing the compound or a composition containing the compound and another compound. Regarding

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of description, and may differ from the actual ratios.

FIG. 5 is a schematic diagram of an organic electroluminescent element according to one embodiment of the present invention. Hereinafter, with reference to FIG. 5, the organic electroluminescent element according to one embodiment of the present invention will be described in detail.

As shown in FIG. 5, an organic electroluminescence element (organic EL element) 100 according to one embodiment of the present invention is provided with a substrate 110, a first electrode 120 disposed on the substrate 110, and a first electrode 120 disposed on the substrate 110. Hole injection layer 130, hole transport layer 140 disposed on hole injection layer 130, light emitting layer 150 disposed on hole transport layer 140, and electron disposed on light emitting layer 150. The electron transport layer 160 includes an electron injection layer 170 disposed on the electron transport layer 160, and a second electrode 180 disposed on the electron injection layer 170.

Here, the compound represented by the general formula (1) may be included in any organic layer disposed between the first electrode 120 and the second electrode 180. The composition containing the compound represented by the general formula (1) and another compound is contained in, for example, one of the organic layers arranged between the first electrode 120 and the second electrode 180. sell.

Specifically, the compound represented by the general formula (1) can be included in the hole injection layer 130 as a hole injection material from the viewpoint of excellent hole transportability and electron transportability. Further, it may be included in the hole transport layer 140 as a hole transport material, or may be included in the light emitting layer 150 as a light emitting layer material (host). Further, it may be included in the electron transport layer 160 as an electron transport material, and may be included in the electron injection layer 170 as an electron injection material. The compound is more preferably contained in the hole injection layer 130, the hole transport layer 140, or the light emitting layer 150. More preferably, it is included in the light emitting layer 150. The composition containing the compound represented by the general formula (1) and another compound is contained in the hole injection layer 130 as a hole injection material from the viewpoint of excellent hole transportability and electron transportability. Can be Further, it may be included in the hole transport layer 140 as a hole transport material, or may be included in the light emitting layer 150 as a light emitting layer material (host). Further, it may be included in the electron transport layer 160 as an electron transport material, and may be included in the electron injection layer 170 as an electron injection material. The composition is more preferably contained in the hole injection layer 130, the hole transport layer 140, or the light emitting layer 150. More preferably, it is included in the light emitting layer 150.

The organic layer containing the compound represented by the general formula (1) is preferably formed by a wet film formation method, and more preferably formed by a coating method. Specific examples of the coating method include a spin coat method, a casting method, a micro gravure coat method, a gravure coat method, a bar coat method, and a roll coat method. (Roll coat method), wire bar coat method (wire bar coat method), dip coat method (dip coat method), spray coat (spray coat) method, screen printing method, flexographic printing method, offset (offset) A printing method, an ink jet printing method and the like can be mentioned. Among these, the inkjet printing method is preferable from the viewpoint of productivity.

The coating liquid used in the coating method is preferably the above liquid composition. Therefore, the details of the coating liquid are the same as the above description of the liquid composition.

Note that the procedures, conditions, devices, etc. of the dry film forming method and coating method are not particularly limited, and the same procedures, conditions, devices, etc. as the known dry film forming method, coating method can be appropriately adopted.

The method for forming layers other than the organic layer containing the compound represented by the general formula (1) is not particularly limited. Such layers other than the organic layer may be formed by a dry film forming method such as a vacuum vapor deposition method or a wet film forming method such as a coating method.

As the substrate 110, a substrate used in a general organic EL element can be used. For example, the substrate 110 may be a semiconductor substrate such as a glass substrate, a silicon substrate, or a transparent plastic substrate.

The first electrode 120 is formed on the substrate 110. The first electrode 120 is preferably an anode. The first electrode 120 is preferably formed of a metal, an alloy, a conductive compound, or the like having a large work function (the minimum energy required to take out one electron in the substance to the outside). For example, the first electrode 120 includes indium tin oxide (In ₂ O ₃ —SnO ₂ :ITO), indium zinc oxide (In ₂ O ₃ —ZnO), tin oxide (SnO ₂ ), and oxide that are excellent in transparency and conductivity. It may be formed as a transmissive electrode by zinc (ZnO) or the like. 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.

The hole injection layer 130 is formed on the first electrode 120. The hole injection layer 130 is a layer that facilitates injection of holes from the first electrode 120. The thickness of the hole injection layer 130 is not particularly limited, but is preferably 10 nm or more and 1000 nm or less. Further, the film thickness is more preferably 10 nm or more and 100 nm or less.

When the organic layers other than the hole injection layer 130 include the compound represented by the general formula (1), the hole injection layer 130 may be formed only from a known material such as a known hole injection material. Good.

Known hole injection materials include, for example, triphenylamine-containing polyether ketone (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 ( copper phthalocyanine), 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine: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 (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 (polyaniline/dodecylbenzenesulphonic acid), poly(3,4-ethylenedioxythiophene)/poly(4-) Styrene sulfonate) (poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate): PEDOT/PSS), and polyaniline/10-camphor sulfonic acid (polyaniline/10-camphorsulfonic acid). Can be mentioned.

The 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. The thickness of the hole transport layer 140 is not particularly limited, but is preferably 10 nm or more and 150 nm or less.

When the organic layers other than the hole transport layer 140 include the compound represented by the general formula (1), the hole transport layer 140 may be formed only from a known material such as a known hole transport material. ..

Known hole transport materials include, for example, 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (1,1-bis[(di-4-tolylamino)phenyl]cyclohexane:TAPC), N-. Carbazole derivatives such as 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 (4,4',4"-tris(N-carbazolyl)triphenylamine:TCTA), and N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (N,N'-di(1-naphthyl)-N,N'-diphenylbenzenezine:NPB) etc. can be mentioned. In addition, the hole transport materials described in WO 2011/159872, US Patent Application Publication No. 2016/0315259, etc. can also be used.

The light emitting layer 150 is formed on the hole transport layer 140. The light emitting layer 150 is a layer that emits light by fluorescence, phosphorescence, or the like. The thickness of the light emitting layer 150 is not particularly limited, but is preferably 10 nm or more and 60 nm or less.

The light emitting material included in the light emitting layer 150 is preferably a light emitting material capable of emitting light (that is, phosphorescence) from triplet excitons. In such a case, the light emission efficiency and the light emission life of the organic EL element 100 can be further improved.

The light emitting layer 150 particularly preferably contains the compound represented by the general formula (1), and more preferably contains a composition containing the compound.

When the organic layer other than the light emitting layer 150 contains the compound represented by the general formula (1), the light emitting layer 150 does not contain the compound represented by the general formula (1), and a known light emitting material or the like is known. It may be formed only from the material.

The light emitting layer 150 is, for example, tris(8-quinolinolato)aluminum (tris(8-quinolinato)aluminum:Alq3), 4,4′-bis(carbazol-9-yl)biphenyl(4,4′-) as a host material. bis(carbazol-9-yl)biphenyl:CBP), poly(n-vinylcarbazole) (poly(n-vinylcarbazole):PVK), 9,10-di(naphthalen-2-yl)anthracene (9,10-) di(naphthalene) anthracene: ADN), 4,4',4"-tris(N-carbazolyl)triphenylamine (4,4',4"-tris(N-carbazolyl)triphenylamine:TCTA), 1,3,3 5-tris(N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenyl-benzimidazol-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-) A known material such as carbazole)-2,2'-dimethyl-biphenyl (4,4'-bis(9-carbazole)2,2'-dimethyl-biphenyl:dmCBP) may be included.

The light emitting layer 150 includes, as a dopant material, for example, perylene and its derivative, rubrene and its derivative, coumarin and its derivative, 4-dicyanomethylene-2-(p-dimethylaminostyryl)-. 6-methyl-4H-pyran (4-dicyanomethylstyrene-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)(bis(1-phenylisoquinoline)(acetylacetone) )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 Iridium (Ir) complexes such as iridium (III), osmium (Os) complexes, platinum complexes and other known materials may be included.

The light emitting layer 150 may include nanoparticles such as quantum dots as a light emitting material. Quantum dots are nanoparticles composed of I-VI group semiconductors, III-V group semiconductors, or IV-IV group semiconductors. Examples of the semiconductor include CdS, CdSe, CdTe, ZnSe, ZnS, PbS, PbSe, HgS, HgSe, HgTe, CdHgTe, CdSe _X Te _1-X , GaAs, InAs and InP. However, the semiconductor is not limited to these. The diameter of nanoparticles such as quantum dots is not particularly limited, but is preferably 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.

The electron transport layer 160 is formed on the light emitting layer 150. The electron transport layer 160 is a layer having a function of transporting electrons. The thickness of the electron transport layer 160 is not particularly limited, but is preferably 15 nm or more and 50 nm or less.

When the organic layers other than the electron transport layer 160 include the compound represented by the general formula (1), the electron transport layer 160 does not include the compound represented by the general formula (1), and a known electron transport material is used. Etc., may be formed only from a known material.

Examples of the known electron transport material include tris(8-quinolinolato)aluminum (tris(8-quinolinato)aluminum:Alq ₃ ), and compounds having a nitrogen-containing aromatic ring. Specific examples of the compound having a nitrogen-containing aromatic ring include, for example, 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-tri[(3-pyridyl)). A compound containing a pyridine ring, such as -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-Phenylbenzinidazolyl-1-yl-phenyl)-9,10-dinaphthylanthracene Compounds containing an imidazole ring such as ). ) And the like.

An electron injection layer 170 is formed on the electron transport layer 160. The electron injection layer 170 is a layer having a function of facilitating injection of electrons from the second electrode 180. The thickness of the electron injection layer 170 is not particularly limited, but is preferably 0.3 nm or more and 20 nm or less.

When the organic layer other than the charge injection layer 170 contains the compound represented by the general formula (1), the electron injection layer 170 does not contain the compound represented by the general formula (1), and the known electron injection transport is performed. It may be formed only of a known material such as a material.

The electron injection layer 170 includes, for example, (8-quinolinato) lithium ((8-quinolinato) lithium: Liq) and a lithium compound such as lithium fluoride (LiF), sodium chloride (NaCl), and cesium fluoride (CsF). ), lithium oxide (Li ₂ O), or barium oxide (BaO).

The second electrode 180 is formed on the electron injection layer 170. The second electrode 180 is preferably a cathode. The second electrode 180 is preferably formed of a metal, an alloy, a conductive compound, or the like having a low work function. For example, the second electrode 180 may be a 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 transmissive electrode made of a transparent conductive film such as a thin film of 20 nm or less of the above metal material, indium tin oxide (In ₂ O ₃ —SnO ₂ ) and indium zinc oxide (In ₂ O ₃ —ZnO). May be formed as.

As described above, the organic EL device 100 according to one embodiment of the present invention has the organic layer containing the compound represented by the general formula (1). As a result, it becomes possible to manufacture an organic EL element having excellent current efficiency and light emission life by the wet film formation method.

Here, the preferred embodiment of the organic layer is the same as the preferred embodiment of the above composition. That is, the organic layer preferably contains the compound represented by the general formula (1) and the carbazole derivative. At this time, it is more preferable that the organic layer is a light emitting layer and contains the compound represented by the general formula (1), the carbazole derivative, and the phosphorescent platinum group metal complex. The organic layer preferably contains the compound represented by the general formula (1) and the azine ring derivative. At this time, it is more preferable that the organic layer is a light emitting layer and contains the compound represented by the general formula (1), the azine ring derivative, and the phosphorescent platinum group metal complex. The organic layer more preferably contains the compound represented by the general formula (1), the carbazole derivative, and the azine ring derivative. At this time, it is more preferable that the organic layer is a light emitting layer and contains the compound represented by the general formula (1), the carbazole derivative, the azine ring derivative, and the phosphorescent platinum group metal complex. preferable.

Here, the preferable content of each component in the organic layer is the same as the preferable aspect of the composition.

The laminated structure of the organic EL element according to one aspect of the present invention is not limited to the above example. The organic EL element according to the present embodiment according to one aspect of the present invention may be formed in another known laminated structure. For example, in the organic EL device, one or more layers of the hole injection layer, the hole transport layer, the electron transport layer and the electron injection layer in FIG. 5 may be omitted, and additionally, another layer may be provided. May be. In addition, each layer of the organic EL element may be formed of a single layer or a plurality of layers.

For example, the organic EL device may further include a hole blocking layer between the light emitting layer and the electron transport layer in order to prevent excitons or holes from diffusing into the electron transport layer. The hole blocking layer can be formed of, for example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or the like.

The present invention will be described in more detail with reference to the following examples and comparative examples, but the technical scope of the present invention is not limited to the following examples.

<Synthesis of compound>
Compounds 1 to 3 were synthesized according to the following procedure.

[Synthesis of Compound 1a]

Under a nitrogen atmosphere, bromochlorobenzene (220 mmol, 42 g), biphenylboronic acid (1.05 eq., 231 mmol, 45.7 g), toluene (880 ml), and EtOH (ethanol) (110 ml) were placed in a three-necked flask and stirred. , A solution was prepared. Then, 2M aqueous potassium carbonate solution (K ₂ CO ₃ 2M aq.) (1.5 eq., 165 ml) was added to this solution, and then Pd(PPh ₃ ) ₄ (tetrakis(triphenylphosphine)palladium(0)) was added. (3 mol%, 6.6 mmol, 7.63 g) was added, and the mixture was stirred at 70° C. for 8 hours. Then, the reaction solution was diluted with toluene (500 ml), filtered using Celite (registered trademark), and washed twice with pure water. Then, this solution was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. The obtained crude product (crude) was dispersed and washed in EtOH (10 ml/1 g), filtered, and dried under vacuum (50° C., 12 hours) to obtain a white solid target product (Compound 1a). The yield of the obtained compound 1a was 57.7 g, and the yield was 99%.

[Synthesis of Compound 1b]

Under a nitrogen atmosphere, the above-obtained compound 1a (255 mmol, 67.4 g), dibenzofuranboronic acid (1.1 eq., 280.5 mmol, 59.5 g), toluene (510 ml) and EtOH (128 ml) were placed in a three-necked flask. A solution was prepared by charging and stirring. Then, a 2M aqueous potassium carbonate solution (K ₂ CO ₃ 2M aq.) (191 ml) was added to this solution, and then palladium acetate (3 mol%, 7.65 mmol, 1.71 g) and S-Phos (2-dicyclohexylphosphine) were added. Fino-2′,6′-dimethoxybiphenyl) (4.5 mol%, 11.5 mmol, 4.72 g) was added, and the mixture was stirred at 80° C. for 6 hours. After cooling to room temperature, the reaction solution was diluted with methanol (1 L) and subjected to ultrasonic irradiation for 30 minutes. Then, the precipitated solid was collected by filtration and rinsed with methanol. The precipitated solid after rinsing was vacuum dried (50° C., 12 hours), dissolved in toluene (1 L) by heating, filtered through a silica gel pad, and concentrated. The obtained crude product (crude) was recrystallized twice using a mixed solvent of toluene and ethanol (toluene:ethanol=6 ml:10 ml/1 g) to obtain a white solid target compound (compound 1b). .. The yield of the obtained compound 1b was 72.8 g, and the yield was 72%.

[Synthesis of Compound 1c]

The compound 1b (183 mmol, 72.2 g) obtained above and tetrahydrofuran (1830 ml) were placed in a three-necked flask and stirred to prepare a solution. Then, this solution was cooled to 0° C., and an nBuLi hexane solution (n-butyllithium/hexane solution) (2.65 M, 1.1 eq., 201.3 mmol, 76 ml) was added. This caused the solution to change from colorless to dark blue. Then, the solution was stirred at 0° C. for 2 hours. Then, trimethyl borate (1.3 eq., 237.9 mmol, 26.6 ml) was added dropwise to this solution. This caused the solution to change from dark blue to light blue. Then, the solution was stirred at room temperature for 5 hours. Then, the reaction system was deactivated with methanol, and pure water was further added. The resulting solution was concentrated to about half and then acidified with a 1N aqueous hydrochloric acid solution (HCl aq. (1N)) (600 ml). Then, the organic phase was extracted with ethyl acetate with a separating funnel and washed twice with pure water. Then, the extracted solution after washing was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. The obtained crude product (crude) was vacuum dried (50° C., 12 hours), dissolved by heating in toluene (500 ml), and then hexane (1 L) was added to precipitate a solid, followed by dispersion washing (reflux, 4 Time). After cooling to room temperature, the precipitated solid was collected by filtration to obtain the target product (Compound 1c) as a white solid. The yield of the obtained compound 1c was 80.6 g, and the yield was 75%.

[Synthesis of Compound 1d]

Under a nitrogen atmosphere, 3-bromo-1,1′:3′,1″-terphenyl (1 mol, 309.2 g), 4-chlorophenylboronic acid (1.05 eq., 1.05 mol, 164. 2 g), toluene (2 L) and EtOH (200 ml) were added and stirred to prepare a solution, and then a 2 M aqueous potassium carbonate solution (K ₂ CO ₃ 2 M aq.) (1.5 eq., 750 ml) was added to the solution. And then Pd(PPh ₃ ) ₄ (3 mol%, 30 mmol, 34.7 g) was added and stirred for 12 hours at 70° C. The reaction solution was cooled to room temperature and filtered through Celite®. The resulting solution was washed with pure water twice, dried over anhydrous magnesium sulfate, filtered through a silica gel pad and concentrated, and the obtained crude product (crude) was mixed with toluene and hexane (toluene: Hexane (2 ml: 10 ml/1 g) was recrystallized three times, and vacuum drying (50° C., 12 hours) was carried out to obtain the target product (compound 1d) as a white solid. 153.7 g, the yield was 45%.

[Synthesis of Compound 1]

Under a nitrogen atmosphere, the above-obtained compound 1c (15 mmol, 6.6 g), compound 1d (1.05 eq., 16.5 mmol, 5.6 g), toluene (150 ml), EtOH (15 ml) were placed in a three-necked flask. The solution was prepared by stirring. Then, 2M aqueous potassium carbonate solution (K ₂ CO ₃ 2M aq.) (1.5 eq., 11.3 ml) was added to this solution, and then palladium acetate (3 mol%, 0.45 mmol, 101 mg) and S-Phos. (4.5 mol%, 0.68 mmol, 279 mg) was added, and the mixture was stirred at 80° C. for 6 hours. The reaction solution was cooled to room temperature, diluted with methanol (200 ml), subjected to ultrasonic irradiation for 30 minutes, the precipitated solid was collected by filtration, and rinsed with methanol. The precipitated solid after rinsing was vacuum dried (50° C., 12 hours), dissolved by heating in toluene (300 ml), filtered through a silica gel pad and concentrated. The obtained crude product (crude) was dispersed and washed three times with a mixed solvent of toluene and ethanol (toluene:ethanol=6 ml:10 ml/1 g) to obtain a white solid target compound (Compound 1). The yield of the obtained compound 1 was 8.9 g, and the yield was 85%.

[Synthesis of Compound 2a]

The compound 1d (129 mmol, 44.0 g) obtained above, bispinacolatodiboron (1.05 eq., 142 mmol, 36.1 g), potassium acetate (2 eq, 258 mmol, 25.3 g) was placed in a three-necked flask under a nitrogen atmosphere. ) And 1,4-dioxane (258 ml) were added and stirred to prepare a dispersion liquid. Then, to this dispersion liquid, palladium acetate (2 mol%, 2.58 mmol, 579 mg) and X-Phos (2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl) (4 mol%, 5.16 mmol) were added. 2.46 g) was added and the mixture was stirred at 80° C. for 10 hours. The reaction solution was cooled to room temperature, diluted with toluene (300 ml), filtered using Celite (registered trademark), and washed 3 times with pure water. The washed solution was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. The obtained crude product (crude) was recrystallized using hexane (10 ml/1 g) and vacuum dried (50° C., 12 hours) to obtain the target product (compound 2a) as a white solid. The yield of the obtained compound 2a was 43.9 g, and the yield was 79%.

[Synthesis of Compound 2]

Under a nitrogen atmosphere, in a three-necked flask, 4,6-dibromodibenzofuran (15 mmol, 4.9 g), compound 1d (2.2 eq., 33.0 mmol, 14.3 g) obtained above, toluene (150 ml), EtOH ( 15 ml) was added and stirred to prepare a solution. Then, 2M aqueous potassium carbonate solution (K ₂ CO ₃ 2M aq.) (1.5 eq., 11.3 ml) was added to this solution, and then Pd(PPh ₃ ) ₄ (3 mol%, 4.5 mmol, 5. 20 g) was added and the mixture was stirred at 70° C. for 8 hours. The reaction solution was cooled to room temperature, diluted with methanol (200 ml), subjected to ultrasonic irradiation for 30 minutes, the precipitated solid was collected by filtration, and rinsed with methanol. The precipitated solid after rinsing was vacuum dried (50° C., 12 hours), dissolved by heating in toluene (500 ml), filtered through a silica gel pad, and concentrated. The obtained crude product (crude) was recrystallized twice using a mixed solvent of toluene and ethanol (toluene:ethanol=10 ml:5 ml/1 g) to obtain a white solid target compound (Compound 2). .. The yield of the obtained compound 2 was 7.6 g, and the yield was 65%.

[Synthesis of Compound 11]

Compound 11 was synthesized in the same manner as in the synthesis of compound 2 above, except that 4,6-dibromodibenzothiophene was used instead of 4,6-dibromodibenzofuran as a raw material. The yield of the obtained compound 11 was 6.2 g, and the yield was 52%.

<Evaluation of compound>
[Solubility evaluation]
The above-obtained compounds 1, 2 and 11 and the following comparative compound C1 (compound C1) were prepared as sample solids.

Sample 50 mg of a solid sample was placed in a colorless transparent sample bottle, 500 mg of methyl benzoate was placed as a solvent, and ultrasonic irradiation was performed for 20 minutes at room temperature. Then, it was visually confirmed whether or not the sample solid remained. Then, if the sample solid remained, the solvent addition and ultrasonic irradiation were repeated little by little, and the solubility was calculated from the amount of the solvent at the time of complete dissolution. The results are shown in Table 1 below.

[Evaluation of pot life of solution]
The above-obtained compounds 1, 2 and 11 and the comparative compound C1 were prepared as sample solids.

50 mg of a sample solid was placed in a colorless and transparent sample bottle, 1.0 g of methyl benzoate was added as a solvent, and the mixture was heated to 150° C. to completely dissolve the sample solid to prepare a 5 mass% solution. Then, the mixture was cooled to room temperature and observation was started, and the time (h) until visually confirming a precipitated solid such as crystals was measured as a pot life. Note that as the pot life becomes longer, crystallization becomes more difficult. The results are shown in Table 1 below.

[Measurement of HOMO value and LUMO value]
The above-obtained compounds 1, 2 and 11 and the following comparative compound C1 (compound C1) were prepared as sample solids. Then, the HOMO and LUMO values were measured according to the following procedure.

1. Preparation of Measurement Sample (1) A sample solution was prepared such that the sample solid was 4 parts by mass with respect to 100 parts by mass of methyl benzoate as a solvent.

(2) The sample solution prepared in (1) above was applied to each of the ITO substrate and the quartz substrate by spin coating under the condition that the dry film thickness was 50 nm to form a coating film. The resulting coatings ^were heated ¹⁰ -1 1 hour at 120 ° C. In the following under vacuum Pa, ^then, formed and cooled to room temperature in the following under vacuum ¹⁰ -1 Pa, thin layer (thin-film sample) did.

2. Measurement of HOMO value 1. Using the thin film sample on the ITO substrate prepared in (2), the HOMO value was measured using an atmospheric photoelectron spectrometer AC-3 (manufactured by Riken Keiki Co., Ltd.).

3. Measurement of LUMO value 1. Using the thin film sample on the quartz substrate prepared in (2), the energy gap value (Eg) was measured from the absorption edge of the UV-visible absorption spectrum using a spectrophotometer U-3900 (manufactured by Hitachi High-Tech Science Co., Ltd.). The LUMO value was calculated from the following equation (3).

The calculation results are shown in Table 2 below.

[Measurement of glass transition temperature (Tg)]
The above-obtained compounds 1, 2 and 11 and the following comparative compound C1 (compound C1) were prepared as sample solids. In addition, an azine ring derivative Az1, a phosphorescent light emitting platinum group metal complex D1, and carbazole derivatives H1-1, H2-34 and H3-3 used in the production of an organic EL device described later were prepared as sample solids.

Then, the step of scanning measurement was repeated three times using a differential scanning calorimeter DSC6220 (manufactured by Seiko Instruments Inc.) using about 5 mg of the sample solid. Here, the measurement conditions were a temperature rising rate of 10° C./min in the range of −50° C. to 300° C. and a cooling rate of −50° C./min in the range of 300° C. to −50° C. The glass transition temperature (Tg) was read from the calorimetric curves of the second and subsequent scans. The measurement results are shown in Table 2 below.

<Production and Evaluation 1 of Organic EL Element>
[Production of organic EL device]
(Example 1)
First, as a first electrode (anode), a glass substrate with ITO was prepared in which stripe-shaped indium tin oxide (ITO) was formed to a thickness of 150 nm. On this glass substrate, poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate): PEDOT/PSS) (Sigma) -Manufactured by Aldrich) was applied by a spin coating method to a dry film thickness of 30 nm to form a hole injection layer.

Next, on the hole injecting layer, anisole as a solvent and a hole transporting polymer (HTP1) having a repeating structure of 3 parts by mass with respect to 100 parts by mass of the solvent (weight average molecular weight Mw=400,000). , PDI (Mw/Mn)=2.7) and 0.6 parts by mass of a low molecular weight compound (AD1) having the following structure with respect to 100 parts by mass of the solvent was prepared to prepare a hole transport layer coating solution. Next, the obtained hole transport layer coating solution was applied by a spin coating method under the condition that the dry film thickness was 125 nm to form a coating film. The obtained coating film was heated for one hour at 230 ° C. In the following vacuum 10 -1 ^Pa, cooled to room temperature in the subsequent following vacuo 10 -1 ^Pa, to form a hole transport layer.

Then, on the hole transport layer, an ink for a light emitting layer which is a liquid composition (Compound 1 obtained above and Az1 as a host material, and D1 (TEG:tris(2-(3-p A methyl benzoate solution of a composition containing -xylyl)phenyl)pyridineiridium) was applied by a spin coating method so that the dry film thickness was 30 nm, and the light emitting layer was formed on the hole transporting layer. In the light emitting layer ink, with respect to 100 parts by mass of methyl benzoate as a solvent, 3.2 parts by mass of Compound 1, 0.8 parts by mass of Az1 below, and 0.4 parts by mass of D1 below were used as solid contents. Was prepared.

Next, (8-quinolinolato)lithium (Liq) and KLET-03 (manufactured by Chemipro Kasei Co., Ltd.) were co-deposited on the light emitting layer using a vacuum vapor deposition device at a mass ratio of 2:8 to obtain a film thickness. An electron transport layer of 30 nm was formed.

Further, lithium fluoride (LiF) was vapor-deposited on the electron transport layer by a vacuum vapor deposition device to form an electron injection layer having a film thickness of 1 nm.

Further, aluminum (Al) was vapor-deposited on the electron injection layer by a vacuum vapor deposition apparatus to form a second electrode (cathode) having a film thickness of 100 nm.

Then, in a nitrogen atmosphere glove box having a water concentration of 1 ppm or less and an oxygen concentration of 1 ppm or less, sealing was performed using a glass-made sealing tube with a desiccant and an ultraviolet curable resin to produce an organic EL element.

(Examples 2 and 3 and Comparative Examples 1 and 2)
As the composition of the ink for the light-emitting layer, the total mass of the solid content was the same as that of 100 parts by mass of methyl benzoate as the solvent, and the kind and the ratio of the compound as the solid content were changed as shown in Table 2 below. Similarly, each organic EL element was produced.

[Evaluation of organic EL device]
The driving voltage, current efficiency, and light emission life (durability) were evaluated according to the following methods.

Using a DC constant voltage power source (manufactured by KEYENCE CORPORATION, source meter (source meter)), the applied voltage is continuously changed from 0 V to 20 V with respect to the organic EL element to energize the organic EL element to emit light, The luminance at this time was measured by a luminance measuring device (SR-3, manufactured by Topcom).

Here, the current value per unit area (current density) is calculated from the area of the organic EL element, and the luminance (cd/m ² ) is divided by the current density (A/m ² ) to obtain the current efficiency (cd /A) was calculated. It should be noted that the current efficiency indicates the efficiency (conversion efficiency) of converting the current into the emission energy, and the higher the current efficiency, the higher the performance of the organic EL element.

In addition, the light emission life (durability) is the time until the light emission brightness that is continuously driven at a current value at which the initial brightness is 6,000 cd/m ² and decreases to 80% of the initial brightness is “LT80( h)”.

The results of these evaluations are shown in Table 3 below. In addition, in Table 3 below, the current efficiency is represented as a relative value when the current efficiency of the organic EL element of Comparative Example 2 is 100. The light emission life (durability) is expressed as a relative value when the device life of the organic EL device of Comparative Example 2 is 100. Further, “*1” indicates that the measurement was impossible because the organic EL element could not be produced.

As shown in Tables 1 and 2 above, it was confirmed that the comparative example compound C1 which is a dibenzothiophene compound which does not belong to the technical scope of the present invention has a poor solubility and an organic EL element cannot be produced by a coating method. (Comparative example 1).

In addition, as shown in Table 3 above, when the compound according to the present invention is used as the host material combined with the azine ring derivative Az1, it is a hole-transporting host material that is conventionally generally used as in Comparative Example 2. It was confirmed that the luminous efficiency and the luminous lifetime were remarkably excellent as compared with the case of using a certain carbazole derivative H2-34.

<Production and Evaluation of Organic EL Element 2>
(Example 4)
1.33 parts by mass of the compound 1 obtained above, 1.33 parts by mass of the above H2-34, 1.33 parts by mass of the above H2-34, and Az1 as the solid content of the ink for a light emitting layer with respect to 100 parts by mass of methyl benzoate as a solvent. An organic EL device was prepared and evaluated in the same manner as in Example 1 of Preparation and evaluation 1 of organic EL device except that the amount was adjusted to 1.33 parts by mass and D1 was 0.4 parts by mass. .. The evaluation results are shown in Table 4 below.

(Examples 5-10, Comparative Examples 3-6)
With respect to the composition of the ink for the light emitting layer, the total mass of the solid content was the same as that of 100 parts by mass of methyl benzoate of the solvent, and the kind and the ratio of the compound as the solid content were changed as shown in Table 3 below. Similarly, an organic EL device was manufactured and evaluated. The results of these evaluations are shown in Table 4 below.

As shown in Table 4 above, in the embodiment of the composition including the carbazole derivative, when the light emitting layer including the composition including the compound according to the present invention is used as the host material, the light emission does not include the compound according to the present invention. It was confirmed that the luminous efficiency and the luminous lifetime were remarkably excellent as compared with the case of the layer.

Further, from the comparison of the evaluation results in Tables 3 and 4, the embodiment in which the composition forming the light emitting layer includes the carbazole ring derivative is compared with the embodiment in which the composition forming the light emitting layer does not include the carbazole ring derivative. It was confirmed that the driving voltage was lower and the power consumption was better.

Although the present invention has been described with reference to the exemplary embodiments and examples, the present invention is not limited to the specific exemplary embodiments and examples, and various modifications are possible within the scope of the invention described in the claims. Can be modified and changed.

100 Organic electroluminescence element (organic EL element)
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 (15)

A compound represented by the following general formula (1):
In the general formula (1),
X represents O, S, or Se,
Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted benzene rings. A naphthalene ring, or a monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond. (However, no further ring is condensed with the benzene ring and the naphthalene ring)
R is independently a deuterium atom, a cyano group, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted Substituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings and substituted Monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (however, the ring is not further condensed with the benzene ring or the naphthalene ring) ),
a1, a2 and a5 each independently represent 0, 1, 2, 3 or 4.
a3 and a4 each independently represent 0, 1, 2 or 3.
a6 represents 0, 1, 2, 3, 4 or 5. The compound according to claim 1, which is a compound represented by the following general formula (2):
In the above general formula (2),
X, Ar ₁ , R, a1, a2, a3, a4 and a5 are the same as in the general formula (1),
Ar ₂ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, substituted or Unsubstituted two or more naphthalene rings, or one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings, which are monovalent and are directly bonded to each other by a single bond. Represents an aromatic hydrocarbon ring assembling group (however, no further ring is condensed with the benzene ring and the naphthalene ring),
a6′ represents 0, 1, 2, 3 or 4. The compound according to claim 2, wherein Ar ₁ and Ar ₂ are groups different from each other. The compound according to claim 2 or 3, which is a compound represented by the following general formula (3):
In the above general formula (3),
X, R, a1, a2, a3, a4 and a5 are respectively the same as in the general formula (1),
Ar ₂ and a6′ are respectively the same as in the general formula (2),
R'is each independently a deuterium atom, a cyano group, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or An unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings, and A monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond (provided that a ring is further condensed with the benzene ring and the naphthalene ring. No)
L ₁ and L ₂ are each independently a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, or two or more substituted or unsubstituted benzene rings, Two or more substituted or unsubstituted naphthalene rings, or one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings directly bonded by a single bond Represents a divalent aromatic hydrocarbon ring assembling group (however, the benzene ring and the naphthalene ring are not further condensed with a ring),
E is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or two or more substituted or unsubstituted benzene rings, two or more substituted or unsubstituted naphthalene A ring, or a monovalent aromatic hydrocarbon ring assembling group in which one or more substituted or unsubstituted benzene rings and one or more substituted or unsubstituted naphthalene rings are directly bonded by a single bond ( However, no further ring is condensed to the benzene ring and the naphthalene ring),
a7 represents 0, 1, 2, 3 or 4,
n represents an integer of 1 or more. The compound represented by the general formula (3) is
X represents O or S,
Ar ₂ is an unsubstituted phenyl group, an unsubstituted naphthyl group, or two or more unsubstituted benzene rings, two or more unsubstituted naphthalene rings, or one or more unsubstituted benzene rings and an unsubstituted group. Represents a monovalent aromatic hydrocarbon ring assembling group in which one or more naphthalene rings are directly bonded by a single bond (however, the benzene ring and the naphthalene ring are not further condensed with a ring),
a1, a2, a3, a4, a5, a6′ and a7 all represent 0,
L ₁ and L ₂ are each independently a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, two or more unsubstituted benzene rings, two or more unsubstituted naphthalene rings, or an unsubstituted group. A divalent aromatic hydrocarbon ring assembling group in which one or more substituted benzene rings and one or more unsubstituted naphthalene rings are directly bonded by a single bond (provided that the benzene ring and the naphthalene ring have a ring Does not condense),
E represents an unsubstituted phenyl group or an unsubstituted naphthyl group,
The compound according to claim 4, wherein n represents 1. The compound according to claim 5, which is the following compound 1, 2 or 11.
A composition comprising the compound according to any one of claims 1 to 6 and at least one of a carbazole derivative and an azine ring derivative. The composition according to claim 7, comprising the compound according to any one of claims 1 to 6, a carbazole derivative, and an azine ring derivative. The composition according to claim 7 or 8, wherein the carbazole derivative is a compound represented by the following formula (C4):
In the general formula (C4),
R _{21 s} are each independently a monovalent group derived from an aromatic hydrocarbon ring composed of one or more substituted or unsubstituted aromatic hydrocarbon rings, or a substituted or unsubstituted 1 Aromatic heterocycle-derived monovalent group composed of the above aromatic heterocycles (excluding those having an azine ring structure), or one or more substituted or unsubstituted aromatic hydrocarbon rings And a monovalent ring-assembling group composed of one or more substituted or unsubstituted aromatic heterocycles (excluding those having an azine ring structure),
R ₂₂₃ and R ₂₂₄ are each independently a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group ( Provided that a group having an azine ring structure is excluded), a substituted or unsubstituted alkylamino group, a substituted or unsubstituted arylamino group (excluding a group having an azine ring structure), a substituted or A monovalent group derived from an aromatic hydrocarbon ring composed of one or more unsubstituted aromatic hydrocarbon rings, and an aromatic heterocycle composed of one or more substituted or unsubstituted aromatic heterocycles. Ring-derived monovalent group (excluding those having an azine ring structure), or one or more substituted or unsubstituted aromatic hydrocarbon rings and one or more substituted or unsubstituted aromatic groups Represents a monovalent ring-collecting group composed of a heterocyclic group (excluding those having an azine ring structure),
d independently represents 0, 1, 2, 3 or 4,
e represents 0, 1, 2 or 3. The composition according to any one of claims 7 to 9, wherein the azine ring derivative is a compound represented by the following formula (A3):
In the general formula (A3), T is a condensed ring bond having a ring structure represented by the following general formula,
Z ₁ , Z ₃ and Z ₅ are each independently CH or N, provided that at least one of Z ₁ , Z ₃ and Z ₅ is N,
R _31's each independently represent a hydrogen atom, a deuterium atom, or an organic group,
R ₃₂ , R ₃₂ ′, R ₃₃ and R ₃₄ are each independently a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or Unsubstituted aryloxy group, substituted or unsubstituted alkylamino group, substituted or unsubstituted arylamino group, aromatic comprising one or more substituted or unsubstituted aromatic hydrocarbon rings A monovalent group derived from an aromatic hydrocarbon ring, a monovalent group derived from an aromatic heterocycle composed of one or more substituted or unsubstituted aromatic heterocycles, or a substituted or unsubstituted 1 Represents a monovalent ring assembly group composed of one or more aromatic hydrocarbon rings and one or more substituted or unsubstituted aromatic heterocycles,
f and g each independently represent 0, 1, 2, 3 or 4,
h represents 0, 1, 2, 3, 4 or 5,
i represents 0, 1 or 2. The composition according to claim 7, further comprising a phosphorescent platinum group metal complex. The composition according to claim 11, wherein the phosphorescent platinum group metal complex is the following compound D1.
A compound according to any one of claims 1 to 6, or a composition according to any one of claims 7 to 12, and a solvent having a boiling point of 100°C or more and 350°C or less at atmospheric pressure, Liquid composition. A material for an organic electroluminescence device, comprising the compound according to any one of claims 1 to 6 or the composition according to any one of claims 7 to 12. An organic electroluminescence device comprising a pair of electrodes and an organic layer arranged between the pair of electrodes,
The said organic layer is an organic electroluminescent element containing the compound in any one of Claims 1-6, or the composition in any one of Claims 7-12.