JP2009096771A - Diarylpyrene compound, material for organic electroluminescent device, composition for organic electroluminescent device, and organic electroluminescent device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound useful for an organic layer of an organic electroluminescent device, having high durability and affording a highly luminous organic electroluminescent device. <P>SOLUTION: A diarylpyrene compound is represented by the formula (wherein, Ar<SP>1</SP>and Ar<SP>2</SP>represent each an aromatic group which may have a substituent and is composed of a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring; X and Z represent each a ≤50C group which may have a substituent; R<SP>1</SP>and R<SP>2</SP>represent each H or a ≤50C group; X, Z, R<SP>1</SP>and R<SP>2</SP>do not comprise an arylamine structure and a straight-chain alkene structure; i and j are each an integer of ≥0 to ≤5; m and n represent each an integer of ≥1 to ≤5, with the proviso that i+j is ≥1; and a plurality of Ar<SP>1</SP>, Ar<SP>2</SP>, X or Z present in one molecule may each be same or different when i, j, m or n is each ≥2). Light can efficiently be emitted from a dopant using the pyrene compound as a host of a light-emitting layer of the organic electroluminescent device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diarylpyrene compound, a material for an organic electroluminescent element, a composition for an organic electroluminescent element, and an organic electroluminescent element. Specifically, the diarylpyrene compound which is stable and preferable for use as a host of the light emitting layer of the organic electroluminescent device, and a material for an organic electroluminescent device, a composition for an organic electroluminescent device using the same, and further, The present invention relates to an organic electroluminescent device having high color purity, high efficiency and long life.

In recent years, as a thin film type electroluminescent element, an organic electroluminescent element using an organic thin film has been developed instead of using an inorganic material. An organic electroluminescent element usually has a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and the like between an anode and a cathode, and materials suitable for these layers are being developed. Furthermore, the organic electroluminescent elements are also being developed for red, green and blue.
However, the blue light emitting element is not satisfactory in terms of efficiency, life, and heat resistance, and there is a problem that application to a full color display is limited.

For example, Patent Document 1 discloses a 4-substituted pyrene blue fluorescent material using a compound represented by the following formula.

  However, this compound is easy to overlap between molecules of the pyrene ring, easily forms an aggregate, and is difficult to use as a blue host material with high purity.

Patent Document 2 discloses a blue fluorescent material using a compound represented by the following formula.

  However, this compound has an amine structure having high activity as a substituent of the pyrene ring, and its durability as a host of an organic electroluminescence device was low.

JP 2004-0775567 A European Patent Office No. 1775335

  The present invention has been made in view of the above problems. That is, an object of the present invention is to provide a compound that is useful for an organic layer of an organic electroluminescent device and that can provide an organic electroluminescent device having high durability, high color purity, high light emission, and long life. To do.

  As a result of intensive studies by the present inventors, it was found that by introducing a specific substituent at positions 2 and 7 of the pyrene skeleton, a stable organic compound can be obtained even after repeated electrical oxidation and reduction, It has been found that by using this organic compound, an organic electroluminescent device, in particular, an organic electroluminescent device having high brightness, high efficiency and long life can be obtained, and the present invention has been achieved.

（式（１）中、Ａｒ¹およびＡｒ²は、各々独立に、置換基を有していてもよい、ピレン環由来の基及びフェナントロリン環由来の基以外の６員環からなる芳香族基を表わす。
Ｘ及びＺは、各々独立に置換基を有していてもよい炭素数５０以下の基を表わす。
Ｒ¹及びＲ²は、各々独立に水素原子または炭素数５０以下の基を表わす。
Ｘ、Ｚ、Ｒ¹及びＲ²は、アリールアミン構造及び直鎖アルケン構造を含まない。
ｉ及びｊは、各々独立に０以上５以下の整数であり、ｍ及びｎは、各々独立に１以上５以下の整数である。但しｉ＋ｊは１以上である。ｉ、ｊ、ｍまたはｎがそれぞれ２以上のとき、一分子内に複数存在するＡｒ¹、Ａｒ²、ＸまたはＺは、それぞれ同一であっても異なっていてもよい。） That is, the gist of the present invention resides in a diarylpyrene compound represented by the following formula (1) (claim 1).

(In the formula (1), Ar ¹ and Ar ² each independently represent an aromatic group composed of a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring, which may have a substituent. Represent.
X and Z each independently represent a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X, Z, R ¹ and R ² do not include an arylamine structure or a linear alkene structure.
i and j are each independently an integer of 0 or more and 5 or less, and m and n are each independently an integer of 1 or more and 5 or less. However, i + j is 1 or more. When i, j, m, or n is 2 or more, Ar ¹ , Ar ² , X, or Z present in a molecule may be the same or different. )

At this time, it is preferable that Ar ¹ and Ar ² are each independently any aromatic group selected from the group of the following formulas (2a) to (2l) (Claim 2).

  X and Z are preferably each independently an aromatic group.

（式（３−１）〜（３−６）中、Ｘ¹、Ｘ²、Ｚ¹およびＺ²は、各々独立に、置換基を有していてもよい炭素数５０以下の基を表わす。
Ｒ¹及びＲ²は、各々独立に水素原子または炭素数５０以下の基を表わす。
Ｘ¹、Ｘ²、Ｚ¹、Ｚ²、Ｒ¹及びＲ²は、アリールアミン構造及び直鎖アルケン構造を含まない。） Further, it is preferable that the diarylpyrene compound is represented by any one of the following formulas (3-1) to (3-6).

(In formulas (3-1) to (3-6), X ¹ , X ² , Z ¹ and Z ² each independently represents a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X ¹ , X ² , Z ¹ , Z ² , R ¹ and R ² do not include an arylamine structure or a linear alkene structure. )

At this time, it is preferable that X ¹ , X ² , Z ¹ and Z ² are each independently an aromatic group (Claim 5).

R ¹ and R ² are preferably hydrogen atoms (claim 6).

  Another subject matter of the present invention lies in an organic electroluminescent element material comprising the above-mentioned diarylpyrene compound (claim 7).

  Another gist of the present invention resides in a composition for an organic electroluminescent device comprising the diarylpyrene compound described above (claim 8).

  At this time, it is preferable that the composition for organic electroluminescent elements contains a solvent.

  Another gist of the present invention is an organic electroluminescent device having an anode, a cathode, and an organic light emitting layer provided between the two electrodes, characterized by having an organic layer containing the diarylpyrene compound. And an organic electroluminescent element (claim 10).

The diarylpyrene compound of the present invention is stable even when it is repeatedly subjected to electrical oxidation and reduction. In addition, when the diarylpyrene compound of the present invention is used for a light emitting layer, particularly a host of the light emitting layer, the dopant can be made to emit light efficiently.
Therefore, according to the organic electroluminescent device using the charge transport material of the present invention or the composition for organic electroluminescent device of the present invention, an organic electroluminescent device having high color purity, high brightness, high efficiency and long life is obtained. Provided.

  Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following description, and various modifications can be made without departing from the gist of the present invention.

In the present invention, the simple term “aromatic group” includes both an aromatic hydrocarbon group and an aromatic heterocyclic group.
In the present invention, “may have a substituent” means that one or more substituents may be present.

The present invention relates to a diarylpyrene compound (hereinafter sometimes referred to as “the diarylpyrene compound of the present invention” as appropriate), which is represented by the formula (1). Further, a material for an organic electroluminescence device comprising the diarylpyrene compound (hereinafter sometimes referred to as “the material for an organic electroluminescence device of the present invention”) and a composition for an organic electroluminescence device (hereinafter referred to as “the present invention” as appropriate). And an organic electroluminescent device containing them (hereinafter sometimes referred to as “the organic electroluminescent device of the present invention” as appropriate).
Hereinafter, these will be described.

（式（１）中、Ａｒ¹およびＡｒ²は、各々独立に、置換基を有していてもよい、ピレン環由来の基及びフェナントロリン環由来の基以外の６員環からなる芳香族基を表わす。
Ｘ及びＺは、各々独立に置換基を有していてもよい炭素数５０以下の基を表わす。
Ｒ¹及びＲ²は、各々独立に水素原子または炭素数５０以下の基を表わす。
Ｘ、Ｚ、Ｒ¹及びＲ²は、アリールアミン構造及び直鎖アルケン構造を含まない。
ｉ及びｊは、各々独立に０以上５以下の整数であり、ｍ及びｎは、各々独立に１以上５以下の整数である。但しｉ＋ｊは１以上である。ｉ、ｊ、ｍまたはｎがそれぞれ２以上のとき、一分子内に複数存在するＡｒ¹、Ａｒ²、ＸまたはＺは、それぞれ同一であっても異なっていてもよい。） [1. Diarylpyrene compound]
<1-1. Structure of diarylpyrene compound>
The diarylpyrene compound of the present invention is a compound having a structure represented by the following formula (1).

(In the formula (1), Ar ¹ and Ar ² each independently represent an aromatic group composed of a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring, which may have a substituent. Represent.
X and Z each independently represent a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X, Z, R ¹ and R ² do not include an arylamine structure or a linear alkene structure.
i and j are each independently an integer of 0 or more and 5 or less, and m and n are each independently an integer of 1 or more and 5 or less. However, i + j is 1 or more. When i, j, m, or n is 2 or more, Ar ¹ , Ar ² , X, or Z present in a molecule may be the same or different. )

<1-1-1. About Ar ¹ and Ar ² >
Ar ¹ and Ar ^{2 in} the formula (1) will be described. Ar ¹ and Ar ^{2 in} formula (1) each independently represent an aromatic group having a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring, which may have a substituent. .
Here, the “aromatic group consisting of 6-membered rings” refers to an aromatic group that is a 6-membered monocyclic ring or an aromatic group that is a condensed ring formed by condensing two or more 6-membered rings.

The phenanthroline ring is preferably not present in the molecule because the nitrogen atom contained in the phenanthroline ring collects metal atom ions, which may reduce the stability and efficiency of the organic electroluminescent element. Therefore, Ar ¹ and Ar ² are preferably other than a group derived from a phenanthroline ring.

Since the pyrene ring is considered to have strong hole transport properties, it is preferable that two or more pyrene rings do not exist in the molecule. Therefore, since formula (1) already has one pyrene ring, Ar ¹ and Ar ² are preferably other than groups derived from the pyrene ring.

In the diarylpyrene compound of the present invention, an aromatic group composed of a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring is introduced at positions 2 and 7 of the pyrene skeleton. Such a structure provides a highly stable diarylpyrene compound.
Furthermore, a diarylpyrene compound having higher stability can be obtained by comprising only a ring having resonance stabilization by conjugation to the main skeleton (pyrene skeleton).

Ar ¹ and Ar ² may be the same group, or different groups may be in any combination and ratio. Moreover, when several Ar < ¹ > or Ar < ² > exists in 1 molecule, those groups may mutually be the same groups, and different groups and arbitrary combinations and ratios may be sufficient as them.
Hereinafter, Ar ¹ and Ar ² will be described in detail. A group derived from a certain aromatic ring is referred to by adding “ring group” to the name of the aromatic ring. For example, a group derived from a benzene ring is called a benzene ring group.

(Aromatic group)
Examples of the aromatic group of Ar ¹ and Ar ² include a benzene ring group, a naphthalene ring group, a phenanthrene ring group, an anthracene ring group, a naphthacene ring group, a chrysene ring group, a triphenylene ring group, a coronene ring group, a pyridine ring group, Examples include a pyrazine ring group, a pyrimidine ring group, a triazine ring group, a quinoxaline ring group, a quinoline ring group, an isoquinoline ring group, and a quinazoline ring group.

  Among them, benzene ring group, naphthalene ring group, phenanthrene ring group, anthracene ring group, pyridine ring group, pyrazine ring group, pyrimidine ring group, triazine ring group, quinoxaline ring group, quinoline ring group, isoquinoline ring group for the convenience of synthesis. A quinazoline ring group and the like are preferable. In view of stability of the compound, a benzene ring group, a naphthalene ring group, a phenanthrene ring group, and an anthracene ring group are preferable, a benzene ring group, a naphthalene ring group, and a phenanthrene ring group are more preferable, and a benzene ring group is particularly preferable.

Among the above, it is preferably an aromatic group selected from the group of the following formulas (2a) to (2l), and any aromatic group selected from the group of the following formulas (2a) to (2d) More preferably, it is a group.

(Substituents Ar ¹ and Ar ² have)
Ar ¹ and Ar ² may have a substituent. Specific examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, and a carbon number. An aromatic heterocyclic group having 3 to 20 carbon atoms, an alkyloxy group having 1 to 20 carbon atoms, a (hetero) aryloxy group having 3 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, and 3 or more carbon atoms Examples include 20 or less (hetero) arylthio groups and cyano groups. Among these, an alkyl group and an aromatic hydrocarbon group are preferable from the viewpoint of stability of the compound, and an aromatic hydrocarbon group is particularly preferable.

  Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group, Examples include a cyclohexyl group, a decyl group, an octadecyl group, and the like. Of these, a methyl group, an ethyl group, and an isopropyl group are preferable. In addition, a methyl group and an ethyl group are preferable from the viewpoint of availability of raw materials and low cost, and an iso-butyl group, a sec-butyl group, and a tert-butyl group are preferable because they have high solubility in nonpolar solvents.

  Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms include a naphthyl group such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group; a phenanthyl group such as a 9-phenanthyl group and a 3-phenanthyl group; Anthryl group such as anthryl group, 2-anthryl group, 9-anthryl group; naphthacenyl group such as 1-naphthacenyl group, 2-naphthacenyl group; 1-chrysenyl group, 2-chrysenyl group, 3-chrysenyl group, 4-chrysenyl group , 5-chrycenyl group, 6-chrycenyl group and the like; pyrenyl group such as 1-pyrenyl group; triphenyl group such as 1-triphenylenyl group; coronenyl group such as 1-coronenyl group; and the like. Among them, a phenyl group, a 2-naphthyl group, a 1-anthryl group, a 9-phenanthryl group, and a 9-anthryl group are preferable from the viewpoint of stability of the compound, and a phenyl group and a 2-naphthyl group are preferable from the viewpoint of easy purification of the compound. Particularly preferred.

  Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms include 2-thienyl group, 2-furyl group, 2-imidazolyl group, 9-carbazolyl group, 2-pyridyl group, 1,3,5-triazine- 2-yl group etc. are mentioned. Among these, a 9-carbazolyl group is preferable from the viewpoint of stability.

  Examples of the alkyloxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, an isopropyloxy group, a cyclohexyloxy group, and an octadecyloxy group.

  Examples of the (hetero) aryloxy group having 3 to 20 carbon atoms include a phenoxy group, a 1-naphthyloxy group, a 9-anthryloxy group, and a 2-thienyloxy group.

  Examples of the alkylthio group having 1 to 20 carbon atoms include a methylthio group, an ethylthio group, an isopropylthio group, a cyclohexylthio group, and the like.

  Examples of the (hetero) arylthio group having 3 to 20 carbon atoms include a phenylthio group, a 1-naphthylthio group, a 9-anthrylthio group, and a 2-thienylthio group.

(About m and n)
In formula (1), m and n are integers of 1 or more and 5 or less. When m or n is 2 or more, a plurality of Ar ¹ or Ar ² are present in one molecule of the diarylpyrene compound of the present invention, and they may be the same or different. .

<1-1-2. About X and Z>
X and Z in the formula (1) will be described. X and Z in Formula (1) each independently represent a group having 50 or less carbon atoms which may have a substituent.
X and Z may be the same group as each other, or different groups may be in any combination and ratio. Moreover, when several X or Z exists in 1 molecule, those groups may mutually be the same groups, and different combinations and ratios may be sufficient as a different group.

(Type of X and Z)
Specific examples of X and Z include an alkyl group, aromatic group, alkyloxy group, (hetero) aryloxy group, alkylthio group, (hetero) arylthio group, and cyano group. Among these, an alkyl group and an aromatic group are preferable from the viewpoint of stability of the compound, and an aromatic group is particularly preferable.

  The alkyl group preferably has 1 to 20 carbon atoms. For example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl Group, cyclohexyl group, decyl group, octadecyl group and the like. Preferably, they are a methyl group, an ethyl group, and an isopropyl group. Methyl group and ethyl group are preferable from the viewpoint of availability of raw materials and low cost, and iso-butyl group, sec-butyl group, and tert-butyl group are preferable because of high solubility in nonpolar solvents.

Examples of the aromatic group include an aromatic hydrocarbon group and an aromatic heterocyclic group, and an aromatic hydrocarbon group is preferable.
The aromatic hydrocarbon group preferably has 6 to 25 carbon atoms, benzene ring group; naphthalene ring group such as 1-naphthalene and 2-naphthalene; phenanthrene ring group such as 9-phenanthrene and 3-phenanthrene; 1-anthracene Anthracene ring groups such as 1-naphthacene and 2-naphthacene; 1-chrysene, 2-chrysene, 3-chrysene, 4-chrysene, 5-chrysene, 6-chrysene Examples include chrysene ring groups such as 1; pyrene ring groups such as 1-pyrene; triphenylene ring groups such as 1-triphenylene; coronene ring groups such as 1-coronene; Among them, a benzene ring group, a 2-naphthalene ring group, a 1-anthracene ring group, a 9-phenanthrene ring group, and a 9-anthracene ring group are preferable from the viewpoint of stability of the compound, and a benzene ring group from the easiness of purification of the compound. 2-naphthalene ring group is particularly preferable.

  The aromatic heterocyclic group preferably has 3 to 20 carbon atoms. For example, a thiophene ring group such as 2-thiophene, a furan ring group such as 2-furan, an imidazole ring group such as 2-imidazole, 9-carbazole, etc. Carbazole ring groups, pyridine ring groups such as 2-pyridine, triazine ring groups such as 1,3,5-triazin-2-yl group, and the like. Of these, a 9-carbazole ring group is preferred from the viewpoint of stability of the compound.

  The alkyloxy group preferably has 1 to 20 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an isopropyloxy group, a cyclohexyloxy group, and an octadecyloxy group. Of these, a methoxy group and an ethoxy group are preferable from the viewpoint of improvement in solubility and glass transition temperature.

  The (hetero) aryloxy group preferably has 3 to 20 carbon atoms, and examples thereof include a phenoxy group, a 3-phenoxyphenoxy group, a 2-naphthyloxy group, a 9-anthryloxy group, and a 2-thienyloxy group. It is done. Of these, a phenoxy group, a 3-phenoxyphenoxy group, and a 2-naphthyloxy group are preferable, and a 3-phenoxyphenoxy group is particularly preferable from the viewpoint of improving solubility.

  The alkylthio group preferably has 1 to 20 carbon atoms, and examples thereof include a methylthio group, an ethylthio group, an isopropylthio group, and a cyclohexylthio group. Of these, a methylthio group and an ethylthio group are preferable from the viewpoints of improved solubility and Tg.

  The (hetero) arylthio group preferably has 3 to 20 carbon atoms, and examples thereof include a phenylthio group, a 1-naphthylthio group, a 9-anthrylthio group, and a 2-thienylthio group. Of these, a phenylthio group is preferred from the viewpoint of improving solubility.

X and Z may be bonded within a range where the total number of carbon atoms does not exceed 50.
Specific examples include [1,1 ′: 3 ′, 1 ″: 3 ″, 1 ′ ″: 3 ′ ″, 1 ″ ″-quinquephenyl] -3-yl, [1,1 ′. : 3 ′, 1 ″: 3 ″, 1 ′ ″-quaterphenyl] -3-yl, [1,1 ′: 3 ′, 1 ″ -terphenyl] -3-yl, [1,1 ′: 4 ′, 1 ″: 4 ″, 1 ′ ″: 4 ′ ″, 1 ″ ″-quinquephenyl] -4-yl, 6- [1,1 ′: 3 ′, 1 ″ -terphenyl ] -3-ylnaphthalen-2-yl and the like.

The groups listed as specific examples of X and Z described above may further have a substituent.
Examples of the substituent include the aforementioned <1-1-1. Ar ^1, for Ar ² include the same substituents as exemplified substituent> of (substituents with the Ar ¹ and Ar ^2).

（上記式中、Ａｒ^a，Ａｒ^b，Ａｒ^cは芳香族基を表わす。） In addition, when using the diarylpyrene compound of the present invention as a host of the light emitting layer of the organic electroluminescent device, X and Z do not have an arylamine structure as a partial structure from the viewpoint of the stability of the organic electroluminescent device. Is preferred. Here, the arylamine structure is a structure represented by the following formula.

(In the above formula, Ar ^a , Ar ^b and Ar ^c represent aromatic groups.)

  Moreover, it is preferable not to have a linear alkene structure as a partial structure of X and Z from the surface of stability of an organic electroluminescent element. This is because the linear alkene structure is very active and has low chemical stability. Here, the linear alkene structure refers to an alkene that does not form a ring.

(About i and j)
In formula (1), i and j are integers of 0 or more and 5 or less, and i + j is 1 or more. When i or j is 2 or more, a plurality of X or Z are present in one molecule of the diarylpyrene compound of the present invention, and they may be the same or different.
When i or j is 0, X or Z does not exist.

<1-1-3. About R ¹ and R ² >
R ¹ and R ^{2 in} the formula (1) will be described. R ¹ and R ² in the formula (1) each independently represent a hydrogen atom or a group having 50 or less carbon atoms. Of these, a hydrogen atom is preferable.

Specific examples of the group having 50 or less carbon atoms include the above <1-1-2. Examples of X and Z include the same groups as those described above.
The introduction position is not limited as long as it is other than the ^2nd and 7th positions in the pyrene skeleton of R ¹ and R ² .

<1-1-4. Other>
The diarylpyrene compound of the present invention preferably does not have a 3, 4, 7, or 8-membered ring structure. The structure is highly distorted and the ring stability may be insufficient. Moreover, it is preferable not to have a 5-membered ring like a fluorene ring. Since it is easily oxidized, the stability of the ring may be insufficient.
From the above, from the viewpoint of obtaining a highly stable organic electroluminescence device, when the diarylpyrene compound of the present invention has a cyclic structure in addition to the pyrene skeleton, the cyclic structure is a six-membered single ring, or two or more. It is preferably formed from a condensed ring formed by condensing 6-membered rings.

（式（３−１）〜（３−６）中、Ｘ¹、Ｘ²、Ｚ¹およびＺ²は、各々独立に、置換基を有していてもよい炭素数５０以下の基を表わす。
Ｒ¹及びＲ²は、各々独立に水素原子または炭素数５０以下の基を表わす。
Ｘ¹、Ｘ²、Ｚ¹、Ｚ²、Ｒ¹及びＲ²は、アリールアミン構造及び直鎖アルケン構造を含まない。） <1-2. Diarylpyrene compound>
The diarylpyrene compound of the present invention is not limited as long as it has the above characteristics. Among these, preferred structures include compounds represented by the following formulas (3-1) to (3-6). In the following formulas (3-1) to (3-6), the same substituents as those in formula (1) are represented by the same reference numerals.

(In formulas (3-1) to (3-6), X ¹ , X ² , Z ¹ and Z ² each independently represents a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X ¹ , X ² , Z ¹ , Z ² , R ¹ and R ² do not include an arylamine structure or a linear alkene structure. )

<1-2-1. Structure of Compounds of Formulas (3-1) to (3-6)>
(For ^{X 1, X 2, Z 1} , Z 2)
In the above formulas (3-1) to (3-6), X ¹ , X ² , Z ¹ and Z ² each independently represent a group having 50 or less carbon atoms which may have a substituent. . Specific examples of the group having 50 or less carbon atoms and the substituent thereof include the above <1-1-2. Examples of X and Z include the same groups as those described above.

X ¹ , X ² , Z ¹ and Z ² are preferably each independently an aromatic group. As the aromatic group, the aforementioned <1-1-2. Examples of X and Z include the same groups as the aromatic groups exemplified in>.

(About R ¹ and R ² )
In formulas (3-1) to (3-6), R ¹ and R ² each independently represent a hydrogen atom or a group having 50 or less carbon atoms. Specific examples of the substituent include <1-1-3. Examples of R ¹ and R ² include the same groups as those described above. The introduction position in the pyrene skeleton of R ¹ and R ² is not limited as long as it is other than the 2nd and 7th positions.
R ¹ and R ² are preferably hydrogen atoms.

<1-2-2. Features of Compounds of Formulas (3-1) to (3-6)>
In the compounds of formulas (3-1) to (3-6), the aromatic hydrocarbon ring is substituted at the 2nd and 7th positions of the pyrene skeleton, whereby the stability of the diarylpyrene compound is improved. At this time, when the diarylpyrene compound of the present invention is used as a host of the light emitting layer of the organic electroluminescent device, X ¹ , X ² , Z ¹ , and Z ² can be used from the viewpoint of the stability of the organic electroluminescent device. It is preferable that no arylamine structure exists as a partial structure.

Since the compounds having the structures of the formulas (3-1) and (3-3) have a curved structure while taking a resonance stabilization structure by conjugation, the solubility is usually improved.
In addition, the compound having the structure of the formula (3-2) usually has improved solubility because the whole molecule is three-dimensionally twisted due to the steric hindrance of the ortho-position substituent.

The compounds having the structures of the formulas (3-4) and (3-5) usually have a structure in which a polycyclic aromatic ring that relatively easily transports electrons is substituted for a pyrene skeleton that relatively easily transports holes. Both positive charge and negative charge are improved in transportability.
In addition, since the compound which has a structure of Formula (3-5) takes an asymmetric structure on both sides of a pyrene ring, the solubility of a molecule | numerator improves.

  The compound having the structure of the formula (3-6) has a skeleton having a branched substituent group, and therefore, due to the improvement of the asymmetry of the normal molecule, the improvement of the degree of freedom by extending the molecular chain, and the effect of the steric hindrance of the molecular chain , The normal solubility of the molecule is improved.

In particular, compounds having a heterocycle in X ¹ , X ² , Z ¹ , and Z ² of formulas (3-1) to (3-6) transport electrons relatively to the pyrene skeleton that easily transports holes. Since it has a structure in which a nitrogen-containing heterocyclic ring is easily substituted, both positive and negative charges are improved in transportability.

<1-2-3. Molecular Weight of Diarylpyrene Compound>
The molecular weight of the diarylpyrene compound of the present invention is usually 400 or more, preferably 500 or more, more preferably 600 or more, and usually 7000 or less, preferably 5000 or less, particularly preferably 2000 or less. Below this range, the thermal durability may be reduced. Moreover, when it exceeds this range, the purification of the compound may be difficult.

[1-3. Method for producing diarylpyrene compound]
The diarylpyrene compound of the present invention can be produced by arbitrarily combining known synthesis methods.
Hereinafter, although the example is demonstrated, the manufacturing method of the diaryl pyrene compound of this invention is not limited to the following examples.

The diarylpyrene compound of the present invention can be synthesized through boronization and a coupling reaction using a metal catalyst using pyrene as a starting material.
Specifically, the case of a compound in which the atomic group A is substituted at the 2nd and 7th positions of pyrene will be described as an example, and the compound can be synthesized according to the following scheme.

以下、上記スキーム中に示した各反応段階について説明する。

Hereinafter, each reaction step shown in the above scheme will be described.

<Boronization reaction>
In an inert gas, 1 mol of the reaction substrate and 1 mol or more and 30 mol or less of the boron reagent are dissolved or suspended in a polar or nonpolar solvent, and the iridium cyclooctadiene catalyst and 2,2′-bipyridyl coordination are used. By adding the element, a mixture of boronated substrates can be obtained. In addition, it is possible to use a rhodium-based catalyst instead of the iridium catalyst.

The solvent is not particularly limited as long as it does not react with the boronizing agent and dissolves or suspends the substrate. However, non-benzene nonpolar solvents such as hexane and cyclohexane; N, N-dimethylformamide, N, Amide solvents such as N-dimethylacetamide; Ether solvents such as diethyl ether, tetrahydrofuran, dioxane and diethylene glycol dimethyl ether; Nonbenzene nonpolar solvents such as hexane and cyclohexane; etc. are preferred, and nonbenzene nonpolar solvents are particularly preferred preferable.
One of these may be used alone, or two or more may be used in any combination and ratio.

  The mixture of boronated substrates may be purified. The purification is not limited as long as the effects of the present invention are not significantly impaired, but any method such as distillation, filtration, extraction, recrystallization, reprecipitation, suspension washing, chromatography, etc. may be performed. You may carry out combining more than a seed.

<Coupling reaction>
1 mol of boronated pyrene (reaction substrate) and 1 mol or more and 30 mol or less of a halide or trifluoromethanesulfonate esterifying reagent having a hydrocarbon aromatic group in the presence of a transition metal element catalyst and a base By reacting in a polar or polar solvent, a mixture of coupled substrates can be obtained.

  Examples of the transition metal element catalyst include an organic palladium catalyst, an organic nickel catalyst, an organic copper catalyst, an organic platinum catalyst, an organic rhodium catalyst, an organic ruthenium catalyst, and an organic iridium catalyst. Among these, an organopalladium catalyst is preferable because of the simplicity of the reaction and the high reaction yield. One of these may be used alone, or two or more may be used in any combination and ratio.

  Although it does not specifically limit as a base, A metal hydroxide, a metal salt, an organic alkali metal reagent, etc. are preferable. One of these may be used alone, or two or more may be used in any combination and ratio.

  The solvent is not particularly limited as long as it is a solvent that is active against the reaction substrate, but non-aromatic hydrocarbon solvents such as hexane, heptane, cyclohexane, etc .; aromatic hydrocarbons such as benzene, toluene, xylene, etc. Solvents; ether solvents such as dimethoxyethane, tetrahydrofuran and dioxane; alcohol solvents such as ethanol and propanol; water; and the like. One of these may be used alone, or two or more may be used in any combination and ratio. Moreover, 1 mol% or more and 100 mol% or less of surfactant can also be added as needed.

<Purification method>
Any known method can be used as a method for purifying the product obtained by the above-mentioned synthesis as long as the effects of the present invention are not significantly impaired.

  Specific examples include "Separation and purification technology handbook" (1993, edited by The Chemical Society of Japan), "Advanced separation of trace components and difficult-to-purify substances by chemical conversion method" (1988, published by IPC Corporation). Alternatively, the method described in the section “Separation and purification” of “Experimental Chemistry Course (4th edition) 1” (1990, edited by The Chemical Society of Japan) can be used.

  More specifically, extraction (including suspension washing, boiling washing, ultrasonic washing, acid-base washing), adsorption, occlusion, melting, crystallization (including recrystallization from solvent, reprecipitation), distillation (ordinary) Pressure distillation, vacuum distillation), evaporation, sublimation (atmospheric pressure sublimation, vacuum sublimation), ion exchange, dialysis, filtration, ultrafiltration, reverse osmosis, pressure osmosis, zone dissolution, electrophoresis, centrifugation, flotation separation, sedimentation separation , Magnetic separation, various chromatography (shape classification: column, paper, thin layer, capillary. Mobile phase classification: gas, liquid, micelle, supercritical fluid. Separation mechanism: adsorption, distribution, ion exchange, molecular sieve, chelate, gel Filtration, exclusion, affinity, etc.). One of these may be used alone, or two or more may be used in any combination and ratio.

The product confirmation and purity analysis methods include gas chromatograph (GC), high performance liquid chromatograph (HPLC), capillary electrophoresis measurement (CE), size exclusion chromatograph (SEC), gel permeation chromatograph (GPC), Cross-fractionation chromatograph (CFC) mass spectrometry (MS, LC / MS, GC / MS, MS / MS), nuclear magnetic resonance apparatus (NMR ( ¹ H-NMR, ¹³ C-NMR)), Fourier transform infrared spectrophotometry Meter (FT-IR), UV-visible near-infrared spectrophotometer (UV.VIS, NIR), electron spin resonance apparatus (ESR), transmission electron microscope (TEM-EDX), electron beam microanalyzer (EPMA), metal element Analysis (ion chromatograph, inductively coupled plasma-emission spectroscopy (ICP-AES) atomic absorption analysis (AAS) X-ray fluorescence analyzer (X RF)), non-metallic element analysis, trace component analysis (ICP-MS, GF-AAS, GD-MS) and the like can be applied as necessary. One of these may be used alone, or two or more may be used in any combination and ratio.

[1-4. Preferred examples of diarylpyrene compounds]
Hereinafter, preferred examples of the diarylpyrene compound of the present invention will be illustrated. In addition, the following is an illustration, Comprising: If the diaryl pyrene compound of this invention is a compound represented by the said Formula (1), there will be no restriction | limiting.

<1-5. Applications of diarylpyrene compounds>
Since the diarylpyrene compound of the present invention has high heat resistance, excellent solubility in an organic solvent, or high charge transportability, an electrophotographic photoreceptor, an organic electroluminescence device, a photoelectric conversion device can be used as a charge transport material or a light emitting material. It can be suitably used for organic solar cells, organic rectifying elements and the like.
In addition, since it has a high singlet excitation level, an excellent fluorescence quantum yield, an excellent electrical durability, or an excellent amorphous property, by using a charge transport material comprising the diarylpyrene compound of the present invention. In addition, an organic electroluminescent element having excellent heat resistance and being stably driven (emitted) for a long period of time can be obtained. Therefore, the diarylpyrene compound and the charge transport material of the present invention are particularly suitable as an organic electroluminescent element material.

[2. Materials for organic electroluminescent elements]
The diarylpyrene compound of the present invention can be used as a charge transport material. Here, the charge transporting material is a material intended to form a film having charge transporting properties when formed using any known method.

  The diarylpyrene compound of the present invention is particularly preferably used as a material for an organic electroluminescent element among charge transport materials. However, since it has a charge transport capability, it is preferably used for a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and the like, and particularly preferably used for a light emitting layer. In particular, it is preferably used as a host material or a dopant material in the light emitting layer. It is particularly preferable to use it as a host material.

When forming an organic layer using the organic electroluminescent element material of the present invention, any known method such as a wet film forming method or a vapor deposition method can be used. preferable.
In this case, an organic layer having a charge transporting property can be formed by forming a film in a state where the diarylpyrene compound of the present invention is dispersed or dissolved in a solvent and then removing a part or all of the solvent. .

[3. Composition for Organic Electroluminescent Device]
The present invention also relates to a composition for an organic electroluminescence device containing the diarylpyrene compound of the present invention.
In addition to the diarylpyrene compound of the present invention, the composition for an organic electroluminescent device of the present invention may contain a charge transporting compound used for an organic electroluminescent device, particularly a light emitting layer. The diarylpyrene compound of the present invention may be used as a host material and another charge transporting compound may be included as a dopant material, or the diarylpyrene compound of the present invention may be used as a dopant material and another charge transporting compound is included as a host material. You may go out. Further, both the dopant material and the host material may be the diarylpyrene compound of the present invention.

  Examples of other charge transporting compounds include perylene, pyrene, anthracene, chrysene, coumarin, p-bis (2-phenylethenyl) benzene and derivatives thereof, quinacridone derivatives, DCM (4- (dicyanomethylene) -2- and methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene and the like.

<Light emitting material>
It is preferable that the composition for organic electroluminescent elements contains a luminescent material.
Here, the light emitting material is a material having a fluorescence quantum yield of 30% or more in a dilute solution at room temperature in an inert gas atmosphere, and it is determined based on the comparison with the fluorescence spectrum in the dilute solution. A part or all of an EL spectrum obtained when an organic electroluminescent element manufactured by using an electric current is energized is defined as a material attributed to light emission of the material.

  Specific examples of the light emitting material include a condensed aromatic ring compound substituted with an arylamino group, a styryl derivative substituted with an arylamino group, and the like.

  As the condensed aromatic ring compound substituted with an arylamino group, compounds represented by the formulas (6) to (11) in International Publication No. 2006/070712 are preferable. In addition, as an aryl group having 5 to 40 nuclear carbon atoms in the formula (11), benzophenanthryl is also preferable in addition to the examples described in International Publication No. 2006/070712 pamphlet.

  As the styryl derivative substituted with an arylamino group, a compound represented by the formula (12) is preferable in the pamphlet of International Publication No. 2006/070712.

In addition, the following compounds can also be used as a blue light-emitting material.

  A preferable compound as a light emitting material for blue is an aryl group in which a central skeleton is preferably 3 or more, more preferably 4 or more, and preferably 7 or less, more preferably 6 or less, condensed with an aromatic ring nucleus. is there. Examples of the central skeleton include a chrycenyl group, a naphthacenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a coronyl group, a fluoranthenyl group, a benzophenanthryl group, an acenaphthofluoranthenyl group, and a fluorenyl group.

As the luminescent material of the composition for organic electroluminescent elements, one kind may be used alone, or two or more kinds may be used in any combination and ratio.
Moreover, the light emitting material with respect to the composition for organic electroluminescent elements is usually 1 part by weight or more, usually 50 parts by weight or less, preferably 30 parts by weight or less, when the composition is 100 parts by weight. If it exceeds this range, there is a possibility that the light emission efficiency, the drive life, the emission spectrum becomes broad, and the like. On the other hand, if it falls below this range, there is a possibility that the light emission life, drive life, and drive voltage increase.

<Solvent>
It is preferable that the composition for organic electroluminescent elements further contains a solvent.
Here, the solvent is a volatile liquid component used for forming a layer containing the diarylpyrene compound of the present invention by wet film formation.

The solvent is not particularly limited as long as the solute dissolves well, but the following examples are preferable.
For example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene, and tetralin; halogenated fragrances such as chlorobenzene, dichlorobenzene, and trichlorobenzene Group hydrocarbons: 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethyl Aromatic ethers such as anisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; Alicyclic ketones such as Sanone, Cyclooctanone and Fencon; Alicyclic alcohols such as cyclohexanol and cyclooctanol; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Aliphatic alcohols such as butanol and hexanol; Ethylene And aliphatic ethers such as glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA).
Of these, alkanes and aromatic hydrocarbons are preferable. One of these solvents may be used alone, or two or more thereof may be used in any combination and ratio.

(boiling point)
The boiling point of the solvent is usually 100 ° C. or higher, preferably 150 ° C. or higher, more preferably 200 ° C. or higher. If it is below this range, there is a possibility that film formation stability may be lowered due to solvent evaporation from the composition for organic electroluminescent elements during wet film formation.
In order to obtain a more uniform film, it is preferable that the solvent evaporates from the liquid film immediately after the film formation at an appropriate rate. For this reason, the boiling point of the solvent is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and usually 270 ° C. or lower, preferably 250 ° C. or lower, more preferably 230 ° C. or lower.

(amount to use)
The amount of the solvent used is preferably 10 parts by weight or more, more preferably 50 parts by weight or more, particularly preferably 80 parts by weight or more, and preferably 99.95 parts per 100 parts by weight of the composition for organic electroluminescent elements. The amount is not more than parts by weight, more preferably not more than 99.9 parts by weight, particularly preferably not more than 99.8 parts by weight. When the content is less than 10 parts by weight, the viscosity becomes too high, and the film forming workability may be lowered. On the other hand, if the amount exceeds 99.95 parts by weight, the thickness of the film obtained by removing the solvent after film formation cannot be obtained, so that film formation tends to be difficult.

<In addition, what may be contained in the composition for organic electroluminescent elements>
The composition for organic electroluminescent elements may further contain other compounds in addition to the above-described compounds as necessary.

  For example, in addition to the above solvent, another solvent may be contained. Examples of such a solvent include amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide. One of these may be used alone, or two or more may be used in any combination and ratio.

  Moreover, you may contain various additives, such as a leveling agent and an antifoamer, for the purpose of the improvement of film formability.

[4. Organic electroluminescent device]
The present invention also provides an organic electroluminescent device having an anode, a cathode, and an organic light emitting layer provided between both electrodes on a substrate, the layer comprising the diarylpyrene compound of the present invention. The present invention relates to an organic electroluminescent device.

<Configuration>
FIG. 1 is a schematic cross-sectional view showing an example of a structure suitable as an organic electroluminescent element of the present invention.
In FIG. 1, an organic electroluminescent element 10 includes an anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, a hole blocking layer 6, an electron transport layer 7, a cathode buffer layer 8 on a substrate 1. The cathode 9 is laminated and formed in this order. Among these layers, the layers from the hole injection layer 3 to the cathode buffer layer 8 (excluding the light emitting layer 5) are laminated as required even if all the layers are laminated. It does not have to be.

  Moreover, the organic electroluminescent element of this invention is not limited to the structure of FIG. 1 unless the effect of this invention is impaired remarkably, Arbitrary shapes, arrangement | positioning, etc. can be taken. For example, the organic light emitting element 10 may be stacked on the substrate in the reverse order (that is, stacked from the cathode side).

The organic electroluminescent element of the present invention contains the diarylpyrene compound of the present invention in at least one layer constituting the organic electroluminescent element. However, since the layer containing the diarylpyrene compound of the present invention has a charge transporting capability, it is preferably used for the hole injection layer 3, the hole transport layer 4, the light emitting layer 5, the electron transport layer 7, and the like. It is preferable to use it for the layer 5.
Hereinafter, the above layers will be described in detail with reference to FIG.

<Substrate 1>
The substrate 1 serves as a support for the organic electroluminescent element 10.
The material of the substrate 1 is not limited so as not to significantly impair the effects of the present invention, but is preferably a quartz or glass plate, a metal plate or a metal foil, a plastic film or a sheet. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. One of these may be used alone, or two or more may be used in any combination and ratio.

  In addition, when using a synthetic resin board | substrate as the board | substrate 1, it is desirable to pay attention to gas barrier property. If the gas barrier property of the substrate 1 is too low, the organic electroluminescent element 10 may be deteriorated by the outside air that has passed through the substrate 1. For this reason, it is preferable to provide a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate.

  The thickness of the substrate 1 is not limited, but is usually 0.01 mm or more, preferably 0.1 mm or more, more preferably 0.2 mm or more, and usually 5 cm or less, preferably 2 cm or less, more preferably 1 cm or less.

  In addition, the board | substrate 1 may be the structure which consists of a single layer, and may have the structure by which the several layer was laminated | stacked. In the latter case, the plurality of layers may be layers made of the same material or layers made of different materials.

<Anode 2>
An anode 2 is formed on the substrate 1.
The anode 2 serves to inject holes into an adjacent layer in the direction opposite to the substrate 1.

  The material of the anode 2 is not limited as long as it has conductivity. For example, a metal such as aluminum, gold, silver, nickel, palladium, or platinum, a metal oxide such as indium and / or tin oxide, Metal halides such as copper iodide, carbon black, or conductive polymers such as poly (3-methylthiophene), polypyrrole, and polyaniline are preferable. One of these may be used alone, or two or more may be used in any combination and ratio.

  Although the method for forming the anode 2 is not limited, a sputtering method, a vacuum deposition method, or the like is usually used. When the anode 2 is formed using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., these are used as an appropriate binder. The anode 2 can also be formed by dispersing it in a resin solution and applying it onto the substrate 1.

  Furthermore, when a conductive polymer is used as a material, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 ( Appl.Phys.Lett., 60, 2711, 1992).

In FIG. 1, the anode 2 has a single-layer structure, but may have a stacked structure in which a plurality of layers are stacked as desired. In the latter case, the plurality of layers may be layers made of the same material or layers made of different materials.
Furthermore, the anode 2 may be formed integrally with the substrate 1 described above, and the anode 2 may also serve as the substrate 1.

The thickness of the anode 2 is appropriately selected depending on the transparency required for the anode 2.
When the anode 2 is required to be transparent, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. If the anode 2 is too thin, the electrical resistance may increase. Moreover, when too thick, transparency will fall.

  On the other hand, when the anode 2 may be opaque, the thickness of the anode 2 is arbitrary.

  For the purpose of removing impurities adhering to the anode 2 and adjusting the ionization potential to improve the hole injection property, the surface of the anode 2 is subjected to ultraviolet (UV) treatment, ozone treatment, It is preferable to perform plasma treatment such as oxygen plasma or argon plasma.

<Hole injection layer 3>
A hole injection layer 3 can be formed on the anode 2.
The hole injection layer 3 is a layer that transports holes to a layer adjacent to the cathode side of the anode 2.
The organic electroluminescent element 10 of the present invention may have a configuration in which the hole injection layer 3 is omitted.

  The hole injection layer 3 preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. Further, the hole injection layer 3 preferably contains a cation radical compound, and particularly preferably contains a cation radical compound and a hole transporting compound.

  The hole injection layer 3 may contain a binder resin and a coating property improving agent as necessary. The binder resin is preferably one that hardly acts as a charge trap.

  In addition, the hole injection layer 3 can be formed by depositing only the electron-accepting compound on the anode 2 by a wet film-forming method, and directly coating and laminating the composition for an organic electroluminescent element directly thereon. . In this case, a part of the composition for organic electroluminescence device interacts with the electron accepting compound, whereby a layer having excellent hole injecting property is formed.

(Hole transporting compound)
As said hole transportable compound, the compound which has the ionization potential of 4.5 eV-6.0 eV is preferable. However, when used in the wet film forming method, it is preferable that the solubility in the solvent used in the wet film forming method is high.

  Examples of the hole transporting compound include aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, and the like. Of these, aromatic amine compounds are preferred from the viewpoints of amorphousness and visible light transmittance.

  The type of the aromatic amine compound is not particularly limited, and may be a low molecular compound or a high molecular compound. From the viewpoint of the surface smoothing effect, the high molecular compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less. (Polymerized hydrocarbon compound in which repeating units are continuous) is preferred.

  Of the aromatic amine compounds, an aromatic tertiary amine compound is particularly preferable. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine.

（上記式（ｉ）中、Ａｒ^a1、Ａｒ^a2は各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表わす。Ａｒ^a3〜Ａｒ^a5は、各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、または置換基を有していてもよい２価の芳香族複素環基を表わす。Ｚ^aは、下記の連結基群の中から選ばれる連結基を表わす。また、Ａｒ^a1〜Ａｒ^a5のうち、同一のＮ原子に結合する二つの基は互いに結合して環を形成してもよい。）

（上記各式中、Ａｒ^a6〜Ａｒ^a16は、各々独立して、置換基を有していてもよい芳香族炭化水素環、または置換基を有していてもよい芳香族複素環由来の１価または２価の基を表わす。Ｒ^a1およびＲ^a2は、各々独立して、水素原子または任意の置換基を表わす。） Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following formula (i).

(In the formula (i), Ar ^a1 and Ar ^a2 each independently represent an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{a3 to} Ar ^a5 each independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent. Z ^a represents ^a linking group selected from the following group of linking groups, and two groups bonded to the same N atom among Ar ^{a1 to} Ar ^a5 are bonded to each other to form a ring. You may do it.)

(In the above formulas, Ar ^{a6 to} Ar ^a16 are each independently an aromatic hydrocarbon ring optionally having a substituent or an aromatic heterocyclic ring optionally having a substituent. R ^a1 and R ^a2 each independently represents a hydrogen atom or an arbitrary substituent.

As Ar ^{a1 to} Ar ^a16 , any monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocyclic ring is applicable. These groups may be the same or different from each other. Further, these groups may further have an arbitrary substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less.

Ar ^a1 and Ar ^a2 are preferably monovalent groups derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of the solubility, heat resistance, and hole injection / transport properties of the polymer compound. More preferred are a phenyl group and a naphthyl group.

Ar ^{a3 to} Ar ^a5 are preferably divalent groups derived from a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring from the viewpoint of heat resistance and hole injection / transport properties including redox potential. A group, a biphenylene group, and a naphthylene group are more preferable.

Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the general formula (i) include compounds described in International Publication No. 2005/089024 pamphlet.
The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more.
When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. It is preferable to use the above together.

(Electron-accepting compound)
As the electron-accepting compound, a compound having an oxidizing power and an ability to accept one electron from the hole transporting compound described above is preferable. Specifically, a compound with an electron affinity of 4 eV or more is preferable, and a compound with a compound of 5 eV or more is more preferable.

  Examples of the electron-accepting compound include onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, iron (III) chloride (Japanese Patent Laid-Open No. 11-251067). Publication), high valence inorganic compounds such as ammonium peroxodisulfate, cyano compounds such as tetracyanoethylene, aromatic boron compounds such as tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365), fullerene derivatives, iodine Etc.

  Of the above-mentioned compounds, an onium salt substituted with an organic group, a high-valence inorganic compound, and the like are preferable because they have strong oxidizing power. In addition, an onium salt substituted with an organic group, a cyano compound, an aromatic boron compound, or the like is preferable because it is soluble in various solvents and can be applied to wet coating.

Specific examples of onium salts, cyano compounds and aromatic boron compounds substituted with an organic group suitable as an electron-accepting compound include those described in International Publication No. 2005/089024, and the preferred examples thereof are also the same. is there. Examples thereof include compounds represented by the following structural formulas, but are not limited thereto.
In addition, an electron-accepting compound may be used individually by 1 type, and may use 2 or more types by arbitrary combinations and a ratio.

(Cation radical compound)
As the cation radical compound, an ionic compound composed of a cation radical which is a chemical species obtained by removing one electron from a hole transporting compound and a counter anion is preferable. However, when the cation radical is derived from a hole transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

  The cation radical is preferably a chemical species obtained by removing one electron from the compound described above as the hole transporting compound. A chemical species obtained by removing one electron from a compound preferable as a hole transporting compound is preferable in terms of amorphousness, visible light transmittance, heat resistance, solubility, and the like.

  Here, the cation radical compound can be generated by mixing the hole transporting compound and the electron accepting compound. That is, by mixing the hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the cation radical and the counter anion of the hole transporting compound A cation ion compound consisting of

  Cation radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, 12, 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, 94, 7716) It is also produced by oxidative polymerization (dehydrogenation polymerization).

  The oxidative polymerization referred to here is a method in which a monomer is chemically or electrochemically oxidized using peroxodisulfate or the like in an acidic solution. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is polymerized by oxidation, and a cation radical that is removed from the polymer repeating unit by using an anion derived from an acidic solution as a counter anion is removed. Generate.

(Method for producing hole injection layer 3)
The hole injection layer 3 can be formed by any method as long as the effects of the present invention are not significantly impaired. For example, the hole injection layer 3 is formed on the anode 2 by a wet film formation method or a vacuum evaporation method.

  In the case of layer formation by a wet film formation method, one or more predetermined amounts of each of the above-described materials (hole transporting compound, electron accepting compound, cation radical compound) act as a charge trap if necessary. First, a coating solution is prepared by dissolving it in a solvent together with a difficult binder resin and coating property improver. Subsequently, the positive hole injection layer 3 can be formed by applying on the anode by a wet film formation method such as spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, and inkjet method, and drying.

As the solvent used for the layer formation by the wet film forming method, any solvent can be used as long as it can dissolve the above-mentioned materials (hole transporting compound, electron accepting compound, cation radical compound). Is not particularly limited. In addition, the material used for the hole injection layer (a hole transporting compound, an electron accepting compound, a cation radical compound) does not contain a deactivating substance or a substance that generates a deactivating substance that may deactivate the material. Is preferred.
Preferably, specific examples of the solvent include ether solvents or ester solvents.

  The concentration of the solvent in the coating solution is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and usually 99.999% by weight or less, preferably 99.99% by weight or less. More preferably, it is 99.9% by weight or less. In addition, when using 2 or more types of solvents in mixture, the total of these solvents should just satisfy this range.

In the case of layer formation by vacuum deposition, first, one or more of the above-mentioned materials (hole transporting compound, electron accepting compound, cation radical compound) are placed in a crucible placed in a vacuum vessel. Put (into each crucible when two or more materials are used), and then evacuate the inside of the vacuum vessel to about 10 ⁻⁴ Pa with an appropriate vacuum pump. After that, the crucible is heated (each crucible is heated when two or more materials are used), and the amount of evaporation is controlled and evaporated (when two or more materials are used, the amount of evaporation is controlled independently). Evaporation) and a hole injection layer can be formed on the anode of the substrate placed facing the crucible. In addition, when using 2 or more types of materials, they can also be put into a crucible, can be heated and evaporated, and can be used for hole injection layer formation.

  The film thickness of the hole injection layer 3 formed as described above is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. If the hole injection layer 3 is too thin, the hole injection property may be insufficient. Moreover, when it is too thick, resistance may become high.

  The hole injection layer 3 may have a single layer structure, or may have a structure in which a plurality of layers are stacked. In the latter case, the plurality of layers may be layers made of the same material or layers made of different materials.

<Hole transport layer 4>
The hole transport layer 4 can be formed on the hole injection layer 3 when the hole injection layer 3 is provided, and on the anode 2 when the hole injection layer 3 is not provided.
Holes can be transported and efficiently injected into the light-emitting layer 5 by the hole transport layer 4.
The organic electroluminescent element 10 of the present invention may have a configuration in which the hole transport layer 4 is omitted.

The material that can be used for the hole transport layer 4 is preferably a material that has high hole transportability and can efficiently transport injected holes. Therefore, it is preferable that the ionization potential is small, the transparency to visible light is high, the hole mobility is large, the stability is high, and impurities that become traps are not easily generated during manufacturing or use.
Further, in many cases, it is in contact with the light emitting layer 5, so it is preferable not to quench the light emitted from the light emitting layer 5 or form an exciplex with the light emitting layer 5 to reduce the efficiency.

  Examples of such a hole transport material include 4,4′-bis [N- (1-naphthyl) -N-phenyl in addition to the hole transport compound used for the hole injection layer 3 described above. Aromatic diamines containing two or more tertiary amines typified by amino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms (Japanese Patent Laid-Open No. 5-234681), 4, 4 ′, 4 "From an aromatic amine compound having a starburst structure such as -tris (1-naphthylphenylamino) triphenylamine (J. Lumin., 72-74, 985, 1997), a tetramer of triphenylamine Aromatic amine compounds (Chem. Commun., 2175, 1996), 2,2 ′, 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene and the like Compound (Synth.Metals, 91 vol, 209 pp., 1997), 4,4'-N, such as a carbazole derivative such as N'- dicarbazole biphenyl.

  Furthermore, after forming a thin film by a film forming method to be described later, it is also possible to use a compound that is polymerized by heating, irradiation with electromagnetic waves such as light or magnetism, or a polymer in which a plurality of arbitrary compounds are polymerized in advance. Examples of such a polymerizing compound include a triarylamine derivative having a crosslinking group and a fluorene derivative.

  Examples of such a polymer include polyvinyl carbazole, polyvinyl triphenylamine (Japanese Patent Laid-Open No. 7-53953), and polyarylene ether sulfone (Polym. Adv. Tech., Vol. 7, page 33) containing tetraphenylbenzidine. 1996). One of these may be used alone, or two or more may be used in any combination and ratio.

  The hole transport layer 4 is formed by, for example, a normal coating method such as a spray method, a printing method, a spin coating method, a dip coating method, or a die coating method, or a wet film forming method such as various printing methods such as an ink jet method or a screen printing method. It can be formed by a dry film formation method such as a vacuum evaporation method.

  In the case of the coating method, one or more of the hole transport materials is mixed with an additive such as a polymerization initiator that does not trap holes if necessary, a binder resin or a coating property improver, and the mixture is added to a suitable solvent. The solution is dissolved to prepare a coating solution, which is coated on the anode 2 or the hole injection layer 3 by a method such as spin coating, and dried to form the hole transport layer 4.

  Examples of the binder resin include polycarbonate, polyarylate, and polyester. When the amount of the binder resin used is large, the hole mobility is lowered. Therefore, a smaller amount is desirable, and the content in the hole transport layer is usually preferably 50% by weight or less.

  In the case of the vacuum deposition method, for example, the hole transport material is put in a crucible installed in a vacuum vessel, the pressure inside the vacuum vessel is reduced with an appropriate vacuum pump, and then the crucible is heated to form a hole transport material. The hole transport layer 4 can be formed on the anode 2 or the hole injection layer 3 placed opposite to the crucible.

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

<Light emitting layer 5>
The light emitting layer 5 is formed on the hole transport layer 4 when the hole transport layer 4 is provided, and on the hole injection layer 3 when the hole transport layer 4 is not provided and the hole injection layer 3 is provided. In the case where the hole transport layer 4 and the hole injection layer 3 are not provided, they are formed on the anode 2.
The light emitting layer 5 may be an independent layer from the hole injection layer 3 and the hole transport layer 4 described above, and the hole blocking layer 6 and the electron transport layer 7 described later. Other organic layers such as the hole transport layer 4 and the electron transport layer 7 may serve as the light emitting layer without being formed.

The light-emitting layer 5 includes holes injected directly from the anode 2 or through the hole injection layer 3 or the hole transport layer 4 between the electrodes to which an electric field is applied, and directly from the cathode 9 or a cathode buffer. It is a layer which is excited by recombination with electrons injected through the layer 8, the electron transport layer 7, the hole blocking layer 6 and the like and becomes a main light emitting source.
In addition, it is preferable that the light emitting layer 5 of this invention is a layer containing the diaryl pyrene compound of this invention. Specifically, it is preferable to use the organic electroluminescent element material of the present invention or the organic electroluminescent element composition of the present invention.

  The light emitting layer 5 can be formed by any method as long as the effects of the present invention are not significantly impaired. For example, the light emitting layer 5 is formed on the anode 2 by a wet film forming method or a vacuum deposition method. However, when manufacturing the light emitting element 10 with a large area, the wet film forming method is preferable. The wet film forming method and the vacuum deposition method can be performed using the same method as that for the hole injection layer 3.

In general, in an organic electroluminescent device, when compared with the same material, the thinner the film thickness between the electrodes, the larger the effective electric field and the larger the injected current, so that the driving voltage may be lowered. Therefore, the total film thickness between the electrodes should be thin. However, if the film thickness is too thin, a projection caused by the electrode such as ITO may cause a short circuit or quenching due to exciton diffusion near the adjacent layer interface. There is sex. Therefore, it is desirable to have a certain film thickness.
Therefore, when it has organic layers, such as the positive hole injection layer 3 and the positive hole transport layer 4, and the positive hole blocking layer 6 and the electron carrying layer 7 mentioned later other than the light emitting layer 5, the light emitting layer 5 and other organic layers are match | combined. The total film thickness is usually 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, 1000 nm or less, preferably 500 nm or less, and more preferably 300 nm or less.

Further, when the organic layers other than the light emitting layer 5 have high conductivity, the amount of charge injected into the light emitting layer 5 increases. For example, by increasing the thickness of the hole injection layer 3 and decreasing the thickness of the light emitting layer 4, it is possible to reduce the driving voltage while maintaining a certain thickness as the total thickness. In such a case, the thickness of the light emitting layer 5 is usually 10 nm or more, preferably 20 nm or more, and usually 300 nm or less, preferably 200 nm or less.
In addition, as the film thickness of the light emitting layer 5 when the organic electroluminescent element 10 of this Embodiment has only the light emitting layer 5 between both electrodes of the anode 2 and the cathode 9, it is 30 nm or more normally, Preferably it is 50 nm or more, Moreover, it is 500 nm or less normally, Preferably it is 300 nm or less.

<Hole blocking layer 6>
The hole blocking layer 6 can be formed on the light emitting layer 5.
The hole blocking layer 6 can block the holes injected from the anode 2 and moving from reaching the cathode 9, and efficiently transport and inject electrons injected from the cathode 9 to the light emitting layer 5. It is desirable to be formed by a compound that can.
The organic electroluminescent element 10 of the present invention may have a configuration in which the hole blocking layer 6 is omitted.

  A material that can be used for the hole blocking layer 6 preferably has a high electron mobility and a low hole mobility. In addition, the energy gap (difference between HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital)) and the energy of excitons generated in the light emitting layer 5 are large. It is more preferable not to move to the material for forming the hole blocking layer 6, or to form an exciplex with the light emitting layer 5 so as not to lower the efficiency.

Examples of the material for the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolate) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum. Mixed ligand complexes such as, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolato) aluminum binuclear metal complexes, distyrylbiphenyl derivatives, etc. Of styryl compounds (JP-A-11-242996), triazole derivatives such as 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole 7-41759); phenanthroline derivatives such as bathocuproine (Japanese Patent Laid-Open No. 10-79297); Position is a compound having at least one pyridine ring substituted (WO 2005/022962 pamphlet); and the like.
One of these may be used alone, or two or more may be used in any combination and ratio.

  The thickness of the hole blocking layer 6 is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less. The hole blocking layer 6 can be formed by the same method as each layer from the hole injection layer 3 to the light emitting layer 5, and a wet film-forming method, a vacuum evaporation method, etc. can be used.

<Electron transport layer 7>
The electron transport layer 7 can be formed on the hole blocking layer 6 when the hole blocking layer 6 is provided, and on the light emitting layer 5 when there is no hole blocking layer.
The electron transport layer 7 is preferably formed of a compound that can efficiently transport electrons injected from the cathode 9 between the electrodes to which an electric field is applied in the direction of the light emitting layer 5.
The organic electroluminescent element 10 of the present invention may have a configuration in which the electron transport layer 7 is omitted.

  As an electron transporting compound that can be used for the electron transport layer 7, the electron injection efficiency from the cathode 9 or the cathode buffer layer 8 is high, and the injected electrons having high electron mobility can be efficiently transported. A compound is preferred.

Examples of the electron transporting compound that satisfies such conditions include a metal complex such as an aluminum complex of 8-hydroxyquinoline (JP 59-194393 A), a metal complex of 10-hydroxybenzo [h] quinoline, and oxadi Azole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3- or 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compounds ( JP-A-6-207169), phenanthroline derivatives (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthracenediimine, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type zinc selenide, etc. The
One of these may be used alone, or two or more may be used in any combination and ratio.

  The film thickness of the electron transport layer 7 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less. The electron transport layer 7 can be formed by the same method as each layer from the hole injection layer 3 to the hole blocking layer 6, and can be formed by, for example, a wet film forming method or a vacuum evaporation method. Of these, vacuum deposition is preferred.

<Cathode buffer layer 8>
The cathode buffer layer 8 is formed on the electron transport layer 7 when the electron transport layer 7 is provided, and on the hole block layer 6 when the electron transport layer 7 is not provided and the hole block layer 6 is provided. When there is no transport layer 7 and hole blocking layer 6, it can be formed on the light emitting layer 5.
The cathode buffer layer 8 is a layer that efficiently injects electrons injected from the cathode 9 into an adjacent organic layer.
The organic electroluminescent element 10 of the present invention may have a configuration in which the cathode buffer layer 8 is omitted.

As a material that can be used for the cathode buffer layer 8, it is preferable to use a metal having a low work function. This is because electrons are efficiently injected into the organic layer.
Specifically, for example, alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium are used. _{Further, LiF, MgF 2, Li 2} O, may also be used a metal salt such as Cs ₂ CO ₃ (Appl.Phys.Lett, 70 vol, 152 pp., 1997;. Hei 10-74586 JP; IEEE Trans. Electron. Devices, 44, 1245, 1997; SID 04 Digest, 154). One of these may be used alone, or two or more may be used in any combination and ratio.

  The thickness of the cathode buffer layer 8 is usually 0.01 nm or more, preferably 0.1 nm or more, usually 10 nm or less, more preferably 5 nm or less.

The cathode buffer layer 8 can be formed by the same method as each of the layers from the hole injection layer 3 to the electron transport layer 7 described above, and can be formed by, for example, a wet film formation method or a vacuum evaporation method.
In the case of the vacuum deposition method, for example, a deposition source is put in a crucible or a metal boat installed in the vacuum vessel, and the inside of the vacuum vessel is depressurized by a suitable vacuum pump. Thereafter, the crucible or metal boat is heated and evaporated to form the cathode buffer layer 8 on the substrate placed facing the crucible or metal boat.

  The alkali metal can be deposited by using, for example, an alkali metal dispenser in which nichrome is filled with an alkali metal chromate and a reducing agent. By heating the dispenser in a vacuum container, the alkali metal chromate is reduced and the alkali metal is evaporated. When the organic electron transport material and the alkali metal are co-evaporated, the organic electron transport material is placed in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is depressurized with a suitable vacuum pump. Thereafter, each crucible and dispenser can be simultaneously heated and evaporated to form a cathode buffer layer 8 on the substrate placed facing the crucible and dispenser. At this time, co-evaporation is uniformly performed in the film thickness direction of the cathode buffer layer 8, but there may be a concentration distribution in the film thickness direction.

<Cathode 9>
The cathode 9 is formed on the cathode buffer layer 8 when the cathode buffer layer 8 is provided, and on the electron transport layer 7 when the cathode buffer layer 8 is not provided and the electron transport layer 7 is provided. When there is no electron transport layer 7 and there is a hole blocking layer 6, when there is no cathode buffer layer 8, electron transport layer 7 and hole blocking layer 6 on the hole blocking layer 6, the light emitting layer 5. Formed on.
The cathode 9 serves to inject electrons into adjacent anode-side layers (cathode buffer layer 8, electron transport layer 7 and the like).

The material used for the anode 2 can be used for forming the cathode 9. In order to perform electron injection efficiently, it is preferable to use a metal having a low work function, and metals such as tin, magnesium, indium, calcium, aluminum, silver, or alloys thereof are used.
Specific examples of the material for forming the low work function alloy electrode include aluminum, magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.
One of these may be used alone, or two or more may be used in any combination and ratio.

  The thickness of the cathode 9 is usually the same as that of the anode 2, but for the purpose of protecting the cathode made of a low work function metal, a metal layer having a higher work function and being stable to the atmosphere is further formed on the cathode 9. Can be stacked. Examples of metals suitable for this purpose include metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum.

<Other constituent layers>
As mentioned above, although it demonstrated centering on the element of the layer structure shown in FIG. 1, the organic electroluminescent element of this invention is between the anode 2 and the cathode 9, and the light emitting layer 5, unless the performance is impaired, You may have arbitrary layers other than the layer in the said description. Moreover, you may abbreviate | omit arbitrary layers other than the lowest layer organic layer which plays the role of a light emitting layer.

  Further, for the same purpose as the hole blocking layer 6, it is possible to provide an electron blocking layer adjacent to the anode side of the light emitting layer 5. The electron blocking layer increases the probability of recombination with holes in the light emitting layer 5 by preventing electrons moving from the light emitting layer 5 from reaching the hole injection layer 3 or the hole transport layer 4. There are a role of confining the generated excitons in the light emitting layer 5 and a role of efficiently injecting holes injected from the layer on the anode side into the light emitting layer 5.

Furthermore, it is possible to adopt a structure in which a plurality of layers shown in FIG. 1 are stacked (a structure in which a plurality of light emitting units are stacked). In this case, when V ₂ O ₅ or the like is used as the charge generation layer (CGL) instead of the interfacial layer (between the light emitting units) (two layers when the anode is ITO and the cathode is Al), This is more preferable from the viewpoint of luminous efficiency and driving voltage.

The organic electroluminescent element of the present invention can be applied to any of a single element, an element having a structure arranged in an array, and a structure in which an anode and a cathode are arranged in an XY matrix.
Moreover, in the organic electroluminescent element of the present invention, by using a transparent cathode, it is possible to form a top emission type element that takes out light emission from above (from the surface opposite to the substrate 1).

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to a following example, unless it deviates from the summary. In the following description, “part” means “part by weight” unless otherwise specified.

[Example 1]
One kind of diarylpyrene compound of the present invention was synthesized. In the synthesis, a multistage reaction was carried out to obtain target compound 1 (diarylpyrene compound of the present invention) using boronated pyrene (compound 2 below) as a starting material.
Hereinafter, the contents of the multistage reaction synthesis will be described in two stages.

(First stage)
The following formula is a scheme representing the synthesis route from 1-bromo-3-iodobenzene and 3-biphenylboronic acid to the synthesis of compound 1 in the multi-step reaction synthesis route.

1-bromo-3-iodobenzene (15 g) and 3-biphenylboronic acid (10 g) at room temperature under nitrogen atmosphere, toluene (252 ml: represented as “Toluene” in the above scheme), and ethanol (126 ml) : In the above scheme, in addition to a mixed solvent with “EtOH”), tetrakis (triphenylphosphine) palladium (0) (2.91 g: in the above scheme, “Pd (PPh ₃ ) ₄ ”). ) And 2M aqueous potassium carbonate solution (63 ml: represented by “K ₂ CO ₃ ” and “H ₂ O” in the above scheme), and refluxed for 7 hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 10/1) to obtain Compound 1 (13.5 g).

(Second stage)
The following formula is a scheme representing the synthesis of the target compound 1 from the compound 1 and the compound 2 in the synthetic route of the multistage reaction.

Compound 2 (1 g) and Compound 1 (1.32 g) are treated with toluene (22 ml: represented as “Toluene” in the above scheme) and ethanol (11 ml: “EtOH in the above scheme) at room temperature under a nitrogen atmosphere. And tetrakis (triphenylphosphine) palladium (0) (0.13 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme) and 2M sodium carbonate. An aqueous solution (5.5 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 10 hours.

  After cooling to room temperature, the reaction mixture was filtered, and the filtered product was purified by recrystallization (N, N-dimethylformamide) to obtain a compound (0.97 g). The compound was subjected to DEI-MS (Desorption electron ionization mass spectrum), and as a result, m / z = 658 (M +). This confirmed that the compound was the target compound 1 (0.97 g).

[Example 2]
One kind of diarylpyrene compound of the present invention was synthesized. In the synthesis, the target compound 2 (diarylpyrene compound of the present invention) was obtained using boronated pyrene (the following compound 2) as a starting material. The following formula is the scheme represented for the synthesis.

Compound 2 (1 g) and Compound 3 (1.22 g) at room temperature under a nitrogen atmosphere were treated with toluene (22 ml: represented as “Toluene” in the above scheme) and ethanol (11 ml: “EtOH in the above scheme). In addition to a mixed solvent with tetrakis (triphenylphosphine) palladium (0) (0.13 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme) and a 2M aqueous cesium carbonate solution. (5.5 ml: represented by “Cs ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 8 hours.

  The reaction mixture was filtered, and the filtered product was purified by recrystallization (N, N-dimethylformamide) to obtain a compound (0.62 g). As a result of performing DEI-MS on the compound, m / z = 606 (M +). This confirmed that the compound was the target compound 2 (0.62 g).

(Physical properties of target compound 2)
The target compound 2 obtained by the above method had a glass transition temperature of 93 ° C. and a weight loss starting temperature under a nitrogen stream of 533 ° C.

[Example 3]
One kind of diarylpyrene compound of the present invention was synthesized. The synthesis was carried out by a multi-step reaction using boronated pyrene (compound 2 below) as a starting material to obtain target compound 3 (diarylpyrene compound of the present invention).
Hereinafter, the contents of the multistage reaction synthesis will be described in four stages.

(First stage)
The method for synthesizing Compound 1 from 1-bromo-3-iodobenzene and 3-biphenylboronic acid is the same as in the first step of Example 1.
The following formula is a scheme representing the synthesis route from Compound 1 to Compound 4 in the multi-step reaction synthesis route.

In a nitrogen atmosphere at −70 ° C., a solution of Compound 1 (6.8 g) in tetrahydrofuran (120 ml: represented as “THF” in the above scheme) was added to a 1.57 M hexane solution of n-butyllithium (16.8 ml: above). In this scheme, “BuLi” is added dropwise, and after stirring for 5 and a half hours, trimethoxyborane (7.4 ml: expressed as “B (OMe) ₃ ” in the above scheme) is added and stirred for 2 and a half hours. .

After raising the temperature to room temperature, 1N hydrochloric acid (represented as “H ⁺ ” in the above scheme) was added to the reaction mixture, and the mixture was stirred for 1 hour, extracted with saturated brine and methylene chloride, dried over magnesium sulfate, and dried under reduced pressure. Concentrated with. The residue is developed on column chromatography packed with silica gel. First, impurities and by-products are eluted with methylene chloride, and then the solvent is changed to a 1: 1 mixed solvent of methylene chloride and ethyl acetate to elute the target product. Compound 4 (3.89 g) was obtained.

(Second stage)
The following formula is a scheme representing the synthesis process of compound 5 from compound 4 and 3,5-dibromophenol in the multi-step reaction synthesis route.

Compound 4 (3.87 g), 3,5-dibromophenol (1.69 g), toluene (67 ml: represented as “Toluene” in the above scheme), and ethanol (34 ml: In addition to a mixed solvent with “EtOH” in the above scheme, tetrakis (triphenylphosphine) palladium (0) (0.39 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme). And 2M aqueous sodium carbonate solution (17 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) were added and refluxed for 7 and a half hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue is developed on a column chromatography packed with silica gel. First, impurities and by-products are eluted with a 1: 1 solvent mixture of hexane and methylene chloride, and then the solvent is changed to a 1: 1 solvent mixture of hexane and methylene chloride. In other words, the target product was eluted to obtain Compound 5 (3.20 g).

(3rd stage)
The following formula is a scheme showing from compound 5 to synthesis of compound 6 in the multi-step reaction synthesis route.

Compound 5 (2.88 g) in methylene chloride (16 ml: in the above scheme dichloromethane is represented as “CH ₂ Cl ₂ ”) and pyridine (0.41 g: in the above scheme represented “Pyridine”). In addition, trifluoromethanesulfonic anhydride (3.45 g: in the above scheme, dichloromethane is represented as “Tf ₂ O”) was added dropwise under ice cooling, and the mixture was stirred for 1 hour and a half and then water cooled for 3 hours.

  Ice water and 1N hydrochloric acid were added to the reaction mixture, and the mixture was extracted with methylene chloride. The organic layer was washed with ice water, 1N hydrochloric acid and saturated brine in that order, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 2/1) to obtain Compound 6 (3.3 g).

(Fourth stage)
The following formula is a scheme that represents the synthesis of the target compound 3 from the compound 2 and the compound 6 in the multi-step reaction synthesis route.

Compound 2 (0.6 g) and Compound 6 (1.89 g) at room temperature under a nitrogen atmosphere were treated with toluene (13 ml: represented as “Toluene” in the above scheme) and ethanol (6.6 ml: above). In the scheme, it is suspended in a mixed solvent with “EtOH”), and further tetrakis (triphenylphosphine) palladium (0) (0.07 g: represented in the above scheme as “Pd (PPh ₃ ) ₄ )”. 2M aqueous sodium carbonate solution (3.3 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 12 hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was developed on column chromatography packed with silica gel, and impurities and by-products were first eluted with a 3: 1 mixed solvent of hexane and methylene chloride, and then the solvent was changed to a 2: 1 mixed solvent of hexane and methylene chloride. The compound (1.17 g) was obtained by re-precipitation (methylene chloride / ethanol). As a result of performing DEI-MS on this compound, it was m / z = 1266 (M +). This confirmed that the compound was the target compound 3 (1.17 g).

(Physical properties of target compound 3)
The target compound 2 obtained by the above method had a glass transition temperature of 118 ° C. and a weight loss starting temperature under a nitrogen stream of 579 ° C.

[Example 4]
One kind of diarylpyrene compound of the present invention was synthesized. In the synthesis, a multistage reaction was carried out to obtain target compound 4 (diarylpyrene compound of the present invention) using boronated pyrene (compound 2 below) as a starting material.
Hereinafter, the contents of the multistage reaction synthesis will be described in three stages.

(First stage)
The following formula is a scheme showing the synthesis route of 1,7-diiodobenzene and 3-bromophenylboronic acid until synthesis of compound 7 in the multi-step reaction synthesis route.

Under nitrogen atmosphere, 1,3-diiodobenzene (4.1 g), 3-bromophenylboronic acid (5 g), toluene (124 ml: represented as “Toluene” in the above scheme), and ethanol at room temperature. (62 ml: represented by “EtOH” in the above scheme) and a mixed solvent of tetrakis (triphenylphosphine) palladium (0) (0.72 g: “Pd (PPh ₃ ) ₄ ” in the above scheme) 2M sodium carbonate aqueous solution (31 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme)) and refluxed for 8 hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 10/1) to obtain Compound 7 (3.79 g).

(Second stage)
The following formula is a scheme representing the synthesis process of compound 8 from compound 7 and 3-biphenylboronic acid in the synthetic route of the multi-step reaction.

Compound 7 (3.79 g), 3-biphenylboronic acid (1.45 g) at room temperature under a nitrogen atmosphere, toluene (48 ml: represented as “Toluene” in the above scheme), and ethanol (24 ml: above) In addition to the mixed solvent with “EtOH”), tetrakis (triphenylphosphine) palladium (0) (0.56 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme), 2M aqueous sodium carbonate solution (12 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 7 and a half hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 5/1) to obtain Compound 8 (2.14 g).

(3rd stage)
The following formula is a scheme representing the synthesis of the target compound 4 from the compound 2 and the compound 8 in the synthesis route of the multistage reaction.

Compound 2 (0.2 g) and Compound 8 (0.43 g) at room temperature under a nitrogen atmosphere, toluene (4 ml: represented as “Toluene” in the above scheme), and ethanol (2 ml: in the above scheme) Suspended in a mixed solvent with “EtOH”), tetrakis (triphenylphosphine) palladium (0) (0.025 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme), and 2M. An aqueous sodium carbonate solution (1 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 7 and a half hours.

  After cooling to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 2/1) to obtain a compound (0.18 g). As a result of performing DEI-MS on the compound, m / z = 962 (M +). This confirmed that the compound was the target compound 4 (0.18 g).

[Example 5]
One kind of diarylpyrene compound of the present invention was synthesized. In the synthesis, the target compound 5 (diarylpyrene compound of the present invention) was obtained using boronated pyrene (the following compound 2) as a starting material. The following formula is the scheme represented for the synthesis.

Compound 2 (0.65 g) and Compound 9 (1.63 g) at room temperature under a nitrogen atmosphere were treated with toluene (9.6 ml: represented as “Toluene” in the above scheme) and ethanol (2.4 ml: It is suspended in a mixed solvent with “EtOH” in the above scheme, and further tetrakis (triphenylphosphine) palladium (0) (0.10 g: “Pd (PPh ₃ ) ₄ ” in the above scheme). ) And 2M aqueous sodium carbonate solution (4.8 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme), and refluxed for 11 and a half hours.

  After allowing to cool to room temperature, the reaction mixture was filtered, and the filtered product was purified by reprecipitation (tetrahydrofuran / ethanol) to obtain a compound (0.81 g). As a result of performing DEI-MS on this compound, it was m / z = 1116 (M +). This confirmed that the compound was the target compound 5 (0.81 g).

(Physical properties of target compound 5)
The glass transition temperature of the target compound 1 obtained by the above method was 125 ° C.
Moreover, the weight reduction start temperature in a nitrogen stream was 756 degreeC.

[Example 6]
One kind of diarylpyrene compound of the present invention was synthesized. The synthesis was carried out by a multi-step reaction using boronated pyrene (compound 2 below) as a starting material to obtain target compound 6 (diarylpyrene compound of the present invention).
Hereinafter, the contents of the multistage reaction synthesis will be described in two stages.

(First stage)
The following formula is a scheme representing the synthesis of compound 10 from compound 2 and 1,2-dimethoxyethane in the multi-step reaction synthesis route.

Compound 2 (3 g) was dissolved in 1,2-dimethoxyethane (260 ml: represented as “DME” in the above scheme) at room temperature under a nitrogen atmosphere, and 9-bromophenanthrene (1.69 g) was added thereto. In addition, the mixture was stirred, and tetrakis (triphenylphosphine) palladium (0) (0.38 g: represented by “Pd (PPh ₃ ) ₄ ” in the above scheme)) and 2M sodium carbonate aqueous solution (16 ml: Na ₂ CO ₃ ”and“ H ₂ O ”) were added and refluxed for 10 and a half hours.

  After allowing to cool to room temperature, the reaction mixture was filtered, the filtrate was concentrated, extracted by dissolving in methylene chloride, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 1/1) and suspended and washed with ethanol to obtain Compound 10 (0.90 g).

(Second stage)
The following formula is a scheme representing the synthesis process of compound 5 from compound 4 and 3,5-dibromophenol in the multi-step reaction synthesis route.

Compound 10 (1.1 g) and Compound 8 (1 g) at room temperature under a nitrogen atmosphere, toluene (11 ml: represented as “Toluene” in the above scheme), and ethanol (5.6 ml: in the above scheme) In addition to a mixed solvent with “EtOH”), tetrakis (triphenylphosphine) palladium (0) (0.13 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme) and 2M sodium carbonate An aqueous solution (2.8 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 8 hours.

  After allowing to cool to room temperature, the reaction mixture was extracted with toluene, the organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane / methylene chloride = 3/1) and reprecipitated (methylene chloride / ethanol) to obtain a compound (1.3 g). As a result of performing DEI-MS on the compound, m / z = 758 (M +). This confirmed that the compound was the target compound 6 (1.3 g).

(Physical properties of target compound 6)
The target compound 2 obtained by the above method had a glass transition temperature of 124 ° C. and a weight loss starting temperature under a nitrogen stream of 553 ° C.

[Example 7]
One kind of diarylpyrene compound of the present invention was synthesized. In the synthesis, the target compound 7 (diarylpyrene compound of the present invention) was obtained using boronated pyrene (compound 2 below) as a starting material. The following formula is the scheme represented for the synthesis.

Compound 10 (0.48 g) and Compound 11 (0.35 g) at room temperature under nitrogen atmosphere were treated with toluene (4.8 ml: represented as “Toluene” in the above scheme) and ethanol (2.4 ml: In the above scheme, it is added to a mixed solvent with “EtOH”) and stirred. Further, tetrakis (triphenylphosphine) palladium (0) (0.055 g: “Pd (PPh ₃ ) ₄ ” in the above scheme) 2M sodium carbonate aqueous solution (1.2 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme)) and refluxed.

  The reaction mixture was filtered, and the filtered product was purified by recrystallization (N, N-dimethylformamide) to obtain a compound (0.5 g). As a result of performing DEI-MS on the compound, m / z = 658 (M +). This confirmed that the compound was the target compound 7 (0.5 g).

(Physical properties of target compound 7)
The target compound 7 obtained by the above method had a glass transition temperature of 149 ° C. and a weight loss starting temperature under a nitrogen stream of 540 ° C.

[Comparative Example 1]
Comparative compound 1 was synthesized as a comparative example. In the synthesis, comparative compound 1 was obtained using boronated pyrene (compound 2 below) and compound 3 as starting materials. The following formula is the scheme represented for the synthesis.

Compound 2 (1 g), Compound 12 (1.39 g) at room temperature under nitrogen atmosphere, toluene (22 ml: represented as “Toluene” in the above scheme), and ethanol (11 ml: “EtOH” in the above scheme) And tetrakis (triphenylphosphine) palladium (0) (0.13 g: represented as “Pd (PPh ₃ ) ₄ ” in the above scheme)) and a 2M aqueous sodium carbonate solution. (5.5 ml: represented by “Na ₂ CO ₃ ” and “H ₂ O” in the above scheme) was added and refluxed for 8 hours.

  After cooling to room temperature, the reaction mixture was filtered, and the filtered product was purified by recrystallization (N, N-dimethylformamide) to obtain a compound (0.67 g). As a result of performing DEI-MS on the compound, m / z = 688 (M +). This confirmed that the compound was Comparative Compound 1 (0.67 g).

[Example 8]
An organic electroluminescent element was produced by the following production method.

(Formation of anode)
An indium tin oxide (ITO) transparent conductive film was formed on a glass substrate with a thickness of 150 nm (sputtered film product, sheet resistance 15Ω). An anode was formed by patterning into a stripe having a width of 2 mm by a normal photolithography technique.
The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, followed by drying with nitrogen blow and ultraviolet ozone cleaning.

(Formation of hole injection layer)
A hole injection layer was formed on the anode. As a material for the hole injection layer, a non-conjugated polymer compound (PB-1 having a weight average molecular weight of 29,400 and a number average molecular weight of 12,600) having an aromatic amino group having the structural formula shown below is used. Spin-coated with compound (PI-1).

The spin coating was performed under the conditions shown in [Table 1]. The use ratio of PB-1 to PI-1 was PB-1: PI-1 = 10: 4 (weight ratio).
After spin coating, drying was performed at 260 ° C. for 180 minutes to form a uniform hole injection layer thin film having a thickness of 30 nm.

(Hole transport layer)
A hole transport layer was formed on the hole injection layer. Using the compound (HT-3) shown below as a material for the hole transport layer, a uniform hole transport layer thin film having a thickness of 20 nm was formed by vacuum deposition.

(Light emitting layer)
A light emitting layer was formed on the hole transport layer. Using the target compound 2 (diarylpyrene compound of the present invention) produced in Example 2 and the fluorescent light-emitting dopant (D-1) as materials for the light-emitting layer, vacuum evaporation deposition (simultaneous vapor deposition) is simultaneously performed. Thus, a light emitting layer was formed.

The co-evaporation was performed so that the target compound 2 and D-1 were the target compound 2: D-1 = 95: 5 (weight ratio), and a thin film having a uniform light emitting layer with a film thickness of 40 nm was formed.

(Hole blocking layer / electron transport layer)
A hole blocking layer was formed on the light emitting layer, and an electron transporting layer was formed on the hole blocking layer.
A hole blocking layer having a thickness of 10 nm was formed by vacuum deposition using HB-1 shown below as a material for the hole blocking layer.
Next, an electronic element layer having a thickness of 30 nm was formed by vacuum deposition using ET-1 shown below as a material for the electron transport layer.

(Cathode buffer layer / cathode)
A cathode buffer layer was formed on the electron transport layer, and a cathode was formed on the cathode buffer layer.
Using a vacuum evaporation method, a cathode buffer layer having a thickness of 0.5 nm using lithium fluoride (LiF) as a material of the cathode buffer layer, and an anode having a thickness of 80 nm using aluminum as the cathode material are anodes. The stripes were stacked in a 2 mm width shape orthogonal to the ITO stripes.

  As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained. Blue light emission having an electroluminescence peak wavelength of 466 nm was obtained from this device. The characteristics and drive life of the organic electroluminescent elements obtained in Example 8 and Example 9 are collectively shown in [Table 2].

[Example 9]
As a material for the light emitting layer, instead of co-evaporating the target compound 2 and D-1 so that the target compound 2: D-1 = 95: 5 (weight ratio), the target compound 2 and the following compound (E- 1) and D-1 were co-evaporated so that the target compound 2: E-1: D-1 = 70: 30: 5, and a thin film having a uniform light emitting layer thickness of 40 nm was formed. In the same manner as in Example 8, an organic electroluminescent device was obtained. Blue light emission having an electroluminescence peak wavelength of 466 nm was obtained from this device.

[Results of Example 8 and Example 9]
The results of Example 8 and Example 9 are shown in Table 2 below.

[Example 10]
An organic electroluminescent element was obtained in the same manner as in Example 8 except for the formation of the hole transport layer and the light emitting layer. Blue light emission having an electroluminescence peak wavelength of 464 nm was obtained from this device. The characteristics and driving life of the organic electroluminescent elements obtained in [Example 10] and [Example 11] are summarized in [Table 5].
Hereinafter, the formation of the hole transport layer and the light emitting layer will be described.

(Hole transport layer)
A hole transport layer was formed on the hole injection layer. A light emitting layer was formed by spin coating using the following compound (HT-1) as a material for the hole transport layer.

The spin coating was performed under the conditions shown in [Table 3]. After spin coating, drying was performed at 230 ° C. for 60 minutes to form a uniform hole transport layer thin film having a thickness of 20 nm.

(Light emitting layer)
A light emitting layer was formed on the hole transport layer. A light emitting layer was formed by spin coating using the target compound 3 (diarylpyrene compound of the present invention) produced in Example 3 and a fluorescent light emitting dopant (D-1) as materials for the light emitting layer.

The spin coating was performed under the conditions of [Table 4]. Moreover, the use ratio of the target compound 3 and D-1 was made into the target compound 3: D-1 = 10: 1 (weight ratio).
After spin coating, drying was performed at 100 ° C. for 60 minutes to form a uniform light-emitting layer thin film having a thickness of 40 nm.

[Example 11]
Instead of using the target compound 3 and D-1 in the usage ratio of target compound 3: D-1 = 10: 1 (weight ratio) as the material for the light emitting layer, the target compound 6 obtained in Example 6 was used. Thus, an organic electroluminescent element was obtained in the same manner as in Example 10, except that a uniform light emitting layer thin film having a thickness of 40 nm was formed. Blue light emission having an electroluminescence peak wavelength of 466 nm was obtained from this device.

[Results of Example 10 and Example 11]
The results of Example 10 and Example 11 are shown in Table 5 below.

  From the above results, it was possible to produce a device having high color purity, high brightness, and long life by using the compound of the present invention.

  The diarylpyrene compound of the present invention is stable even when it is repeatedly subjected to electrical oxidation and reduction. In addition, when the diarylpyrene compound of the present invention is used for a light emitting layer, particularly a host of the light emitting layer, the dopant can be efficiently emitted. Therefore, it can be suitably used for a composition for an organic electroluminescent element, and further, it can be suitably used for an organic electroluminescent element having a high efficiency and a long life using the composition.

It is sectional drawing which shows typically an example of the structure of the organic electroluminescent element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Hole blocking layer 7 Electron transport layer 8 Cathode buffer layer 9 Cathode 10 Organic electroluminescent device

Claims (10)

A diarylpyrene compound represented by the following formula (1):

(1)
(In the formula (1), Ar ¹ and Ar ² each independently represent an aromatic group composed of a 6-membered ring other than a group derived from a pyrene ring and a group derived from a phenanthroline ring, which may have a substituent. Represent.
X and Z each independently represent a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X, Z, R ¹ and R ² do not include an arylamine structure or a linear alkene structure.
i and j are each independently an integer of 0 or more and 5 or less, and m and n are each independently an integer of 1 or more and 5 or less. However, i + j is 1 or more. When i, j, m, or n is 2 or more, Ar ¹ , Ar ² , X, or Z present in a molecule may be the same or different. ) The diarylpyrene compound according to claim 1, wherein Ar ¹ and Ar ² are each independently any aromatic group selected from the group of the following formulas (2a) to (2l).

The diarylpyrene compound according to claim 1 or 2, wherein X and Z are each independently an aromatic group. The diarylpyrene compound according to claim 1 or 2, represented by any one of the following formulas (3-1) to (3-6):

(In formulas (3-1) to (3-6), X ¹ , X ² , Z ¹ and Z ² each independently represents a group having 50 or less carbon atoms which may have a substituent.
R ¹ and R ² each independently represents a hydrogen atom or a group having 50 or less carbon atoms.
X ¹ , X ² , Z ¹ , Z ² , R ¹ and R ² do not include an arylamine structure or a linear alkene structure. ) The diarylpyrene compound according to claim 4, wherein X ¹ , X ² , Z ¹ and Z ² are each independently an aromatic group. The diarylpyrene compound according to any one of claims 1 to 5, wherein R ¹ and R ² are hydrogen atoms. An organic electroluminescent element material comprising the diarylpyrene compound according to any one of claims 1 to 6. An organic electroluminescent element composition comprising the diarylpyrene compound according to any one of claims 1 to 6. The composition for organic electroluminescent elements according to claim 8, further comprising a solvent. An organic electroluminescent device having an anode, a cathode, and an organic light emitting layer provided between the two electrodes,
It has an organic layer containing the diaryl pyrene compound as described in any one of Claims 1-6, The organic electroluminescent element characterized by the above-mentioned.

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