JP7029966B2 - Compounds, compositions, liquid compositions, materials for organic electroluminescence devices, and organic electroluminescence devices. - Google Patents

Description

The present invention relates to compounds, compositions, liquid compositions, materials for organic electroluminescence devices, and organic electroluminescence devices.

In recent years, display devices and lighting devices using an organic electroluminescence device (Organic Electroluminescence Device), which is a self-luminous light emitting device, have been actively developed. The organic electroluminescence device (hereinafter, may be referred to as an organic electroluminescent device or an organic EL device) has an organic layer containing a light emitting material. In the organic layer of the organic EL element, the light emitting material is excited by recombination of electrons and holes, and light emission occurs when the light emitting material returns to the ground state.

In such an organic EL element, various materials for forming an organic layer have been developed for the purpose of improving element characteristics such as current efficiency and light emission life. For example, Patent Documents 1 to 3 disclose an organic electroluminescence device using a spirofluorene compound.

Further, in the manufacture of an organic EL element, it is common to form an organic film constituting the organic EL element 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, instead of such a dry film forming method, it is considered to use a wet film forming method such as a solution coating method (hereinafter, may be referred to as a coating method) which can save time and cost.

Special Table 2012-532902 U.S. Patent Publication No. 2017/0179395 Japanese Unexamined Patent Publication No. 2009-203176 U.S. Patent Publication No. 2007/0262703

However, when the organic EL element is formed by a wet film forming method such as a solution coating method, the organic EL material is difficult to dissolve in the solvent at the time of coating. Further, after the film formation, aggregation of organic molecules in the light emitting layer is likely to occur. Therefore, the organic EL element formed by the coating method does not have sufficient current efficiency and light emission life.

An object of the present invention is to provide a compound and a composition capable of producing an organic electroluminescence device having excellent current efficiency and light emission lifetime by a coating method.

In order to solve the above problems, one aspect of the present invention provides a compound represented by the following general formula (1).

（一般式（１）中、Ｒ_１及びＲ_２は、それぞれ独立して、置換されたもしくは無置換の炭素数６～３０の１価の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の１価の芳香族複素環基を示す。Ｒ_１及びＲ_２の少なくともいずれかは、下記一般式（２）で表される基を含む。）

(In the general formula (1), R ₁ and R ₂ are independently substituted or unsubstituted monovalent aromatic hydrocarbon ring groups having 6 to 30 carbon atoms, or substituted or unsubstituted. Indicates a monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms. At least one of R ₁ and R ₂ includes a group represented by the following general formula (2).)

（一般式（２）中、Ｘ_１～Ｘ_４は、それぞれ独立して、－Ｃ（Ｒ_３）－または窒素原子を示す。

(In the general formula (2), X ₁ to X ₄ independently represent -C (R ₃ )-or a nitrogen atom.

R ₃ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. Shows a monovalent aromatic heterocyclic group. n is an integer of 3 or more.

L ₁ is a single-bonded, substituted or unsubstituted divalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming divalent aromatic having 3 to 30 atoms. Represents a group heterocyclic group.

The n L _1s and X ₁ to X ₄ may be the same or different.

One of * 1 and * 2 represents a bond that binds to the 9,9'-spirobi (fluorene) (9,9'-spirobi [fluorene]) skeleton of the formula (1), and the other of * 1 and * 2. Represents a bond that binds to R.

R is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. Indicates an aromatic heterocyclic group of valence.

According to one aspect of the present invention, it is possible to provide a compound and a composition capable of producing an organic electroluminescence device having excellent current efficiency and light emission lifetime by a coating method.

It is a schematic diagram which shows the organic electroluminescence element which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments.

<Compound>
The compound according to this embodiment is a compound represented by the following general formula (1).

As shown in the above general formula (1), the compound according to the present embodiment is composed of a 9,9'-spirobi (fluorene) (9,9'-spirobi [fluorene]) skeleton. Then, _R1 and _R2 are bound to the 4th and 4'positions of the 9,9'-spirobi (fluorene) (9,9'-spirobi [fluorene]) skeleton, respectively.

In the above general formula (1), R ₁ and R ₂ are independently substituted or unsubstituted monovalent aromatic hydrocarbon ring groups having 6 to 30 carbon atoms, or substituted or unsubstituted. Shows a monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms. R ₁ is bonded to the carbon atom at the 4-position of the spirofluorene skeleton in the general formula (1). On the other hand, R ₂ is bonded to the carbon atom at the 4'position of the spirofluorene skeleton in the general formula (1).

In the present specification and claims, "X and Y are independent of each other" means that X and Y may be the same or different.

In the present specification and claims, "substituted or unsubstituted" means that even if it has other substituents, except when the substituent such as _R1 is a hydrogen atom and a deuterium atom. It means good. Further, these substituents may be bonded to each other to form a ring.

Further, in the present specification and claims, the term "A to B" means the range from A to B including A and B.

The aromatic hydrocarbon ring group having 6 to 30 carbon atoms which can constitute R ₁ and R ₂ is a hydrocarbon having a carbon ring containing one or more aromatic rings having 6 to 30 carbon atoms (aromatic hydrocarbon). It is a ring-derived group. Further, when the aromatic hydrocarbon ring group contains two or more rings, the two or more rings may be condensed with each other. Further, one or more hydrogen atoms present in these aromatic hydrocarbon ring groups may be substituted with a substituent.

The aromatic hydrocarbon ring constituting the aromatic hydrocarbon ring group is not particularly limited, but specifically, benzene, pentalene, inden, naphthalene, anthracene, azulene, heptalene, acenaphthalene, phenalene, fluorene, phenanthrene and biphenyl. , Triphenylene, pyrene, chrysene, picene, perylene, pentaphene, pentasen, tetraphene, hexaphene, hexacene, rubicene, trinaphthylene, heptaphene, pyrantrene and the like.

The monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms that can constitute R ₁ and R ₂ is one or more heteroatoms (for example, nitrogen atom (N), oxygen atom (O), phosphorus atom). Derived from a ring (aromatic heterocycle) having 3 to 30 ring-forming atoms including (P), a sulfur atom (S)) and one or more aromatic rings in which the remaining ring atom is a carbon atom (C). Is the basis of. Further, when the aromatic heterocyclic group contains two or more rings, the two or more rings may be condensed with each other. Further, one or more hydrogen atoms present in these aromatic heterocyclic groups may be substituted with a substituent.

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 bonded in a ring (for example, a single ring, a fused ring, or a ring assembly). When an atom that does not form a ring (for example, a hydrogen atom that terminates a bond of an atom that constitutes a ring) or a ring is substituted with a substituent, the atom contained in the substituent is not included in the number of ring-forming atoms. .. For example, the carbazolyl group (substituent composed of carbazoline) has 13 ring-forming atoms.

The aromatic heterocycle constituting the aromatic heterocyclic group is not particularly limited, and is, for example, a π-electron-deficient aromatic heterocycle, a π-electron-rich aromatic heterocycle, a π-electron-deficient aromatic heterocycle, and π. Examples thereof include a π-electron-deficient-π-electron-rich mixed aromatic heterocycle mixed with an electron-rich aromatic heterocycle.

Specific examples of the π-electron-deficient aromatic heterocycle include pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline, isoquinoline, quinoxaline, quinazoline, diazanaphthalene, aclysine, phenazine, benzoquinoline, benzoisoquinoline, phenanthridine, and phenanthrolin. Examples thereof include benzoquinone, coumarin, anthraquinone and fluorenone.

Specific examples of the π-electron-rich aromatic heterocycle include furan, thiophene, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, pyrrole, indol, carbazole and the like.

Specific examples of the π-electron-deficient-π-electron-rich mixed aromatic heterocycle include imidazole, benzimidazole, pyrazole, indazole, oxazole, isooxazole, benzoxazole, benzoisoxazole, thiazole, isothiazole, benzothiazole, and benzo. Isothiazole, imidazolinone, benzimidazolinone, imidazole pyridine, imidazole pyrimidine, imidazolenanthridine, benzimidazolenansridine, azadibenzofuran, azacarbazole, azadibenzothiophene, diazadibenzofuran, diazacarbazole, diazadibenzothiophene, Examples thereof include xanthone and thioxanthone.

The other substituents in R ₁ and R ₂ are not particularly limited, but are, for example, a hydrocarbon atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, and a substituted or unsubstituted carbon. An alkoxy group having a number of 1 to 30, an substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, an substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted group. Examples thereof include a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 3 to 30 carbon atoms.

In R ₁ and R ₂ , the alkyl group having 1 to 30 carbon atoms which can constitute another substituent is not particularly limited, and is, for example, 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. Of these, a linear or branched alkyl group having 1 to 8 carbon atoms is preferable.

In R ₁ and R ₂ , the alkoxy group having 1 to 30 carbon atoms which can form another substituent is not particularly limited, and is, for example, a linear or branched alkoxy group having 1 to 30 carbon atoms. Specifically, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group. Examples thereof include a group, a tridecyloxy group, a tetradecyloxy group, a pentadecyloxy group, a hexadecyloxy group, a heptadecyloxy group, an octadecyloxy group, a 2-ethylhexyloxy group and a 3-ethylpentyloxy group. Of these, linear or branched alkoxy groups having 1 to 8 carbon atoms are preferable.

In R ₁ and R ₂ , the aryloxy group having 6 to 30 carbon atoms which can constitute another substituent is not particularly limited, but for example, a monocyclic or condensed polycycle having 6 to 30 carbon atoms which may contain a hetero atom may be contained. It is a ring aryloxy 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-indrilloxy group, a 3-indrilloxy group, Examples thereof include 2-benzofuryloxy group and 2-benzothienyloxy group.

In R ₁ and R ₂ , the amino group having 1 to 30 carbon atoms which can constitute another substituent is not particularly limited, and is, for example, a linear or branched alkyl amino 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 -N-alkylamino groups such as tert-butylamino group, N-pentylamino group, N-hexylamino group, N, N, N-dimethylamino group, N-methyl-N-ethylamino group, N, N- Diethylamino group, N, N-dipropylamino group, N, N-diisopropylamino group, N, N-dibutylamino group, N, N-diisobutylamino group, N, N-dipentylamino group, N, N-dihexylamino Examples thereof include N, N-dialkylamino groups such as groups.

In R ₁ and R ₂ , a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms and a monovalent aromatic heterocyclic group having 3 to 30 ring-forming atoms that can form other substituents are R. Since the definition is the same as that of the aromatic hydrocarbon ring group and the aromatic heterocyclic group that can form ₁ or R ₂ , the description thereof will be omitted.

In the above general formula (1), at least one of R ₁ and R ₂ includes a group represented by the following general formula (2).

In the above general formula (2), X ₁ to X ₄ independently represent -C (R ₃ )-or a nitrogen atom. C in -C (R ₃ )-indicates a carbon atom. Further, R ₃ in -C (R ₃ )-is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or substituted one. An unsubstituted ring-forming monovalent aromatic heterocyclic group having 3 to 30 atoms.

In the present specification, "hydrogen atom" is a concept including "deuterium atom" even if there is no special description about "deuterium atom". The hydrogen atom existing in each group may be optionally substituted with a deuterium atom.

In X ₁ to X ₄ , the aromatic hydrocarbon ring group and the aromatic heterocyclic group that can form R ₃ in —C (R ₃ ) — are the aromatics that can form R ₁ or R ₂ described above. Since the definition is the same as that of the group hydrocarbon ring group and the aromatic heterocyclic group, the description thereof will be omitted.

In the above general formula (2), n is an integer of 3 or more. That is, the group represented by the above general formula (2) has at least three structural units in which X ₁ to X ₄ are contained as ring-forming atoms. For example, when n is 3, the group represented by the general formula (2) is composed of three rings including X ₁ to X ₄ .

In the above general formula (2), one of * 1 and * 2 represents a bond that binds to the 9,9'-spirobi (fluorene) skeleton of the formula (1), and the other of * 1 and * 2 is R. Represents a bond that binds to.

In the compound represented by the above general formula (1), R ₁ and R ₂ composed of at least three structural units including X ₁ to X ₄ are bound to the spirofluorene skeleton. Both R ₁ and R ₂ bonded to the spirofluorene skeleton include a structure in which at least three structural units are connected so as to bend (hereinafter, may be referred to as a bending group).

As a result, the compound represented by the general formula (1) has a high triplet energy level and a high carrier mobility, and thus has excellent hole transportability and electron transportability. In addition, it has high solubility in a solvent and has excellent solubility in a solvent. Further, when the organic EL element is formed by the wet film forming method, the aggregation of organic molecules can be suppressed, and a thin film having an excellent film quality can be formed. Therefore, the compound according to the present embodiment can maintain or improve the performance of the organic electroluminescence device even when the organic electroluminescence device is manufactured by the coating method.

Further, the compound according to the present embodiment is not particularly limited in the structure of the group represented by the general formula (2) in the general formula (1). However, in the compound represented by the general formula (1), the group represented by the general formula (2) is described in the following general formula (3) from the viewpoint of improving carrier mobility, solubility in a solvent, and an effect of suppressing aggregation. ) Is preferable.

In the group represented by the general formula (3), at least three structural units (three rings composed of X ₁ to X ₄ ) constituting the group represented by the general formula (2) are meta. Combine at the place. With this configuration, the three structural units in the group represented by the general formula (2) can surely form a bending group. Therefore, in the compound represented by the general formula (1), when the group represented by the general formula (2) is a group represented by the general formula (3), carrier mobility, solubility in a solvent, and so on. The aggregation suppressing effect can be enhanced.

The structure of the compound represented by the general formula (1) is not particularly limited. However, among the compounds represented by the general formula (1), the compound represented by the general formula (1) is described in the following general formula (1) from the viewpoint of surely enhancing the carrier mobility, the solubility in a solvent, and the effect of suppressing aggregation. It is preferably selected from 1-1) or (1-2).

In the compound represented by the above (1-1) or (1-2), the group represented by the above general formula (2) contained in at least one of R ₁ and R ₂ is the above general formula (3). It is composed of the groups represented by. Therefore, when the compound represented by the general formula (1) is the compound represented by the above (1-1) or (1-2), the carrier mobility, the solubility in a solvent, and the aggregation inhibitory effect are further enhanced. Can be done.

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

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

<Composition>
The composition according to the present embodiment contains the compound represented by the above general formula (1), the compound represented by the following general formula (4), and a light emitting material.

The light emitting material is not particularly limited as long as it has a high light emitting function, and a phosphorescent light emitting material composed of an organic fluorescent molecule, an organic metal complex containing a platinum group metal element, a quantum dot, or the like can be used.

The compound represented by the following general formula (4) has a structure in which _R4 is bonded to N at the 9-position of a heterocyclic structure (nitrogen-containing heterocyclic compound) containing a nitrogen atom (N).

In the above general formula (4), R ₄ is a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom number of 3 to 30. It is a monovalent aromatic heterocyclic group of. The aromatic hydrocarbon ring group and aromatic heterocyclic group that can form R ₄ have the same definitions as the above-mentioned aromatic hydrocarbon ring group and aromatic hetero ring group that can form R ₁ or R ₂ . Therefore, the description thereof will be omitted.

Y ₁ to Y ₈ are independently -C (R ₅ )-or nitrogen atoms. C in -C (R ₅ )-indicates a carbon atom. Further, R ₅ in -C (R ₅ )-is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or substituted one. An unsubstituted ring-forming monovalent aromatic heterocyclic group having 3 to 30 atoms. In Y ₁ to Y ₈ , the aromatic hydrocarbon ring group and the aromatic heterocyclic group that can form R ₅ in —C (R ₅ ) — are aromatics that can form the above-mentioned R ₁ or R ₂ . Since the definition is the same as that of the group hydrocarbon ring group and the aromatic heterocyclic group, the description thereof will be omitted.

By containing the compound represented by the general formula (1) and the compound represented by the general formula (4), the composition according to the present embodiment has carrier mobility, solubility in a solvent, and inhibition of aggregation. The effect can be further enhanced. As a result, the composition according to the present embodiment has excellent luminous efficiency, has excellent solubility in a solvent, and is used for an organic EL element for forming an organic layer by a wet film forming method. Has excellent film forming properties.

Further, the compound represented by the general formula (4) is composed of a nitrogen-containing heterocyclic compound composed of 13 ring-forming atoms including a nitrogen atom (N). Since the compound represented by the general formula (4) has a structure in which _R4 is bonded to the nitrogen atom (N) at the 9-position of the nitrogen-containing heterocyclic compound, it emits light in the composition according to the present embodiment. Except for the material, the shallowest HOMO (Highest Occupied Molecular Orbital) is distributed. As a result, the composition according to the present embodiment has high hole injecting property and hole transporting property while suppressing aggregation of organic molecules in the membrane.

Further, their hole injecting property and hole transporting property can be easily and continuously modulated by controlling the composition ratio of the compound represented by the above general formula (4). This facilitates control of the hole density profile, especially with respect to the amount of holes in the light emitting layer and the film thickness direction.

Therefore, the composition according to the present embodiment can enhance the performance (particularly, hole injection property and hole transport property) of the organic electroluminescence device even when it is used for the organic electroluminescence device produced by the coating method. ..

Further, the composition according to the present embodiment may further contain a compound represented by the following general formula (5).

In the above general formula (5), Z ₁ to Z ₆ are independently -C (R ₆ )-or nitrogen atoms. Further, at least one of Z ₁ to Z ₆ is a nitrogen atom. That is, the compound represented by the general formula (5) represents a 6-membered ring heterocyclic compound containing a nitrogen atom (N) (nitrogen-containing heterocyclic compound).

In Z ₁ to Z ₆ , C in —C (R ₆ ) — represents a carbon atom. Further, R ₆ in -C (R ₆ )-is a hydrogen atom, a hydrocarbon atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or substituted one. An unsubstituted ring-forming monovalent aromatic heterocyclic group having 3 to 30 atoms. The aromatic hydrocarbon ring group and aromatic heterocyclic group that can form R ₆ in -C (R ₆ ) -are the aromatic hydrocarbon ring groups and aromatic groups that can form R ₁ or R ₂ described above. Since the definition is the same as that of the group heterocyclic group, the description thereof will be omitted.

In the composition according to the present embodiment, the compound represented by the general formula (1), the compound represented by the general formula (4), and the light emitting material are further subjected to the above general formula (5). By containing the represented compound, carrier mobility, carrier balance, solubility in a solvent, and aggregation inhibitory effect can be further enhanced. As a result, the composition according to the present embodiment has excellent luminous efficiency, has excellent solubility in a solvent, and is used for an organic EL element for forming an organic layer by a wet film forming method. Has excellent film forming properties.

Further, in the compound represented by the general formula (4), HOMO is distributed as described above. Further, since the compound represented by the general formula (5) has a heterocyclic structure of a 6-membered ring containing a nitrogen atom (N) as a ring-forming atom, it has the deepest LUMO in the composition according to the present embodiment. (Lowest Unoccuped Molecular Orbital, lowest empty orbital) is distributed. As a result, among the compositions according to the present embodiment, the composition containing all of the compounds of the above general formulas (1), (4) and (5) further suppresses the aggregation of organic molecules in the membrane. Both the hole injecting property and the hole transporting property and the electron injecting property and the electron transporting property are high.

Therefore, even when the composition according to the present embodiment is used for an organic electroluminescence device produced by a coating method, the performance of the organic electroluminescence device (particularly, hole injection property, hole transport property, electron injection property and electron). Transportability) can be improved.

Further, the hole injectability and hole transport property of the organic electroluminescence device can be easily and continuously modulated by controlling the composition ratio of the compound represented by the above general formula (4). Further, the electron injection property and the electron transport property of the organic electroluminescence device can be easily and continuously modulated by controlling the composition ratio of the compound represented by the above general formula (5). Therefore, the hole control and the electron control of the organic electroluminescence device can be independently performed by controlling each composition ratio. For this reason, using the composition according to the present embodiment is extremely convenient in the process of optimizing the performance of the organic electroluminescence device.

Further, the composition according to the present embodiment contains the compound represented by the general formula (1), the compound represented by the general formula (5), and a light emitting material.

The composition according to the present embodiment also contains the compound represented by the general formula (1) and the compound represented by the general formula (5) in terms of carrier mobility, solubility in a solvent, and inhibition of aggregation. The effect can be further enhanced. As a result, the composition according to the present embodiment has excellent luminous efficiency, has excellent solubility in a solvent, and is used for an organic EL element for forming an organic layer by a wet film forming method. Has excellent film forming properties.

Further, in the compound represented by the general formula (5), as described above, the deepest LUMO in the composition according to the present embodiment is distributed. As a result, the composition according to the present embodiment has higher electron injectability and electron transportability.

Further, the electron injection property and the electron transport property of the organic electroluminescence device can be easily and continuously modulated by controlling the composition ratio of the compound represented by the above general formula (5). This makes it easy to control the electron density profile with respect to the amount of electrons and the film thickness direction in the light emitting layer. Therefore, the composition according to the present embodiment can enhance the performance (particularly, electron injection property and electron transport property) of the organic electroluminescence device even when it is used for the organic electroluminescence device produced by the coating method.

<Liquid composition>
The liquid composition according to the present embodiment contains the compound represented by the above general formula (1) and a solvent. Further, the liquid composition according to the present embodiment is a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4), according to the general formula (1). A composition containing the compound represented by the compound, the compound represented by the general formula (4), and the compound represented by the general formula (5), or the compound represented by the general formula (1). And a composition containing the compound represented by the above general formula (5), and a solvent can be contained.

The solvent is not particularly limited, but contains the above-mentioned compound represented by the general formula (1), the above-mentioned compound represented by the general formula (1), and the above-mentioned compound represented by the general formula (4). A composition containing the compound represented by the general formula (1), the compound represented by the general formula (4), and the compound represented by the general formula (5). It is preferable that the composition containing the compound represented by the general formula (1) and the compound represented by the general formula (5) can be dissolved.

The solvent contained in the liquid composition is not particularly limited, and is, for example, toluene, xylene, ethylbenzene, diethylbenzene, meshylene, propylbenzene, cyclohexylbenzene, and the like. (Cyclohexylbene), dimethoxybenzene, anisole, ethoxytoluene, phenoxytoluene, isopropylbiphenyl (isoplopylbiphenyl), dimethylanisol (Phenyl productic acid), methyl benzoate (methyl benzoate), ethyl benzoate (ethyl benzoate) and the like can be mentioned.

The concentration of the compound in the liquid composition is not particularly limited and can be appropriately adjusted depending on the intended use. However, from the viewpoint of ease of application and the like, the concentration of such a compound is such that the concentration of the compound represented by the above general formula (1) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0. It is adjusted to be .5% by mass to 5% by mass.

On the other hand, in the case of a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4) according to the present embodiment, the concentration of the compound represented by the general formula (1) is It is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass to 5% by mass. The concentration of the compound represented by the general formula (4) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass.

Further, in the case of a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (5) according to the present embodiment, the concentration of the compound represented by the general formula (1) is determined. It is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass to 5% by mass. The concentration of the compound represented by the general formula (5) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass.

Further, in the case of a composition containing the compound represented by the general formula (1), the compound represented by the general formula (4) and the compound represented by the general formula (5) according to the present embodiment, the general formula ( The concentration of the compound represented by 1) is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass to 5% by mass. The concentration of the compound represented by the general formula (4) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass. Further, the concentration of the compound represented by the general formula (5) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass.

<Materials for organic electroluminescence devices>
The material for an organic electroluminescence device (hereinafter referred to as a material for an organic EL device) according to the present embodiment contains the compound represented by the above-mentioned general formula (1). The compound represented by the general formula (1) exhibits high solubility (solubility) in a solvent as described above, and by suppressing the aggregation of molecules, carrier trap sites or exciton loss by a wet coating method. It is possible to form a thin film with excellent film quality with few active sites. Further, the compound has high hole injecting property and hole transporting property or high electron injecting property and electron transporting property when combined with the compound represented by the general formula (4) or the general formula (5). Therefore, the material for an organic EL device containing the compound can be used as a material for, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer.

As a result, the organic electroluminescence device using the compound represented by the general formula (1) can improve the current efficiency and the light emission life even when manufactured by the wet coating method. Therefore, the compound represented by the general formula (1) can be used as a material for an organic EL device.

That is, the present embodiment can provide a material for an organic EL device containing a compound represented by the general formula (1). Therefore, an organic electroluminescence device having excellent current efficiency and light emission life can be manufactured by a coating method even with a material for an organic EL device containing a compound represented by the general formula (1). The organic electroluminescence device material of the present embodiment is an example of a material for an electroluminescence device using the compound according to the present invention.

Further, the material for the organic electroluminescence element (hereinafter referred to as the material for the organic EL element) according to the present embodiment is the composition of the present embodiment (the compound represented by the above general formula (1) and the above general formula (4). A composition containing the compound represented by the above general formula (1), a composition containing the compound represented by the above general formula (1) and the compound represented by the above general formula (5), or the above general formula (1). A composition containing the compound represented by the above general formula (4), the compound represented by the above general formula (4), and the compound represented by the above general formula (5)).

As described above, the composition according to the present embodiment exhibits high solubility (solubility) in a solvent and suppresses molecular aggregation, so that a carrier trap site or an exciton deactivation site can be obtained by a wet coating method. It is possible to form a thin film with excellent film quality. In addition, the composition according to this embodiment has high hole transportability and / or high electron transportability. Therefore, the material for an organic EL device containing the compound can be used as a material for, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, or an electron injection layer.

Therefore, the organic electroluminescence device using the composition according to the present embodiment can improve the current efficiency and the light emission life even when manufactured by the wet coating method. Therefore, the composition of the present embodiment (a composition containing a compound represented by the general formula (1) and a compound represented by the general formula (4), a compound represented by the general formula (1) and a general formula ( A composition containing the compound represented by the general formula (5), and a compound represented by the general formula (1), a compound represented by the general formula (4), and a compound represented by the general formula (5) are included. The composition) can be used as a material for an organic EL element.

That is, the present embodiment can provide a material for an organic EL device containing the composition according to the present embodiment. Therefore, even with the material for an organic EL device containing the composition according to the present embodiment, an organic electroluminescence device having excellent current efficiency and light emission life can be manufactured by a coating method. The organic electroluminescence device material of the present embodiment is an example of a material for an electroluminescence device using the composition according to the present invention.

<Organic electroluminescence element>
Hereinafter, the organic electroluminescence device according to the present embodiment will be described in detail with reference to FIG. 1. FIG. 1 is a schematic diagram of an organic electroluminescence device according to this embodiment. In addition, in this specification, "organic electroluminescence element" may be abbreviated as "organic EL element".

As shown in FIG. 1, the organic electroluminescence element (organic EL element) 100 according to the present embodiment is arranged on the substrate 110, the first electrode 120 arranged on the substrate 110, and the first electrode 120. The hole injection layer 130, the hole transport layer 140 arranged on the hole injection layer 130, the light emitting layer 150 arranged on the hole transport layer 140, and the electron transport layer arranged on the light emitting layer 150. It includes 160, an electron injection layer 170 arranged on the electron transport layer 160, and a second electrode 180 arranged on the electron injection layer 170.

Here, the compound represented by the general formula (1) of the present embodiment is contained in, for example, any organic layer arranged between the first electrode 120 and the second electrode 180. Further, the composition containing the compound represented by the general formula (1) of the present embodiment is contained in, for example, any organic layer arranged between the first electrode 120 and the second electrode 180.

Specifically, the compound represented by the general formula (1) has a hole injection layer 130 as a hole injection material and a positive hole transport material from the viewpoint of being excellent in both hole transport property and electron transport property. It is preferably contained in the hole transport layer 140, the light emitting layer 150 as the light emitting layer material (host), the electron transport layer 160 as the electron transport material, and the electron injection layer 170 as the electron injection material, and more preferably the hole transport layer 140. It is contained in the light emitting layer 150 or the electron transport layer 160, and more preferably contained in the light emitting layer 150.

Further, the composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4) is a hole injection layer 130 as a hole injection material from the viewpoint of excellent hole transportability. , The hole transporting material is preferably contained in the hole transporting layer 140, and the light emitting layer material (host) is preferably contained in the light emitting layer 150, more preferably contained in the hole transporting layer 140 or the light emitting layer 150, and further preferably. , Included in the light emitting layer 150.

A composition containing the compound represented by the general formula (1), the compound represented by the general formula (4), and the compound represented by the general formula (5) has a hole transport property and an electron transport property. From the viewpoint of being excellent in all of the above, the hole injection layer 130 as the hole injection material, the hole transport layer 140 as the hole transport material, the light emitting layer 150 as the light emitting layer material (host), and the electron transport layer 160 as the electron transport material. The electron injection material is preferably contained in the electron injection layer 170, more preferably contained in the hole transport layer 140, the light emitting layer 150, or the electron transport layer 160, and further preferably contained in the light emitting layer 150.

The composition containing the compound represented by the general formula (1) and the compound represented by the general formula (5) has a light emitting layer 150 as a light emitting layer material (host) and electron transport from the viewpoint of excellent electron transportability. It is preferably contained in the electron transport layer 160 as a material and in the electron injection layer 170 as an electron injection material, more preferably contained in the light emitting layer 150 or the electron transport layer 160, and further preferably contained in the light emitting layer 150.

Further, the organic layer containing the compound represented by the general formula (1) of the present embodiment is formed by a coating method. Specifically, the organic layer containing the compound represented by the general formula (1) includes a spin coat method, a casting method, a micro gravure coat method, and a gravure coat. ) Method, bar coat method, roll coat method, wire bar coat method, dip coat method, spray coat method, screen printing. The film can be formed by a solution coating method such as a method, a flexographic printing method, an offset printing method, or an ink jet printing method.

As the solvent used in the solution coating method, any solvent can be used as long as it can dissolve the compound represented by the general formula (1). Examples of such a solvent include toluene, xylene, ethylbenzene, diethylbenzene, methicylene, propylbenzene, cyclohexylbenzene, dimethoxybenzene, anisole, ethoxytoluene, phenoxytoluene, isopropylbiphenyl, dimethylanisole, phenylacetate, phenylpropionate, and benzoic acid. Examples thereof include methyl acid, ethyl benzoate and the like.

Further, the amount of the solvent used is not particularly limited. However, from the viewpoint of ease of application and the like, in the case of the compound according to the present embodiment, the concentration of the compound represented by the general formula (1) is preferably 0.1% by mass to 10% by mass, more preferably 0. It is 5.5% by mass to 5% by mass.

On the other hand, in the case of a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4) according to the present embodiment, the concentration of the compound represented by the general formula (1) is The concentration of the compound represented by the general formula (4) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and the concentration of the compound represented by the general formula (4) is preferably 0.1% by mass to 5% by mass. It is 10% by mass, more preferably 0.5% by mass to 5% by mass.

Further, in the case of a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (5) according to the present embodiment, the concentration of the compound represented by the general formula (1) is The concentration of the compound represented by the general formula (5) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and the concentration of the compound represented by the general formula (5) is preferably 0.1% by mass to 5% by mass. It is 10% by mass, more preferably 0.5% by mass to 5% by mass.

Further, in the case of a composition containing the compound represented by the general formula (1), the compound represented by the general formula (4) and the compound represented by the general formula (5) according to the present embodiment, the general formula is used. The concentration of the compound represented by (1) is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and the concentration of the compound represented by the general formula (4). The concentration is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 5% by mass, and the concentration of the compound represented by the general formula (5) is preferably 0.1% by mass. % To 10% by mass, more preferably 0.5% by mass to 5% by mass.

The method for forming a layer other than the organic layer containing the compound represented by the general formula (1) is not particularly limited. The layer other than the organic layer may be formed by, for example, a vacuum vapor deposition method or a solution 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 glass substrate, a semiconductor substrate such as a silicon substrate, a transparent plastic substrate, or the like.

The first electrode 120 is formed on the substrate 110. Specifically, the first electrode 120 is an anode, and a metal, an alloy, a conductive compound, or the like having a large work function (minimum energy required to extract one electron in a substance to the outside) has a large work function. It is formed. For example, the first electrode 120 has indium tin oxide (In ₂ O ₃ -SnO ₂ : ITO), indium zinc oxide (In ₂ O ₃ -ZnO), tin oxide (SnO ₂ ), and oxidation, which are excellent in transparency and conductivity. It may be formed as a transmissive electrode by zinc (ZnO) or the like. Further, the first electrode 120 may be formed as a reflective electrode by laminating magnesium (Mg), aluminum (Al), or the like on the transparent conductive film.

A hole injection layer 130 is formed on the first electrode 120. The hole injection layer 130 is a layer that facilitates the injection of holes from the first electrode 120, and specifically has a thickness of about 10 nm to about 1000 nm, and more specifically, a thickness of about 10 nm to about 100 nm. May be formed with.

The hole injection layer 130 can be formed of a known hole injection material. Known hole-injecting materials that form the hole-injecting layer 130 include, for example, triphenylamine-containing polyether ketone (poly (ether ketone) -containg triphenyllamine: TCAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis. (Pentafluorophenyl) borate (4-isopropyl-4'-methyldiphenylliodonium tetracis (pentafluorophenyl) boreta: PPBI), N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-tril-amino) -Phenyl] -biphenyl-4,4'-diamine (N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-polyyl-amino) -phenyl] -biphenyl-4,4'- diamine: DNTPD), copper phthalocyanine, 4,4', 4 "-tris (3-methylphenylphenylamino) triphenylamine (4,4', 4" -tris (3-methylphenylphenyllamino) triphenyllamine: m -MTDATA), N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine (N, N'-di (1-naphthyl) -N, N'-diphenyllbenzidine: NPB), 4,4' , 4 "-tris (diphenylamino) triphenylamine (4,4', 4" -tris (diphenyllamino) triphenyllamine: TDATA), 4,4', 4 "-tris (N, N-2-naphthylphenylamino) Triphenylamine (4,4', 4 "-tris (N, N-2-naphylphenyllamino) triphenyllamine: 2-TNATA), polyaniline / dodecylbenzenesulfonic acid, poly (3,4-ethylenedi). Oxythiophene) / poly (4-styrene sulfonate) (poly (3,4-ethylenedioxythiophene) / poly (4-tylenesulfonate): PEDOT / PSS), and polyaniline / 10-camparsulfonic acid (polyaniline / 10-camphorsulf). Onic acid) and the like can be mentioned.

A hole transport layer 140 is formed on the hole injection layer 130. The hole transport layer 140 is a layer having a function of transporting holes, and may be formed, for example, with a thickness of about 10 nm to 150 nm. The hole transport layer 140 is preferably formed by a solution coating method using the compound of the present embodiment. According to this method, a compound capable of improving the current efficiency and drive life of the organic EL element 100 can be efficiently formed into a large area.

However, when any other organic layer of the organic EL element 100 contains the compound of the present embodiment, the hole transport layer 140 may be formed of a known hole transport material. Known hole transport materials include, for example, 1,1-bis [(di-4-tolylamino) phenyl] cyclohexane (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) triphenyllamine: TCTA), and N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine: NPB) and the like can be mentioned.

A 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 light emitting layer 150 may be formed, for example, with a thickness of about 10 nm to about 60 nm. As the light emitting material of the light emitting layer 150, a known light emitting material can be used. However, the light emitting material contained in the light emitting layer 150 is preferably a light emitting material capable of emitting light from triplet excitons (that is, phosphorescent light emission). In such a case, the current efficiency and light emission life of the organic EL element 100 can be further improved.

Further, the light emitting layer 150 can be formed into a film by a solution coating method using the material for an organic EL element according to the present embodiment. Further, in the present embodiment, the light emitting layer 150 containing the compound represented by the general formula (1) capable of improving the current efficiency and the light emitting life of the organic EL element 100 by such a solution coating method is efficiently used. It is possible to form a film in a large area.

However, when any other organic layer of the organic EL element 100 contains the compound represented by the general formula (1) according to the present embodiment, the light emitting layer 150 may be made of a known material.

Among the known materials constituting the light emitting layer 150, as the host material, for example, tris (8-quinolinato) aluminum (Alq3), 4,4'-bis (carbazole-9-yl), etc. Biphenyl (4,4'-bis (carbazole-9-yl) biphenyl: CBP), poly (n-vinylcarbazole) (poly (n-vinyl carbazole): PVK), 9,10-di (naphthalen-2-yl) ) Anthracene (9,10-di (naphthalene) anthracene: ADN), 4,4', 4 "-tris (N-carbazolyl) triphenylamine (4,4', 4" -tris (N-carbazolyl) triphenyllamine: TCTA), 1,3,5-tris (N-phenylbenzimidazole-2-yl) benzene (1,3,5-tris (N-phenyl-benzimidazol-2-yl) bendene: TPBI), 3-tert- Benzene-9,10-di (naphth-2-yl) anthracene (3-tert-butyl-9,10-di (naphth-2-yl) anthracene: TBADN), distyrylylene (DSA), 4, It may contain 4'-bis (9-carbazole) -2,2'-dimethyl-biphenyl (4,4'-bis (9-carbazole) 2,2'-dimethyl-biphenyl: dmCBP) and the like.

Further, the light emitting layer 150 has, 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-dyanomethylene-2- (plexylaminostylyl) -6-methyl-4H-pyran: DCM) and its derivatives, bis [2- (4,6-difluorophenyl) pyridinate] picolinate. Iridium (III) (bis [2- (4,6-difluorophenyl) complex] picolinate iridium (III): FIrpic), bis (1-phenylisoquinoline) (acetylacetonate) iridium (III) (bis (1-phenylisokuinline)) (Acetylcatenate) derivative (III): Ir (piq) 2 (acac)), tris (2-phenylpyridine) iridium (III) (tris (2-phenylpyridine) iridium (III): Ir (ppy) 3), tris (2-phenylpyridine) iridium (III) It may contain an iridium (Ir) complex such as 2- (3-p-xyl) phenyl) pyridine iridium (III), an osmium (Os) complex, a platinum complex and the like.

Further, the light emitting layer 150 may contain 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, but are limited to, CdS, CdSe, CdTe, ZnSe, ZnS, PbS, PbSe, HgS, HgSe, HgTe, CdHgTe, CdSe _X Te _1-X , GaAs, InAs and InP. It's not something.

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

An electron transport layer 160 is formed on the light emitting layer 150. The electron transport layer 160 is a layer having a function of transporting electrons. The electron transport layer 160 may be formed, for example, with a thickness of about 15 nm to about 50 nm.

The electron transport layer 160 may be formed of a known electron transport material. Examples of known electron transport materials include tris (8-quinolinato) aluminum (tris (8-quinolinato) aluminum: Alq3), compounds having a nitrogen-containing aromatic ring, and the like. 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)). -Pyridine ring-containing compounds such as -phenyl-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-phenylbenzoindazolyl-1-yl-phenyl) -9,10-dinaphthylanthracene (2- (4- (N-phenylbenzoimidazolyl-1-yl-phenyl) -9,10-dinaphylanthracene) ), And the like, a compound containing an imidazole ring and the like can be mentioned.

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 the injection of electrons from the second electrode 180. The electron injection layer 170 may be formed with a thickness of about 0.3 nm to about 20 nm. The electron injection layer 170 is not particularly limited, and a known material can be used as the material for forming the electron injection layer 170. For example, the electron injection layer 170 is composed of a lithium compound such as (8-quinolinato) lithium ((8-quinolinato) lithium: Liq) and lithium fluoride (LiF), sodium chloride (NaCl), and cesium fluoride (CsF). ), Lithium oxide (Li ₂ O), barium oxide (BaO), or the like.

A second electrode 180 is formed on the electron injection layer 170. The second electrode 180 is specifically a cathode, and is formed of a metal, an alloy, a conductive compound, or the like having a small 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), or the like. It may be formed as a reflective electrode with an alloy such as magnesium-silver (Mg-Ag). The second electrode 180 is a transmissive electrode made of a thin film of the metal material having a diameter of 20 nm or less, and a transparent conductive film such as indium tin oxide (In ₂ O ₃ -SnO ₂ ) and zinc oxide (In ₂ O ₃ -ZnO). May be formed as.

The organic EL element 100 according to the present embodiment has an organic layer containing a compound represented by the general formula (1), so that an organic electroluminescence element having excellent current efficiency and light emission life can be produced by a coating method. .. Further, the compound represented by the general formula (1) has excellent hole transportability and electron transportability, and each organic layer (hole injection layer, hole transport layer, etc.) constituting the organic EL device. It can be used for a light emitting layer, an electron transport layer, and an electron injection layer). The organic EL device 100 according to the present embodiment is an example of the electroluminescence device according to the present invention.

Further, the organic EL device 100 according to the present embodiment has an organic layer containing a composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4), whereby the current is generated. An organic electroluminescence device having excellent efficiency and light emission life can be manufactured by a coating method. Further, the composition containing the compound represented by the general formula (1) and the compound represented by the general formula (4) is further excellent in hole transportability, and each organic layer constituting the organic EL device is formed. It can be used for (hole injection layer, hole transport layer, light emitting layer).

The organic EL device 100 according to the present embodiment has an organic layer containing a composition containing a compound represented by the general formula (1) and a compound represented by the general formula (5), thereby achieving current efficiency. An organic electroluminescence device having an excellent luminescence life can be produced by a coating method. Further, the composition containing the compound represented by the general formula (1) and the compound represented by the general formula (5) has each organic layer constituting the organic EL device (from the viewpoint of further excellent electron transportability). It can be used for a light emitting layer, an electron transport layer, and an electron injection layer).

The organic EL element 100 according to the present embodiment is a composition containing a compound represented by the general formula (1), a compound represented by the general formula (4), and a compound represented by the general formula (5). By having the organic layer containing the organic layer, an organic electroluminescence element having excellent current efficiency and light emission life can be manufactured by a coating method. Further, the composition containing the compound represented by the general formula (1), the compound represented by the general formula (4) and the compound represented by the general formula (5) further has hole transporting property and electron transporting property. From the viewpoint of excellent properties, it can be used for each organic layer (hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer) constituting the organic EL element. The organic EL device 100 according to the present embodiment is an example of the electroluminescence device according to the present invention.

The laminated structure of the organic EL element 100 according to the present embodiment is not limited to the above example. The organic EL element 100 according to the present embodiment may be formed by another known laminated structure. For example, in the organic EL element 100, one or more of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170 may be omitted, or another layer may be additionally used. You may be prepared. Further, each layer of the organic EL element 100 may be formed of a single layer or may be formed of a plurality of layers.

For example, the organic EL device 100 may further include a hole blocking layer between the light emitting layer 150 and the electron transporting layer 160 in order to prevent excitons or holes from diffusing into the electron transporting layer 160. good. The hole blocking layer can be formed by, for example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or the like.

Hereinafter, the present invention will be described with reference to more detailed examples. The present invention is not limited to these examples. In the following, "%" is a weight standard unless otherwise specified. The tests and evaluations were as follows.

<Compound synthesis>
[Synthesis Example 1]
Compound (1-1) was first synthesized by the following reaction scheme (6).

Specifically, under a nitrogen atmosphere, 2,2'-dibromo-1,1'-biphenyl (31.7 g, 101.6 mmol) and diethyl ether (500 ml) were added to a three-necked flask to dissolve the sample, and -80 was dissolved. Cooled to ° C. To this solution, n-BuLi (2.66 M hexane solution, 34.7 ml, 92.4 mmol) was added dropwise over 10 minutes. After stirring at -80 ° C for 5 minutes, 4-bromo-9H-fluorene-9-one (25.0 g, 97 mmol) was added, and the mixture was stirred at -80 ° C for 5 minutes and then to room temperature for about 30 minutes. The temperature was raised and the mixture was stirred at room temperature for 3 hours. The reaction system was deactivated with a small amount of water, diluted with chloroform (500 ml), and washed twice with pure water using a separating funnel. This was dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated to obtain a crude product of compound (1-1). The obtained crude product of compound (1-1) was used as it was for the synthesis of the next compound (1-2) without further purification.

Then, compound (1-2) was synthesized by the following reaction scheme (7).

Specifically, the compound (1-1) and chloroform (500 ml) obtained in the above reaction scheme (6) were placed in a three-necked flask under a nitrogen atmosphere, and methanesulfonic acid (6.0 ml, 92.4 mmol) was placed at room temperature. ) Was added, and the mixture was stirred at 60 ° C. for 3 hours. After cooling to room temperature, it was washed twice with pure water using a separating funnel. This was dried over anhydrous magnesium sulfate, filtered using a silica gel pad, and concentrated to obtain a crude product of compound (1-2). This was purified by silica gel chromatography (developing solvent hexane: chloroform = 9: 1), and further recrystallized from hexane to obtain compound (1-2). The yield of compound (1-2) was 10.7 g, and the yield was 24%.

Then, compound 1 was synthesized by the following reaction scheme (8).

Specifically, in a nitrogen atmosphere, the compound (1-2) (7.1 g, 15 mmol) obtained by the above reaction scheme (7), 2- ([1,1', 3', 1') was placed in a three-necked flask. '-Terphenyl] -3-yl) -4,4,5,5-tetramethyl-1,3,2-dioxabololane (12.8 g, 36 mmol), toluene 150 ml, ethanol 30 ml, potassium carbonate 2M aqueous solution (60 mmol, 30 ml) ) Was added and mixed, tri (o-tolyl) phosphine (1.2 mmol) and palladium acetate (0.87 g, 0.75 mmol) were added, and the mixture was stirred at 80 ° C. for 8 hours. Toluene (500 ml) was added to dilute the mixture, the mixture was cooled to room temperature, washed twice with pure water using a liquid separation funnel, dried over anhydrous ו44, filtered using a silica gel pad, and then concentrated. This was purified by silica gel chromatography (developing solvent hexane: toluene = 8: 2), and further recrystallized from hexane to obtain compound 1. The yield of compound 1 was 6.96 g, and the yield was 60%.

[Synthesis Example 2]
Compound 3 was synthesized in the same manner as in Synthesis Example 1 except that the reaction scheme (9) was changed and the corresponding reagent was changed.

Specifically, 2-([1,1', 3', 1''-terphenyl] -3-yl) -4,4,5,5-tetramethyl-1,3,2-dioxabolorane is used as a raw material. 4,4,5,5-tetramethyl-2- (5'-phenyl- [1,1', 3', 1''-terphenyl] -3-yl) -1,3,2-Dioxabolorane Obtained compound 3 in the same manner as in the synthesis of compound 1. The yield of compound 3 was 7.63 g, and the yield was 55%.

[Synthesis Example 3]
Comparative Example compound C1 was obtained in the same manner as in Synthesis Example 1 except that the reaction scheme was changed and the corresponding reagent was changed.

<Measurement of triplet energy level>
Each compound was dissolved in toluene to a concentration of 3% by mass to prepare a solution. This solution was applied by spin coating at a rotation speed of 1600 rpm and dried on a hot plate at 120 ° C. for 15 minutes to obtain a film (sample) having a thickness (dry film thickness) of about 50 nm. The sample was cooled to 77K (-196 ° C.) and the photoluminescence (PL) spectrum was measured. The triplet energy level (eV) was calculated from the peak value on the shortest wavelength side of this PL spectrum. The results are shown in Table 1.

<Measurement of solubility>
50 mg of a sample solid sample was placed in a colorless and transparent sample bottle, 500 mg of a solvent was added, and ultrasonic irradiation was performed at room temperature for 5 minutes, and the presence or absence of residual sample solid was visually confirmed. At this point, if there is no residual sample solid and it is dissolved, the solubility will be 10 wt% or more. If there was a residual sample solid, solvent addition and ultrasonic irradiation were repeated little by little, and the solubility was calculated from the amount of solvent at the time of complete dissolution. The results are shown in Table 2.

<Organic EL element evaluation method>
[Evaluation of current efficiency and durability (light emission life)]
The current efficiency and durability (emission life) of Examples and Comparative Examples were evaluated under the following conditions. First, the voltage and current applied to the organic EL element are measured using a DC constant voltage power supply (KEYENCE, source meter), and the emission brightness of the organic EL element is measured by a brightness measuring device (Topcon, SR-3). ) Was measured.

The current value (current density) per unit area is calculated from the area and current value of the organic EL element, and the brightness (cd / m ² ) is divided by the current density (A / m ² ) to achieve the current efficiency (cd). / A) was calculated. The current efficiency indicates the efficiency of converting the current into light emission energy (conversion efficiency), and the higher the current efficiency, the higher the performance of the organic EL element.

Durability (light emission life) is the time (time) for each organic EL element to be continuously driven at a current value at which the initial brightness is 6000 cd / m ² until the light emission brightness attenuates with the passage of time becomes 80% of the initial brightness. Was set to "LT80 (h)". Table 3 shows the current efficiency of each compound and the relative value of LT80 (h) when the comparative example compound is 100.

<Examples and comparative examples>
[Example 1]
First, as the first electrode (anode), a glass substrate with ITO in which striped indium tin oxide (ITO) is formed in a film thickness of 150 nm is prepared. On this glass substrate, poly (3,4-ethylenedioxythiophene) / poly (4-styrene sulfonate) (poly (3,4-ethylenedioxythiophene) / poly (4-styrene sulfonate): PEDOT / PSS) (Sigma). -Made by Aldrich) was applied by a spin coating method so that the dry film thickness was 30 nm to form a hole injection layer.

Next, a commercially available TFB was dissolved in xylene at 1% by mass to prepare a hole transport layer coating solution. A hole transport layer coating liquid was applied onto the hole injection layer by a spin coating method so that the dry film thickness was 30 nm, and heated at 230 ° C. for 1 hour to form a hole transport layer.

Next, compound 1 synthesized in the above synthesis example as the first host material, H1 as the hole transporting host material, E1 as the electron transporting host material, and Tris (2- (3-p) as the light emitting dopant material. -Methyl benzoate solution was prepared with xyl) phenyl) pyridine iridium (TEG). This was applied onto the hole transport layer by a spin coating method to form a light emitting layer having a film thickness of 30 nm (the molecular structures of H1, E1 and TEG are shown below). The mass ratios of the first host material, the hole transporting host material, the electron transporting host material, and the light emitting dopant material in the light emitting layer were 50% by mass and 40% by mass, respectively, with respect to the total mass of the light emitting layer. It was 5% by mass and 5% by mass.

11- (4,6-diphenyl-1,3,5-triazine-2-yl) -12-phenyl-11,12-dihydroindro [2,3-a] carbazole (HB1) was placed on the light emitting layer. The holes were vapor-deposited with a vacuum vapor deposition apparatus to form a hole blocking layer having a film thickness of 10 nm. (8-Kinolinolato) lithium (Liq) and KLET-03 (manufactured by Chemipro Kasei) were co-deposited on the hole blocking layer by a vacuum vapor deposition apparatus to form an electron transport layer having a film thickness of 30 nm (Liq, HB1). The molecular structure is shown below). Aluminum (Al) was deposited on the electron transport layer by a vacuum vapor deposition apparatus to form a cathode having a film thickness of 100 nm. This element was sealed with a glass sealing tube with a desiccant and an ultraviolet curable resin in a glove box having a moisture and oxygen concentration of 1 ppm or less, and used for the evaluation of an organic EL element described later.

[Example 2]
An organic EL device was manufactured by the same method as in Example 1 except that compound 3 was used as the host material instead of compound 1. The results are shown in Table 3.

[Comparative Example 1]
An organic EL device was manufactured by the same method as in Example 1 except that Compound C1 of Comparative Example was used as the host material. The results are shown in Table 3.

[Comparative Examples 2 to 5]
An organic EL device was manufactured by the same method as in Example 1 except that the composition of the light emitting layer material was changed to the composition shown in Table 3. The results are shown in Table 3.

First, from Table 1, it is shown that compounds 1 and 3 have a higher triplet energy level (eV) and are suitable for triplet exciton confinement with respect to the comparative example compound C1 and are advantageous in luminous efficiency. ing. Therefore, compounds 1 and 3 can be expected as materials for organic EL devices.

Further, from Table 2, it is shown that Compounds 1 and 3 have high solubility (%) in an organic solvent (methyl benzoate) and excellent solubility in a solvent with respect to Comparative Example Compound C1. Therefore, the compound according to this embodiment can be expected to produce a low-cost organic EL device using a coating method.

Further, from Table 3, Examples 1 and 2 in which the compound according to the present embodiment was used as the host material and the light emitting layer composition showed higher current efficiency and improved light emission life as compared with Comparative Examples 1 to 5. You can see that it is doing. Further, Examples 1 and 2 also emit light even in the case of Comparative Example 2 in which the carrier balance is optimized in Comparative Examples 2 to 5 in which the compound represented by the general formula (1) is not contained as a host material. It can be seen that the lifespan is the same and the current efficiency is higher. Therefore, the compound according to the present embodiment or the composition according to the present embodiment can produce an organic EL device having excellent luminous efficiency and emission lifetime by using a coating method.

Further, the compounds 1 and 3 used in Examples 1 and 2 are preferable from the viewpoint of mass production because the light emitting layer of the organic electroluminescence device can be formed by the coating method.

Although the present invention has been described above with reference to embodiments and examples, the present invention is not limited to specific embodiments and examples, and is various within the scope of the invention described in the claims. Can be transformed 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 (12)

The following equation (1-1) or (1-2):

( In the formula, X ₁ to X ₄ each independently indicate -C (R ₃ )-or a nitrogen atom;
X ₁ to X ₄ may be the same or different;
R ₃ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. Shows a monovalent aromatic heterocyclic group )
A compound selected from. The following compounds 1, 3-5 , 11, 13-16 :

The compound according to claim 1. With the compound according to claim 1 or 2.
The following formula (4)

(In the formula, _R4 is a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent ring having 3 to 30 atoms. It is an aromatic heterocyclic group;
Y ₁ to Y ₈ are independently -C (R ₅ )-or nitrogen atoms;
R5 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having ₆ to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. It is a monovalent aromatic heterocyclic group. )
And the compound represented by
A composition comprising a luminescent material. The following formula (5):

(In formula (5), Z ₁ to Z ₆ are independently -C (R ₆ )-or nitrogen atoms;
At least one of Z ₁ to Z ₆ is a nitrogen atom;
R ₆ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. It is a monovalent aromatic heterocyclic group. )
The composition according to claim 3, further comprising the compound represented by. With the compound according to claim 1 or 2.
The following formula (5):

(In formula (5), Z ₁ to Z ₆ are independently -C (R ₆ )-or nitrogen atoms;
At least one of Z ₁ to Z ₆ is a nitrogen atom;
R ₆ is a hydrogen atom, a deuterium atom, a substituted or unsubstituted monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming atom having 3 to 30 atoms. It is a monovalent aromatic heterocyclic group. )
And the compound represented by
A composition comprising a luminescent material. A liquid composition comprising the compound according to claim 1 or 2 and a solvent. A liquid composition containing the composition according to any one of claims 3 to 5 and a solvent. A material for an organic electroluminescence device containing the compound according to claim 1 or 2. A material for an organic electroluminescence device, which comprises the composition according to any one of claims 3 to 5. With a pair of electrodes,
It comprises one or more organic layers arranged between the pair of electrodes.
At least one of the organic layers contains the composition according to any one of claims 3 to 5.
Organic electroluminescence element. With a pair of electrodes,
It comprises one or more organic layers arranged between the pair of electrodes.
An organic electroluminescence device in which at least one of the organic layers contains a light emitting material and the composition according to any one of claims 3 to 5. The organic electroluminescence device according to claim 10 or 11, wherein the organic layer containing the composition is formed by a coating method.

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