WO2022255402A1

WO2022255402A1 - Aromatic compound and organic electroluminescent element

Info

Publication number: WO2022255402A1
Application number: PCT/JP2022/022279
Authority: WO
Inventors: 司長谷川; 一毅岡部; 延軍李; 大輔弘
Original assignee: 三菱ケミカル株式会社
Priority date: 2021-06-04
Filing date: 2022-06-01
Publication date: 2022-12-08
Also published as: TW202313532A; KR20240016268A; JPWO2022255402A1

Abstract

An organic electroluminescent element which comprises a positive electrode and a negative electrode on a substrate, while having an organic layer between the positive electrode and the negative electrode, wherein the organic layer comprises a layer that contains an aromatic compound represented by formula (1). (In the formula, each of Ar1 to Ar5 represents a hydrogen atom or an aromatic hydrocarbon group having 6 to 60 carbon atoms; at least one of Ar1, Ar2 and Ar5 is represented by formula (2) or formula (3); each of L1 to L5 represents an aromatic hydrocarbon group having 6 to 60 carbon atoms; and R represents a specific substituent.)

Description

Aromatic compounds and organic electroluminescent devices

The present invention relates to aromatic compounds that can be used in organic electroluminescent devices (hereinafter sometimes referred to as "OLED" or "device"). The present invention also provides an organic electroluminescent device comprising the aromatic compound, a display device and a lighting device comprising the organic electroluminescent device, a composition containing the compound and an organic solvent, a thin film forming method using the composition and an organic The present invention relates to a method for manufacturing an electroluminescent device.

In recent years, as thin-film electroluminescent elements, instead of those using inorganic materials, organic electroluminescent elements using organic thin films have been developed. An organic electroluminescent device (OLED) typically has a hole-injection layer, a hole-transport layer, an organic light-emitting layer, an electron-transport layer, etc. between an anode and a cathode. Materials suitable for each of these layers are being developed, and the development of red, green, and blue emission colors is progressing. In addition, research is being conducted on coating-type OLEDs, which are more efficient in material utilization than conventional evaporation-type OLEDs and can reduce manufacturing costs.

For coating-type OLEDs, there is a demand for longer life of the elements and lower power consumption. Various factors are conceivable as factors that affect the life of the device and the improvement in power consumption. For example, the lifetime is considered to be greatly affected by the heat resistance and durability of the material forming the element and the crystallinity.

In order to manufacture an organic electroluminescence device by a wet film-forming method, all materials used must be soluble in an organic solvent and usable as an ink. If the material to be used has poor solubility, the material may deteriorate before use because an operation such as heating for a long period of time is required. If the uniform state cannot be maintained for a long time in a solution state, the material will precipitate from the solution, making it impossible to form a film using an inkjet device or the like.
Materials used in the wet film-forming method are required to have solubility in two senses: rapid dissolution in an organic solvent and maintenance of a homogeneous state without precipitating after dissolution.

In order to form all the organic layers by a wet film-forming method and to produce an organic electroluminescence element, the ink to be applied thereon after the wet film-forming is applied. There is a demand for solvent resistance against

Patent Document 1 reports OLED materials using aromatic compounds such as the following compound (C-1) and the following compound (C-2) as charge transport materials for phosphorescent compounds.

WO2007/043357

Although the above compounds have high solubility and a large bandgap, the glass transition temperature is as low as 99°C for compound (C-1) and 87°C for compound (C-2), and the heat resistance is not sufficient. Moreover, when laminating a thin film on a thin film formed from the above compound by a wet film-forming method using an alcoholic solvent, the solvent resistance to the alcoholic solvent used is not sufficient.

An object of the present invention is to provide a compound which is excellent in heat resistance and solvent solubility, is excellent in solvent resistance to alcohol solvents in a thin film, and has a large bandgap.
The present invention also provides an organic electroluminescence device comprising the compound, a display device and a lighting device comprising the organic electroluminescence device, a composition containing the compound and a solvent, a method for forming a thin film using the composition, and organic electroluminescence. An object of the present invention is to provide a device manufacturing method.

The inventors have found that the above problems can be solved by using an aromatic compound with a specific structure.

The gist of the present invention is as follows <1> to <32>.

<1> An organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
An organic electroluminescence device, wherein the organic layer includes a layer containing an aromatic compound represented by the following formula (1).

(In formula (1),
Ar ¹ to Ar ⁵ are each independently a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms,
At least one of Ar ¹ , Ar ² and Ar ⁵ is represented by the following formula (2) or the following formula (3).
L ¹ to L ⁵ are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms.
Each R is independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group , or represents an aromatic hydrocarbon group.
m1, m2 and m5 each independently represents an integer of 0 to 5;
m3 and m4 each independently represent an integer of 1 to 5;
n represents an integer from 0 to 10;
a1 and a2 each independently represent an integer of 0 to 3;
a3 represents an integer of 0 to 4;
a4 represents an integer of 0 or 1;
However, when a3 is 4, a4 is 0.
A substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in Ar ¹ to Ar ⁵ may have, and a divalent carbon number of 6 or more and 60 or less in L ¹ to L ⁵ . The substituents that the aromatic hydrocarbon group may have are each independently an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group;
In formula (1), Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ³ -(L ³ ) _m3 -, and Ar ⁴ -(L ⁴ ) _m4 - are all hydrogen does not become an atom. )

(In formula (2) or (3),
An asterisk (*) represents a bond with formula (1).
R ¹ to R ²⁶ are each independently hydrogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group. )

<2> Ar ¹ and Ar ² and Ar ⁵ when n is 1 or more or at least one Ar ⁵ when n is 2 or more are represented by the above formula (2) or the above formula (3) The organic electroluminescence device according to <1>.

<3> The organic electric field according to <1> or <2>, wherein L ¹ to L ⁵ are each independently a phenylene group or a group in which two or more phenylene groups are linked, each of which may have a substituent. light-emitting element.

<4> The organic electroluminescence device according to <3>, wherein L ¹ to L ⁵ are each independently a 1,3-phenylene group optionally having a substituent.

<5> The organic electroluminescence device according to any one of <1> to <4>, wherein the aromatic compound has a molecular weight of 1200 or more.

<6> The organic electroluminescence device according to any one of <1> to <5>, wherein the layer containing the aromatic compound is a light-emitting layer.

<7> A display device comprising the organic electroluminescence device according to any one of <1> to <6>.

<8> A lighting device comprising the organic electroluminescence device according to any one of <1> to <6>.

<9> An aromatic compound represented by the following formula (1).

(In formula (1),
Ar ¹ to Ar ⁵ are each independently a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms,
At least one of Ar ¹ , Ar ² and Ar ⁵ is represented by the following formula (2) or the following formula (3).
L ¹ to L ⁵ are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms.
Each R independently represents an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group.
m1, m2 and m5 each independently represents an integer of 0 to 5;
m3 and m4 each independently represent an integer of 1 to 5;
n represents an integer from 0 to 10;
a1 and a2 each independently represent an integer of 0 to 3;
a3 represents an integer of 0 to 4;
a4 represents an integer of 0 or 1;
However, when a3 is 4, a4 is 0.
A substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in Ar ¹ to Ar ⁵ may have, and a divalent carbon number of 6 or more and 60 or less in L ¹ to L ⁵ . The substituents that the aromatic hydrocarbon group may have are each independently an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group or an aromatic hydrocarbon group;
In formula (1), Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ³ -(L ³ ) _m3 -, and Ar ⁴ -(L ⁴ ) _m4 - are all hydrogen does not become an atom. )

(In formula (2) or (3),
An asterisk (*) represents a bond with formula (1).
R ¹ to R ²⁶ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group. represents a hydrogen group. )

<10> The aromatic compound according to <9>, wherein a1, a2 and a4 are 0.

<11> The aromatic compound according to <9>, wherein a4 is 1 and a3 is an integer of 0-3.

<12> The aromatic compound according to <11>, wherein a1, a2 and a3 are the same.

<13> Ar ¹ and Ar ² and Ar ⁵ when n is 1 or more or at least one Ar ⁵ when n is 2 or more are represented by the above formula (2) or the above formula (3) The aromatic compound according to any one of <9> to <12>.

<14> Any one of <9> to <13>, wherein L ¹ to L ⁵ are each independently a phenylene group or a group in which two or more phenylene groups are linked, each of which may have a substituent. of aromatic compounds.

<15> The aromatic compound according to <14>, wherein each of L ¹ to L ⁵ is independently an optionally substituted 1,3-phenylene group.

<16> The aromatic compound according to any one of <9> to <15>, which has a molecular weight of 1200 or more.

<17> A composition containing the aromatic compound according to any one of <9> to <16> and an organic solvent.

<18> The composition according to <17>, further comprising a phosphorescent material and a charge-transporting material.

<19> The composition according to <18>, wherein the charge-transporting material contains a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

(In formula (250),
Each W independently represents CH or N, and at least one W is N.
Xa ¹ , Ya ¹ , and Za ¹ are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon represents a divalent aromatic heterocyclic group of numbers 3 to 30;
Xa ² , Ya ² and Za ² are each independently a hydrogen atom, a monovalent aromatic hydrocarbon group optionally having 6 to 30 carbon atoms, or optionally having a substituent It represents a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms.
g11, h11, and j11 each independently represent an integer of 0 to 6,
At least one of g11, h11 and j11 is an integer of 1 or more.
When g11 is 2 or more, multiple ^Xa1 may be the same or different.
When h11 is 2 or more, a plurality of Ya ¹ may be the same or different.
When j11 is 2 or more, a plurality of ^Za1 may be the same or different.
R ³¹ represents a hydrogen atom or a substituent, and the four R ³¹ may be the same or different.
However, when g11, h11 or j11 is 0, the corresponding Xa ² , Ya ² and Za ² are not hydrogen atoms. )

(In formula (240),
Ar ⁶¹¹ and Ar ⁶¹² each independently represent an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
R ⁶¹¹ and R ⁶¹² each independently represent a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
G represents a single bond or an optionally substituted divalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
n ⁶¹¹ and n ⁶¹² are each independently an integer of 0-4. )

<20> The composition according to <19>, wherein at least two of the three Ws in the formula (250) are N.

<21> The composition according to <20>, wherein all W in the formula (250) are N.

<22> Ar ⁶¹¹ and Ar ⁶¹² in formula (240) are each independently a monovalent group in which a plurality of optionally substituted benzene rings are linked in a chain or branched manner, <19 >.

<23><19>, wherein R ⁶¹¹ and R ⁶¹² in the formula (240) are each independently a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; The described composition.

<24> The composition according to <19>, wherein n ⁶¹¹ and n ⁶¹² in formula (240) are each independently 0 or 1.

<25> A method for forming a thin film, comprising a step of forming a film from the composition according to any one of <17> to <24> by a wet film-forming method.

<26> A method for producing an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, comprising:
A method for producing an organic electroluminescence device, comprising the step of forming the organic layer by a wet film-forming method using the composition according to any one of <17> to <24>.

<27> The method for producing an organic electroluminescent device according to <26>, wherein the organic layer is a light-emitting layer.

<28> A method for producing an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, comprising:
the organic layer comprises a light-emitting layer and an electron-transporting layer;
forming the light-emitting layer by a wet film-forming method using the composition according to any one of <17> to <24>;
and forming the electron transport layer by a wet film-forming method using an electron transport layer-forming composition containing an electron transport material and a solvent.

<29> The method for producing an organic electroluminescence device according to <28>, wherein the solvent contained in the composition for forming an electron transport layer is an alcohol solvent.

<30> An organic electroluminescence device having an anode and a cathode on a substrate, and an organic layer between the anode and the cathode,
the organic layer comprises a light-emitting layer;
The light-emitting layer contains the aromatic compound according to any one of <9> to <16>, a phosphorescent light-emitting material and a charge transport material,
An organic electroluminescence device, wherein the charge-transporting material contains a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

<31> The organic electroluminescence device according to <30>, wherein at least two of the three Ws in the formula (250) are N.

<32> The organic electroluminescence device according to <31>, wherein all Ws in the formula (250) are N.

ADVANTAGE OF THE INVENTION By this invention, while being excellent in heat resistance and solvent solubility, an aromatic compound with a large bandgap can be provided.
The aromatic compound of the present invention is also excellent in solvent resistance to alcohol solvents in thin films. Therefore, it is also possible to laminate another layer on the film containing the aromatic compound of the present invention by a wet film-forming method.

According to the present invention, an organic electroluminescent device comprising the aromatic compound, a display device and a lighting device comprising the organic electroluminescent device, a composition containing the compound and a solvent, a method for forming a thin film, and a method for producing an organic electroluminescent device are provided. can provide.

FIG. 1 is a cross-sectional view schematically showing an example of the structure of the organic electroluminescence device of the present invention.

The embodiments of the present invention will be described in detail below. The present invention is not limited to the following embodiments, and can be modified in various ways within the scope of the gist thereof.

In the present invention, "optionally having a substituent" means that it may have one or more substituents.

[Aromatic compound according to the present invention]
The aromatic compound contained in the organic layer of the organic electroluminescent device of the present invention is an aromatic compound represented by the following formula (1) (hereinafter sometimes referred to as "aromatic compound (1)"). be.

<Mechanism of action by aromatic compound (1)>
In the present invention, the action mechanism by which the aromatic compound (1) provides effective effects is presumed as follows.

Aromatic compound (1) has one or more para-bonded terphenyl groups represented by formula (2) or (3), and thus has a high glass transition temperature.
The para-bonded terphenyl group represented by formula (2) or (3) bonds to formula (1) at the ortho- or meta-position, thereby suppressing the spread of the π-conjugated system and increasing the bandgap. As a result, the excited triplet energy level (T1) increases, the solubility increases, and the crystallinity decreases.

The aromatic hydrocarbon structure represented by formula (1) has a para-bonded terphenyl group represented by formula (2) or (3), thereby improving the solvent resistance of the thin film to alcohol-based solvents. can.
The aromatic hydrocarbon structure represented by formula (1) has a terphenyl group bonded at the para position represented by formula (2) or (3), so that HOMO and LUMO are represented by formula (2) or (3 ) is easily localized to the terphenyl group bonded at the para position, and durability can be improved.

By using the aromatic compound (1), it is possible to easily provide an organic electroluminescent device that has excellent driving stability and can be driven at a low driving voltage and with high efficiency.

The organic electroluminescent device of the present invention containing the aromatic compound (1) has excellent electrochemical stability, low driving voltage and high efficiency. Therefore, the organic electroluminescence device of the present invention can be used as a flat panel display (for example, an OA computer display or a wall-mounted TV), an in-vehicle display device, a mobile phone display, or a light source (for example, a copier (light sources for liquid crystal displays and instruments, backlight sources for instruments), display boards, and indicator lamps, and their technical value is great.

< ^Ar1 , ^Ar2 , ^Ar5 >
Ar ¹ , Ar ² and Ar ⁵ are each independently a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms.
At least one of Ar ¹ , Ar ² and Ar ⁵ is represented by the following formula (2) or the following formula (3).
From the viewpoint of stability, Ar ¹ , Ar ² and Ar ⁵ each independently preferably have a structure represented by formula (3).

Ar ¹ , Ar ² and Ar ⁵ are a hydrogen atom, a benzene ring monovalent group, a naphthalene ring monovalent group, the above formula (2) or formula (3), from the viewpoint of the solubility and durability of the compound. A structure represented by is preferable, a hydrogen atom, a monovalent group of a benzene ring, a structure represented by the above formula (2) or formula (3) is more preferable, a hydrogen atom, a monovalent group of a benzene ring, the above A structure represented by formula (3) is more preferable, and a structure represented by the above formula (3) is most preferable.

From the viewpoint of durability, Ar ¹ and Ar ² , and Ar ⁵ when n is 1 or more, or at least one Ar ⁵ when n is 2 or more satisfy the above formula (2) or the above formula (3) is preferably a structure represented by and particularly preferably a structure represented by the above formula (3).

<Ar ³ , Ar ⁴ >
Ar ³ and Ar ⁴ each independently represent a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms.

Examples of monovalent aromatic hydrocarbon groups having 6 to 60 carbon atoms include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, tetraphenylene ring, chrysene ring, pyrene ring, benzanthracene ring, perylene ring, A monovalent group of a biphenyl ring or a terphenyl ring can be mentioned.

Ar ³ and Ar ⁴ are each independently preferably a hydrogen atom, a monovalent group of a benzene ring, or a monovalent group of a naphthalene ring, from the viewpoint of the solubility and durability of the compound, and More preferred are valence groups.

< ^L1 to ^L5 >
Each of L ¹ to L ⁵ independently represents an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms.

Examples of divalent aromatic hydrocarbon rings having 6 to 60 carbon atoms include benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzanthracene ring, or perylene ring or a divalent group in which two or more of these aromatic hydrocarbon rings are directly linked.

L ¹ to L ⁵ each independently optionally have a substituent, preferably a phenylene group or a divalent group in which 2 or more, for example 2 to 5, phenylene groups are directly linked, and the substituent is A 1,3-phenylene group, which may be present, is more preferable from the viewpoint of solubility.

<R>
Each R is independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group , or represents an aromatic hydrocarbon group. Specific examples and preferred structures of these substituents are described in Substituent Group Z below.

From the viewpoint of heat resistance and durability, each R is independently an alkyl group, an alkenyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group. , an aromatic hydrocarbon group is preferable, an alkyl group, an alkoxy group, an aralkyl group, an aromatic hydrocarbon group is more preferable, an alkyl group having 10 or less carbon atoms, an aralkyl group having 30 or less carbon atoms, an aromatic hydrocarbon group having 30 or less carbon atoms A hydrocarbon group is more preferred, and a benzene ring or a group in which 2 to 5 benzene rings are directly linked is particularly preferred.

<m1 to m5>
m1, m2 and m5 each independently represent an integer of 0 to 5,
m3 and m4 each independently represents an integer of 1 to 5;

m1, m2, and m5 are preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, particularly preferably 1 or less, and most preferably 0, from the viewpoint of compound solubility and durability.

From the viewpoint of compound solubility and durability, m3 and m4 are 1 or more, preferably 4 or less, more preferably 3 or less, and particularly preferably 2 or less.

When m1 is 2 or more, multiple ^L1s may be the same or different. When m2 is 2 or more, multiple ^L2s may be the same or different. When m3 is 2 or more, multiple ^L3s may be the same or different. When m4 is 2 or more, multiple ^L4s may be the same or different. When m5 is 2 or more, multiple ^L5s may be the same or different.

<Ar ¹ −(L ¹ ) _m1 −, Ar ² −(L ² ) _m2 −, Ar ⁵ −(L ⁵ ) _m5 −>
At least one of Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, and Ar ⁵ -(L ⁵ ) _m5 - has the formula (2) or the formula The structure represented by (3) is preferable, at least one structure represented by the formula (3) is more preferable, at least two structures represented by the formula (3) are more preferable, and at least three is more preferably a structure represented by the above formula (3), and more preferably a structure represented by the above formula (3).
None of Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ³ -(L ³ ) _m3 - and Ar ⁴ -(L ⁴ ) _m4 - becomes a hydrogen atom.

<( ^L3 ) _m3 , ( ^L4 ) _m4 >
At least one of (L ³ ) _m3 and (L ⁴ ) _m4 is a partial structure represented by the following formula (11) or a moiety represented by the following formula (12) from the viewpoint of the solubility and durability of the compound. It preferably has at least one partial structure selected from structures and partial structures represented by the following formula (13).

In each of formulas (11) to (13) above, * represents a bond with an adjacent structure or a hydrogen atom when Ar ³ and Ar ⁴ are hydrogen atoms. At least one of the two * represents a binding position to an adjacent structure. In the following description, the definition of * is the same unless otherwise specified.

More preferably, at least one of (L ³ ) _m3 and (L ⁴ ) _m4 has a partial structure represented by formula (11) or a partial structure represented by formula (12).
More preferably, (L ³ ) _m3 and (L ⁴ ) _m4 each have a partial structure represented by formula (11) or a partial structure represented by formula (12).
Particularly preferably, (L ³ ) _m3 and (L ⁴ ) _m4 each have a partial structure represented by formula (11) and a partial structure represented by formula (12).

The partial structure represented by formula (12) is preferably a partial structure represented by formula (12-2) below.

A partial structure represented by the following formula (12-3) is more preferable as the partial structure represented by the formula (12).

From the viewpoint of solvent solubility and durability of the compound, the partial structure that at least one of (L ³ ) _m3 and (L ⁴ ) _m4 preferably has is a partial structure represented by formula (11) and a partial structure represented by formula (12). Partial structures having the represented partial structure are included.

As the partial structure having the partial structure represented by formula (11) and the partial structure represented by formula (12), the partial structure represented by formula (11) and the partial structure represented by formula (12) A partial structure represented by at least one selected from the following formulas (14) to (18), which is a structure containing a plurality of selected structures, is more preferable.

The structure containing a plurality of structures selected from the partial structure represented by formula (11) and the partial structure represented by formula (12) is, for example, the partial structure represented by formula (14), which has the following formula (14a ), which can be regarded as having one partial structure represented by formula (11) and two partial structures represented by formula (12).

More preferably, at least one of (L ³ ) _m3 and (L ⁴ ) _m4 has at least the partial structure represented by formula (14) or the partial structure represented by formula (15).

The partial structure represented by formula (14) is preferably a partial structure represented by formula (14-2) below.

A partial structure represented by the following formula (14-3) is more preferable as the partial structure represented by the formula (14).

The partial structure represented by formula (15) is preferably a partial structure represented by formula (15-2) below.

A partial structure represented by the following formula (15-3) is more preferable as the partial structure represented by the formula (15).

The partial structure represented by formula (17) is preferably a partial structure represented by formula (17-2) below.

The partial structure represented by formula (18) is preferably a partial structure represented by formula (18-2) below.

At least one of (L ³ ) _m3 and (L ⁴ ) _m4 is a partial structure including a partial structure represented by formula (13), a partial structure represented by formula (19) below, or a partial structure represented by formula (20) below. It is more preferable to have the represented partial structure.

In each of the above formulas (14) to (20), * represents a bond with an adjacent structure or a hydrogen atom when Ar ³ and Ar ⁴ are hydrogen atoms. At least one of the two * represents a binding position to an adjacent structure.

Among the partial structures represented by the formulas (14) to (20), the partial structure represented by the formula (14-3) and the partial structure represented by the formula (15-3) are preferable, and the partial structure represented by the formula (14 -3) is more preferred.

<Preferred partial structures of L ¹ to L ⁵ >
In formula (1), L ¹ to L ⁵ are a partial structure represented by formula (12-3), a partial structure represented by formula (14-3), or a moiety represented by formula (15-3) Having a structure is preferred.

<n>
n represents an integer from 0 to 10;
From the viewpoint of solubility and durability of the compound, n is preferably 1 or more, more preferably 2 or more, preferably 6 or less, more preferably 5 or less, and particularly preferably 4 or less.

<a1 to a4>
a1 and a2 each independently represent an integer of 0 to 3;
a3 represents an integer of 0 to 4;
a4 represents an integer of 0 or 1;
However, when a3 is 4, a4 is 0.
From the viewpoint of compound solubility and durability, the following combinations of a1 to a4 are preferred.
a1 = a2 = a4 = 0, and a3 = an integer from 0 to 4;
a1=a2=a4=0 and a3=0 or 1;
a1=a2=a3=a4=0;
a4=1 and a1=a2=a3;
a4 = 1, and a1 to a3 are each independently an integer of 0 to 3;
a4 = 1, and a1 to a3 are each independently 0 or 1;
a4=1 and a1=a2=a3=0 or 1;
More preferably,
a1=a2=a3=a4=0;
a4=1 and a1=a2=a3=0
is.
That is, a1 to a3 are each independently preferably 0 or 1, most preferably 0, from the viewpoints of solubility and durability of the compound.

< ^R1 to ^R26 >
R ¹ to R ²⁶ are each independently hydrogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group.
Specific examples and preferred structures of these substituents are described in Substituent Group Z below.

From the viewpoint of durability, each of R ¹ to R ²⁶ is independently a hydrogen atom, an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, or an aralkyl group. A group or an aromatic hydrocarbon group is preferred, a hydrogen atom or an aromatic hydrocarbon group is more preferred, and a hydrogen atom is particularly preferred.

<Substituent>
A substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in Ar ¹ to Ar ⁵ may have, and a divalent carbon number of 6 or more and 60 or less in L ¹ to L ⁵ . The substituents that the aromatic hydrocarbon group may have are each independently an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group, preferably each independently an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, or a halogen atom , a haloalkyl group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group.

The substituents that Ar ¹ to Ar ⁵ and L ¹ to L ⁵ may have, and the aforementioned R and R ¹ to R ²⁶ are specifically the substituents described in the following substituent group Z is mentioned.

<Substituent Group Z>
Substituent group Z includes an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, It is a substituent group consisting of an aralkyl group and an aromatic hydrocarbon group.

The alkyl group includes, for example, a methyl group, an ethyl group, a branched, straight-chain or cyclic propyl group, a branched, straight-chain or cyclic butyl group, a branched, straight-chain or cyclic pentyl group, a branched, straight-chain or cyclic The number of carbon atoms is usually 1 or more, preferably 4 or more, and usually 24, such as a hexyl group, a branched, straight-chain or cyclic octyl group, a branched, straight-chain or cyclic nonyl group, a branched, straight-chain or cyclic dodecyl group. Hereafter, linear, branched or cyclic alkyl groups, preferably 10 or less, are mentioned. From the viewpoint of compound stability, a methyl group, an ethyl group, a branched, linear or cyclic propyl group, and a branched, linear or cyclic butyl group are preferred, and a branched propyl group is particularly preferred.

Examples of alkenyl groups include alkenyl groups having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms such as vinyl groups.

Examples of alkynyl groups include alkynyl groups having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms such as ethynyl groups.

Examples of alkoxy groups include alkoxy groups having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms such as methoxy and ethoxy groups.

Examples of aryloxy groups include aryloxy groups or heteroaryloxy groups having usually 4 or more, preferably 5 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms such as phenoxy, naphthoxy, and pyridyloxy groups. groups.

Examples of alkoxycarbonyl groups include alkoxycarbonyl groups having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms such as methoxycarbonyl and ethoxycarbonyl groups.

The acyl group includes, for example, an acyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as an acetyl group and a benzoyl group.

Examples of halogen atoms include halogen atoms such as fluorine atoms and chlorine atoms.

The haloalkyl group includes, for example, a haloalkyl group having usually 1 or more carbon atoms and usually 12 or less, preferably 6 or less carbon atoms such as trifluoromethyl group.

Examples of alkylthio groups include alkylthio groups having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms such as methylthio and ethylthio groups.

The arylthio group includes, for example, an arylthio group or a heteroarylthio group having usually 4 or more, preferably 5 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenylthio group, a naphthylthio group and a pyridylthio group. be done.

Silyl groups include, for example, silyl groups having usually 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms such as trimethylsilyl and triphenylsilyl groups.

Siloxy groups include, for example, siloxy groups having usually 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms such as trimethylsiloxy and triphenylsiloxy groups.

Examples of aralkyl groups include benzyl, 2-phenylethyl, 2-phenylpropyl-2-yl, 2-phenylbutyl-2-yl, 3-phenylpentyl-3-yl, 3-phenyl- 1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, 7-phenyl-1-heptyl group, 8-phenyl-1-octyl group, etc. and an aralkyl group having usually 7 or more, preferably 9 or more carbon atoms and usually 30 or less, preferably 18 or less, more preferably 10 or less carbon atoms.

Examples of the aromatic hydrocarbon group include, for example, a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzanthracene ring, or perylene ring, which usually have 6 or more carbon atoms, An aromatic hydrocarbon group having a number of usually 30 or less, preferably 18 or less, more preferably 10 or less is mentioned.

Among the substituent group Z, an alkyl group, an alkoxy group, an aralkyl group and an aromatic hydrocarbon group are preferable, and an alkyl group having 10 or less carbon atoms, an aralkyl group having 30 or less carbon atoms, and an aralkyl group having 30 or less carbon atoms are more preferable. It is an aromatic hydrocarbon group of 30 or less, more preferably an aromatic hydrocarbon group of 30 or less carbon atoms, and particularly preferably having no substituent.

Each substituent in the above substituent group Z may further have a substituent. As such additional substituents, the same substituents as those described above (substituent group Z) can be used. It is preferred that the substituents in the above substituent group Z do not have further substituents.

<Molecular weight>
The molecular weight of the aromatic compound (1) is preferably 1000 or more, more preferably 1100 or more, particularly preferably 1200 or more, most preferably 1300 or more, preferably 5000 or less, more preferably 4000 or less. It is preferably 3,000 or less, and most preferably 2,000 or less.

<Specific example>
Specific examples of the aromatic compound (1) are shown below, but the present invention is not limited thereto.

<Method for producing aromatic compound (1)>
Aromatic compound (1) can be produced, for example, according to the method described in the Examples.

<Use of aromatic compound (1)>
The aromatic compound (1) is preferably used in an organic layer of an organic electroluminescence device, and the organic layer is preferably a light-emitting layer. When the aromatic compound (1) is used in the light-emitting layer, it is preferably used as a host material for the light-emitting layer.

The organic layer containing the aromatic compound (1) may be formed by a vapor deposition method or by a wet film forming method. Since the organic layer containing the aromatic compound (1) can form a more uniform film, it is particularly preferable to form it by a wet film-forming method.

[Aromatic compound of the present invention]
The aromatic compound of the present invention is an aromatic compound represented by the following formula (1), and is one aspect of the aromatic compound (1).

The aromatic compound of the present invention is a substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in R and Ar ¹ to Ar ⁵ in the formula (1) may have, and Substituents that may be possessed by the divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in L ¹ to L ⁵ , R ¹ to R ²⁶ in formulas (2) and (3) are aromatic It is the same as for aromatic compound (1) except that it is more limited than those for aromatic compound (1), and the above description for aromatic compound (1) applies.
Preferred embodiments and specific examples of the aromatic compound of the present invention are also the same as in the aromatic compound (1).

[Composition]
When the organic layer containing the aromatic compound of the present invention is formed by a wet film-forming method, a composition containing at least the aromatic compound of the present invention represented by the above formula (1) and an organic solvent is wet-formed. The composition of the invention contains at least the aromatic compound of the invention and an organic solvent.
The composition of the present invention may contain only one aromatic compound of the present invention, or may contain two or more thereof.
The composition of the invention preferably further comprises a light-emitting material, preferably a phosphorescent light-emitting material, and a charge transport material. The composition of the present invention is suitably used as a composition for forming a light-emitting layer of an organic electroluminescent device.

<Organic solvent>
The organic solvent contained in the composition of the present invention is a volatile liquid component used for forming the layer containing the aromatic compound of the present invention by wet film formation.

The organic solvent is not particularly limited as long as it is an organic solvent in which the aromatic compound of the present invention, which is the solute, and the luminescent material described later are well dissolved.

Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin and methylnaphthalene; Halogenated aromatic hydrocarbons such as chlorobenzene and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3 - aromatic ethers such as dimethylanisole, 2,4-dimethylanisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate and n-butyl benzoate; Alicyclic ketones such as cyclohexanone, cyclooctanone and fenchone; Alicyclic alcohols such as cyclohexanol and cyclooctanol; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Aliphatic alcohols such as butanol and hexanol; aliphatic ethers such as glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA);

Among these, from the viewpoint of viscosity and boiling point, alkanes, aromatic hydrocarbons, aromatic ethers, and aromatic esters are preferred, and aromatic hydrocarbons, aromatic ethers, and aromatic esters are more preferred. , aromatic hydrocarbons and aromatic esters are particularly preferred.

One type of these organic solvents may be used alone, or two or more types may be used in any combination and ratio.

The boiling point of the organic solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 380°C or lower, preferably 350°C or lower, more preferably 330°C or lower. If the boiling point of the organic solvent is below this range, the film formation stability may decrease due to evaporation of the solvent from the composition during wet film formation. If the boiling point of the organic solvent exceeds this range, there is a possibility that the film formation stability will decrease due to the solvent remaining after film formation during wet film formation.

In particular, by combining two or more organic solvents having a boiling point of 150° C. or higher among the above organic solvents, a uniform coating film can be produced. If the number of organic solvents having a boiling point of 150° C. or higher is one or less, a uniform film may not be formed during coating.

<Luminescent material>
The composition of the present invention is preferably a composition for forming a light-emitting layer. In this case, it is preferable to further contain a light-emitting material. A luminescent material refers to a component that mainly emits light in the composition of the present invention, and corresponds to a dopant component in an organic electroluminescent device.

As the light-emitting material, known materials can be applied, and fluorescent light-emitting materials or phosphorescent light-emitting materials can be used singly or in combination. From the viewpoint of internal quantum efficiency, phosphorescent materials are preferred.

(Phosphorescent material)
A phosphorescent material is a material that emits light from an excited triplet state. For example, metal complex compounds containing Ir, Pt, Eu, etc. are typical examples, and materials containing metal complexes are preferable as the structure of the material.

Among metal complexes, the long-period periodic table (unless otherwise specified, the long-period periodic table ) include Werner-type complexes or organometallic complex compounds containing a metal selected from Groups 7 to 11 as a central metal. As such a phosphorescent material, a compound represented by the following formula (201) or a compound represented by the following formula (205) is preferable, and a compound represented by the following formula (201) is more preferable. .

In the above formula (201), M is a metal selected from Groups 7 to 11 of the periodic table, such as ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and europium.

Ring A1 represents an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure.
Ring A2 represents an aromatic heterocyclic structure optionally having a substituent.

R ²⁰¹ and R ²⁰² each independently represent a structure represented by the above formula (202), and "*" represents the bonding position with ring A1 or ring A2. R ²⁰¹ and R ²⁰² may be the same or different. When multiple R ²⁰¹ and R ²⁰² are present, they may be the same or different.

In formula (202), Ar ²⁰¹ and Ar ²⁰³ each independently represent an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic ring structure. .
Ar ²⁰² is an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic ring structure, or an optionally substituted aliphatic hydrocarbon structure represents
The substituents bonded to ring A1, the substituents bonded to ring A2, or the substituents bonded to ring A1 and the substituents bonded to ring A2 may be bonded to each other to form a ring.

B ²⁰¹ -L ²⁰⁰ -B ²⁰² represents an anionic bidentate ligand. B ²⁰¹ and B ²⁰² each independently represent a carbon atom, an oxygen atom or a nitrogen atom. These atoms may be ring-constituting atoms. L ²⁰⁰ represents a single bond or an atomic group forming a bidentate ligand together with B ²⁰¹ and B ²⁰² . When there are multiple groups of B ²⁰¹ -L ²⁰⁰ -B ²⁰² , they may be the same or different.

In formulas (201) and (202),
i1 and i2 each independently represent an integer of 0 or more and 12 or less.
i3 is an integer greater than or equal to 0 up to the number that can be substituted for Ar ²⁰² .
j is an integer greater than or equal to 0 up to the number that can be substituted for Ar ²⁰¹ .
k1 and k2 are each independently an integer of 0 or more, with the upper limit being the number that can be substituted on ring A1 and ring A2.
m is an integer of 1-3.

The aromatic hydrocarbon ring for ring A1 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, and specifically includes a benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluoranthene ring, A fluorene ring is preferred.

The aromatic heterocyclic ring in ring A1 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, more preferably a furan ring or a benzofuran ring. , thiophene ring, and benzothiophene ring.

The ring A1 is more preferably a benzene ring, a naphthalene ring or a fluorene ring, particularly preferably a benzene ring or a fluorene ring, most preferably a benzene ring.

The aromatic heterocyclic ring in ring A2 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing either a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom,
Specifically, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, Naphthyridine ring, phenanthridine ring,
more preferably pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring,
More preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring and quinazoline ring,
Most preferred are pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, quinoxaline ring and quinazoline ring.

Preferred combinations of ring A1 and ring A2 are represented by (ring A1-ring A2), (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring), (benzene ring- quinazoline ring), (benzene ring-imidazole ring), and (benzene ring-benzothiazole ring).

The substituents that ring A1 and ring A2 may have may be arbitrarily selected, but are preferably one or more substituents selected from the group S of substituents described below.

When any one of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is an aromatic hydrocarbon ring structure which may have a substituent, the aromatic hydrocarbon ring structure is preferably an aromatic ring structure having 6 to 30 carbon atoms. is a hydrocarbon ring,
Specifically, benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluoranthene ring, and fluorene ring are preferred.
more preferably a benzene ring, a naphthalene ring or a fluorene ring,
A benzene ring is most preferred.

When any of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is a fluorene ring optionally having a substituent, the 9- and 9′-positions of the fluorene ring have a substituent or are bonded to the adjacent structure. preferably.

When any one of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is a benzene ring optionally having a substituent, at least one benzene ring is preferably bonded to the adjacent structure at the ortho- or meta-position. , more preferably, at least one benzene ring is attached to the adjacent structure at the meta position.

When any one of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is an aromatic heterocyclic structure which may have a substituent, the aromatic heterocyclic structure preferably contains a nitrogen atom, an oxygen atom, or an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any of a sulfur atom,
Specifically, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring,
Preferred are pyridine ring, pyrimidine ring, triazine ring, carbazole ring, dibenzofuran ring and dibenzothiophene ring.

When any of Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ is a carbazole ring optionally having a substituent, the N-position of the carbazole ring may have a substituent or be bonded to an adjacent structure. preferable.

When Ar ²⁰² is an optionally substituted aliphatic hydrocarbon structure, the aliphatic hydrocarbon structure is an aliphatic hydrocarbon structure having a linear, branched, or cyclic structure, preferably It is an aliphatic hydrocarbon having 1 or more and 24 or less carbon atoms, more preferably an aliphatic hydrocarbon having 1 or more and 12 or less carbon atoms, and still more preferably an aliphatic hydrocarbon having 1 or more and 8 or less carbon atoms. .

i1 and i2 are each independently an integer of 0 to 12, preferably an integer of 1 to 12, more preferably an integer of 1 to 8, and still more preferably an integer of 1 to 6. Within this range, improved solubility and improved charge transport properties can be expected.

i3 is preferably an integer of 0-5, more preferably an integer of 0-2, still more preferably 0 or 1.

j preferably represents an integer of 0 to 2, more preferably 0 or 1.

k1 and k2 are each independently preferably an integer of 0 to 3, more preferably an integer of 1 to 3, still more preferably 1 or 2, and particularly preferably 1.

The substituents that Ar ²⁰¹ , Ar ²⁰² and Ar ²⁰³ may have can be arbitrarily selected, but are preferably one or more substituents selected from the group S of substituents described later, more preferably hydrogen It is an atom, an alkyl group or an aryl group, particularly preferably a hydrogen atom or an alkyl group, and most preferably unsubstituted (hydrogen atom).

Unless otherwise specified, the substituent is preferably a group selected from the following substituent group S.

<Substituent group S>
- an alkyl group, preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably an alkyl group having 1 to 6 carbon atoms .
- An alkoxy group, preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and still more preferably an alkoxy group having 1 to 6 carbon atoms.
- an aryloxy group, preferably an aryloxy group having 6 to 20 carbon atoms, more preferably an aryloxy group having 6 to 14 carbon atoms, still more preferably an aryloxy group having 6 to 12 carbon atoms, particularly preferably an aryloxy group having 6 carbon atoms; aryloxy group;
- A heteroaryloxy group, preferably a heteroaryloxy group having 3 to 20 carbon atoms, more preferably a heteroaryloxy group having 3 to 12 carbon atoms.
- an alkylamino group, preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms;
- An arylamino group, preferably an arylamino group having 6 to 36 carbon atoms, more preferably an arylamino group having 6 to 24 carbon atoms.
- An aralkyl group, preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and still more preferably an aralkyl group having 7 to 12 carbon atoms.
- A heteroaralkyl group, preferably a heteroaralkyl group having 7 to 40 carbon atoms, more preferably a heteroaralkyl group having 7 to 18 carbon atoms.
- an alkenyl group, preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 12 carbon atoms, still more preferably an alkenyl group having 2 to 8 carbon atoms, particularly preferably an alkenyl group having 2 to 6 carbon atoms .
- an alkynyl group, preferably an alkynyl group having 2 to 20 carbon atoms, more preferably an alkynyl group having 2 to 12 carbon atoms;
- An aryl group, preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 24 carbon atoms, still more preferably an aryl group having 6 to 18 carbon atoms, particularly preferably an aryl group having 6 to 14 carbon atoms .
- a heteroaryl group, preferably a heteroaryl group having 3 to 30 carbon atoms, more preferably a heteroaryl group having 3 to 24 carbon atoms, still more preferably a heteroaryl group having 3 to 18 carbon atoms, particularly preferably 3 to 3 carbon atoms 14 heteroaryl groups.
An alkylsilyl group, preferably an alkylsilyl group having 1 to 20 carbon atoms, more preferably an alkylsilyl group having 1 to 12 carbon atoms.
- An arylsilyl group, preferably an arylsilyl group in which the aryl group has 6 to 20 carbon atoms, more preferably an arylsilyl group in which the aryl group has 6 to 14 carbon atoms.
- an alkylcarbonyl group, preferably an alkylcarbonyl group having 2 to 20 carbon atoms;
- an arylcarbonyl group, preferably an arylcarbonyl group having 7 to 20 carbon atoms;
In the above groups, one or more hydrogen atoms may be replaced with fluorine atoms, or one or more hydrogen atoms may be replaced with deuterium atoms.
- A hydrogen atom, a deuterium atom, a fluorine atom, a cyano group, or -SF ₅ .

Unless otherwise specified, aryl is an aromatic hydrocarbon and heteroaryl is an aromatic heterocycle.

(Preferred Group in Substituent Group S)
Among these substituent group S,
Preferably, an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group, and at least one hydrogen atom of these groups is fluorine. a group substituted with an atom, a fluorine atom, a cyano group, or _-SF5 ,
More preferably, an alkyl group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, a group in which one or more hydrogen atoms of these groups are replaced with a fluorine atom, a fluorine atom, a cyano group, or , −SF ₅ , and
more preferably an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group,
Particularly preferred are alkyl groups, arylamino groups, aralkyl groups, alkenyl groups, aryl groups and heteroaryl groups,
Most preferred are alkyl groups, arylamino groups, aralkyl groups, aryl groups and heteroaryl groups.

These substituent group S may further have a substituent selected from the substituent group S as a substituent. Preferred groups, more preferred groups, further preferred groups, particularly preferred groups, and most preferred groups of the substituents which may be present are the same as the preferred groups in Substituent Group S and the like.

(preferred structure of formula (201))
Among the structures represented by the above formula (202) in the above formula (201), (i) a structure having a group to which a benzene ring is linked, (ii) an alkyl group or an aralkyl group in ring A1 or ring A2 A structure having a bound aromatic hydrocarbon group or aromatic heterocyclic group, and (iii) a structure in which a dendron is bound to ring A1 or ring A2 are preferred.

(i) In the structure having a group to which benzene rings are linked, Ar ²⁰¹ is a benzene ring structure, i1 is 1 to 6, and at least one of the benzene rings is bonded to the adjacent structure at the ortho- or meta-position. is doing.
This structure is expected to improve the solubility and the charge transport property.

(ii) In a structure having an aromatic hydrocarbon group or aromatic heterocyclic group to which an alkyl group or an aralkyl group is bonded to ring A1 or ring A2, Ar ²⁰¹ is an aromatic hydrocarbon structure or an aromatic heterocyclic ring structure. , i1 is 1 to 6, Ar ²⁰² is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, Ar ²⁰³ is a benzene ring structure, i3 is 0 or 1.
In this structure, Ar ²⁰¹ is preferably the above aromatic hydrocarbon structure, more preferably a structure in which 1 to 5 benzene rings are linked, and more preferably one benzene ring.
This structure is expected to improve the solubility and the charge transport property.

(iii) In the structure in which a dendron is bound to ring A1 or ring A2, Ar ²⁰¹ and Ar ²⁰² are a benzene ring structure, Ar ²⁰³ is a biphenyl or terphenyl structure, and i1 and i2 are 1 to 6. , i3 is 2 and j is 2.
This structure is expected to improve the solubility and the charge transport property.

Among the structures represented by B ²⁰¹ -L ²⁰⁰ -B ²⁰² in the formula (201), structures represented by the following formulas (203) and (204) are preferable.

In formula (203) above, R ²¹¹ , R ²¹² and R ²¹³ represent substituents.
Although the substituent is not particularly limited, it is preferably a group selected from the substituent group S described above.

In formula (204) above, ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom, which may have a substituent. Ring B3 is preferably a pyridine ring.
Although the substituent that ring B3 may have is not particularly limited, it is preferably a group selected from the substituent group S described above.

Although the phosphorescent light-emitting material represented by the formula (201) is not particularly limited, specific examples include the following structures.
In the following, Me means a methyl group and Ph means a phenyl group.

Next, the compound represented by the following formula (205) will be explained.

In formula (205), ^M2 represents a metal. T represents a carbon atom or a nitrogen atom. R ⁹² to R ⁹⁵ each independently represent a substituent. However, when T is a nitrogen atom, ^R94 and ^R95 do not exist.

In formula (205), ^M2 represents a metal. Specific examples include metals selected from groups 7 to 11 of the periodic table. Among them, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

In formula (205), R ⁹² and R ⁹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an alkoxy group. , an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group or an aromatic heterocyclic group.

Furthermore, when T is a carbon atom, ^R94 and ^R95 each independently represent a substituent represented by the same examples as ^R92 and ^R93 . When T is a nitrogen atom, there is no ^R94 or ^R95 directly bonded to said T.

R ⁹² to R ⁹⁵ may further have a substituent. The substituents may be the aforementioned substituents exemplified for R ⁹² and R ⁹³ . Furthermore, any two or more groups selected from R ⁹² to R ⁹⁵ may be linked together to form a ring.

(molecular weight)
The molecular weight of the phosphorescent material is preferably 5,000 or less, more preferably 4,000 or less, and particularly preferably 3,000 or less. The molecular weight of the phosphorescent material is usually 1000 or more, preferably 1100 or more, more preferably 1200 or more. It is believed that within this molecular weight range, the phosphorescent light-emitting materials do not aggregate with each other and are uniformly mixed with the compound of the present invention and/or other charge-transporting materials, so that a light-emitting layer with high light-emitting efficiency can be obtained.

The molecular weight of the phosphorescent light-emitting material has a high Tg, melting point, decomposition temperature, etc., and the phosphorescent light-emitting material and the formed light-emitting layer have excellent heat resistance, and the film quality due to gas generation, recrystallization, molecular migration, etc. A large value is preferable from the viewpoint that it is difficult to cause a decrease in the concentration of impurities and an increase in the concentration of impurities due to thermal decomposition of the material. The molecular weight of the phosphorescent light-emitting material is preferably small from the viewpoint of facilitating purification of the organic compound.

<Charge transport material>
When the composition of the present invention is a composition for forming a light emitting layer, it preferably contains a charge transport material as a further host material in addition to the aromatic compound of the present invention.

The charge-transporting material used as the host material of the light-emitting layer is a material having a skeleton with excellent charge-transporting properties, and is composed of an electron-transporting material, a hole-transporting material, and a bipolar material capable of transporting both electrons and holes. preferably selected.

Specific examples of skeletons with excellent charge transport properties include aromatic structures, aromatic amine structures, triarylamine structures, dibenzofuran structures, naphthalene structures, phenanthrene structures, phthalocyanine structures, porphyrin structures, thiophene structures, benzylphenyl structures, fluorene structure, quinacridone structure, triphenylene structure, carbazole structure, pyrene structure, anthracene structure, phenanthroline structure, quinoline structure, pyridine structure, pyrimidine structure, triazine structure, oxadiazole structure, imidazole structure, and the like.

As the electron-transporting material, a compound having a pyridine structure, a pyrimidine structure, and/or a triazine structure, which is excellent in electron-transporting properties and has a relatively stable structure, is more preferable, and a compound having a pyrimidine structure and/or a triazine structure is further preferable. preferable. Particularly preferred is a compound represented by formula (250) described later.

A hole-transporting material is a compound having a structure with excellent hole-transporting properties, and among the skeletons with excellent charge-transporting properties, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure. is preferable as a structure having excellent hole-transporting properties, and a carbazole structure, a dibenzofuran structure, or a triarylamine structure is more preferable. Particularly preferred is a compound represented by formula (240) described later.

When the composition of the present invention is a composition for forming a light-emitting layer, in addition to the aromatic compound of the present invention, a compound represented by the formula (250) described below and / or the formula ( 240) is preferably contained. Inclusion of such a material as an additional host material is preferable from the viewpoint of charge balance adjustment in the light-emitting layer and from the viewpoint of luminous efficiency.

The charge-transporting material used as the host material of the light-emitting layer is preferably a compound having a condensed ring structure of three or more rings, and at least a compound having two or more condensed ring structures of three or more rings or a condensed ring of five or more rings. Compounds having one are more preferred. These compounds increase the rigidity of the molecules, making it easier to obtain the effect of suppressing the degree of molecular motion in response to heat. Further, the 3 or more condensed rings and the 5 or more condensed rings preferably have an aromatic hydrocarbon ring or an aromatic heterocyclic ring from the viewpoint of charge transportability and material durability.

Specific examples of condensed ring structures having three or more rings include anthracene structure, phenanthrene structure, pyrene structure, chrysene structure, naphthacene structure, triphenylene structure, fluorene structure, benzofluorene structure, indenofluorene structure, indolofluorene structure, Carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, dibenzothiophene structure and the like.

At least one selected from the group consisting of a phenanthrene structure, a fluorene structure, an indenofluorene structure, a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, a dibenzofuran structure, and a dibenzothiophene structure, from the viewpoints of charge transportability and solubility. preferable. A carbazole structure or an indolocarbazole structure is more preferable from the viewpoint of resistance to electric charge.

The charge-transporting material used as the host material of the light-emitting layer is preferably a polymeric material from the viewpoint of excellent flexibility. A light-emitting layer formed using a material having excellent flexibility is preferable as a light-emitting layer of an organic electroluminescent device formed on a flexible substrate. When the charge-transporting material used as the host material contained in the light-emitting layer is a polymeric material, the molecular weight is preferably 5,000 or more and 1,000,000 or less, more preferably 10,000 or more and 500,000 or less. It is preferably 10,000 or more and 100,000 or less.

The charge-transporting material used as the host material of the light-emitting layer is easy to synthesize and purify, easy to design electron-transporting performance and hole-transporting performance, and easy to adjust the viscosity when dissolved in a solvent. Therefore, it is preferably a low molecular weight compound. When the charge-transporting material used as the host material contained in the light-emitting layer is a low molecular weight material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, and most preferably It is 2,000 or less, usually 600 or more, preferably 800 or more. When the layer formed in contact with the light-emitting layer is formed by a wet film-forming method, the molecular weight of the low-molecular-weight charge transport material is preferably 1,000 or more, more preferably 1,100 or more, and particularly preferably 1,200 or more.

The compound represented by formula (250) is preferably a charge-transporting compound, that is, a charge-transporting host material.

(W)
W in formula (250) represents CH or N, at least one of which is N. At least two of W are preferably N, and more preferably all are N, from the viewpoint of electron transportability and electron durability.

< ^Xa1 , ^Ya1 , ^Za1 , ^Xa2 , ^Ya2 , ^Za2 >
When Xa ¹ , Ya ¹ and Za ¹ in the formula (250) are an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and Xa ² , Ya ² , When Za ² is an optionally substituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, the aromatic hydrocarbon ring of the aromatic hydrocarbon group having 6 to 30 carbon atoms is , a 6-membered monocyclic ring, or 2 to 5 condensed rings are preferred. Specific examples thereof include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, fluoranthene ring, and indenofluorene ring. Among them, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, or fluorene ring is preferable, benzene ring, naphthalene ring, phenanthrene ring, or fluorene ring is more preferable, and benzene ring, naphthalene ring, or fluorene ring is still more preferable. be.

When Xa ¹ , Ya ¹ and Za ¹ in formula (250) are an optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms, and Xa ² , Ya ² , When Za ² is an optionally substituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms, the aromatic heterocyclic ring of the aromatic heterocyclic group having 3 to 30 carbon atoms includes: A 5- or 6-membered monocyclic ring or 2 to 5 condensed rings are preferred. Specifically, furan ring, benzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, indolocarbazole ring, indenocarbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, Pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, shinoline ring, quinoxaline ring, perimidine ring, quinazoline ring, quinazolinone ring and the like. Among them, thiophene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, indolocarbazole ring, phenanthroline ring, or indenocarbazole ring are preferred. and more preferably a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring, and still more preferably a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring.

Particularly preferred aromatic hydrocarbon rings for Xa ¹ , Ya ¹ , Za ¹ , Xa ² , Ya ² and Za ² in formula (250) are benzene, naphthalene and phenanthrene rings. A particularly preferred heteroaromatic ring is a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring.

(g11, h11, j11)
g11, h11, and j11 each independently represents an integer of 0 to 6, and at least one of g11, h11, and j11 is an integer of 1 or more. From the viewpoint of charge transportability and durability, g11 is preferably 2 or more, or at least one of h11 and j11 is preferably 3 or more.

The compound represented by the formula (250) should have 8 to 18 rings in total, including a ring having three central Ws, to improve charge transport properties, durability, and solubility in organic solvents. is preferable from the viewpoint of

( ^R31 )
R ³¹ when it is a substituent is preferably an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms or an optionally substituted aromatic hydrocarbon group having 3 to 30 carbon atoms. is a heterocyclic group. From the viewpoint of durability improvement and charge transport property, R ³¹ is more preferably an aromatic hydrocarbon group which may have a substituent. When there are a plurality of R ³¹ in the case of being a substituent, they may be different from each other.

The substituent that the aromatic hydrocarbon group having 6 to 30 carbon atoms described above may have, the substituent that the aromatic heterocyclic group having 3 to 30 carbon atoms may have, and the substituent R ³¹ can be selected from the following substituent group Z2.

(Substituent group Z2)
Substituent group Z2 includes an alkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, A group consisting of an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. These substituents may contain any structure of linear, branched and cyclic.

More specific examples of the substituent group Z2 include the following structures.
For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group, etc. , a linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more carbon atoms and usually 24 or less, preferably 12 or less, more preferably 8 or less, and still more preferably 6 or less;
For example, an alkoxy group having a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less, such as a methoxy group or an ethoxy group;
For example, an aryloxy or heteroaryloxy group having usually 4 or more, preferably 5 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenoxy group, a naphthoxy group, a pyridyloxy group;
For example, an alkoxycarbonyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less, such as a methoxycarbonyl group or an ethoxycarbonyl group;
For example, a dialkylamino group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less, such as a dimethylamino group or a diethylamino group;
For example, a diarylamino group having usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a diphenylamino group or a ditolylamino group;
For example, an arylalkylamino group having usually 7 or more carbon atoms, usually 36 or less, preferably 24 or less, such as a phenylmethylamino group;
For example, an acyl group having usually 2 or more and usually 24 or less, preferably 12 carbon atoms such as an acetyl group or a benzoyl group;
Halogen atoms such as, for example, fluorine atoms and chlorine atoms;
For example, a haloalkyl group having usually 1 or more carbon atoms, usually 12 or less, preferably 6 or less, such as a trifluoromethyl group;
For example, an alkylthio group having usually 1 or more carbon atoms, usually 24 or less, preferably 12 or less, such as a methylthio group or an ethylthio group;
For example, an arylthio group having usually 4 or more, preferably 5 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenylthio group, a naphthylthio group, a pyridylthio group;
For example, a silyl group having usually 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a trimethylsilyl group or a triphenylsilyl group;
Siloxy groups having usually 2 or more, preferably 3 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms, such as trimethylsiloxy and triphenylsiloxy;
cyano group;
aromatic hydrocarbon groups having usually 6 or more carbon atoms, usually 36 or less, preferably 24 or less, such as phenyl group and naphthyl group;
For example, an aromatic heterocyclic group having usually 3 or more, preferably 4 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms such as thienyl group or pyridyl group.

Among the substituent group Z2 described above, an alkyl group, an alkoxy group, a diarylamino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group is preferred. From the viewpoint of charge transportability, the substituent is more preferably an aromatic hydrocarbon group or an aromatic heterocyclic group, more preferably an aromatic hydrocarbon group, and particularly preferably has no substituent. From the viewpoint of improving solubility, the substituent is preferably an alkyl group or an alkoxy group.

Each substituent in the substituent group Z2 may further have a substituent. Examples of these substituents include the same substituents as those described above (substituent group Z2). Each substituent that the substituent group Z2 may have is preferably an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, It is an alkoxy group having 6 or less carbon atoms or a phenyl group. From the viewpoint of charge-transporting properties, each substituent in the substituent group Z2 preferably does not have a further substituent.

(molecular weight)
The compound represented by formula (250) is a low-molecular-weight material. The molecular weight of the compound represented by formula (250) is preferably 3,000 or less, more preferably 3,000 or less, even more preferably 2,000 or less, and particularly preferably 1,500 or less. The lower limit of the molecular weight of the compound is usually 300 or more, preferably 350 or more, more preferably 400 or more.

(Specific examples of compounds represented by formula (250))
The compound represented by formula (250) is not particularly limited, and examples thereof include the following compounds.

The composition of the present invention may contain only one type of compound represented by formula (250), or may contain two or more types.

( ^Ar611 , ^Ar612 )
Ar ⁶¹¹ and Ar ⁶¹² each independently represent an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
The number of carbon atoms in the aromatic hydrocarbon group is generally 6-50, preferably 6-30, more preferably 6-18. Specific examples of the aromatic hydrocarbon group include a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzanthracene ring, perylene ring, and the like, which usually have 6 carbon atoms. Above, usually 30 or less, preferably 18 or less, more preferably 14 or less monovalent groups of aromatic hydrocarbon structures, or a plurality of structures selected from these structures are chained or branched Monovalent groups of bonded structures are included. When a plurality of aromatic hydrocarbon rings are linked, a structure in which 2 to 8 rings are linked is usually mentioned, and a structure in which 2 to 5 rings are linked is preferable. When a plurality of aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

Ar ⁶¹¹ and Ar ⁶¹² are preferably each independently
phenyl group,
a monovalent group in which a plurality of benzene rings are bonded in a chain or branched manner;
a monovalent group in which one or more benzene rings and at least one naphthalene ring are linked in a chain or branched manner;
a monovalent group in which one or more benzene rings and at least one phenanthrene ring are linked in a chain or branch, or
a monovalent group in which one or more benzene rings and at least one tetraphenylene ring are linked in a chain or branched manner;
and these may have a substituent. More preferably, it is a monovalent group in which a plurality of benzene rings are linked in a chain or branched manner. In either case, the order of coupling does not matter.
Ar ⁶¹¹ and Ar ⁶¹² are each independently particularly preferably a monovalent group in which a plurality of optionally substituted benzene rings are bonded in a chain or branched manner, and each independently represents a plurality of benzene Most preferably, the ring is a multi-chain or branched monovalent group.

The number of bonded benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is usually 2-8, preferably 2-5, as described above. Among them, a monovalent group having 1 to 4 benzene rings connected, a monovalent group having 1 to 4 benzene rings and a naphthalene ring connected, and 1 having 1 to 4 benzene rings and a phenanthrene ring connected It is a valent group or a monovalent group in which 1 to 4 benzene rings and a tetraphenylene ring are linked.

These aromatic hydrocarbon groups may have substituents. The substituent that the aromatic hydrocarbon group may have can be selected from the above-described substituent group Z2. Preferred substituents are the preferred substituents of the aforementioned substituent group Z2.

At least one of Ar ⁶¹¹ and Ar ⁶¹² preferably has at least one partial structure selected from the following formulas (72-1) to (72-7) from the viewpoint of compound solubility and durability.

In each of formulas (72-1) to (72-7) above, * represents a bond with an adjacent structure or a hydrogen atom. At least one of the two * represents a binding position to an adjacent structure. In the following description, the definition of * is the same unless otherwise specified.

More preferably, at least one of Ar ⁶¹¹ and Ar ⁶¹² has at least one partial structure selected from formulas (72-1) to (72-4) and formula (72-7).
More preferably, each of Ar ⁶¹¹ and Ar ⁶¹² has at least one partial structure selected from formulas (72-1) to (72-3) and formula (72-7).
Particularly preferably, each of Ar ⁶¹¹ and Ar ⁶¹² has at least one partial structure selected from formula (72-1), formula (72-2) and formula (72-7).

Formula (72-2) is preferably the following formula (72-2-2).

The formula (72-2) is more preferably the following formula (72-2-3).

Further, from the viewpoint of the solubility and durability of the compound, the partial structure that at least one of Ar ⁶¹¹ and Ar ⁶¹² preferably has is the partial structure represented by formula (72-1) and the partial structure represented by formula (72-2). and partial structures that are

( ^R611 , ^R612 )
R ⁶¹¹ and R ⁶¹² are each independently a deuterium atom, a halogen atom such as a fluorine atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
A monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent is preferred.
The aromatic hydrocarbon group is more preferably a monovalent aromatic hydrocarbon ring group having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, and particularly preferably 6 to 10 carbon atoms.
Specific examples of the monovalent aromatic hydrocarbon group are the same as those of Ar ⁶¹¹ , and the same is true of the preferred aromatic hydrocarbon group, and the phenyl group is particularly preferred.
These aromatic hydrocarbon groups may have a substituent. The substituents that the aromatic hydrocarbon group may have are as described above, and specifically can be selected from the above-described substituent group Z2. Preferred substituents are the preferred substituents of the aforementioned substituent group Z2.

( ⁿ⁶¹¹ , ⁿ⁶¹² )
n ⁶¹¹ and n ⁶¹² are each independently an integer of 0-4. n ⁶¹¹ and n ⁶¹² are each independently preferably 0 to 2, more preferably 0 or 1.

(substituent)
When Ar ⁶¹¹ , Ar ⁶¹² , R ⁶¹¹ and R ⁶¹² are monovalent or divalent aromatic hydrocarbon groups, the substituents they may have are preferably substituents selected from the aforementioned substituent group Z2.

(G)
G represents a single bond or an optionally substituted divalent aromatic hydrocarbon group having 6 to 50 carbon atoms.

The number of carbon atoms in the aromatic hydrocarbon group of G is usually 6-50, preferably 6-30, more preferably 6-18. Specific examples of the aromatic hydrocarbon group include a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzanthracene ring, perylene ring, and the like, which usually have 6 carbon atoms. Above, usually 30 or less, preferably 18 or less, more preferably 14 or less divalent groups of aromatic hydrocarbon structures, or a plurality of structures selected from these structures are chained or branched Divalent groups of bonded structures are included. When a plurality of aromatic hydrocarbon rings are linked, a structure in which 2 to 8 rings are linked is usually mentioned, and a structure in which 2 to 5 rings are linked is preferable. When a plurality of aromatic hydrocarbon rings are linked, the same structure may be linked, or different structures may be linked.

G is preferably
single bond,
a phenylene group,
a divalent group in which a plurality of benzene rings are bonded in a chain or branched manner;
a divalent group in which one or more benzene rings and at least one naphthalene ring are linked in a chain or branched manner;
a divalent group in which one or more benzene rings and at least one phenanthrene ring are linked in a chain or branched manner, or
a divalent group in which one or more benzene rings and at least one tetraphenylene ring are linked in a chain or branched manner;
and more preferably a divalent group in which a plurality of benzene rings are linked in a chain or branched manner. In either case, the order of coupling does not matter.

The number of bonded benzene rings, naphthalene rings, phenanthrene rings and tetraphenylene rings is usually 2-8, preferably 2-5, as described above. Among them, more preferably, a divalent group in which 1 to 4 benzene rings are linked, a divalent group in which 1 to 4 benzene rings and a naphthalene ring are linked, 1 to 4 benzene rings and a phenanthrene ring are linked It is a divalent group or a divalent group in which 1 to 4 benzene rings and a tetraphenylene ring are linked.

(molecular weight)
The compound represented by the formula (240) is a low-molecular-weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, still more preferably 2,000 or less, and particularly preferably It is 1,500 or less, usually 300 or more, preferably 350 or more, more preferably 400 or more.

(Specific examples of compounds represented by formula (240))
Preferred specific examples of the compound represented by formula (240) are shown below, but the present invention is not limited thereto.

The composition of the present invention may contain only one type of compound represented by formula (240), or may contain two or more types.

<Other ingredients>
The composition of the present invention may optionally contain various other solvents in addition to the organic solvent and light-emitting material described above. Examples of such other solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethylsulfoxide.

The composition of the present invention may contain various additives such as leveling agents and antifoaming agents.
The composition of the present invention is a photocurable resin for the purpose of curing and insolubilizing after film formation in order to prevent these layers from being compatible when laminating two or more layers by a wet film formation method. Alternatively, it may contain a thermosetting resin.

<Blending ratio>
The solid content concentration in the composition of the present invention (including the aromatic compound of the present invention, the light emitting material, the host material other than the aromatic compound of the present invention, and the optional components (leveling agent, etc.) that can be added) concentration of solids) is usually 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and most preferably 1% by mass. Above, it is usually 80% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and most preferably 20% by mass or less.
When the solid content concentration is within this range, it is easy to form a thin film having a desired film thickness with a uniform thickness, which is preferable.

A preferred blending ratio of the aromatic compound and the light-emitting material of the present invention to all the host materials contained in the composition of the present invention, that is, a light-emitting layer formed using the composition of the present invention (hereinafter referred to as the "light-emitting layer of the present invention ”) is as follows. All host materials refer to all host materials other than the aromatic compound of the present invention and the aromatic compound of the present invention.

In the composition of the present invention and the light-emitting layer of the present invention, the mass ratio of the aromatic compound of the present invention to the mass of all host materials of 100 is generally 1 or more, preferably 5 or more, more preferably 10 or more, and still more preferably 15. Above, it is usually 90 or less, preferably 80 or less, more preferably 70 or less, and particularly preferably 50 or less.

In the composition of the present invention and the light emitting layer of the present invention, the molar ratio of the aromatic compound of the present invention to the total host material is usually 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, Especially preferably 15 mol% or more, usually 90 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, particularly preferably 60 mol% or less.

In the composition of the present invention and the light-emitting layer of the present invention, the mass ratio of the light-emitting material to 100 of the mass of all the host materials is usually 0.1 or more, preferably 0.5 or more, more preferably 1 or more, and particularly preferably 2. Above, it is usually 100 or less, preferably 60 or less, more preferably 50 or less, and particularly preferably 40 or less. If this ratio falls below the above lower limit or exceeds the above upper limit, the luminous efficiency may significantly decrease.

<Method for preparing composition>
The composition of the present invention comprises the aromatic compound of the present invention, a light-emitting material such as the phosphorescent light-emitting material described above if necessary, a charge transport material, a host material other than the aromatic compound of the present invention, and further optionally added It is prepared by dissolving a solute comprising various additive components such as possible leveling agents and antifoaming agents in the suitable organic solvent described above.

In order to shorten the time required for this dissolution step and to keep the solute concentration in the composition of the present invention uniform, the solute is usually dissolved while stirring the liquid. The dissolution step may be performed at room temperature, but if the dissolution rate is slow, the dissolution may be performed by heating. After completion of the dissolving step, a filtering step such as filtering may be performed as necessary.

<Characteristics, physical properties, etc. of the composition>
(moisture concentration)
When an organic electroluminescence device is produced by forming layers by a wet film-forming method using the composition of the present invention, if water is present in the composition, the formed film will be contaminated with water, resulting in poor film uniformity. is impaired. Therefore, it is preferable that the water content in the composition of the present invention is as low as possible. In general, organic electroluminescence devices use many materials such as cathodes that are significantly deteriorated by moisture. Possibility of deteriorating the characteristics is considered, which is not preferable.

Specifically, the amount of water contained in the composition of the present invention is usually 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0.01% by mass or less.

As a method for measuring the water concentration in the composition, the method described in the Japanese Industrial Standards "Method for measuring water content of chemical products" (JIS K0068:2001) is preferable. For example, it can be analyzed by the Karl Fischer reagent method (JIS K0211-1348).

(uniformity)
The composition of the present invention is preferably in a uniform liquid state at room temperature in order to improve stability in a wet film formation process, for example, ejection stability from a nozzle in an inkjet film formation method. The uniform liquid state at room temperature means that the composition is a liquid consisting of a uniform phase and does not contain a particle component having a particle size of 0.1 μm or more in the composition.

(physical properties)
When the viscosity of the composition of the present invention is extremely low, for example, excessive liquid film flow in the film formation process tends to cause non-uniformity of the coated surface, nozzle discharge failure in ink jet film formation, and the like. If the viscosity of the composition of the present invention is extremely high, nozzle clogging and the like tend to occur during inkjet film formation.
Therefore, the viscosity of the composition of the present invention at 25° C. is usually 2 mPa·s or more, preferably 3 mPa·s or more, more preferably 5 mPa·s or more, and usually 1000 mPa·s or less, preferably 100 mPa·s or less. More preferably, it is 50 mPa·s or less.

When the surface tension of the composition of the present invention is high, problems such as a decrease in wettability with respect to the substrate, poor leveling of the liquid film, and susceptibility to disturbance of the film formation surface during drying may occur.
Therefore, the surface tension at 20° C. of the composition of the invention is usually less than 50 mN/m, preferably less than 40 mN/m.

When the vapor pressure of the composition of the present invention is high, problems such as a change in solute concentration due to evaporation of the organic solvent may easily occur.
Therefore, the vapor pressure at 25° C. of the composition of the present invention is usually 50 mmHg or less, preferably 10 mmHg or less, more preferably 1 mmHg or less.

[Thin film formation method]
The film forming method using the composition of the present invention in the thin film forming method of the present invention is a wet film forming method.
The wet film-forming method is a method in which a composition is applied to form a liquid film, dried to remove the organic solvent, and a film is formed. If the composition of the present invention contains a light-emitting material, the light-emitting layer can be formed by this method. Examples of coating methods include spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, and gravure. It refers to a method of forming a film by employing a wet film-forming method such as a printing method or a flexographic printing method, and drying the coating film. Among these film forming methods, the spin coating method, the spray coating method, the inkjet method, the nozzle printing method, and the like are preferable. In the case of manufacturing an organic EL display device having an organic electroluminescence element, an inkjet method or a nozzle printing method is preferable, and an inkjet method is particularly preferable.

Although the drying method is not particularly limited, natural drying, reduced pressure drying, heat drying, or reduced pressure drying while heating can be used as appropriate. Heat drying may be carried out in order to further remove residual organic solvents after natural drying or vacuum drying.

In vacuum drying, it is preferable to reduce the pressure below the vapor pressure of the organic solvent contained in the composition of the present invention.

When drying by heating, the heating method is not particularly limited, but heating with a hot plate, heating in an oven, infrared heating, or the like can be used.
The heating temperature is usually 80° C. or higher, preferably 100° C. or higher, more preferably 110° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower.
The heating time is generally 1 minute or longer, preferably 2 minutes or longer, generally 60 minutes or shorter, preferably 30 minutes or shorter, and more preferably 20 minutes or shorter.

As will be described later, in the organic electroluminescent device, an electron transport layer is formed on the light emitting layer. In the present invention, it is preferred that the composition of the present invention is used to form a light-emitting layer by a wet film-forming method, and a layer such as an electron transport layer is formed in contact with the light-emitting layer by a wet film-forming method.

The composition for forming the electron transport layer used when forming the electron transport layer in contact with the light-emitting layer by a wet film-forming method contains at least an electron transport layer material and a solvent. As the solvent for the composition for forming the electron transport layer, an alcoholic solvent (a solvent having an alcoholic hydroxyl group) is preferable because the aromatic compound of the present invention is sparingly soluble and has excellent solvent resistance. As the electron transport layer material of the electron transport layer-forming composition, an electron transport material soluble in such an alcohol-based solvent is preferable.

As the alcohol-based solvent, aliphatic alcohols having 3 or more carbon atoms are preferred.
Aliphatic alcohols having 6 or more carbon atoms are more preferable because they easily dissolve the electron-transporting material, have a moderately high boiling point, and easily form a flat film.

Aliphatic alcohols preferred as alcohol solvents include 1-butanol, isobutyl alcohol, 2-hexanol, 1-hexanol, 1-heptanol, 2-methyl-2-pentanol, 4-methyl-3-heptanol, 3-methyl -2-pentanol, 4-methyl-1-pentanol, 4-heptanol, 1-methoxy-2-propanol, 3-methyl-1-pentanol, 4-octanol, 3-(methylamino)-1-propanol etc. These alcohol solvents may be used in combination of two or more.

As for the method for forming the electron transport layer by the wet film forming method, it is preferable to use the wet film forming method described in the method for forming the light emitting layer.

[Organic electroluminescent element]
As an example of the structure of the organic electroluminescence device of the present invention, FIG. 1 shows a schematic diagram (cross section) of a structural example of the organic electroluminescence device 8 . In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light emitting layer, 6 is an electron transport layer, and 7 is a cathode.

<Substrate>
The substrate 1 serves as a support for the organic electroluminescence element, and is usually made of a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Among these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate and polysulfone are preferred. The substrate is preferably made of a material having a high gas barrier property because deterioration of the organic electroluminescence element due to outside air is unlikely to occur. Therefore, especially when using a material having low gas barrier properties such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve the gas barrier properties.

<Anode>
The anode 2 has the function of injecting holes into the layer on the light-emitting layer 5 side.

Anode 2 is typically made of metals such as aluminum, gold, silver, nickel, palladium, platinum; metal oxides such as indium and/or tin oxide; metal halides such as copper iodide; carbon black and poly(3 -methylthiophene), polypyrrole, and polyaniline.

The formation of the anode 2 is usually carried out by dry methods such as sputtering and vacuum deposition. In the case of forming an anode using metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., they are dispersed in an appropriate binder resin solution. It can also be formed by coating on the substrate. In the case of a conductive polymer, a thin film can be formed directly on a substrate by electrolytic polymerization, or an anode can be formed by coating a conductive polymer on a substrate (Appl. Phys. Lett., 60 2711, 1992).

The anode 2 usually has a single-layer structure, but may have a laminated structure as appropriate. When the anode 2 has a laminated structure, different conductive materials may be laminated on the first layer of the anode.

The thickness of the anode 2 may be determined according to the required transparency and material. When particularly high transparency is required, the thickness is preferably such that the visible light transmittance is 60% or more, and more preferably the thickness is such that the visible light transmittance is 80% or more. In this case, the thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. When transparency is not required, the thickness of the anode 2 may be arbitrarily set according to the required strength and the like. In this case, the anode 2 may have the same thickness as the substrate.

When another layer is formed on the surface of the anode 2, the impurity on the anode 2 is removed and its ionization potential is changed by treating with ultraviolet rays/ozone, oxygen plasma, argon plasma, etc. before the film formation. is preferably adjusted to improve the hole injection property.

<Hole injection layer>
A layer that functions to transport holes from the anode 2 side to the light emitting layer 5 side is usually called a hole injection transport layer or a hole transport layer. When there are two or more layers that function to transport holes from the anode 2 side to the light emitting layer 5 side, the layer closer to the anode 2 side may be called the hole injection layer 3 . The hole injection layer 3 is preferably formed in order to enhance the function of transporting holes from the anode 2 to the light emitting layer 5 side. When forming the hole injection layer 3 , the hole injection layer 3 is usually formed on the anode 2 .

The film thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

The method for forming the hole injection layer may be a vacuum deposition method or a wet film formation method. From the viewpoint of excellent film-forming properties, it is preferable to form the film by a wet film-forming method.

A general method for forming a hole injection layer will be described below. In the organic electroluminescence device of the present invention, the hole injection layer 3 is preferably formed by a wet film formation method using the following composition for forming a hole injection layer.

The composition for forming a hole injection layer usually contains a hole-transporting compound for a hole-injection layer that becomes the hole-injection layer 3 . The hole injection layer-forming composition usually further contains an organic solvent in the case of the wet film-forming method. It is preferable that the composition for forming a hole injection layer has a high hole-transporting property and can efficiently transport the injected holes. For this reason, it is preferable that the hole mobility is large and that impurities that become traps are less likely to occur during manufacture or use. Moreover, it is preferable that it has excellent stability, a small ionization potential, and a high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable to use a material that does not quench light emitted from the light-emitting layer or that forms an exciplex with the light-emitting layer so as not to lower the light emission efficiency.

The hole-transporting compound for the hole-injection layer is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of a charge injection barrier from the anode to the hole-injection layer. Examples of such hole-transporting compounds include aromatic amine-based compounds, phthalocyanine-based compounds, porphyrin-based compounds, oligothiophene-based compounds, polythiophene-based compounds, benzylphenyl-based compounds, and tertiary amines linked with fluorene groups. compounds, hydrazone-based compounds, silazane-based compounds, quinacridone-based compounds, and the like.

Among the exemplified compounds described above, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, in terms of amorphousness and visible light transparency. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine.

The type of the aromatic tertiary amine compound is not particularly limited, but from the viewpoint of easily obtaining uniform light emission due to the surface smoothing effect, a polymer compound having a weight average molecular weight of 1000 or more and 1000000 or less (polymeric compound in which repeating units are linked) ) is preferably used.

When the hole injection layer 3 is formed by a wet film-forming method, the film-forming composition (positive A composition for forming a hole injection layer) is prepared. The hole injection layer 3 is formed by coating the hole injection layer-forming composition on a layer corresponding to the lower layer of the hole injection layer 3 (usually, the anode 2) to form a film and drying the composition.

The concentration of the hole-transporting compound in the hole-injection layer-forming composition is arbitrary as long as it does not significantly impair the effects of the present invention. A higher value is preferable from the viewpoint that defects are less likely to occur in the layer 3 . Specifically, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more. It is preferably 60% by mass or less, and particularly preferably 50% by mass or less.

Examples of organic solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

Examples of ether-based solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and anisole. , phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole and 2,4-dimethylanisole.

Examples of ester-based solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene. be done.

Examples of amide-based solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

In addition to these, dimethyl sulfoxide and the like can also be used.

Formation of the hole injection layer 3 by a wet film-forming method is usually carried out by preparing a composition for forming a hole injection layer and then applying it on a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2). It is carried out by coating and forming a film on the surface and drying it.

After forming the hole injection layer 3, the coating film is usually dried by heating, drying under reduced pressure, or the like.

When the hole injection layer 3 is formed by a vacuum deposition method, one or more of the constituent materials of the hole injection layer 3 are usually placed in a crucible placed in a vacuum vessel (two or more materials are placed in separate crucibles), and the inside of the vacuum chamber is evacuated to about 10 ⁻⁴ Pa by a vacuum pump. After that, the crucible is heated (usually each crucible is heated when two or more materials are used) to evaporate while controlling the amount of evaporation of the material in the crucible (when two or more materials are used, usually evaporate while independently controlling the amount of evaporation) to form a hole injection layer 3 on the anode 2 on the substrate 1 placed facing the crucible. When two or more materials are used, a mixture thereof can be placed in a crucible, heated and evaporated to form the hole injection layer 3 .

The degree of vacuum during vapor deposition ^is not limited as long as ^it does not significantly impair the effects ^of the present invention. 12.0×10 ⁻⁴ Pa) or less. The vapor deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å/second or more and 5.0 Å/second or less. The film formation temperature during vapor deposition is not particularly limited as long as the effects of the present invention are not significantly impaired, but is preferably 10° C. or higher and 50° C. or lower.

The hole injection layer 3 may be crosslinked in the same manner as the hole transport layer 4 described later.

<Hole transport layer>
The hole transport layer 4 is a layer that functions to transport holes from the anode 2 side to the light emitting layer 5 side. The hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, but it is preferable to form this layer in terms of enhancing the function of transporting holes from the anode 2 to the light emitting layer 5. . When forming the hole transport layer 4 , the hole transport layer 4 is usually formed between the anode 2 and the light emitting layer 5 . If the hole-injection layer 3 described above is present, the hole-transport layer 4 is formed between the hole-injection layer 3 and the light-emitting layer 5 .

A material that forms the hole transport layer 4 is preferably a material that has a high hole transport property and can efficiently transport the injected holes. Therefore, it is preferable that the ionization potential is low, the transparency to visible light is high, the hole mobility is high, the stability is excellent, and impurities that act as traps are less likely to occur during manufacture or use. In many cases, since the hole transport layer 4 is in contact with the light emitting layer 5, it does not quench the light emitted from the light emitting layer 5 or form an exciplex with the light emitting layer 5 to reduce the efficiency. is preferred.

As the material for such a hole transport layer 4, any material can be used as long as it is a material conventionally used as a constituent material of a hole transport layer. Examples of compounds include those exemplified. Also, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatic group derivatives, metal complexes, and the like.

Materials for the hole transport layer 4 also include, for example, polyvinylcarbazole derivatives, polyarylamine derivatives, polyvinyltriphenylamine derivatives, polyfluorene derivatives, polyarylene derivatives, polyarylene ether sulfone derivatives containing tetraphenylbenzidine, poly Examples include arylene vinylene derivatives, polysiloxane derivatives, polythiophene derivatives, poly(p-phenylene vinylene) derivatives and the like. These may be alternating copolymers, random polymers, block polymers or graft copolymers. Also, a polymer having a branched main chain and three or more terminal portions, or a so-called dendrimer may be used.

Among them, polyarylamine derivatives and polyarylene derivatives are preferred.
As the polyarylamine derivative, a polymer containing a repeating unit represented by the following formula (II) is preferable. In particular, a polymer composed of repeating units represented by the following formula (II) is preferable, and in this case, Ar ^a or Ar ^b may be different in each repeating unit.

(In formula (II), Ar ^a and Ar ^b each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group .)

Examples of polyarylene derivatives include polymers having arylene groups such as optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups in their repeating units. .

As the polyarylene derivative, a polymer having repeating units represented by the following formula (III-1) and/or the following formula (III-2) is preferable.

(In formula (III-1), R ^a , R ^b , R ^c and R ^d are each independently an alkyl group, an alkoxy group, a phenylalkyl group, a phenylalkoxy group, a phenyl group, a phenoxy group, an alkylphenyl group, represents an alkoxyphenyl group, an alkylcarbonyl group, an alkoxycarbonyl group or a carboxy group, and t and s each independently represents an integer of 0 to 3. When t or s is 2 or more, a plurality of groups contained in one molecule may be ^the same or different, and adjacent Ra ^or ^Rb may form a ring. ⁾

(In formula (III-2), R ^e and R ^f are each independently synonymous with R ^a , R ^b , R ^c or R ^d in formula (III-1) above. r and u are each independently represents an integer of 0 to 3. When r or u is 2 or more, a plurality of R ^e and R ^f contained in one molecule may be the same or different, and adjacent R ^e or R ^f may form a ring together, and X represents an atom or a group of atoms constituting a 5- or 6-membered ring.)

Specific examples of X include an oxygen atom, an optionally substituted boron atom, an optionally substituted nitrogen atom, an optionally substituted silicon atom, and an optionally substituted an optionally substituted phosphorus atom, an optionally substituted sulfur atom, an optionally substituted carbon atom, or a group formed by combining these atoms.

The polyarylene derivative preferably has a repeating unit represented by the following formula (III-3) in addition to the repeating unit represented by the above formula (III-1) and/or the above formula (III-2). .

(In formula (III-3), Ar ^c to Ar ⁱ each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group; and v and w each independently represent 0 or 1.)

Specific examples of the above formulas (III-1) to (III-3) and specific examples of the polyarylene derivative include those described in JP-A-2008-98619.

When the hole transport layer 4 is formed by a wet film formation method, a composition for forming a hole transport layer is prepared in the same manner as in the formation of the hole injection layer 3, and after wet film formation, heat drying is performed. .

The hole-transporting layer-forming composition contains an organic solvent in addition to the hole-transporting compound described above. The organic solvent to be used is the same as that used for the composition for forming the hole injection layer. The film formation conditions, heat drying conditions, and the like are the same as in the case of forming the hole injection layer 3 .

When the hole transport layer 4 is formed by vacuum evaporation, the film formation conditions and the like are the same as those for forming the hole injection layer 3 described above.

The hole-transporting layer 4 may contain various light-emitting materials, electron-transporting compounds, binder resins, coatability improvers, etc., in addition to the above hole-transporting compounds. Therefore, the composition for forming a hole transport layer may contain various luminescent materials, electron transport compounds, binder resins, coatability improvers, etc., in addition to the above hole transport compounds.

The hole transport layer 4 may be a layer formed by cross-linking a cross-linkable compound. The crosslinkable compound is a compound having a crosslinkable group, and forms a network polymer compound by crosslinking.

Examples of crosslinkable groups include groups derived from cyclic ethers such as oxetane and epoxy; groups derived from unsaturated double bonds such as vinyl, trifluorovinyl, styryl, acryl, methacryloyl, and cinnamoyl; Examples thereof include groups derived from cyclobutene.

The crosslinkable compound may be a monomer, oligomer, or polymer. The crosslinkable compound may have only one type, or may have two or more types in any combination and ratio.

A hole-transporting compound having a crosslinkable group is preferably used as the crosslinkable compound.
Examples of the hole-transporting compound of the hole-transporting compound having a crosslinkable group include those exemplified above. or those bound to side chains. In particular, the crosslinkable group is preferably bonded to the main chain via a linking group such as an alkylene group. In particular, the hole-transporting compound is preferably a polymer containing a repeating unit having a crosslinkable group, and is represented by the above formula (II) or formulas (III-1) to (III-3). It is preferably a polymer having repeating units in which a crosslinkable group is bonded directly or via a linking group to the repeating units.

In order to form the hole transport layer 4 by cross-linking a cross-linkable compound, a composition for forming a hole transport layer is usually prepared by dissolving or dispersing a cross-linkable compound in an organic solvent, and the composition is formed by a wet film forming method. Film and crosslink.

The film thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

<Light emitting layer>
The light-emitting layer 5 is a layer that functions to emit light by being excited by recombination of holes injected from the anode 2 and electrons injected from the cathode 7 when an electric field is applied between a pair of electrodes. .
The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7 . The light emitting layer 5 is formed between the hole injection layer 3 and the cathode 7 if there is a hole injection layer 3 on the anode 2 . If there is a hole-transporting layer 4 on top of the anode 2 , the light-emitting layer 5 is formed between the hole-transporting layer 4 and the cathode 7 .

The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material) and preferably contains one or more host materials.
As described above, the light-emitting layer 5 of the organic electroluminescent device of the present invention is formed by a wet film-forming method using the composition of the present invention.
The light-emitting layer formed using the composition of the present invention preferably contains the aromatic compound of the present invention, a phosphorescent light-emitting material and a charge-transporting material, and the charge-transporting material is a compound represented by the formula (250) and / or a compound represented by the above formula (240) is included.

The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention, but a thicker one is preferable from the viewpoint that defects are less likely to occur in the film, while a thinner one is preferable from the viewpoint that a low driving voltage can be easily achieved. The thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and preferably 200 nm or less, more preferably 100 nm or less.

<Hole blocking layer>
A hole blocking layer may be provided between the light emitting layer 5 and the electron injection layer 6 described below. The hole-blocking layer is a layer laminated on the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 7 side.

The hole-blocking layer has a role of blocking holes moving from the anode 2 from reaching the cathode 7 and a role of efficiently transporting electrons injected from the cathode 7 toward the light-emitting layer 5. . The physical properties required for the material constituting the hole blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and an excited triplet level (T ₁ ). is high.

Examples of materials for the hole blocking layer that satisfy these conditions include bis(2-methyl-8-quinolinolato)(phenolato)aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolate)aluminum, and the like. mixed ligand complexes, bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolato) aluminum binuclear metal complexes such as metal complexes, distyrylbiphenyl derivatives and the like Styryl compounds (JP-A-11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (JP-A-11-242996) 7-41759), phenanthroline derivatives such as bathocuproine (JP-A-10-79297), and the like. Furthermore, the compound having at least one pyridine ring substituted at the 2,4,6 positions described in WO 2005/022962 is also preferable as a material for the hole blocking layer.

There are no restrictions on the method of forming the hole blocking layer. Therefore, it can be formed by a wet film forming method, a vapor deposition method, or other methods.

The film thickness of the hole-blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but it is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

<Electron transport layer>
The electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 for the purpose of further improving the current efficiency of the device.

The electron transport layer 6 is made of a compound that can efficiently transport electrons injected from the cathode 7 toward the light-emitting layer 5 between electrodes to which an electric field is applied. The electron-transporting compound used in the electron-transporting layer 6 is a compound that has high electron injection efficiency from the cathode 7, high electron mobility, and can efficiently transport the injected electrons. is required.

Specific examples of the electron-transporting compound used in the electron-transporting layer 6 include a metal complex such as an aluminum complex of 8-hydroxyquinoline (JP-A-59-194393) and a metal of 10-hydroxybenzo[h]quinoline. complexes, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948). book), quinoxaline compound (JP-A-6-207169), phenanthroline derivative (JP-A-5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogen amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

The electron-transporting layer 6 is formed by laminating on the hole-blocking layer by a wet film-forming method or a vacuum deposition method in the same manner as described above. A vacuum deposition method is usually used. In the present invention, as described above, the electron transport layer 6 can be formed on the light-emitting layer containing the compound of the present invention by a wet film-forming method.

The thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

<Electron injection layer>
An electron injection layer may be provided between the electron transport layer 6 and the cathode 7 in order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5 .

In order to efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. Examples thereof include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like.
The film thickness of the electron injection layer is preferably 0.1 nm or more and 5 nm or less.

Furthermore, an organic electron-transporting material typified by a nitrogen-containing heterocyclic compound such as bathophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium or rubidium ( JP-A-10-270171, JP-A-2002-100478, JP-A-2002-100482, etc.) also improves the electron injection and transport properties and makes it possible to achieve both excellent film quality. preferable.

The thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer is formed by laminating the light emitting layer 5 or the hole blocking layer or the electron transport layer 6 thereon by a wet film forming method or a vacuum deposition method.
The details of the wet film formation method are the same as those of the light-emitting layer described above.

In some cases, the hole-blocking layer, electron-transporting layer, and electron-injecting layer are formed into a single layer by co-doping the electron-transporting material and the lithium complex.

<Cathode>
The cathode 7 plays a role of injecting electrons into a layer (an electron injection layer, a light-emitting layer, or the like) on the light-emitting layer 5 side.

As the material for the cathode 7, the material used for the anode 2 can be used. For efficient electron injection, it is preferable to use a metal with a low work function as the material of the cathode 7. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof are used. be done. Specific examples include low work function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

From the viewpoint of the stability of the organic electroluminescent device, it is preferable to protect the cathode made of a metal with a low work function by stacking a metal layer that has a high work function and is stable against the atmosphere on the cathode. Metals to be laminated include, for example, metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum.

The film thickness of the cathode is usually the same as that of the anode.

<Other layers>
The organic electroluminescence device of the present invention may further have other layers as long as they do not significantly impair the effects of the present invention. That is, it may have any of the other layers described above between the anode and cathode.

<Other device configurations>
The organic electroluminescence device of the present invention has a structure opposite to that described above. It is also possible to laminate the injection layer and the anode in this order.

When the organic electroluminescent element of the present invention is applied to an organic electroluminescent device, it may be used as a single organic electroluminescent element or may be used in a configuration in which a plurality of organic electroluminescent elements are arranged in an array. A configuration in which anodes and cathodes are arranged in an XY matrix may be used.

[Display device]
The display device of the present invention (organic electroluminescent element display device: organic EL display device) comprises the organic electroluminescent element of the present invention. The type and structure of the organic EL display device of the present invention are not particularly limited, and the organic electroluminescence device of the present invention can be assembled according to a conventional method.

For example, the organic EL display device of the present invention can be manufactured by the method described in "Organic EL Display" (Ohmsha, August 20, 2004, by Shizuo Tokito, Chihaya Adachi, and Hideyuki Murata). can be formed.

[Lighting device]
The lighting device of the present invention (organic electroluminescent element lighting device: organic EL lighting device) includes the organic electroluminescent element of the present invention. There are no particular restrictions on the type and structure of the organic EL lighting device of the present invention, and it can be assembled according to a conventional method using the organic electroluminescence device of the present invention.

The organic electroluminescence device of the present invention is used in display devices such as organic EL displays and lighting devices such as organic EL lighting. Using the organic electroluminescent device of the present invention, for example, by the method described in "Organic EL Display" (Ohmsha, August 20, 2004, by Shizuo Tokito, Chihaya Adachi, Hideyuki Murata) Organic EL display Organic EL lighting can be formed.

EXAMPLES The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.
Various conditions and values of evaluation results in the following examples have meanings as preferred values of the upper limit or lower limit in the embodiments of the present invention, and the preferred range is the above upper limit or lower limit value and the following example It may be a range defined by the value of or in combination with the values of the examples.

As used herein, Ac means an acetyl group, Ph means a phenyl group, dppf means 1,1′-bis(diphenylphosphino)ferrocene, and DMSO means dimethylsulfoxide.
Comparative compound 1 and comparative compound 2 were synthesized according to the method described in the aforementioned Patent Document 1 (International Publication No. 2007/043357).

[Synthesis Example I-1: Synthesis Example of Compound (H-1)]
<Synthesis of Compound 1-c>

Under a nitrogen atmosphere, compound 1-a (14.1 g, 30.4 mmol) and compound 1-b (7.23 g, 20.3 mmol) were subjected to nitrogen bubbling toluene (130 mL), ethanol (30 mL), triphosphate A potassium aqueous solution (2.0 mol/L, 30 mL) was sequentially added and heated to 60°C. After that, Pd(PPh ₃ ) ₄ (0.23 g, 0.20 mmol) was added, and the mixture was heated and stirred at 90° C. for 3 hours. After cooling to room temperature, a saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 1-c (9.0 g, 72% yield).

(Synthesis of compound (H-1))

Under a nitrogen atmosphere, compound 1-c (2.0 g, 3.26 mmol) and compound 1-d (0.66 g, 1.63 mmol) were subjected to nitrogen bubbling toluene (40 mL), ethanol (20 mL), triphosphate A potassium aqueous solution (2.0 mol/L, 20 mL) was sequentially added and heated to 60°C. After that, Pd(PPh ₃ ) ₄ (0.23 g, 0.20 mmol) was added and heated with stirring at 90° C. for 5 hours. After cooling to room temperature, a saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-1) (1.44 g, 72% yield).

[Synthesis Example I-2: Synthesis Example of Compound (H-2)]
<Synthesis of compound 2-c>

Compound 2-a (10.6 g, 26.1 mmol) and compound 2-b (16.2 g, 57.4 mmol) were subjected to nitrogen bubbling toluene (130 mL), ethanol (65 mL), tripotassium phosphate aqueous solution (2 .0 mol/L, 65 mL) was sequentially added and heated to 50°C. PdCl ₂ (PPh ₃ ) ₂ (0.37 g, 0.52 mmol) was then added and stirred at 65° C. for 2 hours. After cooling to room temperature, a saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-c (yield 9.12 g, yield 75%).

Dehydrated DMSO (200 mL) was added to compound 2-c (9.12 g, 19.6 mmol), bis(pinacolatodiboron) (15.0 g, 58.9 mmol) and potassium acetate (11.5 g, 117.6 mmol). , and heated to 50°C. PdCl ₂ (dppf)CH ₂ Cl ₂ (0.80 g, 0.98 mmol) was added and stirred at 90° C. for 3 hours. After cooling to room temperature, distilled water was added and suction filtration was performed. The filtrate was dissolved in toluene, washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 2-d (8.0 g, 73% yield).

Under a nitrogen atmosphere, compound 1-c (9.4 g, 15.4 mmol) and compound 2-d (3.9 g, 6.99 mmol) were subjected to nitrogen bubbling toluene (60 mL), ethanol (30 mL), triphosphate A potassium aqueous solution (2.0 mol/L, 30 mL) was sequentially added and heated to 60°C. After that, Pd(PPh ₃ ) ₄ (0.081 g, 0.070 mmol) was added, and the mixture was heated and stirred at 90° C. for 3 hours. After cooling to room temperature, a saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-2) (8.0 g, 83% yield).

[Synthesis Example I-3: Synthesis of compound (H-3)]
<Synthesis of Compound 3-a>

Dehydrated DMSO (60 mL) was added to compound 1-c (4.60 g, 7.5 mmol), bis(pinacolatodiboron) (2.85 g, 11.2 mmol) and potassium acetate (2.21 g, 22.5 mmol). , and heated to 50°C. PdCl ₂ (dppf)CH ₂ Cl ₂ (0.31 g, 0.38 mmol) was added and stirred at 90° C. for 2 hours. After cooling to room temperature, distilled water was added and suction filtration was performed. The filtrate was dissolved in toluene, washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound 3-a (4.88 g, 98% yield).

Under a nitrogen atmosphere, compound 3-a (4.88 g, 7.39 mmol) and compound 1-a (1.71 g, 3.69 mmol) were subjected to nitrogen bubbling toluene (60 mL), ethanol (30 mL), triphosphate A potassium aqueous solution (2.0 mol/L, 30 mL) was sequentially added and heated to 60°C. After that, Pd(PPh ₃ ) ₄ (0.085 g, 0.074 mmol) was added and heated with stirring at 90° C. for 3 hours. After cooling to room temperature, a saturated sodium chloride aqueous solution was added, and extraction was performed using toluene. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain compound (H-3) (3.21 g, 63% yield).

[Evaluation of each compound]
Compounds (H-1), (H-2) and (H-3), which are the following aromatic compounds of the present invention synthesized in Synthesis Examples I-1 to I-3, and Comparative Compound (C-1) and Comparative Compound (C-2) were evaluated as follows.

<Evaluation of Tg, Ip, Ea, Eg>
The glass transition temperature (Tg) of each compound was evaluated by differential scanning calorimetry (DSC).
The ionization potential (Ip) of each compound was evaluated by photoelectron spectroscopy.
The electron affinity (Ea) of each compound was calculated by subtracting Ip from the bandgap (Eg) calculated from the absorption edge of the absorption spectrum.
Table 1 shows the results.

<Solvent solubility evaluation>
To evaluate the solubility of each compound in cyclohexylbenzene (CHB), prepare a cyclohexylbenzene solution of about 1 to 2 mL (concentration of each compound: 2.0% by mass), and dissolve each compound in the solution. It was evaluated whether or not
The compounds (H-1), (H-2) and (H-3) of the present invention have a solubility in CHB of 2.0% by mass, similar to the comparative compounds (C-1) and (C-2). Thus, it showed good solubility.

<Solvent resistance evaluation>
The solvent resistance of the obtained compound after film formation was evaluated as follows.
First, a solution was prepared by dissolving 1.5% by mass of a compound to be tested in toluene.
In a nitrogen glove box, this solution was dropped onto a glass substrate, spin-coated, and dried on a hot plate at 100° C. for 10 minutes to form a compound film to be tested. The film thickness of each compound film formed is as shown in Table 2.
Next, the substrate on which the compound film was formed was set in a spin coater, 150 μL of the test solvent was dropped onto the substrate, and after the dropping, the substrate was allowed to stand for 60 seconds to conduct a solvent resistance test. 1-butanol was used as the test solvent.
After that, the substrate was spun at 1500 rpm for 30 seconds and then at 4000 rpm for 30 seconds to spin out the dropped solvent. This substrate was dried on a hot plate at 100° C. for 10 minutes. The film thickness change before and after the solvent resistance test was estimated from each film thickness difference.

The solvent resistance of the compound after film formation was evaluated based on the following criteria.
◯: No decrease in film thickness was observed.
x: A film thickness reduction in the range of 5 nm or more and less than 15 nm was observed.
XX: The film was dissolved and disappeared.
Table 2 shows the results of the solvent resistance test.

From the above results, it can be seen that the aromatic compound of the present invention is a compound that has excellent heat resistance and solvent solubility, excellent solvent resistance to alcohol-based solvents in thin films, and a large bandgap.

[Device Example II-1]
An organic electroluminescence device was produced by the following method.
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate to a thickness of 50 nm (manufactured by Geomatec, a sputter-deposited product) was subjected to a 2 mm-wide stripe using ordinary photolithography and etching with hydrochloric acid. was patterned to form an anode. The substrate on which the ITO pattern is formed in this manner is washed with ultrasonic waves using an aqueous solution of surfactant, washed with ultrapure water, ultrasonically washed with ultrapure water, and washed with ultrapure water in this order, and then dried with compressed air. , and finally performed ultraviolet ozone cleaning.

As a composition for forming a hole injection layer, 3.0% by weight of a hole-transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6% by weight of an electron-accepting compound (HI-1) was dissolved in ethyl benzoate to prepare a composition.

This composition for forming a hole injection layer was spin-coated on the substrate in the atmosphere and dried on a hot plate in the atmosphere at 240° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm, forming a hole injection layer. and

Next, a charge-transporting polymer compound having the following formula (HT-1) was dissolved in 1,3,5-trimethylbenzene to prepare a 2.0% by weight solution.
This solution was spin-coated on the substrate on which the hole injection layer was formed as described above in a nitrogen glove box and dried on a hot plate in the nitrogen glove box at 230° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm. to form a hole transport layer.

Subsequently, as materials for the light-emitting layer, 2.3% by weight of the compound (H-1) of the present invention synthesized in Synthesis Example I-1, 1.15% by weight of the following compound (EH-1), and the following 1.15% by weight of compound (EH-2) and 1.4% by weight of compound (D-1) below were dissolved in cyclohexylbenzene to prepare a composition for forming a light-emitting layer.

The composition for forming a light emitting layer was spin-coated on the substrate on which the hole transport layer was formed in a nitrogen glove box, dried on a hot plate in the nitrogen glove box at 120 ° C. for 20 minutes, and a uniform film thickness of 40 nm. A thin film was formed to form a light-emitting layer.

The substrate on which up to the light-emitting layer was formed was placed in a vacuum deposition apparatus, and the inside of the apparatus was evacuated to 2×10 ⁻⁴ Pa or less.
Next, the following compound (ET-1) and 8-hydroxyquinolinolatritium were co-deposited on the light-emitting layer at a film thickness ratio of 2:3 by a vacuum vapor deposition method to form an electron-transporting layer having a film thickness of 30 nm. formed.

Subsequently, a striped shadow mask with a width of 2 mm was adhered to the substrate so as to be orthogonal to the ITO stripes of the anode as a mask for cathode evaporation, and aluminum was heated with a molybdenum boat to form an aluminum layer with a thickness of 80 nm. formed to form the cathode.

As described above, an organic electroluminescence device having a light emitting area with a size of 2 mm x 2 mm was obtained.

[Device Example II-2]
An organic compound was prepared in the same manner as in Device Example II-1, except that the compound (H-2) of the present invention synthesized in Synthesis Example I-2 was used as the material for the light-emitting layer instead of the compound (H-1). An electroluminescence device was produced.

[Device Example II-3]
An organic compound was prepared in the same manner as in Device Example II-1, except that the compound (H-3) of the present invention synthesized in Synthesis Example I-3 was used instead of the compound (H-1) as the material for the light-emitting layer. An electroluminescence device was produced.

[Element Comparative Example II-1]
An organic electroluminescence device was fabricated in the same manner as in Device Example II-1, except that the comparative compound (C-2) described above was used instead of the compound (H-1) as the material for the light-emitting layer.

[Evaluation of element]
Current efficiency (cd/ ^A ) and external quantum efficiency (% ) was measured. Also, the time (LT95) for the luminance to decrease to 95% of the initial luminance was measured when the device was continuously energized at a current density of 15 mA/cm ² . These measurement results are shown in Table 3. In Table 3, the values of Element Examples II-1 to 3 are relative values with the value of Element Comparative Example II-1 set to 1.
From the results in Table 3, it was found that the performance of the organic electroluminescence device using the aromatic compound of the present invention was improved.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application 2021-094593 filed on June 4, 2021 and Japanese Patent Application 2021-148727 filed on September 13, 2021, the entirety of which is incorporated by reference. .

REFERENCE SIGNS LIST 1 substrate 2 anode 3 hole injection layer 4 hole transport layer 5 light emitting layer 6 electron transport layer 7 cathode 8 organic electroluminescence element

Claims

An organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
An organic electroluminescence device, wherein the organic layer includes a layer containing an aromatic compound represented by the following formula (1).

(In formula (1),
Ar 1 to Ar 5 are each independently a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms,
At least one of Ar 1 , Ar 2 and Ar 5 is represented by the following formula (2) or the following formula (3).
L 1 to L 5 are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms.
Each R is independently an alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group , or represents an aromatic hydrocarbon group.
m1, m2 and m5 each independently represents an integer of 0 to 5;
m3 and m4 each independently represent an integer of 1 to 5;
n represents an integer from 0 to 10;
a1 and a2 each independently represent an integer of 0 to 3;
a3 represents an integer of 0 to 4;
a4 represents an integer of 0 or 1;
However, when a3 is 4, a4 is 0.
A substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in Ar 1 to Ar 5 may have, and a divalent carbon number of 6 or more and 60 or less in L 1 to L 5 . The substituents that the aromatic hydrocarbon group may have are each independently an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group;
In formula (1), Ar 1 -(L 1 ) m1 -, Ar 2 -(L 2 ) m2 -, Ar 3 -(L 3 ) m3 -, and Ar 4 -(L 4 ) m4 - are all hydrogen does not become an atom. )

(In formula (2) or (3),
An asterisk (*) represents a bond with formula (1).
R 1 to R 26 are each independently hydrogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, alkylthio group, arylthio group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group. )
Ar 1 and Ar 2 and Ar 5 when n is 1 or more or at least one Ar 5 when n is 2 or more are represented by the above formula (2) or the above formula (3). Item 1. The organic electroluminescence device according to item 1.
3. The organic electroluminescence device according to claim 1, wherein L 1 to L 5 are each independently a phenylene group or a group in which two or more phenylene groups are linked, each of which may have a substituent.
4. The organic electroluminescence device according to claim 3, wherein each of L 1 to L 5 is independently a 1,3-phenylene group which may have a substituent.
The organic electroluminescence device according to any one of claims 1 to 4, wherein the aromatic compound has a molecular weight of 1200 or more.
The organic electroluminescent device according to any one of claims 1 to 5, wherein the layer containing the aromatic compound is a light-emitting layer.
A display device comprising the organic electroluminescence device according to any one of claims 1 to 6.
A lighting device comprising the organic electroluminescent device according to any one of claims 1 to 6.
An aromatic compound represented by the following formula (1).

(In formula (1),
Ar 1 to Ar 5 are each independently a hydrogen atom or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms,
At least one of Ar 1 , Ar 2 and Ar 5 is represented by the following formula (2) or the following formula (3).
L 1 to L 5 are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 60 carbon atoms.
Each R independently represents an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group.
m1, m2 and m5 each independently represents an integer of 0 to 5;
m3 and m4 each independently represent an integer of 1 to 5;
n represents an integer from 0 to 10;
a1 and a2 each independently represent an integer of 0 to 3;
a3 represents an integer of 0 to 4;
a4 represents an integer of 0 or 1;
However, when a3 is 4, a4 is 0.
A substituent that the monovalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms in Ar 1 to Ar 5 may have, and a divalent carbon number of 6 or more and 60 or less in L 1 to L 5 . The substituents that the aromatic hydrocarbon group may have are each independently an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group or an aromatic hydrocarbon group;
In formula (1), Ar 1 -(L 1 ) m1 -, Ar 2 -(L 2 ) m2 -, Ar 3 -(L 3 ) m3 -, and Ar 4 -(L 4 ) m4 - are all hydrogen does not become an atom. )

(In formula (2) or (3),
An asterisk (*) represents a bond with formula (1).
R 1 to R 26 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryloxy group, an alkoxycarbonyl group, an acyl group, a halogen atom, a haloalkyl group, a silyl group, a siloxy group, an aralkyl group, or an aromatic hydrocarbon group. represents a hydrogen group. )
The aromatic compound according to claim 9, wherein a1, a2 and a4 are 0.
The aromatic compound according to claim 9, wherein a4 is 1 and a3 is an integer of 0-3.
The aromatic compound according to claim 11, wherein a1, a2 and a3 are the same.
Ar 1 and Ar 2 and Ar 5 when n is 1 or more or at least one Ar 5 when n is 2 or more are represented by the above formula (2) or the above formula (3). Item 13. The aromatic compound according to any one of items 9 to 12.
The aromatic according to any one of claims 9 to 13, wherein L 1 to L 5 are each independently a phenylene group or a group in which two or more phenylene groups are linked, which may have a substituent. Compound.
15. The aromatic compound according to claim 14, wherein each of L 1 to L 5 is independently an optionally substituted 1,3-phenylene group.
The aromatic compound according to any one of claims 9 to 15, which has a molecular weight of 1200 or more.
A composition containing the aromatic compound according to any one of claims 9 to 16 and an organic solvent.
The composition according to claim 17, further comprising a phosphorescent material and a charge transport material.
19. The composition according to claim 18, wherein the charge transport material comprises a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

(In formula (250),
Each W independently represents CH or N, and at least one W is N.
Xa 1 , Ya 1 , and Za 1 are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon represents a divalent aromatic heterocyclic group of numbers 3 to 30;
Xa 2 , Ya 2 and Za 2 are each independently a hydrogen atom, a monovalent aromatic hydrocarbon group optionally having 6 to 30 carbon atoms, or optionally having a substituent It represents a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms.
g11, h11, and j11 each independently represent an integer of 0 to 6,
At least one of g11, h11 and j11 is an integer of 1 or more.
When g11 is 2 or more, multiple Xa1 may be the same or different.
When h11 is 2 or more, a plurality of Ya 1 may be the same or different.
When j11 is 2 or more, a plurality of Za1 may be the same or different.
R 31 represents a hydrogen atom or a substituent, and the four R 31 may be the same or different.
However, when g11, h11 or j11 is 0, the corresponding Xa 2 , Ya 2 and Za 2 are not hydrogen atoms. )

(In formula (240),
Ar 611 and Ar 612 each independently represent an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
R 611 and R 612 each independently represent a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
G represents a single bond or an optionally substituted divalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
n 611 and n 612 are each independently an integer of 0-4. )
The composition according to claim 19, wherein at least two of the three Ws in said formula (250) are N.
The composition according to claim 20, wherein all W in the formula (250) are N.
Ar 611 and Ar 612 in the formula (240) are each independently a monovalent group in which a plurality of optionally substituted benzene rings are linked in a chain or branched form, according to claim 19 composition.
The composition according to claim 19, wherein R 611 and R 612 in the formula (240) are each independently an optionally substituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. thing.
20. The composition of claim 19, wherein n 611 and n 612 in formula (240) are each independently 0 or 1.
A method for forming a thin film, comprising the step of forming a film from the composition according to any one of claims 17 to 24 by a wet film-forming method.
A method for producing an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, the method comprising:
A method for producing an organic electroluminescence device, comprising the step of forming the organic layer by a wet film-forming method using the composition according to any one of claims 17 to 24.
The method for manufacturing an organic electroluminescence device according to claim 26, wherein the organic layer is a light-emitting layer.
A method for producing an organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, the method comprising:
the organic layer comprises a light-emitting layer and an electron-transporting layer;
A step of forming the light-emitting layer by a wet film-forming method using the composition according to any one of claims 17 to 24;
and forming the electron transport layer by a wet film-forming method using an electron transport layer-forming composition containing an electron transport material and a solvent.
The method for producing an organic electroluminescence device according to claim 28, wherein the solvent contained in the composition for forming an electron transport layer is an alcohol solvent.
An organic electroluminescence device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
the organic layer comprises a light-emitting layer;
The light-emitting layer comprises the aromatic compound according to any one of claims 9 to 16, a phosphorescent light-emitting material and a charge transport material,
An organic electroluminescence device, wherein the charge-transporting material contains a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

(In formula (250),
Each W independently represents CH or N, and at least one W is N.
Xa 1 , Ya 1 , and Za 1 are each independently an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon represents a divalent aromatic heterocyclic group of numbers 3 to 30;
Xa 2 , Ya 2 and Za 2 are each independently a hydrogen atom, a monovalent aromatic hydrocarbon group optionally having 6 to 30 carbon atoms, or optionally having a substituent It represents a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms.
g11, h11, and j11 each independently represent an integer of 0 to 6,
At least one of g11, h11 and j11 is an integer of 1 or more.
When g11 is 2 or more, multiple Xa1 may be the same or different.
When h11 is 2 or more, a plurality of Ya 1 may be the same or different.
When j11 is 2 or more, a plurality of Za1 may be the same or different.
R 31 represents a hydrogen atom or a substituent, and the four R 31 may be the same or different.
However, when g11, h11 or j11 is 0, the corresponding Xa 2 , Ya 2 and Za 2 are not hydrogen atoms. )

(In formula (240),
Ar 611 and Ar 612 each independently represent an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
R 611 and R 612 each independently represent a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
G represents a single bond or an optionally substituted divalent aromatic hydrocarbon group having 6 to 50 carbon atoms.
n 611 and n 612 are each independently an integer of 0-4. )
31. The organic electroluminescence device according to claim 30, wherein at least two of the three Ws in said formula (250) are N.
32. The organic electroluminescent device according to claim 31, wherein all Ws in formula (250) are N.