KR20240016268A - Aromatic compounds and organic electroluminescent devices - Google Patents

Abstract

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

(Ar ¹ to Ar ⁵ are a hydrogen atom or an 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 (3). L ¹ to L ⁵ is an aromatic hydrocarbon group with 6 or more carbon atoms and 60 or less carbon atoms. R is a specific substituent.)

Description

Aromatic compounds and organic electroluminescent devices

The present invention relates to an aromatic compound that can be used in an organic electroluminescent device (hereinafter sometimes referred to as “OLED” or “device”). The present invention also provides an organic electroluminescent device having the aromatic compound, a display device and a lighting device having the organic electroluminescent device, a composition containing the compound and an organic solvent, a thin film forming method using the composition, and organic electroluminescence. It relates to a method of manufacturing a device.

Recently, as a thin film type electroluminescent element, an organic electroluminescent element using an organic thin film has been developed instead of one using an inorganic material. An organic electroluminescent device (OLED) usually 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 layer are being developed, and development of red, green, and blue luminous colors is underway. In addition, research is underway on coating-type OLEDs, which have higher material utilization efficiency and can lower manufacturing costs compared to conventional deposition-type OLEDs.

For coating-type OLEDs, longer lifespan of the device and driving at lower power consumption are required. Various factors are thought to affect the lifespan of the device or improvement in power consumption. For example, with regard to lifespan, it is thought that the heat resistance durability and crystallinity of the materials constituting the device have a significant influence.

In order to manufacture an organic electroluminescent element by a wet film forming method, all materials used must be dissolved in an organic solvent and used as ink. If the material used has poor solubility, there is a possibility that the material may deteriorate before use because operations such as heating for a long time are required. If a uniform state cannot be maintained in the solution state for a long time, precipitation of material from the solution occurs, making film formation by an inkjet device or the like impossible.

Materials used in the wet film formation method are required to have solubility in two senses: that they dissolve quickly in an organic solvent, and that they maintain a uniform state without precipitating after dissolution.

In order to form an organic electroluminescent device by forming the entire organic layer by a wet film formation method by depositing the organic layer in multiple layers, the ink applied thereon after the wet film formation is required to have solvent resistance.

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

[Formula 1]

International Publication No. 2007/043357

Although the above compounds have high solubility and a large band gap, the glass transition temperature is low at 99°C for compound (C-1) and 87°C for compound (C-2), so heat resistance is not sufficient. Additionally, when a thin film is laminated on a thin film formed from the above compound by a wet film forming method using an alcohol-based solvent, the solvent resistance to the alcohol-based solvent used is not sufficient.

The object of the present invention is to provide a compound that is not only excellent in heat resistance and solvent solubility, but also has excellent solvent resistance to alcohol-based solvents in thin films, and further has a large band gap.

In addition, the present invention relates to an organic electroluminescent device having the compound, a display device and a lighting device having the organic electroluminescent device, a composition containing the compound and a solvent, a thin film forming method using the composition, and an organic electroluminescent device. The task is to provide a manufacturing method.

The present inventor found that the above problems could 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 electroluminescent device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,

An organic electroluminescent element in which the organic layer has a layer containing an aromatic compound represented by the following formula (1).

[Formula 2]

(In equation (1),

Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;

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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.

R is each 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 represent 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 from 0 to 4.

a4 represents an integer of 0 or 1.

However, if a3 is 4, a4 is 0.

For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. each 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 aromatic group. It is a 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 atoms. does not work.)

[Formula 3]

(In equation (2) or (3),

Asterisk (*) indicates combination with equation (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). Organic electroluminescent device.

<3> The organic electroluminescent device according to <1> or <2>, wherein L ¹ to L ⁵ are each independently a phenylene group or a group of two or more phenylene groups linked, which may have a substituent.

<4> The organic electroluminescent device according to <3>, wherein L ¹ to L ⁵ are each independently a 1,3-phenylene group which may have a substituent.

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

<6> The organic electroluminescent 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 electroluminescent element according to any one of <1> to <6>.

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

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

[Formula 4]

(In equation (1),

Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;

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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.

R each independently represents an alkyl group, alkenyl group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group.

m1, m2, and m5 each independently represent 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 from 0 to 4.

a4 represents an integer of 0 or 1.

However, if a3 is 4, a4 is 0.

For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. 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 atoms. does not work.)

[Formula 5]

(In equation (2) or (3),

Asterisk (*) indicates combination with equation (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. )

<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 to 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), <9> to <12> The aromatic compound according to any one of the above.

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

<15> The aromatic compound according to <14>, wherein L ¹ to L ⁵ are each independently a 1,3-phenylene group which may have a substituent.

<16> The aromatic compound according to any one of <9> to <15>, wherein the molecular weight is 1200 or more.

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

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

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

[Formula 6]

(In equation (250),

W each independently represents CH or N, and at least one W is N.

Xa ¹ , Ya ¹ , and Za ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent.

Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. indicates.

g11, h11, and j11 each independently represent an integer from 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 Xa ¹ 's may be the same or different.

When h11 is 2 or more, multiple Ya ¹ 's may be the same or different.

When j11 is 2 or more, multiple Za ¹ 's 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, respectively.)

[Formula 7]

(In equation (240),

Ar ⁶¹¹ and Ar ⁶¹² each independently represent a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

R ⁶¹¹ and R ⁶¹² each independently represent a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

n ⁶¹¹ and n ⁶¹² are each independently integers from 0 to 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) is N.

<22> The composition according to <19>, wherein Ar ⁶¹¹ and Ar ⁶¹² in the formula (240) are each independently a monovalent group in which a plurality of benzene rings, which may have a substituent, are bonded in a chain or branched form.

<23> The composition according to <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.

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

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

<26> A method of manufacturing an organic electroluminescent 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 electroluminescent element, 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 of manufacturing an organic electroluminescent device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode, comprising:

The organic layer includes a light-emitting layer and an electron transport layer,

A step of forming the light emitting layer by a wet film forming method using the composition according to any one of <17> to <24>;

A method of manufacturing an organic electroluminescent device, comprising forming the electron transport layer by a wet film forming method using a composition for forming an electron transport layer containing an electron transport material and a solvent.

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

<30> An organic electroluminescent device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,

The organic layer includes a light emitting layer,

The light emitting layer contains the aromatic compound, phosphorescent material, and charge transport material according to any one of <9> to <16>,

An organic electroluminescent element in which the charge transport material contains a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

[Formula 8]

(In equation (250),

W each independently represents CH or N, and at least one W is N.

Xa ¹ , Ya ¹ , and Za ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent.

Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. indicates.

g11, h11, and j11 each independently represent an integer from 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 Xa ¹ 's may be the same or different.

When h11 is 2 or more, multiple Ya ¹ 's may be the same or different.

When j11 is 2 or more, multiple Za ¹ 's 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, respectively.)

[Formula 9]

(In equation (240),

Ar ⁶¹¹ and Ar ⁶¹² each independently represent a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

R ⁶¹¹ and R ⁶¹² each independently represent a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

n ⁶¹¹ and n ⁶¹² are each independently integers from 0 to 4.)

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

<32> The organic electroluminescent device according to <31>, wherein all W in the formula (250) is N.

According to the present invention, it is possible to provide an aromatic compound that is excellent in heat resistance and solvent solubility and has a large band gap.

The aromatic compound of the present invention also has excellent solvent resistance to alcohol-based solvents in thin films. For this reason, it is also possible to laminate and form a separate layer on the film containing the aromatic compound of the present invention by a wet film forming method.

The present invention provides an organic electroluminescent device containing the aromatic compound, a display device and a lighting device including the organic electroluminescent device, a composition containing the compound and a solvent, a thin film formation method, and a method for producing the organic electroluminescent device. can do.

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

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described in detail. The present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

In the present invention, “may have a substituent” means that it may have one or more substituents.

[Aromatic compounds related 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)”).

[Formula 10]

(In equation (1),

Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;

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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.

R is each 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 represent 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 from 0 to 4.

a4 represents an integer of 0 or 1.

However, if a3 is 4, a4 is 0.

For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. each 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 aromatic group. It is a 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 atoms. does not work.)

[Formula 11]

(In equation (2) or (3),

Asterisk (*) indicates combination with equation (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.)

<Mechanism of action by aromatic compound (1)>

In the present invention, the mechanism of action by which the effective effect is obtained by the aromatic compound (1) is estimated as follows.

Since the aromatic compound (1) has one or more terphenyl groups bonded at the para position represented by formula (2) or (3), the glass transition temperature is high.

The terphenyl group bonded at the para position represented by formula (2) or (3) is bonded to formula (1) at the ortho or meta position, suppressing diffusion of the π conjugate system, increasing the band gap, and increasing the triplet energy level here. (T1) increases, solubility becomes high and crystallinity becomes low.

When the aromatic hydrocarbon structure represented by formula (1) has a terphenyl group bonded at the para position represented by formula (2) or (3), the solvent resistance to alcohol-based solvents in the thin film can be improved.

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 have a terphenyl group bonded at the para position represented by formula (2) or (3). It is easy to localize and can improve durability.

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 low driving voltage and high efficiency.

The organic electroluminescent device of the present invention containing an aromatic compound (1) has excellent electrochemical stability and high efficiency due to low driving voltage. Therefore, the organic electroluminescent device of the present invention can be used as a light source that takes advantage of the characteristics of 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 surface light emitter (for example, It is expected to be applied to light sources for copiers, backlight light sources for liquid crystal displays and instruments), display boards, signs, etc., and its technical value is great.

<Ar ¹ , Ar ² , Ar ⁵ >

Ar ¹ , Ar ² and Ar ⁵ each independently represent a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a hydrogen atom or a substituent.

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, it is preferable that Ar ¹ , Ar ² and Ar ⁵ each independently have a structure represented by formula (3).

[Formula 12]

(In equation (2) or (3),

Asterisk (*) indicates combination with equation (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 , Ar ² and Ar ⁵ are, from the viewpoint of the solubility and durability of the compound, a hydrogen atom, a monovalent group of a benzene ring, a monovalent group of a naphthalene ring, or a structure represented by formula (2) or (3) above. Preferred, a hydrogen atom, a monovalent group of a benzene ring, and a structure represented by the formula (2) or (3) above are more preferable, and a hydrogen atom, a monovalent group of a benzene ring, and a structure represented by the formula (3) are more preferable. More preferably, the structure represented by the above formula (3) is most preferable.

From the viewpoint of durability, it is preferable that 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 have a structure represented by the formula (2) or (3) above. And, it is especially preferable that these have a structure represented by the above formula (3).

<Ar ³ , Ar ⁴ >

Ar ³ and Ar ⁴ each independently represent a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent.

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, benzoanthracene ring, perylene ring, and A monovalent group of a phenyl ring or a terphenyl ring can be mentioned.

From the viewpoint of the solubility and durability of the compound, 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, and more preferably a hydrogen atom or a monovalent group of a benzene ring. do.

<L ¹ to L ⁵ >

L ¹ to L ⁵ each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.

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, benzoanthracene ring, or perylene ring, Alternatively, a divalent group in which two or more of these aromatic hydrocarbon rings are connected by a direct bond may be mentioned.

L ¹ to L ⁵ each independently are preferably a phenylene group or a divalent group of two or more phenylene groups, for example, 2 to 5 phenylene groups connected by a direct bond, which may have a substituent, and are preferably 1, A 3-phenylene group is more preferable from the viewpoint of solubility.

<R>

R is each 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, which will be published later.

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

<m1 ~ m5>

m1, m2 and m5 each independently represent an integer from 0 to 5,

m3 and m4 each independently represent an integer of 1 to 5.

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

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

When m1 is 2 or more, a plurality of L ¹ may be the same or different. When m2 is 2 or more, the plurality of ^L2 's may be the same or different. When m3 is 2 or more, a plurality of L ³ may be the same or different. When m4 is 2 or more, plural ^L4 's may be the same or different. When m5 is 2 or more, a plurality of L ⁵ may be the same or different.

<Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ⁵ -(L ⁵ ) _m5 ->

Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ⁵ -(L ⁵ ) _m5 -, from the viewpoint of durability of the compound, at least one of the above formula (2) or formula (3) ) is preferable, at least one structure is more preferably represented by the formula (3), at least two structures are more preferably represented by the formula (3), and at least three structures are more preferably represented by the formula (3). The structure represented by is more preferable, and the structure represented by the above formula (3) is even more preferable.

Ar ¹ -(L ¹ ) _m1 -, Ar ² -(L ² ) _m2 -, Ar ³ -(L ³ ) _m3 -, and Ar ⁴ -(L ⁴ ) _m4 - are all hydrogen atoms.

<(L ³ ) _m3 , (L ⁴ ) _m4 >

At least one of (L ³ ) _m3 and (L ⁴ ) _m4 has a partial structure represented by the following formula (11), a partial structure represented by the following formula (12), and the following formula ( 13) It is preferable to have at least one partial structure selected from the partial structures represented by .

[Formula 13]

In each of the above formulas (11) to (13), * represents a bond to an adjacent structure or the hydrogen atom when Ar ³ and Ar ⁴ are hydrogen atoms. At least one of the two * indicates a bonding position with 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 have a partial structure represented by Formula (11) and a partial structure represented by Formula (12), respectively.

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

[Formula 14]

The partial structure represented by formula (12) is more preferably the partial structure represented by the following formula (12-3).

[Formula 15]

From the viewpoint of solvent solubility and durability of the compound, it is preferable that at least one of (L ³ ) _m3 and (L ⁴ ) _m4 have the partial structure, which has the partial structure represented by formula (11) and the partial structure represented by formula (12). Partial structures can be mentioned.

The partial structure having the partial structure represented by formula (11) and the partial structure represented by formula (12) includes a plurality of structures selected from 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) is more preferable.

[Formula 16]

A structure containing a plurality of structures selected from the partial structure represented by formula (11) and the partial structure represented by formula (12) means, for example, the partial structure represented by formula (14) is expressed as formula (14a) below. It is a partial structure that can be considered to have one partial structure represented by (11) and two partial structures represented by equation (12).

[Formula 17]

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

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

[Formula 18]

The partial structure represented by formula (14) is more preferably the partial structure represented by the following formula (14-3).

[Formula 19]

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

[Formula 20]

The partial structure represented by formula (15) is more preferably the partial structure represented by the following formula (15-3).

[Formula 21]

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

[Formula 22]

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

[Formula 23]

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

[Formula 24]

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

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

<Preferred partial structures of L ¹ to L ⁵ >

In formula (1), L ¹ to L ⁵ preferably have a partial structure represented by formula (12-3), a partial structure represented by formula (14-3), or a partial structure represented by formula (15-3) .

<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 especially preferably 4 or less.

<a1 ∼ a4>

a1 and a2 each independently represent an integer of 0 to 3.

a3 represents an integer from 0 to 4.

a4 represents an integer of 0 or 1.

However, if a3 is 4, a4 is 0.

From the viewpoint of solubility and durability of the compound, the following combinations of a1 to a4 are preferable.

a1 = a2 = a4 = 0, also a3 = integer from 0 to 4;

a1 = a2 = a4 = 0, also a3 = 0 or 1 ;

a1 = a2 = a3 = a4 = 0 ;

a4 = 1, also a1 = a2 = a3 ;

a4 = 1, and a1 to a3 are each independently integers from 0 to 3;

a4 = 1, and a1 to a3 are each independently 0 or 1;

a4 = 1, also a1 = a2 = a3 = 0 or 1;

More preferably,

a1 = a2 = a3 = a4 = 0 ;

a4 = 1, also a1= a2 = a3 = 0

am.

That is, a1 to a3 are each independently preferably 0 or 1, and 0 is most preferable from the viewpoint of solubility and durability of the compound.

<R ¹ to R ²⁶ >

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, which will be published later.

From the viewpoint of durability, 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 is preferable, a hydrogen atom or an aromatic hydrocarbon group is more preferable, and a hydrogen atom is especially preferable.

<Substituent>

For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. each 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 aromatic group. It is a hydrocarbon group, and is preferably each independently an alkyl group, alkenyl group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group.

The substituents that Ar ¹ to Ar ⁵ , L ¹ to L ⁵ may have, the above-mentioned R, and R ¹ to R ²⁶ specifically include the substituents described in the substituent group Z below.

<Substituent group Z>

Substituent group Z is 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, cyano group, Ar. It is a substituent group consisting of an alkyl group and an aromatic hydrocarbon group.

Alkyl groups include, for example, methyl group, ethyl group, branched, straight-chain or cyclic propyl group, branched, straight-chain or cyclic butyl group, branched, straight-chain or cyclic pentyl group, branched, straight-chain or cyclic group. A cyclic 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, etc., usually has 1 or more carbon atoms, preferably Examples of linear, branched, or cyclic alkyl groups include 4 or more, usually 24 or less, preferably 10 or less. From the viewpoint of compound stability, a methyl group, an ethyl group, a branched, straight-chain or cyclic propyl group, and a branched, straight-chain or cyclic butyl group are preferred, and branched propyl groups are particularly preferred.

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

Examples of the alkynyl group include alkynyl groups such as an ethynyl group, where the carbon number is usually 2 or more and usually 24 or less, preferably 12 or less.

Examples of the alkoxy group include alkoxy groups such as methoxy groups and ethoxy groups, where the number of carbon atoms is usually 1 or more and usually 24 or less, preferably 12 or less.

Examples of the aryloxy group include an aryloxy group or heteroaryl group, such as a phenoxy group, naphthoxy group, or pyridyloxy group, having a carbon number of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less. Oxygen groups can be mentioned.

Examples of the alkoxycarbonyl group include alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, where the carbon number is usually 2 or more and usually 24 or less, preferably 12 or less.

Examples of the acyl group include acyl groups such as acetyl group and benzoyl group, which usually have 2 or more carbon atoms and usually 24 or less carbon atoms, preferably 12 or less carbon atoms.

Examples of the halogen atom include halogen atoms such as a fluorine atom and a chlorine atom.

Examples of the haloalkyl group include haloalkyl groups such as trifluoromethyl group, which usually have 1 or more carbon atoms and usually 12 or less carbon atoms, preferably 6 or less carbon atoms.

Examples of the alkylthio group include alkylthio groups such as methylthio groups and ethylthio groups, where the carbon number is usually 1 or more and usually 24 or less, preferably 12 or less.

Examples of the arylthio group include arylthio groups or hetero groups, such as phenylthio groups, naphthylthio groups, and pyridylthio groups, that have a carbon number of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less. Examples include arylthio groups.

Examples of the silyl group include silyl groups such as trimethylsilyl group and triphenylsilyl group, which have a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less.

Examples of the siloxy group include siloxy groups such as trimethylsiloxy group and triphenylsiloxy group, which have a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less.

Examples of aralkyl groups include benzyl group, 2-phenylethyl group, 2-phenylpropyl-2-yl group, 2-phenylbutyl-2-yl group, 3-phenylpentyl-3-yl group, and 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. Examples include aralkyl groups where the carbon number is usually 7 or more, preferably 9 or more, and usually 30 or less, preferably 18 or less, and more preferably 10 or less.

The aromatic hydrocarbon group usually has 6 or more carbon atoms, such as a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzoanthracene ring, or perylene ring. and an aromatic hydrocarbon group that is usually 30 or less, preferably 18 or less, and more preferably 10 or less.

Among the substituent group Z, an alkyl group, an alkoxy group, an aralkyl group, and an aromatic hydrocarbon group are preferable, and more preferably, an alkyl group with 10 or less carbon atoms, an aralkyl group with 30 or less carbon atoms, and an aromatic hydrocarbon group with 30 or less carbon atoms, More preferably, it is an aromatic hydrocarbon group with 30 or less carbon atoms, and especially preferably, it is a group that does not have a substituent.

Each substituent in the above substituent group Z may further have a substituent. As these additional substituents, the same ones as the above substituents (substituent group Z) can be used. It is preferable that the substituents of the substituent group Z do not have additional 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, and more preferably 4000. or less, particularly preferably 3000 or less, and most preferably 2000 or less.

<Specific example>

Specific examples of the aromatic compound (1) are shown below, but the present invention is not limited to these.

[Formula 25]

[Formula 26]

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

<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 the organic layer of an organic electroluminescent element, and this 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 a wet film forming method. The organic layer containing the aromatic compound (1) is particularly preferably formed by a wet film forming method because a more uniform film can be formed.

[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).

[Formula 36]

(In equation (1),

Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;

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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.

R each independently represents an alkyl group, alkenyl group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group.

m1, m2, and m5 each independently represent 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 from 0 to 4.

a4 represents an integer of 0 or 1.

However, if a3 is 4, a4 is 0.

For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. 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 atoms. does not work.)

[Formula 37]

(In equation (2) or (3),

Asterisk (*) indicates combination with equation (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. )

The aromatic compound of the present invention is a substituent that may be possessed by an aromatic hydrocarbon group having a monovalent carbon number of 6 or more and 60 or less for R in formula (1), Ar ¹ to Ar ⁵ , and a divalent carbon number of 6 for L ¹ to L ⁵ As mentioned above, except that the substituents that the aromatic hydrocarbon group may have of 60 or less and R ¹ to R ²⁶ in formulas (2) and (3) are more limited than those in the aromatic compound (1), the aromatic compound (1) It is the same as in , and the explanation for the aromatic compound (1) described above applies.

Preferred aspects and specific examples of the aromatic compound of the present invention are the same as those for aromatic compound (1).

[Composition]

When forming an organic layer containing the aromatic compound of the present invention into a wet film, at least a composition containing the aromatic compound of the present invention represented by the above formula (1) and an organic solvent is deposited into a wet film. The composition of the present invention contains at least the aromatic compound and organic solvent of the present invention.

The composition of the present invention may contain only one type of the aromatic compound of the present invention, or may contain two or more types.

The composition of the present invention preferably further comprises a luminescent material, preferably a phosphorescent material, and a charge transport material. The composition of the present invention is preferably 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 to form a 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 as 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, dichlorobenzene, and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2, Aromatic ethers such as 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 pencone; 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 ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); etc. can be mentioned.

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

These organic solvents may be used individually, 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, and more preferably 330°C or lower. If the boiling point of the organic solvent is below this range, film formation stability may decrease due to solvent evaporation from the composition during wet film formation. If the boiling point of the organic solvent exceeds this range, during wet film formation, film formation stability may decrease due to solvent residue after film formation.

In particular, a uniform coating film can be produced by combining two or more of the above organic solvents with a boiling point of 150°C or higher. It is thought that if there is one or less organic solvents with a boiling point of 150°C or higher, a uniform film may not be formed during application.

<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 additionally contain a light-emitting material. The light-emitting 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 luminescent material, known materials can be applied, and fluorescent luminescent materials or phosphorescent luminescent materials can be used individually or in combination. From the viewpoint of internal quantum efficiency, it is preferably a phosphorescent material.

(phosphorescent material)

A phosphorescent material refers to a material that emits light from a triplet excited state. For example, metal complex compounds having Ir, Pt, Eu, etc. are representative examples, and it is preferable that the material structure includes a metal complex.

Among metal complexes, it is a phosphorescent organic metal complex that emits light via a triplet state, and has a long periodic table (hereinafter, unless otherwise specified, the term “periodic table” refers to the long periodic table). A Werner-type complex or organometallic complex compound containing a metal selected from Groups 7 to 11 as a central metal can be mentioned. As such a phosphorescent material, a compound represented by the following formula (201) or a compound represented by the formula (205) described later is preferable, and more preferably, it is a compound represented by the following formula (201).

[Formula 38]

In the formula (201), M is a metal selected from groups 7 to 11 of the periodic table, examples of which include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and europium. there is.

Ring A1 represents an aromatic hydrocarbon ring structure that may have a substituent or an aromatic heterocyclic ring structure that may have a substituent.

Ring A2 represents an aromatic heterocyclic ring structure that may have a substituent.

R ²⁰¹ and R ²⁰² are each independently a structure represented by the above formula (202), and “*” indicates the bonding position with ring A1 or ring A2. R ²⁰¹ and R ²⁰² may be the same or different. When R ²⁰¹ and R ²⁰² each exist in plural numbers, they may be the same or different.

In formula (202), Ar ²⁰¹ and Ar ²⁰³ each independently represent an aromatic hydrocarbon ring structure that may have a substituent, or an aromatic heterocyclic ring structure that may have a substituent.

Ar ²⁰² represents an aromatic hydrocarbon ring structure that may have a substituent, an aromatic heterocyclic ring structure that may have a substituent, or an aliphatic hydrocarbon structure that may have a substituent.

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 bond with 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 atoms constituting a ring. L ²⁰⁰ represents a single bond or an atomic group that together with B ²⁰¹ and B ²⁰² constitutes a bidentate ligand. When there is a plurality of B ²⁰¹ -L ²⁰⁰ -B ²⁰² , they may be the same or different.

In equations (201) and (202),

i1 and i2 each independently represent an integer between 0 and 12.

i3 is an integer greater than or equal to 0, with the upper limit being the number that can be replaced by Ar ²⁰² .

j is an integer greater than or equal to 0 with the upper limit being the number that can be replaced with Ar ²⁰¹ .

k1 and k2 are each independently an integer of 0 or more that sets the upper limit on the number of rings that can be substituted for ring A1 and ring A2.

m is an integer from 1 to 3.

The aromatic hydrocarbon ring in ring A1 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms, and specifically includes a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an acenaphthene ring, a fluoranthene ring, Fluorene rings are preferred.

The aromatic heterocycle in ring A1 is preferably an aromatic heterocycle with 3 to 30 carbon atoms containing any of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably a furan ring or a benzoyl ring. They are a furan ring, a thiophene ring, and a benzothiophene ring.

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

The aromatic heterocycle in ring A2 is preferably an aromatic heterocycle with 3 to 30 carbon atoms containing any of 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, benzoimidazole ring, quinoline ring, isoquinoline. ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring,

More preferably, they are a pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, and quinazoline ring,

More preferably, they are a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, and a quinazoline ring,

Most preferably, they are a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, a quinoxaline ring, and a quinazoline ring.

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

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

When Ar ²⁰¹ , Ar ²⁰² , or Ar ²⁰³ is an aromatic hydrocarbon ring structure that may have a substituent, the aromatic hydrocarbon ring structure is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms,

Specifically, a benzene ring, naphthalene ring, anthracene ring, triphenylyl ring, acenaphthene ring, fluoranthene ring, and fluorene ring are preferred,

More preferably, it is a benzene ring, a naphthalene ring, or a fluorene ring,

Most preferably it is a benzene ring.

When Ar ²⁰¹ , Ar ²⁰² , or Ar ²⁰³ is a fluorene ring that may have a substituent, the 9-position and 9' positions of the fluorene ring preferably have a substituent or are bonded to an adjacent structure.

When Ar ²⁰¹ , Ar ²⁰² , or Ar ²⁰³ is a benzene ring that may have a substituent, it is preferable that at least one benzene ring is bonded to a structure adjacent to the ortho or meta position, and at least one benzene ring is It is more preferable that it is bound to a structure adjacent to the meta position.

When Ar ²⁰¹ , Ar ²⁰² , or Ar ²⁰³ is an aromatic heterocyclic ring structure that may have a substituent, the aromatic heterocyclic ring structure preferably contains any of a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom. , is an aromatic heterocycle having 3 to 30 carbon atoms,

Specifically, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzoimidazole ring, quinoline ring, isoquinoline. ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring,

Preferably, they are a pyridine ring, pyrimidine ring, triazine ring, carbazole ring, dibenzofuran ring, and dibenzothiophene ring.

When Ar ²⁰¹ , Ar ²⁰² , or Ar ²⁰³ is a carbazole ring that may have a substituent, the N position of the carbazole ring preferably has a substituent or is bonded to an adjacent structure.

When Ar ²⁰² is an aliphatic hydrocarbon structure that may have a substituent, the aliphatic hydrocarbon structure is an aliphatic hydrocarbon structure having a straight chain, branched chain, or cyclic structure, and is preferably an aliphatic hydrocarbon structure with a carbon number of 1 to 24, More preferably, it is an aliphatic hydrocarbon having 1 to 12 carbon atoms, and even more preferably an aliphatic hydrocarbon having 1 to 8 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, improvement in solubility and charge transport are expected.

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

j Preferably represents an integer of 0 to 2, and is 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, further preferably 1 or 2, and especially preferably 1.

The substituent that Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ may have can be selected arbitrarily, but is preferably one or more types of substituents selected from the substituent group S described later, and more preferably a hydrogen atom, an alkyl group, or an aryl group. , especially 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 with 1 to 20 carbon atoms, more preferably an alkyl group with 1 to 12 carbon atoms, further preferably an alkyl group with 1 to 8 carbon atoms, particularly preferably an alkyl group with 1 to 6 carbon atoms.

- An alkoxy group, preferably an alkoxy group with 1 to 20 carbon atoms, more preferably an alkoxy group with 1 to 12 carbon atoms, and even more preferably an alkoxy group with 1 to 6 carbon atoms.

An aryloxy group, preferably an aryloxy group with 6 to 20 carbon atoms, more preferably an aryloxy group with 6 to 14 carbon atoms, even more preferably an aryloxy group with 6 to 12 carbon atoms, particularly preferably with 6 carbon atoms. Aryloxy group.

-Heteroaryloxy group, preferably a heteroaryloxy group having 3 to 20 carbon atoms, more preferably a heteroaryloxy group having 3 to 12 carbon atoms.

-Alkylamino group, preferably an alkylamino group having 1 to 20 carbon atoms, more preferably an alkylamino group having 1 to 12 carbon atoms.

- Arylamino group, preferably an arylamino group with 6 to 36 carbon atoms, more preferably an arylamino group with 6 to 24 carbon atoms.

- An aralkyl group, preferably an aralkyl group with 7 to 40 carbon atoms, more preferably an aralkyl group with 7 to 18 carbon atoms, even more preferably an aralkyl group with 7 to 12 carbon atoms.

- A heteroaralkyl group, preferably a heteroaralkyl group with 7 to 40 carbon atoms, more preferably a heteroaralkyl group with 7 to 18 carbon atoms.

An alkenyl group, preferably an alkenyl group with 2 to 20 carbon atoms, more preferably an alkenyl group with 2 to 12 carbon atoms, even more preferably an alkenyl group with 2 to 8 carbon atoms, particularly preferably an alkenyl group with 2 to 6 carbon atoms. .

- An alkynyl group, preferably an alkynyl group with 2 to 20 carbon atoms, more preferably an alkynyl group with 2 to 12 carbon atoms.

An aryl group, preferably an aryl group with 6 to 30 carbon atoms, more preferably an aryl group with 6 to 24 carbon atoms, even more preferably an aryl group with 6 to 18 carbon atoms, particularly preferably an aryl group with 6 to 14 carbon atoms. .

A heteroaryl group, preferably a heteroaryl group with 3 to 30 carbon atoms, more preferably a heteroaryl group with 3 to 24 carbon atoms, even more preferably a heteroaryl group with 3 to 18 carbon atoms, particularly preferably 3 to 30 carbon atoms. 14 heteroaryl group.

- An alkylsilyl group, preferably an alkylsilyl group in which the alkyl group has 1 to 20 carbon atoms, more preferably an alkylsilyl group in which the alkyl group has 1 to 12 carbon atoms.

· 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.

· Arylcarbonyl group, preferably an arylcarbonyl group having 7 to 20 carbon atoms.

In the above group, one or more hydrogen atoms may be substituted with a fluorine atom, or one or more hydrogen atoms may be substituted with a deuterium atom.

·Hydrogen atom, deuterium atom, fluorine atom, 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 groups S,

Preferably, alkyl group, alkoxy group, aryloxy group, arylamino group, aralkyl group, alkenyl group, aryl group, heteroaryl group, alkylsilyl group, arylsilyl group, and groups in which at least one hydrogen atom of these groups is substituted with a fluorine atom. , a fluorine atom, a cyano group, or -SF ₅ ,

More preferably, it is an alkyl group, arylamino group, aralkyl group, alkenyl group, aryl group, heteroaryl group, a group in which at least one hydrogen atom of these groups is replaced with a fluorine atom, a fluorine atom, a cyano group, or -SF ₅ ,

More preferably, they are 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 group, arylamino group, aralkyl group, alkenyl group, aryl group, and heteroaryl group,

Most preferably, they are an alkyl group, arylamino group, aralkyl group, aryl group, and heteroaryl group.

These substituent groups S may further have a substituent selected from the substituent group S as a substituent. The preferred group, more preferred group, further preferred group, particularly preferred group, and most preferred group of the substituents that may be included are the same as the preferred groups in substituent group S.

(Preferred structure of equation (201))

Among the structures represented by the formula (202) in the formula (201), (i) a structure having a group linked to a benzene ring, (ii) an aromatic hydrocarbon group or an aromatic heterocycle in which an alkyl group or aralkyl group is bonded to ring A1 or ring A2. A structure having a group, (iii) a structure in which a dendron is bonded to ring A1 or ring A2 is preferable.

(i) In the structure having a group to which a benzene ring is linked, Ar ²⁰¹ is a benzene ring structure, i1 is 1 to 6, and at least one of the benzene rings is linked to a structure adjacent to the ortho or meta position.

This structure is expected to improve solubility and charge transport properties.

(ii) In the structure having an aromatic hydrocarbon group or an aromatic heterocyclic group to which an alkyl group or 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, and Ar ²⁰² is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, Ar ²⁰³ is a benzene ring structure, and i3 is 0 or 1.

In the case of this structure, Ar ²⁰¹ is preferably the aromatic hydrocarbon structure described above, more preferably a structure in which 1 to 5 benzene rings are linked, and even more preferably one benzene ring.

This structure is expected to improve solubility and charge transport properties.

(iii) In the structure where a dendron is bonded to ring A1 or ring A2, Ar ²⁰¹ and Ar ²⁰² are a benzene ring structure, Ar ²⁰³ is a biphenyl or terphenyl structure, i1 and i2 are 1 to 6, and i3 is 2, and j is 2.

This structure is expected to improve solubility and charge transport properties.

In the above formula (201), among the structures represented by B ²⁰¹ -L ²⁰⁰ -B ²⁰² , the structure represented by the following formula (203) or (204) is preferable.

[Formula 39]

In the above formula (203), R ²¹¹ , R ²¹² , and R ²¹³ represent a substituent.

The substituent is not particularly limited, but is preferably a group selected from the above substituent group S.

[Formula 40]

In the formula (204), ring B3 represents an aromatic heterocyclic ring structure containing a nitrogen atom that may have a substituent. Ring B3 is preferably a pyridine ring.

The substituent that ring B3 may have is not particularly limited, but is preferably a group selected from the above substituent group S.

The phosphorescent material represented by the above formula (201) is not particularly limited, but specifically includes the following structures.

Hereinafter, Me means a methyl group and Ph means a phenyl group.

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

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

[Formula 45]

In formula (205), M ² 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, R ⁹⁴ and R ⁹⁵ do not exist.

In formula (205), M ² represents a metal. Specific examples include metals selected from groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold are preferred, and divalent metals such as platinum and palladium are particularly preferred.

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

In addition, when T is a carbon atom, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same example as R ⁹² and R ⁹³ . When T is a nitrogen atom, R ⁹⁴ or R ⁹⁵ directly bonded to T does not exist.

R ⁹² to R ⁹⁵ may further have a substituent. As the substituent, the above substituents exemplified as R ⁹² and R ⁹³ can be used. Additionally, any two or more groups among R ⁹² to R ⁹⁵ may be connected to each other to form a ring.

(Molecular Weight)

The molecular weight of the phosphorescent material is preferably 5000 or less, more preferably 4000 or less, and particularly preferably 3000 or less. The molecular weight of the phosphorescent material is usually 1000 or more, preferably 1100 or more, and more preferably 1200 or more. It is believed that within this molecular weight range, the phosphorescent materials do not agglomerate and are uniformly mixed with the compound of the present invention and/or other charge transport materials to obtain a light emitting layer with high luminescence efficiency.

The molecular weight of the phosphorescent material has a high Tg, melting point, and decomposition temperature, and the heat resistance of the phosphorescent material and the formed light-emitting layer is excellent, and it is resistant to degradation of film quality or thermal decomposition of the material due to gas generation, recrystallization, and migration of molecules, etc. A larger size is preferable in that it is difficult for an accompanying increase in impurity concentration to occur. The molecular weight of the phosphorescent material is preferably small to facilitate 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 is preferable to contain a charge transport material as an additional host material in addition to the aromatic compound of the present invention.

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

Skeletons with excellent charge transport properties include, specifically, aromatic structure, aromatic amine structure, triarylamine structure, dibenzofuran structure, naphthalene structure, phenanthrene structure, phthalocyanine structure, porphyrin structure, thiophene structure, benzylphenyl structure, Fluorene structure, quinacridone structure, triphenylene structure, carbazole structure, pyrene structure, anthracene structure, phenanthroline structure, quinoline structure, pyridine structure, pyrimidine structure, triazine structure, oxadiazole structure or imidazole structure. structure, etc.

As the electron transport material, compounds having a pyridine structure, a pyrimidine structure, and/or a triazine structure, which have excellent electron transport properties and a relatively stable structure, are more preferable, and compounds having a pyrimidine structure and/or a triazine structure are more preferable. This is more preferable. Particularly preferred is a compound represented by formula (250) described later.

A hole transport material is a compound having a structure excellent in hole transport, and among the skeletons excellent in charge transport, a carbazole structure, a dibenzofuran structure, a triarylamine structure, a naphthalene structure, a phenanthrene structure, or a pyrene structure has hole transport properties. It is preferable as an excellent structure, 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, it contains a compound represented by the formula (250) described later and/or a compound represented by the formula (240) described later as an additional host material. It is desirable. It is preferable to include such a material as an additional host material from the viewpoint of adjusting the charge balance in the light-emitting layer and from the viewpoint of luminous efficiency.

The charge transport 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 is a compound having two or more condensed ring structures of three or more rings or a compound having at least one condensed ring of five or more rings. It is more desirable. By using these compounds, the rigidity of the molecules increases, making it easier to obtain the effect of suppressing the degree of molecular movement in response to heat. In addition, it is preferable that the condensed ring of three or more rings and the condensed ring of five or more rings have an aromatic hydrocarbon ring or an aromatic heterocycle from the viewpoint of charge transport properties and durability of the material.

Condensed ring structures of three or more rings specifically include anthracene structure, phenanthrene structure, pyrene structure, chrysene structure, naphthacene structure, triphenylene structure, fluorene structure, benzofluorene structure, and indenofluorene structure. , indolofluorene structure, carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, dibenzothiophene structure, etc.

In terms of charge transport and solubility, it consists 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. At least one selected from the group is preferred. From the viewpoint of durability against electric charge, a carbazole structure or an indolocarbazole structure is more preferable.

The charge transport material used as the host material of the light-emitting layer is preferably a polymer material from the viewpoint of excellent flexibility. A light-emitting layer formed using a material with excellent flexibility is preferable as a light-emitting layer of an organic electroluminescent device formed on a flexible substrate. When the charge transport material used as the host material included in the light-emitting layer is a polymer 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, and even more preferably 10,000 or more and 100,000 or less.

The charge transport material used as the host material of the light-emitting layer is preferably low molecule from the viewpoints of ease of synthesis and purification, ease of designing electron transport performance and hole transport performance, and ease of viscosity adjustment when dissolved in a solvent. When the charge transport 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, most preferably 2,000 or less, and usually It is 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 1000 or more, more preferably 1100 or more, and particularly preferably 1200 or more.

<Compound represented by formula (250)>

[Formula 46]

(In equation (250),

W each independently represents CH or N, and at least one W is N.

Xa ¹ , Ya ¹ , and Za ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent.

Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. indicates.

g11, h11, and j11 each independently represent an integer from 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 Xa ¹ 's may be the same or different.

When h11 is 2 or more, multiple Ya ¹ 's may be the same or different.

When j11 is 2 or more, multiple Za ¹ 's 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, respectively.)

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, and at least one of them is N. From the viewpoint of electron transport properties and electron durability, it is preferable that at least two of W are N, and it is more preferable that all of them are N.

<Xa ¹ , Ya ¹ , Za ¹ , Xa ² , Ya ² , Za ² >

In formula ⁽ 250), when Xa ¹ , Ya ¹ , and Za ¹ are divalent aromatic hydrocarbon groups having 6 to ³⁰ carbon atoms that may have ^a substituent, and In the case of a 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 preferably a single 6-membered ring or a 2 to 5 condensed ring. Specifically, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, fluoranthene ring, An indenofluorene ring, etc. can be mentioned. Among them, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, or a fluorene ring is preferable, a benzene ring, a naphthalene ring, a phenanthrene ring, or a fluorene ring is more preferable, and even more preferably a benzene ring, It is a naphthalene ring or a fluorene ring.

In formula (250 ⁾ , when Xa ¹ , Ya ¹ , and Za ¹ are divalent aromatic heterocyclic groups having 3 to ³⁰ carbon atoms which may have ^a substituent, and In the case of a 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 is preferably a single ring of 5 or 6 membered rings or a 2 to 5 fused ring. Specifically, a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, Carbazole ring, indolocarbazole ring, indenocarbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring , thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzoimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring. , quinoxaline ring, perimidine ring, quinazoline ring, quinazolinone ring, etc. Among them, a thiophene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and an indole. It is a locarbazole ring, a phenanthroline ring, or an indenocarbazole ring, 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 dibenzofuran ring. It is a benzothiophene ring, and more preferably a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring.

In the formula (250 ^{) ,} for Xa ¹ , Ya ^{1 ,} Za ¹ , Particularly preferred aromatic heterocycles are carbazole rings, dibenzofuran rings, or dibenzothiophene rings.

(g11, h11, j11)

g11, h11, and j11 each independently represent 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 transport properties and durability, it is preferable that g11 is 2 or more, or that at least one of h11 and j11 is 3 or more.

The compound represented by formula (250) includes a ring having three W at the center, and preferably has a total of 8 to 18 rings from the viewpoint of charge transport properties, durability, and solubility in organic solvents.

(R ³¹ )

R ³¹ in the case of a substituent is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. From the viewpoint of improved durability and charge transport properties, it is more preferable that R ³¹ is an aromatic hydrocarbon group that may have a substituent. When there are two or more R ³¹ in the case of a substituent, they may be different from each other.

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

(Substituent group Z2)

Substituent group Z2 is 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, an arylthio group. , a group consisting of a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. These substituents may have any of linear, branched, and cyclic structures.

More specifically, the substituent group Z2 includes 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 straight-chain, branched, or cyclic alkyl group having a carbon number of usually 1 or more, preferably 4 or more, 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 such as a methoxy group or an ethoxy group, which has a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less;

For example, an aryloxy group or heteroaryloxy group having a carbon number of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, such as a phenoxy group, naphthoxy group, and pyridyloxy group;

For example, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, which have a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less;

For example, dialkylamino groups such as dimethylamino group and diethylamino group, which have a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less;

For example, diarylamino groups such as diphenylamino group and ditolylamino group, which have a carbon number of usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less;

For example, an arylalkylamino group such as phenylmethylamino group, which usually has 7 or more carbon atoms and usually has 36 or less carbon atoms, preferably 24 or less carbon atoms;

For example, an acyl group such as an acetyl group or benzoyl group, which has a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less;

For example, halogen atoms such as fluorine atom and chlorine atom;

For example, a haloalkyl group such as a trifluoromethyl group, which usually has 1 or more carbon atoms and usually has 12 or less carbon atoms, preferably 6 or less carbon atoms;

For example, alkylthio groups such as methylthio groups and ethylthio groups, which have a carbon number of usually 1 or more and usually 24 or less, preferably 12 or less;

For example, an arylthio group having a carbon number of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, such as a phenylthio group, naphthylthio group, and pyridylthio group;

For example, silyl groups having a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less, such as trimethylsilyl group and triphenylsilyl group;

For example, a siloxy group having a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less, such as a trimethylsiloxy group or triphenylsiloxy group;

Cyano group;

For example, aromatic hydrocarbon groups, such as phenyl group and naphthyl group, usually having 6 or more carbon atoms and usually 36 or less, preferably 24 or less;

For example, aromatic heterocyclic groups such as thienyl group and pyridyl group, which have a carbon number of usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less.

Among the above substituent group Z2, an alkyl group, an alkoxy group, a diarylamino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group is preferable. From the viewpoint of charge transport properties, the substituent is more preferably an aromatic hydrocarbon group or an aromatic heterocyclic group, more preferably an aromatic hydrocarbon group, and it is especially preferable that the substituent has no substituent. From the viewpoint of improving solubility, an alkyl group or an alkoxy group is preferable as the substituent.

Each substituent in the above substituent group Z2 may further have a substituent. Those substituents include the same substituents as the above (substituent group Z2). Each substituent that the substituent group Z2 may have is preferably an alkyl group with 8 or less carbon atoms, an alkoxy group with 8 or fewer carbon atoms, or a phenyl group, more preferably an alkyl group with 6 or fewer carbon atoms, an alkoxy group with 6 or fewer carbon atoms, or It is a phenyl group. It is more preferable that each substituent of the substituent group Z2 does not have an additional substituent from the viewpoint of charge transport properties.

(Molecular Weight)

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

(Specific examples of compounds represented by formula (250))

The compound represented by formula (250) is not particularly limited, but examples include the following compounds.

[Formula 47]

[Formula 48]

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

<Compound represented by formula (240)>

[Formula 49]

(In equation (240),

Ar ⁶¹¹ and Ar ⁶¹² each independently represent a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

R ⁶¹¹ and R ⁶¹² each independently represent a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

n ⁶¹¹ and n ⁶¹² are each independently integers from 0 to 4.)

(Ar ⁶¹¹ , Ar ⁶¹² )

Ar ⁶¹¹ and Ar ⁶¹² each independently represent a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

The carbon number of the aromatic hydrocarbon group is usually 6 to 50, preferably 6 to 30, and more preferably 6 to 18. The aromatic hydrocarbon group specifically includes a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzoanthracene ring, or perylene ring, and the number of carbon atoms is usually 6 or more. and a monovalent group of an aromatic hydrocarbon structure, which is usually 30 or less, preferably 18 or less, more preferably 14 or less, or a monovalent group of a structure in which a plurality of structures selected from these structures are combined in a chain or branched form. . When a plurality of aromatic hydrocarbon rings are connected, a structure in which 2 to 8 rings are connected is usually included, and a structure in which 2 to 5 rings are connected is preferable. When multiple aromatic hydrocarbon rings are connected, the same structure may be connected, or different structures may be connected.

Ar ⁶¹¹ and Ar ⁶¹² are preferably each independently,

phenyl group,

A monovalent group in which multiple benzene rings are combined in a chain or branched form,

A monovalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a chain or branched form,

A monovalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a chain or branched form, or

A monovalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a chain or branched form,

, and these may have substituents. More preferably, it is a monovalent group in which a plurality of benzene rings are chained or branched. In either case, the order of combination does not matter.

It is particularly preferable that Ar ⁶¹¹ and Ar ⁶¹² are each independently a monovalent group in which a plurality of benzene rings, which may have substituents, are bonded in a chain or branched form, and each independently, a plurality of benzene rings are in a chain or branched form. It is most preferable that it is a bonded monovalent group.

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

These aromatic hydrocarbon groups may have a substituent. The substituents that the aromatic hydrocarbon group may have can be selected from the substituent group Z2 described above. Preferred substituents are those of the above-described 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 solubility and durability of the compound.

[Formula 50]

In each of the above formulas (72-1) to (72-7), * represents a bond to an adjacent structure or a hydrogen atom. At least one of the two * indicates a bonding position with 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 (72-7).

More preferably, Ar ⁶¹¹ and Ar ⁶¹² each have at least one partial structure selected from formulas (72-1) to (72-3) and (72-7).

Particularly preferably, Ar ⁶¹¹ and Ar ⁶¹² each have at least one partial structure selected from formula (72-1), formula (72-2) and formula (72-7).

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

[Formula 51]

More preferably, the formula (72-2) is the following formula (72-2-3).

[Formula 52]

In addition, from the viewpoint of solubility and durability of the compound, the partial structure that is preferably possessed by at least one of Ar ⁶¹¹ and Ar ⁶¹² includes the partial structure represented by formula (72-1) and the partial structure represented by formula (72-2). there is.

(R ⁶¹¹ , R ⁶¹² )

R ⁶¹¹ and R ⁶¹² each independently represent a halogen atom such as a deuterium atom or a fluorine atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

Preferably, it is a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

The aromatic hydrocarbon group is more preferably a monovalent group of an aromatic hydrocarbon ring having 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, and particularly preferably 6 to 10 carbon atoms.

The monovalent aromatic hydrocarbon group is specifically the same as Ar ⁶¹¹ above, and the preferred aromatic hydrocarbon group is the same, and 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 can be specifically selected from the substituent group Z2 described above. Preferred substituents are those of the above-described substituent group Z2.

(n ⁶¹¹ , n ⁶¹² )

n ⁶¹¹ and n ⁶¹² are each independently integers from 0 to 4. n ⁶¹¹ and n ⁶¹² are each independently preferably 0 to 2, and more preferably 0 or 1.

(substituent)

When Ar ⁶¹¹ , Ar ⁶¹² , R ⁶¹¹ , and R ⁶¹² are monovalent or divalent aromatic hydrocarbon groups, the substituent they may have is preferably a substituent selected from the above-mentioned substituent group Z2.

(G)

G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

The carbon number of the aromatic hydrocarbon group of G is usually 6 to 50, preferably 6 to 30, and more preferably 6 to 18. The aromatic hydrocarbon group specifically includes a benzene ring, naphthalene ring, anthracene ring, tetraphenylene ring, phenanthrene ring, chrysene ring, pyrene ring, benzoanthracene ring, or perylene ring, and the number of carbon atoms is usually 6 or more. and a divalent group having an aromatic hydrocarbon structure, which is usually 30 or less, preferably 18 or less, more preferably 14 or less, or a divalent group having a structure in which a plurality of structures selected from these structures are bonded in a chain or branched form. . When a plurality of aromatic hydrocarbon rings are connected, a structure in which 2 to 8 rings are connected is usually used, and a structure in which 2 to 5 rings are connected is preferable. When multiple aromatic hydrocarbon rings are connected, the same structure may be connected, or different structures may be connected.

G is preferably,

single bond,

phenylene group,

A divalent group in which multiple benzene rings are joined in a chain or branched form,

A divalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a chain or branched form,

A divalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a chain or branched form, or

A divalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a chain or branched form,

And, more preferably, it is a divalent group in which a plurality of benzene rings are bonded in a chain or branched form. In either case, the order of combination does not matter.

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

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

(Molecular Weight)

The compound represented by the above formula (240) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, further preferably 2,000 or less, especially preferably 1,500 or less, and usually 300 or more, Preferably it is 350 or more, more preferably 400 or more.

(Specific examples of compounds represented by formula (240))

Below, preferred specific examples of the compound represented by formula (240) are shown, but the present invention is not limited to these.

[Formula 53]

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

<Other ingredients>

In addition to the organic solvent and luminescent material described above, the composition of the present invention may contain various other solvents as needed. Examples of other such solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethyl sulfoxide.

The composition of the present invention may contain various additives such as a leveling agent and an antifoaming agent.

The composition of the present invention contains a photocurable resin or a thermosetting resin for the purpose of curing and insolubilizing the film after film formation in order to prevent these layers from miscible when laminating two or more layers by a wet film forming method. You can do it.

<Mixing ratio>

The solids concentration in the composition of the present invention (the concentration of all solids including the aromatic compound of the present invention, the light-emitting material, host materials other than the aromatic compound of the present invention, and components that can be added as needed (leveling agent, etc.)) is usually 0.01 mass% or more, preferably 0.05 mass% or more, more preferably 0.1 mass% or more, further preferably 0.5 mass% or more, most preferably 1 mass% or more, usually 80 mass% or less, preferably 80 mass% or less. It is 50 mass% or less, more preferably 40 mass% or less, further preferably 30 mass% or less, and most preferably 20 mass% or less.

If the solid content concentration is within this range, it is preferable because it is easy to form a thin film of the desired film thickness with a uniform thickness.

The preferred mixing ratio of the aromatic compound of the present invention and the light-emitting material to all host materials contained in the composition of the present invention, that is, the light-emitting layer formed using the composition of the present invention (hereinafter sometimes referred to as the “light-emitting layer of the present invention”) .) The preferable mixing ratio of the compound of the invention and the light-emitting material relative to all host materials contained in is as follows. In addition, 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 100 mass of the entire host material is usually 1 or more, preferably 5 or more, more preferably 10 or more, even more preferably is 15 or more, usually 90 or less, preferably 80 or less, more preferably 70 or less, and especially preferably 50 or less.

In the composition of the present invention and the 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, and more preferably 10 mol% or more, Particularly preferably, it is 15 mol% or more, usually 90 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, and 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 mass of the entire host material is usually 0.1 or more, preferably 0.5 or more, more preferably 1 or more, particularly preferably 2 or more. and is usually 100 or less, preferably 60 or less, more preferably 50 or less, and particularly preferably 40 or less. If this ratio is less than the above lower limit or exceeds the above upper limit, there is a risk that the luminous efficiency will significantly decrease.

<Method for preparing composition>

The composition of the present invention includes the aromatic compound of the present invention, a luminescent material such as the above-described phosphorescent material, if necessary, a charge transport material, a host material other than the aromatic compound of the present invention, and a leveling agent or anti-foaming agent that can be added as needed. It is prepared by dissolving the solute consisting of various added components in the appropriate organic solvent described above.

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

<Properties of the composition, physical properties, etc.>

(moisture concentration)

When an organic electroluminescent element is manufactured by forming a layer by a wet film forming method using the composition of the present invention, if moisture is present in the composition, moisture is incorporated into the formed film, thereby impairing the uniformity of the film. For this reason, it is preferable that the moisture content in the composition of the present invention is as small as possible. Additionally, in general, organic electroluminescent devices use many materials that are significantly deteriorated by moisture, such as cathodes. Therefore, if moisture is present in the composition, the moisture will remain in the film after drying, which may deteriorate the properties of the device. Considering the possibility, it is not desirable.

Specifically, the moisture content 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 moisture concentration in the composition, the method described in the Japanese Industrial Standards "Method for measuring moisture in chemical products" (JIS K0068: 2001) is preferable. For example, it can be analyzed by the Curl Fisher 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 increase stability in a wet film formation process, for example, ejection stability from a nozzle in an inkjet film formation method. A uniform liquid phase at room temperature means that the composition is a liquid consisting of a homogeneous phase and that the composition does not contain particle components with a particle size of 0.1 μm or more.

(Properties)

If the viscosity of the composition of the present invention is extremely low, for example, drawing unevenness due to excessive liquid film flow in the film forming process, nozzle discharge defects in inkjet film forming, etc. are likely to occur. When the viscosity of the composition of the present invention is extremely high, nozzle clogging during inkjet film formation is likely to occur.

For this reason, 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 it is 100 mPa·s or less, more preferably 50 mPa·s or less.

When the surface tension of the composition of the present invention is high, problems such as reduced wettability to the substrate, poor leveling properties of the liquid film, and the tendency for the film-forming surface to become disturbed during drying may occur.

For this reason, the surface tension of the composition of the present invention at 20°C 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 changes in solute concentration due to evaporation of the organic solvent may easily occur.

For this reason, the vapor pressure of the composition of the present invention at 25°C is usually 50 mmHg or less, preferably 10 mmHg or less, and 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 of forming a film by applying a composition to form a liquid film and drying it to remove the organic solvent. When the composition of the present invention contains a light-emitting material, a light-emitting layer can be formed by this method. Application methods include, for example, spin coat method, dip coat method, die coat method, bar coat method, blade coat method, roll coat method, spray coat method, capillary coat method, inkjet method, nozzle printing method, This refers to a method of forming a film by employing a wet film forming method such as screen printing, gravure printing, or flexo printing, and drying the coating film. Among these film forming methods, spin coating method, spray coating method, inkjet method, nozzle printing method, etc. are preferable. When manufacturing an organic EL display device equipped with an organic electroluminescent element, the inkjet method or nozzle printing method is preferable, and the inkjet method is particularly preferable.

The drying method is not particularly limited, but natural drying, reduced pressure drying, heat drying, or reduced pressure drying with heating can be used as appropriate. Heat drying may be performed to further remove residual organic solvents after natural drying or reduced pressure drying.

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

In the case of heat drying, the heating method is not particularly limited, but heating with a hot plate, heating in an oven, infrared heating, etc. can be used.

The heating temperature is usually 80°C or higher, preferably 100°C or higher, more preferably 110°C or higher, preferably 200°C or lower, and more preferably 150°C or lower.

The heating time is usually 1 minute or more, preferably 2 minutes or more, usually 60 minutes or less, preferably 30 minutes or less, and more preferably 20 minutes or less.

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

The composition for forming an electron transport layer used when forming an 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 a solvent for this composition for forming an electron transport layer, an alcohol-based solvent (a solvent having an alcoholic hydroxyl group) is preferable because the aromatic compound of the present invention is poorly soluble and has excellent solvent resistance. Moreover, as the electron transport layer material of the composition for forming the electron transport layer, an electron transport material soluble in such an alcohol-based solvent is preferable.

As the alcohol-based solvent, an aliphatic alcohol having 3 or more carbon atoms is preferable.

Aliphatic alcohols with 6 or more carbon atoms are more preferable because they easily dissolve electron-transporting materials, have a moderately high boiling point, and are easy to form a flat film.

Aliphatic alcohols preferred as alcohol-based solvents include 1-butanol, isobutyl alcohol, 2-hexanol, 1-hexanol, 1-heptanol, 2-methyl-2-pentanol, and 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. can be mentioned. These alcohol-based solvents may be used in mixture of two or more types.

It is preferable to use the wet film formation method described in the method of forming the light-emitting layer above as the method for forming the electron transport layer by the wet film formation method.

[Organic electroluminescent device]

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

<Substrate>

The substrate 1 serves as a support for the organic electroluminescent element, and usually a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, etc. are used. Among these, glass plates and plates of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferable. The substrate is preferably made of a material with high gas barrier properties because deterioration of the organic electroluminescent element due to external air is unlikely to occur. For this reason, especially when using a material with low gas barrier properties, such as a synthetic resin substrate, it is desirable to increase the gas barrier properties by forming a dense silicon oxide film on at least one side of the substrate.

<Anode>

The anode 2 serves the function of injecting holes into the layer on the light-emitting layer 5 side.

Anode (2) Metals such as silver, cylindrical, aluminum, gold, silver, nickel, palladium, and platinum; Metal oxides such as oxides of indium and/or tin; Halogenated metals such as copper iodide; It is composed of carbon black and conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

The formation of the anode 2 is usually performed by dry methods such as sputtering and vacuum deposition. When 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 can be formed by dispersing them in a suitable binder resin solution and applying it on a substrate. It may be possible. Additionally, in the case of conductive polymers, a thin film can be formed directly on the substrate by electrolytic polymerization, or the anode can be formed by applying the conductive polymer on the substrate (Appl. Phys. Lett., Vol. 60, Page 2711, 1992 year).

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

The thickness of the anode 2 may be determined depending on the required transparency, material, etc. In particular, when high transparency is required, a thickness with a visible light transmittance of 60% or more is preferable, and a thickness with a visible light transmittance of 80% or more is more preferable. In this case, the thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably 500 nm or less. When transparency is not required, the thickness of the anode 2 may be arbitrarily determined depending on the required strength, etc. In this case, the anode 2 may have the same thickness as the substrate.

When forming another layer on the surface of the anode 2, impurities on the anode 2 are removed and the ionization potential is adjusted by performing treatment with ultraviolet rays/ozone, oxygen plasma, argon plasma, etc. before forming the film. Thus, it is desirable to improve hole injection properties.

<Hole injection layer>

The layer responsible for transporting holes from the anode 2 side to the light emitting layer 5 side is usually called a hole injection and transport layer or a hole transport layer. When there are two or more layers responsible for transporting 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 because it enhances 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 is 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 forming method. In terms of excellent film forming properties, it is preferable to form by a wet film forming method.

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

The composition for forming a hole injection layer usually contains a hole transport compound for the hole injection layer that becomes the hole injection layer (3). In the case of a wet film forming method, the composition for forming a hole injection layer usually further contains an organic solvent. The composition for forming a hole injection layer preferably has high hole transport properties and is capable of efficiently transporting injected holes. For this reason, it is desirable that the hole mobility is high and that impurities that become traps are unlikely to be generated during manufacturing or use. Additionally, it is desirable to have excellent stability, small ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable not to quench the light emission from the light-emitting layer or to form an exciplex with the light-emitting layer and not reduce the light emission efficiency.

As the hole transport compound for the hole injection layer, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable from the viewpoint of the 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, compounds in which a tertiary amine is linked to a fluorene group, Hydrazone-based compounds, silazane-based compounds, quinacridone-based compounds, etc. can be mentioned.

Among the above-mentioned exemplary compounds, aromatic amine compounds are preferable, and aromatic tertiary amine compounds are particularly preferable from the viewpoint of amorphousness and visible light transparency. Here, the aromatic tertiary amine compound refers to a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from an aromatic tertiary amine.

The type of aromatic tertiary amine compound is not particularly limited, but because it is easy to obtain uniform light emission due to the surface smoothing effect, a polymer compound (polymerized compound with continuous repeating units) with a weight average molecular weight of 1,000 or more and 1,000,000 or less is used. It is desirable to use

When forming the hole injection layer 3 by a wet film formation method, the material forming the hole injection layer 3 is usually mixed with an organic solvent (solvent for the hole injection layer) capable of dissolving the film forming composition (hole injection). A composition for layer formation) is prepared. The hole injection layer 3 is formed by applying this composition for forming a hole injection layer on the layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2), forming a film, and drying it.

The concentration of the hole-transporting compound in the composition for forming a hole injection layer is arbitrary as long as it does not significantly impair the effect of the present invention, but in terms of film thickness uniformity, it is preferable to be low, and the concentration of the hole-transporting compound in the hole injection layer 3 is Since defects are less likely to occur, a higher value is preferable. Specifically, it is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, particularly preferably 0.5 mass% or more, while it is preferable that it is 70 mass% or less, more preferably 60 mass% or less, and 50 mass% or more. It is especially preferable that it is % by mass or less.

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

Ether-based solvents include, for example, aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA), and 1,2-dimethoxybenzene, 1,3- Aromatic ethers such as dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole. You can.

Examples of the ester-based solvent 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, and methylnaphthalene. etc. can be mentioned.

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

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

The formation of the hole injection layer 3 by a wet film formation method usually involves preparing a composition for forming the hole injection layer, and then applying this to a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2). This is carried out by applying a film onto the surface and drying it.

After the hole injection layer 3 is formed, the coating film is usually dried by heating or reduced-pressure drying.

When forming the hole injection layer 3 by a vacuum deposition method, usually one or two or more types of constituent materials of the hole injection layer 3 are placed in a crucible installed in a vacuum container (two or more types of materials are used) In this case, each is usually placed in a different crucible), and the inside of the vacuum container is evacuated to about 10 ^-4 Pa with a vacuum pump. Afterwards, the crucible is heated (when using two or more types of materials, usually by heating each crucible) and evaporated while controlling the evaporation amount of the material in the crucible (when using two or more types of materials, usually by heating each crucible). evaporate while independently controlling the evaporation amount), and form a hole injection layer (3) on the anode (2) on the substrate (1) placed facing the crucible. When two or more types of materials are used, the hole injection layer 3 can be formed by placing their mixture in a crucible, heating and evaporating it.

The degree of vacuum during deposition is not limited as long as it does not significantly impair the effect of the present invention, but is usually 0.1 × 10 ^-6 Torr (0.13 × 10 ^-4 Pa) or more, 9.0 × 10 ^-6 Torr (12.0 × 10 ^-4 Pa) or less. The deposition rate is not limited as long as it does not significantly impair the effect of the present invention, but is usually 0.1 Å/sec or more and 5.0 Å/sec or less. The film formation temperature during vapor deposition is not limited as long as it does not significantly impair the effect of the present invention, 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. Although the hole transport layer 4 is not an essential layer in the organic electroluminescent device of the present invention, 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. do. 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. When 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.

The material forming the hole transport layer 4 is preferably a material that has high hole transport properties and can efficiently transport injected holes. Therefore, it is desirable that the ionization potential is small, the transparency to visible light is high, the hole mobility is high, the stability is excellent, and impurities that become traps are unlikely to be generated during production or use. In addition, in many cases, since the hole transport layer 4 is in contact with the light-emitting layer 5, it quenches light emission from the light-emitting layer 5 or forms an exciplex between the light-emitting layer 5 and reduces efficiency. It is advisable not to do this.

The material of the hole transport layer 4 may be any material that has conventionally been used as a constituent material of the hole transport layer, and examples include those exemplified as the hole transport compound used in the hole injection layer 3 described above. there is. In addition, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silol derivatives, and oligothiamine derivatives. Examples include ophene derivatives, condensed polycyclic aromatic derivatives, and metal complexes.

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

Among them, polyarylamine derivatives and polyarylene derivatives are preferable.

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 of the repeating units.

[Formula 54]

(In formula (II), Ar ^a and Ar ^b each independently represent an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent.)

Examples of polyarylene derivatives include polymers having an arylene group in the repeating unit, such as an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent.

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

[Formula 55]

(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, an alkoxyphenyl group, or an alkyl group. Represents a carbonyl group, an alkoxycarbonyl group, or a carboxyl group. t and s each independently represent an integer from 0 to 3. When t or s is 2 or more, a plurality of R ^a or R ^b contained in one molecule may be the same. They may be different, and adjacent R ^a or R ^b may form a ring.)

[Formula 56]

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

Specific examples of It is a carbon atom that may have a substituent or a group formed by combining them.

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

[Formula 57]

(In formula (III-3), Ar ^c to Ar ⁱ each independently represent an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that may have a substituent. v and w each independently represent 0 or It represents 1.)

Specific examples of the above formulas (III-1) to (III-3) and polyarylene derivatives include those described in Japanese Patent Application Laid-Open No. 2008-98619.

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

The composition for forming a hole transport layer contains an organic solvent in addition to the hole transport compound described above. The organic solvent used is the same as that used in the composition for forming the hole injection layer. Film formation conditions, heating and drying conditions, etc. are also the same as those for forming the hole injection layer 3.

In the case of forming the hole transport layer 4 by vacuum deposition, the film formation conditions, etc. are the same as those in the case of forming the hole injection layer 3.

The hole transport layer 4 may contain various light-emitting materials, electron transport compounds, binder resins, coating improvers, etc. in addition to the hole transport compounds. Therefore, the composition for forming a hole transport layer may contain various light-emitting materials, electron transport compounds, binder resin, coating improver, etc. in addition to the hole transport compound.

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

Examples of this crosslinkable group include groups derived from cyclic ethers such as oxetane and epoxy; Groups derived from unsaturated double bonds such as vinyl group, trifluorovinyl group, styryl group, acrylic group, methacryloyl group, and cinnamoyl group; Groups derived from benzocyclobutene, etc. can be mentioned.

The crosslinkable compound may be any of monomers, oligomers, and polymers. The crosslinkable compound may have only one type or two or more types in any combination and ratio.

As the crosslinkable compound, it is preferable to use a hole transporting compound having a crosslinkable group.

Examples of the hole transporting compounds having a crosslinkable group include those exemplified above, and examples of the crosslinkable compounds include those in which the crosslinkable group is bonded to the main chain or side chain of these hole transporting compounds. You can. In particular, it is preferable that the crosslinkable group is bonded to the main chain through a linking group such as an alkylene group. In particular, the hole transport compound is preferably a polymer containing a repeating unit having a crosslinkable group, and the repeating unit represented by the formula (II) or formulas (III-1) to (III-3) contains a crosslinkable group. It is preferable that it is a polymer having repeating units bonded directly or through a linking group.

In order to form the hole transport layer 4 by crosslinking a crosslinkable compound, a composition for forming a hole transport layer is usually prepared by dissolving or dispersing the crosslinkable compound in an organic solvent, and then forming a film by a wet film forming method to crosslink it.

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.

<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 when the hole injection layer 3 is on the anode 2. In the case where the hole transport layer 4 is on the anode 2, the light emitting layer 5 is formed between the hole transport layer 4 and the cathode 7.

The light-emitting layer 5 contains at least a material (light-emitting material) having light-emitting properties, and preferably contains one or more host materials.

The light-emitting layer 5 of the organic electroluminescent element in the present invention is formed by a wet film forming method using the composition of the present invention as described above.

The light emitting layer formed using the composition of the present invention preferably contains the aromatic compound, the phosphorescent material, and the charge transport material of the present invention, and the charge transport material is a compound represented by the formula (250) and/or the formula (250). Includes compounds represented by (240).

The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effect of the present invention, but a thicker film is preferable because defects are less likely to occur in the film, while a thinner film is preferable because it is easier to achieve a low driving voltage. . The film thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, while it is preferably 200 nm or less, and more preferably 100 nm or less.

<Hole blocking layer>

A hole blocking layer may be formed between the light emitting layer 5 and the electron injection layer 6 described later. The hole blocking layer is a layer laminated on the light emitting layer (5) so as to be in contact with the interface on the cathode (7) side of the light emitting layer (5).

The hole blocking layer has a role of preventing holes moving from the anode 2 from reaching the cathode 7 and a role of efficiently transporting electrons injected from the cathode 7 in the direction of 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 a high triplet excitation level (T ₁ ). I can hear it.

Materials for the hole blocking layer that satisfy these conditions include, for example, bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato). Mixed ligand complex such as (triphenylsilanolato)aluminum, bis(2-methyl-8-quinolinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum 2 nucleus Metal complexes such as metal complexes, styryl compounds such as distyryl biphenyl derivatives (Japanese Patent Application Laid-Open No. 11-242996), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl) Triazole derivatives such as phenyl)-1,2,4-triazole (Japanese Patent Application Laid-Open No. 7-41759), phenanthroline derivatives such as vasocuproin (Japanese Patent Application Laid-Open No. 10-79297), etc. can be mentioned. Additionally, compounds having at least one pyridine ring substituted at the 2, 4, and 6 positions described in International Publication No. 2005/022962 are 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 wet film formation method, 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 effect of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and is usually 100 nm or less, preferably 50 nm or less.

<Electron transport layer>

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

The electron transporting compound used in the electron transport layer 6 specifically includes metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Application Laid-Open No. 59-194393), and 10-hydroxybenzo[h]. Metal complex of quinoline, oxadiazole derivative, distyrylbiphenyl derivative, silol derivative, 3-hydroxy flavone metal complex, 5-hydroxy flavone metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimida Zolylbenzene (US Patent No. 5645948 specification), quinoxaline compound (Japanese Patent Application Laid-open No. 6-207169), phenanthroline derivative (Japanese Patent Application Laid-Open No. 5-331459), 2-tert-butyl-9, Examples include 10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

The electron transport layer 6 is formed by laminating it on the hole blocking layer by a wet film forming method or a vacuum deposition method in the same manner as above. Usually, a vacuum deposition method is 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 film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

<Electron injection layer>

In order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5, an electron injection layer may be formed between the electron transport layer 6 and the cathode 7.

In order to perform electron injection efficiently, the material forming the electron injection layer is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium.

The film thickness of the electron injection layer is usually preferably 0.1 nm or more and 5 nm or less.

In addition, organic electron transport materials such as nitrogen-containing heterocyclic compounds such as vasophenanthroline and metal complexes such as aluminum complexes of 8-hydroxyquinoline are doped with alkali metals such as sodium, potassium, cesium, lithium, and rubidium. (Described in Japanese Patent Application Laid-Open No. 10-270171, Japanese Patent Application Publication No. 2002-100478, Japanese Patent Application Publication No. 2002-100482, etc.) It is also preferable because electron injection and transport properties are improved, making it possible to achieve both excellent film qualities. do.

The film thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and is 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 electron transport layer 6 thereon by a wet film forming method or a vacuum evaporation method.

The details of the wet film forming method are the same as those of the above-mentioned light emitting layer.

In some cases, the hole blocking layer, the electron transport layer, and the electron injection layer are formed into one layer by manipulating the electron transport material and the lithium complex co-dope.

<Cathode>

The cathode 7 serves to inject electrons into a layer (electron injection layer or light emitting layer, etc.) on the light emitting layer 5 side.

As the material for the cathode 7, it is possible to use the material used for the above-mentioned anode 2. In order to efficiently inject electrons, it is desirable 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 their alloys, etc. are used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

In terms of stability of the organic electroluminescent device, it is desirable to protect the cathode made of a low work function metal by laminating a metal layer with a high work function and stable to the atmosphere on the cathode. Examples of metals to be laminated include 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 floors>

The organic electroluminescent device of the present invention may further have other layers as long as the effect of the present invention is not significantly impaired. That is, between the anode and the cathode, you may have any of the other layers described above.

<Other element configuration>

The organic electroluminescent device of the present invention has a structure opposite to the above description, that is, for example, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light emitting layer, a hole transport layer, a hole injection layer, They can also be laminated in the order of the anodes.

When applying the organic electroluminescent element of the present invention 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, and an anode and It may be used in a configuration where the cathode is arranged in an X-Y matrix.

[Display device]

The display device (organic electroluminescent element display device: organic EL display device) of the present invention includes the organic electroluminescent element of the present invention. There are no particular restrictions on the form or structure of the organic EL display device of the present invention, and it can be assembled by conventional methods using the organic electroluminescent device of the present invention.

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

[Lighting device]

The lighting device (organic electroluminescent element lighting device: organic EL lighting device) of the present invention is equipped with the organic electroluminescent element of the present invention. There are no particular restrictions on the form or structure of the organic EL lighting device of the present invention, and it can be assembled by conventional methods using the organic electroluminescent device of the present invention.

The organic electroluminescent element of the present invention is used in display devices such as organic EL displays and lighting devices such as organic EL lighting. By the organic electroluminescent device of the present invention, for example, organic EL can be produced by the method described in “Organic EL Display” (Oumsa, published on August 20, 2004, by Shizuo Tokito, Chihaya Adachi, and Hideyuki Murata). A display can form organic EL lighting.

Example

Hereinafter, the present invention will be described in more detail through examples. The present invention is not limited to the following examples without departing from the gist thereof.

The values of various conditions and evaluation results in the examples below are meant as preferable upper or lower limits in the embodiments of the present invention, and the preferable ranges are those of the above-mentioned upper or lower limits and the following examples. It may be a range defined by a value or a combination of values between examples.

In this specification, Ac means an acetyl group, Ph means a phenyl group, dppf means 1,1'-bis(diphenylphosphino)ferrocene, and DMSO means dimethyl sulfoxide.

Comparative Compound 1 and Comparative Compound 2 were synthesized according to the method described in the above-mentioned Patent Document 1 (International Publication No. 2007/043357).

[Synthesis Example I-1: Synthesis example of compound (H-1)]

<Synthesis of Compound 1-c>

[Formula 58]

Under a nitrogen atmosphere, Compound 1-a (14.1 g, 30.4 mmol) and Compound 1-b (7.23 g, 20.3 mmol) were bubbled with nitrogen and added toluene (130 mL), ethanol (30 mL), and an aqueous solution of tripotassium phosphate ( 2.0 mol/L, 30 mL) were 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, saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with 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 (amount 9.0 g, yield 72%).

(Synthesis of Compound (H-1))

[Formula 59]

Under a nitrogen atmosphere, Compound 1-c (2.0 g, 3.26 mmol) and Compound 1-d (0.66 g, 1.63 mmol) were bubbled with nitrogen and added toluene (40 mL), ethanol (20 mL), and an aqueous solution of tripotassium phosphate ( 2.0 mol/L, 20 mL) were 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 5 hours. After cooling to room temperature, saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with 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) (amount 1.44 g, yield 72%).

[Synthesis Example I-2: Synthesis example of compound (H-2)]

<Synthesis of Compound 2-c>

[Formula 60]

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), and tripotassium phosphate aqueous solution (2.0 mol/L). , 65 mL) were sequentially added and heated to 50°C. After that, PdCl ₂ (PPh ₃ ) ₂ (0.37 g, 0.52 mmol) was added, and the mixture was stirred at 65°C for 2 hours. After cooling to room temperature, saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with 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 (amount 9.12 g, yield 75%).

<Synthesis of Compound 2-d>

[Formula 61]

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 the mixture was heated to 50°C. Heated. 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 filtered product was dissolved in toluene, washed with 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 (amount 8.0 g, yield 73%).

<Synthesis of Compound (H-2)>

[Formula 62]

Under a nitrogen atmosphere, compound 1-c (9.4 g, 15.4 mmol) and compound 2-d (3.9 g, 6.99 mmol) were bubbled with nitrogen and added toluene (60 mL), ethanol (30 mL), and an aqueous solution of tripotassium phosphate ( 2.0 mol/L, 30 mL) were 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, saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with 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) (amount 8.0 g, yield 83%).

[Synthesis Example I-3: Synthesis of Compound (H-3)]

<Synthesis of Compound 3-a>

[Formula 63]

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 the mixture was heated to 50°C. Heated. 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 filtered product was dissolved in toluene, washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was treated with silica gel column chromatography to obtain compound 3-a (amount 4.88 g, 98% yield).

<Synthesis of Compound (H-3)>

[Formula 64]

Under a nitrogen atmosphere, Compound 3-a (4.88 g, 7.39 mmol) and Compound 1-a (1.71 g, 3.69 mmol) were bubbled with nitrogen and added toluene (60 mL), ethanol (30 mL), and an aqueous solution of tripotassium phosphate ( 2.0 mol/L, 30 mL) were sequentially added and heated to 60°C. After that, Pd(PPh ₃ ) ₄ (0.085 g, 0.074 mmol) was added, and the mixture was heated and stirred at 90°C for 3 hours. After cooling to room temperature, saturated aqueous sodium chloride solution was added, and extraction was performed using toluene. The organic layer was washed with 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) (amount 3.21 g, yield 63%).

[Evaluation of each compound]

Compounds (H-1), (H-2) and (H-3), which are aromatic compounds of the present invention synthesized in Synthesis Examples I-1 to 3, and comparative compound (C-1) and comparative compound For (C-2), the following evaluations were performed respectively.

[Formula 65]

<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 band gap (Eg) calculated from the absorption edge of the absorption spectrum.

The results are shown in Table 1.

<Evaluation of solvent solubility>

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 mass%), and determine whether each compound is dissolved in the solution. was evaluated.

Compounds (H-1), (H-2) and (H-3) of the present invention, like comparative compounds (C-1) and (C-2), have a solubility in CHB of 2.0% by mass or more. , showed good solubility.

<Evaluation of solvent resistance>

The solvent resistance of the obtained compound after film formation was evaluated as follows.

First, a solution was prepared in which the compound to be tested was dissolved in toluene at 1.5% by mass.

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, and 150 µL of test solvent was added dropwise onto the substrate. After the dropwise addition, the substrate was allowed to stand for 60 seconds to conduct a solvent resistance test. 1-Butanol was used as a test solvent.

After that, the substrate was rotated at 1500 rpm for 30 seconds and then at 4000 rpm for 30 seconds to spin out the dropwise solvent. This substrate was dried on a hot plate at 100°C for 10 minutes. The change in film thickness 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.

×: A decrease in film thickness in the range of 5 nm or more and less than 15 nm was observed.

××: The film melted and disappeared.

The results of the solvent resistance test are shown in Table 2.

From the above results, it can be seen that the aromatic compound of the present invention is not only excellent in heat resistance and solvent solubility, but also excellent in solvent resistance to alcohol-based solvents in thin films, and is a compound with a large band gap.

[Device Example II-1]

An organic electroluminescent device was manufactured by the following method.

An indium/tin oxide (ITO) transparent conductive film deposited to a thickness of 50 nm (manufactured by Geomatec, Inc., sputter-deposited product) on a glass substrate was patterned into stripes 2 mm wide using conventional photolithography techniques and hydrochloric acid etching. This formed an anode. The substrate on which the ITO pattern was formed in this way is cleaned in the following order: ultrasonic cleaning with an aqueous surfactant solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, followed by drying with compressed air, and finally ultraviolet ozone cleaning. was carried out.

As a composition for forming a hole injection layer, a composition was prepared by dissolving 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) in ethyl benzoate. did.

[Formula 66]

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

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 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. It was used as a transport layer.

[Formula 67]

Subsequently, as a material for the 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 compound (EH- 2) was dissolved in cyclohexylbenzene at a concentration of 1.15% by weight and the following compound (D-1) at a concentration of 1.4% by weight to prepare a composition for forming an emitting layer.

[Formula 68]

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

The substrate on which the light-emitting layer was formed was placed in a vacuum evaporation device, and the inside of the device was evacuated until the temperature became 2 x 10 ^-4 Pa or less.

Next, the following compound (ET-1) and 8-hydroxyquinolinolatrium were co-deposited on the light emitting layer using a vacuum evaporation method at a film thickness ratio of 2:3 to form an electron transport layer with a film thickness of 30 nm. .

[Formula 69]

Subsequently, a 2 mm wide striped shadow mask as a mask for cathode deposition was brought into close contact with the substrate so as to be perpendicular to the ITO stripe of the anode, and aluminum was heated with a molybdenum boat to form an aluminum layer with a film thickness of 80 nm. This formed a cathode.

As described above, an organic electroluminescent element having a light emitting area of 2 mm x 2 mm was obtained.

[Device Example II-2]

An organic electroluminescent device was prepared in the same manner as in Device Example II-1, except that 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 Compound (H-1). was manufactured.

[Device Example II-3]

An organic electroluminescent device was prepared in the same manner as in Device Example II-1, except that Compound (H-3) of the present invention synthesized in Synthesis Example I-3 was used as the material for the emitting layer instead of Compound (H-1). was manufactured.

[Device Comparative Example II-1]

An organic electroluminescent device was manufactured in the same manner as Device Example II-1, except that the previously disclosed comparative compound (C-2) was used as the material for the emitting layer instead of compound (H-1).

[Evaluation of device]

The current efficiency (cd/A) and external quantum efficiency (%) of the organic electroluminescent devices obtained in Device Examples II-1 to 3 and Device Comparative Example II-1 when emitting light at 1,000 cd/m 2 were measured. Additionally, when electricity was continuously supplied to the device at a current density of 15 mA/cm2, the time (LT95) for the luminance to decrease to 95% of the initial luminance was measured. These measurement results are shown in Table 3. In Table 3, the values of Device Examples II-1 to 3 represent relative values with the value of Device Comparative Example II-1 set to 1.

From the results in Table 3, it was found that performance was improved in the organic electroluminescent device using the aromatic compound of the present invention.

Although the present invention has been described in detail using specific embodiments, it is clear to those skilled in the art that various changes can be made without departing from the intent and scope of the present 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, which are incorporated by reference in their entirety.

1: substrate
2: anode
3: hole injection layer
4: hole transport layer
5: light emitting layer
6: electron transport layer
7: cathode
8: Organic electroluminescent device

Claims (32)

An organic electroluminescent device having an anode and a cathode on a substrate and an organic layer between the anode and the cathode,
An organic electroluminescent element in which the organic layer has a layer containing an aromatic compound represented by the following formula (1).

(In equation (1),
Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;
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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.
R is each 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 represent 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 from 0 to 4.
a4 represents an integer of 0 or 1.
However, if a3 is 4, a4 is 0.
For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. each 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 aromatic group. It is a 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 atoms. does not work.)

(In equation (2) or (3),
Asterisk (*) indicates combination with equation (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.) According to claim 1,
An organic electroluminescent element in which 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 formula (2) or (3). The method of claim 1 or 2,
An organic electroluminescent element in which L ¹ to L ⁵ each independently represent a phenylene group or a group of two or more phenylene groups linked, which may have a substituent. According to claim 3,
An organic electroluminescent element in which L ¹ to L ⁵ are each independently a 1,3-phenylene group which may have a substituent. The method according to any one of claims 1 to 4,
An organic electroluminescent device wherein the aromatic compound has a molecular weight of 1200 or more. The method according to any one of claims 1 to 5,
An organic electroluminescent device wherein the layer containing the aromatic compound is a light-emitting layer. A display device comprising the organic electroluminescent element according to any one of claims 1 to 6. A lighting device comprising the organic electroluminescent element according to any one of claims 1 to 6. An aromatic compound represented by the following formula (1).

(In equation (1),
Ar ¹ to Ar ⁵ are each independently a hydrogen atom or a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent;
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 each independently represent a divalent aromatic hydrocarbon group having 6 or more and 60 or less carbon atoms which may have a substituent.
R each independently represents an alkyl group, alkenyl group, aryloxy group, alkoxycarbonyl group, acyl group, halogen atom, haloalkyl group, silyl group, siloxy group, aralkyl group, or aromatic hydrocarbon group.
m1, m2, and m5 each independently represent 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 from 0 to 4.
a4 represents an integer of 0 or 1.
However, if a3 is 4, a4 is 0.
For Ar ¹ to Ar ⁵ , the substituent that may be included is a monovalent aromatic hydrocarbon group having 6 to 60 carbon atoms, and for L ¹ to L ⁵ the substituent that may be included is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms. 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 atoms. does not work.)

(In equation (2) or (3),
Asterisk (*) indicates combination with equation (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. ) According to clause 9,
An aromatic compound where a1, a2 and a4 are 0. According to clause 9,
An aromatic compound in which a4 is 1 and a3 is an integer of 0 to 3. According to claim 11,
An aromatic compound in which a1, a2 and a3 are the same. The method according to any one of claims 9 to 12,
An aromatic compound in which 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 formula (2) or (3). The method according to any one of claims 9 to 13,
An aromatic compound in which L ¹ to L ⁵ are each independently a phenylene group or a group of two or more phenylene groups linked, which may have a substituent. According to claim 14,
An aromatic compound in which L ¹ to L ⁵ are each independently a 1,3-phenylene group which may have a substituent. The method according to any one of claims 9 to 15,
An aromatic compound with 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. According to claim 17,
A composition further comprising a phosphorescent material and a charge transport material. According to claim 18,
A composition in which the charge transport material contains a compound represented by the following formula (250) and/or a compound represented by the following formula (240).

(In equation (250),
W each independently represents CH or N, and at least one W is N.
Xa ¹ , Ya ¹ , and Za ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent.
Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. indicates.
g11, h11, and j11 each independently represent an integer from 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 Xa ¹ 's may be the same or different.
When h11 is 2 or more, multiple Ya ¹ 's may be the same or different.
When j11 is 2 or more, multiple Za ¹ 's 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, respectively.)

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

(In equation (250),
W each independently represents CH or N, and at least one W is N.
Xa ¹ , Ya ¹ , and Za ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent.
Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. indicates.
g11, h11, and j11 each independently represent an integer from 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 Xa ¹ 's may be the same or different.
When h11 is 2 or more, multiple Ya ¹ 's may be the same or different.
When j11 is 2 or more, multiple Za ¹ 's 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, respectively.)

(In equation (240),
Ar ⁶¹¹ and Ar ⁶¹² each independently represent a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.
R ⁶¹¹ and R ⁶¹² each independently represent a deuterium atom, a halogen atom, or a monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.
G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.
n ⁶¹¹ and n ⁶¹² are each independently integers from 0 to 4.) According to claim 30,
An organic electroluminescent device wherein at least two of the three Ws in the formula (250) are N. According to claim 31,
An organic electroluminescent device wherein all W in the above formula (250) are N.

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