WO2014006913A1

WO2014006913A1 - Benzodiazaborole compound, and material for organic electroluminescent element and organic electroluminescent element each utilizing same

Info

Publication number: WO2014006913A1
Application number: PCT/JP2013/004167
Authority: WO
Inventors: 真樹沼田; 俊裕岩隈; 圭吉田
Original assignee: 出光興産株式会社
Priority date: 2012-07-06
Filing date: 2013-07-04
Publication date: 2014-01-09
Also published as: TW201418268A

Abstract

A benzodiazaborole compound represented by formula (1) (wherein ring Q that is condensed with a diazaborole ring is a substituted or unsubstituted benzene ring, a substituted or unsubstituted condensed aromatic ring, or a substituted or unsubstituted benzene ring with which at least one substituted or unsubstituted heteroaromatic ring is condensed).

Description

Benzodiazaborol compound, organic electroluminescent element material and organic electroluminescent element using the same

The present invention relates to a novel benzodiazaborol compound, an organic electroluminescence element material using the same, and an organic electroluminescence element.

In an organic EL device, if the compound constituting the organic compound layer has poor electrochemical stability, particularly oxidation stability, these compounds decompose in a short time when a charge is applied from the anode and the cathode, and the device The lifetime is short.
Among known organic materials for organic EL devices, the voltage is reduced when used as a material in a layer where holes are injected or transported, with excellent electrochemical oxidation stability and a shallow ionization potential. There are several things that can be expected.

On the other hand, various organic compounds have been studied as materials for organic EL devices, and compounds having a 1,3,2-diazaborol ring are disclosed as one of them (Patent Documents 1 and 2).

In addition, there are research reports on the optoelectronic properties of compounds having a 1,3,2-benzodiazaborol ring (Non-Patent Documents 1 to 5). Non-Patent Documents 4 and 5 also examine the electrochemical properties.

WO2010 / 108579 WO2006 / 117052

Patent Documents 1 and 2 disclose the use of a benzodiazaborol compound as a material for an organic EL device, but the compounds disclosed therein do not have a substituent on the benzene ring. Similarly, Patent Document 2 discloses the following compound having a 6-membered ring containing two nitrogen atoms and one boron atom, but these compounds have a triplet energy smaller than that of a 5-membered diazaborol.

Most conventional benzodiazaborol compounds have no substituent on the benzene ring constituting the skeleton. Although there are compounds in which a methoxy ring or a cyano group is substituted on the benzene ring, the two nitrogen atom substituents of the diazaborol ring are hydrogen atoms (Non-patent Documents 4 and 5). In addition, although there are compounds in which an aromatic ring is condensed to a benzene ring, the substituents of the two nitrogen atoms of the diazabolol ring are a hydrogen atom or an ethyl group (Non-patent Document 5).
Non-Patent Documents 4 and 5 are examining the electrochemical (oxidation) stability of these compounds in addition to the optoelectronic properties, but pointed out that all of these compounds are electrochemically unstable. ing.

Therefore, any of the compounds having a 1,3,2-benzodiazaborol ring reported so far has poor electrochemical stability and is insufficient as an organic material for an organic EL device.

An object of the present invention is to provide a benzodiazaborol compound which is excellent in electrochemical stability, particularly oxidation stability, and is suitable as a material for an organic compound layer of an organic EL device.
In order to achieve the above object, the present inventor has advanced research on compounds having a 1,3,2-benzodiazaborol ring, and the benzene ring constituting the benzodiazaborol skeleton has sp ² hybrid orbital properties. A benzodiazaborol compound having a specific substituent bonded by an atom or having a condensed ring and having an aromatic ring group or a heteroaromatic ring group at two nitrogen atoms of the diazaborol ring has been found. When the 1,3,2-benzodiazaborol ring has a specific substituent or condensed ring at a predetermined position in this manner, electrochemical oxidation stability is improved. It has been found that by using such a compound in an organic compound layer of an organic EL device, the device life can be improved.
In addition, the inventor has a skeleton in which two benzodiazaborol skeletons are condensed via a boron atom and a nitrogen atom, and an aromatic ring group or a heterocycle is added to two nitrogen atoms that are not used for the condensation of a diazaborol ring. A novel benzodiazaborol compound having an aromatic ring group has been found. By having a skeleton in which two 1,3,2-benzodiazaborol rings are condensed and having a specific substituent or condensed ring at a predetermined position, electrochemical oxidation stability is improved. It has been found that by using such a compound in an organic compound layer of an organic EL device, the device life can be improved.
The present invention has been completed based on these findings.

According to the present invention, the following benzodiazaborol compounds, materials for organic electroluminescence elements, and organic EL elements are provided.
1. A benzodiazaborol compound represented by formula (1).

(Where
A ¹ and A ² are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group,
A substituted or unsubstituted sulfone group, or a single bond,
A ³ is,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms,
A fluoro group,
A cyano group or a single bond,
A ¹ and A ³ , or A ² and A ³ may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A ¹ , A ² , and A ³ are not bonded to each other to form the following ring in which three diazaborol rings are condensed.

Ring Q fused with the diazaborol ring is
A substituted or unsubstituted benzene ring,
A substituted or unsubstituted benzene ring in which at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic aromatic ring having 5 to 24 ring atoms is condensed And
n is an integer from 1 to 6,
When n is 1, L does not exist,
when n is 2 to 6, L is a linking group that bridges between any of Q, A ¹ , A ² , and A ³ , or a single bond;
When n is 2 to 6, n, Q, A ¹ , A ² , and A ³ may be the same as or different from each other.
However,
(I) When n is 1 and Q is an unsubstituted benzene ring,
(Ii) when n is 2 to 6, Q is an unsubstituted benzene ring, and L is a single bond, when the unsubstituted benzene rings Q are bonded to each other by a single bond L, And (iii) When n is 2 to 6 and Q is an unsubstituted benzene ring, any of A ¹ , A ² or A ³ is bonded by L. )

ADVANTAGE OF THE INVENTION According to this invention, the benzodiazaborol compound excellent in electrochemical stability, especially oxidation stability can be provided.
ADVANTAGE OF THE INVENTION According to this invention, the material for organic EL elements excellent in electrochemical stability, especially oxidation stability can be provided.
ADVANTAGE OF THE INVENTION According to this invention, the organic EL element with improved element lifetime can be provided.

It is the schematic which shows the layer structure of one Embodiment of the organic EL element of this invention. It is fu. 4 is a graph showing the results of cyclic voltammetry measurement of Compound 7. It is a graph which shows the measurement result of the cyclic voltammetry of the comparative example compound E1.

The benzodiazaborol compound of the present invention is represented by the formula (1).

Where
A ¹ and A ² are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group,
It is a substituted or unsubstituted sulfone group, or a single bond.

A ³ is,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms,
A fluoro group,
It is a cyano group or a single bond.

A ¹ and A ³ , or A ² and A ³ may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A ¹ , A ² , and A ³ are not bonded to each other to form the following ring in which three diazaborol rings are condensed.

Ring Q fused with the diazaborol ring is
A substituted or unsubstituted benzene ring,
A substituted or unsubstituted benzene ring in which at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic aromatic ring having 5 to 24 ring atoms is condensed And
n is an integer of 1 to 6, preferably 1 to 3.
When n is 1, L does not exist,
when n is 2 to 6, L is a linking group that bridges between any of Q, A ¹ , A ² , and A ³ , or a single bond;
When n is 2 to 6, n, Q, A ¹ , A ² , and A ³ may be the same as or different from each other.
However,
(I) When n is 1 and Q is an unsubstituted benzene ring,
(Ii) when n is 2 to 6, Q is an unsubstituted benzene ring, and L is a single bond, when the unsubstituted benzene rings Q are bonded to each other by a single bond L, And (iii) When n is 2 to 6 and Q is an unsubstituted benzene ring, any of A ¹ , A ² or A ³ is bonded by L.

A preferred first aspect of the present invention will be described.
The benzodiazaborol compound of the present invention is preferably represented by the following formula (I-1).

Where
A ¹ and A ² are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group,
A substituted or unsubstituted sulfone group, or a single bond,

A ¹ and A ³ , or A ² and A ³ may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A ¹ and A ³ , or A ² and A ³ are not bonded to each other to form the following 5-membered ring.

A ¹ , A ² , and A ³ are each independently a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaromatic group having 5 to 30 ring atoms. It is preferably an aromatic ring group, substituted or unsubstituted phenyl group, substituted or unsubstituted tolyl group, substituted or unsubstituted xylyl group, substituted or unsubstituted mesityl group, substituted or unsubstituted biphenyl group, substituted Or an unsubstituted fluorenyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted triphenylenine group, a substituted or unsubstituted m-terphenyl group, a substituted or unsubstituted dibenzofuranyl group, substituted or unsubstituted Of these, a dibenzothiophenyl group or a substituted or unsubstituted carbazolyl group is more preferable.

The ring Q condensed with the diazaborol ring has at least one substituent R, and may further have an optional substituent, a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted ring It is a benzene ring in which at least one heteroaromatic ring is condensed and may further have an arbitrary substituent.

Substituent R is
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
a substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms bonded by an atom having sp ² hybrid orbital property,
a substituted or unsubstituted ring-formed unsaturated aliphatic hydrocarbon ring group having 3 to 20 carbon atoms bonded by an atom having sp ² hybrid orbital property,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl sulfide group having 6 to 30 ring carbon atoms.

Specific examples of each group of the substituent R will be described later together with specific examples of the optional substituent of Q and the substituent of “substituted or unsubstituted”.

Examples of the “atom having sp ² hybrid orbital” include, for example, a carbon atom having a trivalent bonding state in an aromatic ring, a carbon atom having a trivalent bonding state in a heteroaromatic ring, or a nitrogen atom. , Carbon atom of ethylene group, oxygen atom of ether group, nitrogen atom of amino group, boron atom of boryl group, phosphorus atom of phosphino group, sulfur atom of sulfide group, trivalent bonding state in aromatic ring A carbon atom having a carbon atom, a carbon atom having a trivalent bonding state in a heteroaromatic ring, or a nitrogen atom is preferable.

Substituent R is a substituted or unsubstituted phenyl group, a substituted or unsubstituted o-biphenyl group, a substituted or unsubstituted m-biphenyl group, a substituted or unsubstituted p-biphenyl group, a substituted or unsubstituted m- Terphenyl group, substituted or unsubstituted p-terphenyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted phenanthryl group, substituted or unsubstituted triphenylenine group, substituted or unsubstituted dibenzofuranyl group , A substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted carbazolyl group is preferable.

When Q is a substituted or unsubstituted aromatic ring or a benzene ring fused with a substituted or unsubstituted heteroaromatic ring, the condensed ring containing the benzene ring is:
A condensed aromatic hydrocarbon ring having 9 to 30 ring carbon atoms formed by condensation of 2 or more, preferably 3 or more, 5- to 7-membered hydrocarbon rings, or 1 or more, preferably 2 or more A condensed heteroaromatic ring having 9 to 30 ring atoms formed by condensation of a 5- to 7-membered hydrocarbon ring and one or more 5- to 7-membered heterocyclic rings,
And
More preferably, it is substituted or unsubstituted phenanthrene, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, or substituted or unsubstituted carbazole.

As an optional substituent of Q,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms,
A substituted or unsubstituted cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted sulfoxide group,
Substituted or unsubstituted sulfone group,
Examples include a fluoro group and a cyano group.

Specific examples of each of the arbitrary substituents of Q will be described later together with specific examples of the substituent R and the substituent of “substituted or unsubstituted”.

n is an integer of 1 to 6, preferably an integer of 1 to 4, and more preferably 1 or 2.
When n is 1, L does not exist,
When n is 2 to 6, L is a linking group that bridges between Q, A ¹ , A ² , and A ³ , or a single bond.
When n is 2 to 6, n, Q, A ¹ , A ² , and A ³ may be the same as or different from each other.

Examples of the case where L is a linking group include an ether group, a thioether group, a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, a substituted or unsubstituted ring atom number of 6 to 30 Heteroaromatic ring groups, and substituted or unsubstituted amino groups, ether groups, substituted or unsubstituted benzene rings, substituted or unsubstituted dibenzofuran rings, dibenzothiophene rings, carbazole rings, substituted or unsubstituted And a n-valent group derived from a substituted or unsubstituted biphenyl.

The benzodiazaborol compound represented by the formula (I-1) preferably has a basic skeleton selected from the group consisting of the following structural formulas (I-2) to (I-14). Q is preferably a ring that is condensed with the diazaborol ring in the following structural formulas (I-2) to (I-14).
Here, the “basic skeleton” means that the benzene ring of the benzodiazaborol skeleton, the ring condensed to the benzene ring, and the substituent of the benzene ring may have a substituent.

In the formula, A ¹ to A ³ , L, and n are as defined in the formula (I-1).
X is each independently an oxygen atom, a nitrogen atom, or a sulfur atom.

In the case where A ¹ and A ³ or A ² and A ³ are bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the diazaborol skeleton, the following structural formulas (I-15) and (I It preferably has a basic skeleton selected from the group consisting of -16).
Here, the “basic skeleton” means that the benzene ring condensed to the 6-membered ring formed including the nitrogen atom and boron atom of the benzodiazaborol skeleton may have a substituent. .

In the formula, A ¹ , A ² , Q, L, and n are as defined in the formula (I-1).

As the “substituted or unsubstituted” substituent in each group in the formulas (I-1) to (I-16),
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms,
A substituted or unsubstituted cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted alkylsulfide group having 1 to 20 carbon atoms, and a substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted sulfoxide group,
Substituted or unsubstituted sulfone group,
Examples include a fluoro group and a cyano group.

Hereinafter, each of the substituent R of Q, the arbitrary substituent of Q, and the “substituted or unsubstituted” substituent will be described in detail.
In the present specification, the aromatic ring group includes a monocyclic aromatic hydrocarbon ring group, a condensed aromatic hydrocarbon ring group in which a plurality of hydrocarbon rings are condensed, and a group in which a plurality of hydrocarbon rings are connected by a single bond. And the heteroaromatic ring group includes a monocyclic heteroaromatic ring group, a heterofused aromatic ring group in which a plurality of heteroaromatic rings are condensed, and an aromatic hydrocarbon ring and a heteroaromatic ring are condensed. Contains a hetero-fused aromatic ring group.
“Ring-forming carbon” means a carbon atom constituting a saturated hydrocarbon ring, an unsaturated hydrocarbon ring or an aromatic ring, and “ring-forming atom” means an atom constituting a heteroaromatic ring.

Examples of the aromatic ring group having 6 to 30 ring carbon atoms include phenyl group, tolyl group, xylyl group, mesityl group, o-biphenyl group, m-biphenyl group, p-biphenyl group, o-terphenyl group, m- Examples thereof include a terphenyl group, a p-terphenyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, an anthryl group, a phenalenyl group, a fluoranthenyl group, a triphenylenyl group, a naphthacenyl group, a chrycenyl group, and a pyrenyl group. Of these, phenyl, o-biphenyl, m-biphenyl, p-biphenyl, m-terphenyl, p-terphenyl, naphthyl, phenanthryl, and triphenylenyl are preferred.

Heteroaromatic ring groups having 5 to 30 ring atoms include pyrrolyl, pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, triazinyl, indolyl, isoindolyl, quinolyl, isoquinolyl, quinoxalinyl, carbazolyl Group, azacarbazolyl group, phenanthridinyl group, acridinyl group, phenanthrolinyl group, pyrrolidinyl group, piperidinyl group, piperazinyl group, triazolyl group, imidazolyl group, benzoimidazolyl group, furyl group, benzofuranyl group, isobenzofuranyl group, Dibenzofuranyl group, dioxanyl group, oxazolyl group, pyranyl group, benzo [c] dibenzofuranyl group dibenzothiophenyl group, thienyl group, thiophenyl group, azadibenzofuranyl group, morpholinyl group, oxadiazolyl , Benzoxazolyl group, aza dibenzothiophenyl group, thiazolyl group, thiadiazolyl group, benzothiazolyl group, Zia Szabo roll ring group, and the like, are preferred for these ring atoms 6 to 14.

Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, and n-hexyl group. N-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group N-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, 3-methylpentyl group, etc. Of these, those having 1 to 6 carbon atoms are preferred.
Further, the alkyl group having 3 to 20 carbon atoms is one obtained by removing the methyl group and the ethyl group from the examples of the alkyl group having 1 to 20 carbon atoms.

Examples of the cycloalkyl group having 3 to 20 ring carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a norbornyl group, an adamantyl group, and the like. Are preferred.

Examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group and the like, and those having 3 or more carbon atoms are linear, cyclic or branched Among them, those having 1 to 6 carbon atoms are preferable.

Examples of the cycloalkoxy group having 3 to 20 carbon atoms include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, etc. Among them, those having 5 or 6 ring carbon atoms are preferable.

Examples of the aryloxy group having 6 to 30 ring carbon atoms include a phenoxy group and a biphenyloxy group, and a phenoxy group is preferable.

Examples of the unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms include ethylene group, propylene group, 1-butene group, 2-butene group, 1,3-butadiene group, 2-methylpropene group, 1-pentene group, Examples include 2-pentene group, 1-hexene group, 2-hexene group, 3-hexene group and the like.
In addition, when it is the substituent R, it is an unsaturated aliphatic hydrocarbon group bonded to the benzene ring of the benzodiazaborol skeleton by an atom having sp ² hybrid orbital among the above groups. Specifically, ethylene group, 1-propen-1-yl group, 1-propen-2-yl group, 1-buten-1-yl group, 1-buten-2-yl group, 2-buten-2- Yl group, 1,3-butadiene-1-yl group, 1,3-butadiene-2-yl group, 2-methylpropen-1-yl group, 1-penten-1-yl group, 1-penten-2- Yl, 2-penten-2-yl, 2-penten-3-yl, 1-hexen-1-yl, 1-hexen-2-yl, 2-hexen-2-yl, 2- Examples include a hexen-3-yl group, a 3-hexen-3-yl group, and a 3-hexen-4-yl group.

Examples of the unsaturated aliphatic hydrocarbon ring group having 3 to 20 ring carbon atoms include a cyclopropene group, a cyclobutene group, a cyclopentene group, a cyclohexene group, a cycloheptene group, and a cyclooctene group.
In addition, when it is the substituent R, it is an unsaturated aliphatic hydrocarbon ring group bonded to the benzene ring of the benzodiazaborol skeleton by an atom having sp ² hybrid orbital among the above groups. Specifically, a cyclopropen-1-yl group, a cyclobuten-1-yl group, a cyclopenten-1-yl group, a cyclohexen-1-yl group, a cyclohepten-1-yl group, a cycloocten-1-yl group, etc. Can be mentioned.

The alkyl sulfide group having 1 to 20 carbon atoms is represented by —SX, and X is the above alkyl group having 1 to 20 carbon atoms.

An aryl sulfide group having 6 to 30 ring carbon atoms is represented by —SY, and Y is an aromatic ring group having 6 to 30 ring carbon atoms.

“Unsubstituted” in “substituted or unsubstituted...” Means that a hydrogen atom is substituted. In the present invention, a hydrogen atom is an isotope having a different neutron number, that is, light hydrogen. (Protium), deuterium, tritium.

Specific examples of the benzodiazaborol compounds represented by the formulas (I-1) to (I-16) of the present invention are described below, but the present invention is not limited to the following compounds.

The compound of the present invention represented by the formula (I-1) can be synthesized by the method described in Examples or a method known to those skilled in the art.

The compound of the present invention represented by the formula (I-1) is excellent in electrochemical oxidation stability as compared with the conventional benzodiazaborol compound. This is because the compound of the present invention has a specific substituent or condensed ring bonded to the benzene ring constituting the benzodiazaborol skeleton with an atom having sp ² hybrid orbital, and two nitrogen atoms of the diazabolol ring This is because it has an aromatic ring group or a heteroaromatic ring group. The electrochemical oxidative stability of the compound can be evaluated by the cyclic voltammetric measurement described in the examples.
In addition to the method described in the Examples, those skilled in the art can carry out the cyclic voltammetry by appropriately changing the method based on known knowledge according to the properties of the compound.

Further, the compound of the present invention not only improves the electrochemical oxidation stability but also reduces the ionization potential, so that it can be used as a material in a layer into which holes of an organic EL element are injected or transported. Further lower voltage can be expected.
Further, although it is known that the triplet energy of the 1,3,2-diazaborol ring itself is a wide gap, the compound having a substituent having sp ² hybrid orbital property at a predetermined position (I-1) to Even in the case of having the structure represented by (I-16), even a person skilled in the art cannot predict that the triplet energy is maintained in a wide gap.

Next, a preferred second aspect of the present invention will be described.
The benzodiazaborol compound of the present invention is represented by the following formula (II-1).

Where
A ¹¹ and A ¹² are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group, or a substituted or unsubstituted sulfone group,

A ¹¹ and A ¹² may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A ¹¹ and A ¹² are not bonded to each other to form the following 5-membered ring.

That is, A ¹¹ and A ¹² are bonded to each other, and the compound having the following skeleton is excluded from the formula (II-1).

Rings Q ¹ and Q ² fused with the diazaborol ring are each independently
A substituted or unsubstituted benzene ring,
A substituted or unsubstituted benzene ring in which at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic aromatic ring having 5 to 24 ring atoms is condensed It is.

n ² is an integer of 1 to 6, preferably 1 to 3.
When n ² is 1, L ² is not present,
When n ² is 2 to 6, L ² is a linking group that bridges between any of Q ¹ , Q ² , A ¹¹ , and A ¹² , or a single bond,
When n ² is 2 to 6, n ² Q ¹ , Q ² , A ¹¹ , and A ¹² may be the same as or different from each other.

Examples of the case where L ² is a linking group include, for example, an ether group, a thioether group, a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, a substituted or unsubstituted ring atom number of 6 to 30 heteroaromatic ring groups, and substituted or unsubstituted amino groups, ether groups, substituted or unsubstituted benzene rings, substituted or unsubstituted dibenzofuran rings, dibenzothiophene rings, carbazole rings, substituted or unsubstituted substituted fluorene ring, and a substituted or n ² divalent group derived from an unsubstituted biphenyl is preferred.

Q ¹ and Q ² are fused with at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 ring carbon atoms, or substituted or unsubstituted heteroaromatic ring having 5 to 24 ring atoms. Specific examples of the condensed ring containing the benzene ring in the case of a substituted or unsubstituted benzene ring include, for example, substituted or unsubstituted phenanthrene, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorene, substituted or unsubstituted Examples thereof include substituted dibenzofuran, substituted or unsubstituted dibenzothiophene, or substituted or unsubstituted carbazole.
Q ¹ and Q ² are preferably substituted or unsubstituted benzene rings.

Specific examples of the substituents A ¹¹ and A ¹² will be described later.

The benzodiazaborol compound represented by the above formula (II-1) is preferably a compound represented by the following formula (II-2).

Where
A ¹¹ and A ¹² are as defined in Formula (II-1),

R ¹ to R ⁸ are each independently
Hydrogen atom,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
a substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms bonded by an atom having sp ² hybrid orbital property,
a substituted or unsubstituted ring-formed unsaturated aliphatic hydrocarbon ring group having 3 to 20 carbon atoms bonded by an atom having sp ² hybrid orbital property,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group, or a substituted or unsubstituted sulfone group,
Adjacent groups of R ¹ to R ⁸ may be bonded to form a ring.

As the "atoms having sp ² hybrid orbital properties", for example, carbon atoms having a trivalent bonding states in the aromatic ring, carbon atom or a nitrogen atom having a trivalent bonding states in the heteroaromatic ring , Carbon atom of ethylene group, oxygen atom of ether group, nitrogen atom of amino group, boron atom of boryl group, phosphorus atom of phosphino group, sulfur atom of sulfide group, trivalent bonding state in aromatic ring A carbon atom having a carbon atom, a carbon atom having a trivalent bonding state in a heteroaromatic ring, or a nitrogen atom is preferable.

Specific examples of each group of A ¹¹ , A ¹² , and R ¹ to R ⁸ will be described together with specific examples of the optional substituent of Q ¹ and Q ² and the substituent of “substituted or unsubstituted”.

As an optional substituent of Q ¹ and Q ² ,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms,
A substituted or unsubstituted cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted sulfoxide group,
Substituted or unsubstituted sulfone group,
Examples include a fluoro group and a cyano group.

As the “substituted or unsubstituted” substituent in each group in the formulas (II-1) and (II-2),
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms,
A substituted or unsubstituted cyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted alkylsulfide group having 1 to 20 carbon atoms, and a substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted sulfoxide group,
Substituted or unsubstituted sulfone group,
Examples include a fluoro group and a cyano group.

Hereinafter, the arbitrary substituents of Q ¹ and Q ² and each group of the “substituted or unsubstituted” substituent will be specifically described.
In the present specification, the aromatic ring group includes a monocyclic aromatic hydrocarbon ring group, a condensed aromatic hydrocarbon ring group in which a plurality of hydrocarbon rings are condensed, and a group in which a plurality of hydrocarbon rings are connected by a single bond. The aromatic heterocyclic group includes a monocyclic heteroaromatic ring group, a hetero-fused aromatic ring group in which a plurality of heteroaromatic rings are condensed, and an aromatic hydrocarbon ring and a heteroaromatic ring are condensed. Contains a hetero-fused aromatic ring group.
“Ring-forming carbon” means a carbon atom constituting a saturated hydrocarbon ring, an unsaturated hydrocarbon ring or an aromatic ring, and “ring-forming atom” means an atom constituting a heteroaromatic ring.

Heteroaromatic ring groups having 5 to 30 ring atoms include pyrrolyl, pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, triazinyl, indolyl, isoindolyl, quinolyl, isoquinolyl, quinoxalinyl, carbazolyl Group, azacarbazolyl group, phenanthridinyl group, acridinyl group, phenanthrolinyl group, pyrrolidinyl group, piperidinyl group, piperazinyl group, triazolyl group, imidazolyl group, benzoimidazolyl group, furyl group, benzofuranyl group, isobenzofuranyl group, Dibenzofuranyl, dioxanyl, oxazolyl, pyranyl, benzo [c] dibenzofuranyl, dibenzothiophenyl, thienyl, thiophenyl, azadibenzofuranyl, morpholinyl, oxadiazoli Group, benzoxazolyl group, aza dibenzothiophenyl group, thiazolyl group, thiadiazolyl group, benzothiazolyl group, Zia Szabo roll ring group, and the like, are preferred for these ring atoms 6 to 14.

Examples of the unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms include ethylene group, propylene group, 1-butene group, 2-butene group, 1,3-butadiene group, 2-methylpropene group, 1-pentene group, Examples include 2-pentene group, 1-hexene group, 2-hexene group, 3-hexene group and the like.

Examples of the unsaturated aliphatic hydrocarbon ring group having 3 to 20 ring carbon atoms include a cyclopropene group, a cyclobutene group, a cyclopentene group, a cyclohexene group, a cycloheptene group, and a cyclooctene group.

A ¹¹ and A ¹² are each independently
It is preferably a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms.

A ¹¹ and A ¹² are each independently
A substituted or unsubstituted phenyl group,
A substituted or unsubstituted biphenyl group,
A substituted or unsubstituted terphenyl group,
A substituted or unsubstituted fluorenyl group,
A substituted or unsubstituted pyridinyl group,
A substituted or unsubstituted pyrimidinyl group,
A substituted or unsubstituted triazinyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted azadibenzofuranyl group,
A substituted or unsubstituted azadibenzothiophenyl group,
A substituted or unsubstituted azacarbazolyl group,
More preferably, it is selected from the group consisting of a substituted or unsubstituted benzimidazolyl group and a substituted or unsubstituted imidazolyl group.

At least one of R ¹ to R ⁸ is preferably a substituent bonded by an atom having sp ² property that is not a hydrogen atom.

One or two of R ¹ to R ⁸ are each independently
A substituted or unsubstituted phenyl group,
A substituted or unsubstituted biphenyl group,
A substituted or unsubstituted terphenyl group,
A substituted or unsubstituted fluorenyl group,
A substituted or unsubstituted pyridinyl group,
A substituted or unsubstituted pyrimidinyl group,
A substituted or unsubstituted triazinyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted azadibenzofuranyl group,
A substituted or unsubstituted azadibenzothiophenyl group,
A substituted or unsubstituted azacarbazolyl group,
A group selected from the group consisting of a substituted or unsubstituted benzimidazolyl group and a substituted or unsubstituted imidazolyl group,
The other R ¹ to R ⁸ are preferably hydrogen atoms.

Any substituents of Q ¹ , Q ² , A ¹¹ , A ¹² , and R ¹ to R ⁸ may further have a substituent.

Specific examples of the benzodiazaborol compounds represented by the formulas (II-1) and (II-2) of the present invention are described below, but the present invention is not limited to the following compounds.

The compound of the present invention represented by the formula (II-1) can be synthesized by the method described in Examples or a method known to those skilled in the art.

The compound of the present invention represented by the formula (II-1) is excellent in electrochemical oxidative stability as compared with conventional benzodiazaborol compounds.
This effect is obtained when each of the benzene rings constituting the two benzodiazaborol skeletons further has an aromatic ring group or a heteroaromatic ring group at the nitrogen atom of the two diazaborol rings condensed with the compound of the present invention. In particular, it is more prominent when it has a specific substituent or fused ring bonded by an atom having sp ² hybrid orbital properties.

Further, the compound of the present invention represented by the formula (II-1) not only improves the electrochemical oxidation stability, but also has a shallow ionization potential, so that holes of the organic EL element are injected or transported. When used as a material in a layer, a further lower voltage can be expected.
Furthermore, although it is known that the triplet energy of the 1,3,2-diazaborol ring itself is a wide gap, it has a skeleton in which two benzodiazaborol skeletons are condensed via a boron atom and a nitrogen atom. However, the triplet energy has a wide gap even when it has a structure represented by the formula (II-1) having an aromatic ring group or a heteroaromatic ring group at two nitrogen atoms that are not used for the condensation of the diazaborol ring. It will not be anticipated by those skilled in the art that it will be maintained.

(Materials for organic electroluminescence elements)
The material for an organic electroluminescence element (organic EL element) of the present invention (hereinafter sometimes referred to as the material of the present invention) includes the compound of the present invention represented by the above formula (1).
The material for an organic EL device of the present invention can be suitably used as a material for an organic thin film layer constituting the organic EL device.

Next, the organic EL element of the present invention will be described.
The organic EL device of the present invention has one or more organic thin film layers including a light emitting layer between an anode and a cathode. And at least 1 layer of an organic thin film layer contains the organic EL element material of this invention.

(Organic electroluminescence device)
Next, an embodiment of the organic EL element of the present invention will be described.
The organic EL device of the present invention has an organic thin film layer containing a light emitting layer between a cathode and an anode, and at least one of the organic thin film layers contains the above-described organic EL device material of the present invention. Thus, the life of the organic EL element can be extended.
Examples of the organic thin film layer containing the organic EL device material of the present invention include a hole transport layer, a light emitting layer, an electron transport layer, a space layer, and a barrier layer, but are not limited thereto. Absent. The material for an organic EL device of the present invention is preferably contained in the light emitting layer, and particularly preferably used as a host material for the light emitting layer. Further, the light emitting layer preferably contains a fluorescent light emitting material or a phosphorescent light emitting material, and particularly preferably contains a phosphorescent light emitting material. Furthermore, the organic EL device material of the present invention is also suitable as an organic layer used in a hole transport zone,
It is also suitable as a material added to the hole transport zone.

The organic EL element of the present invention may be a fluorescent or phosphorescent monochromatic light emitting element, a fluorescent / phosphorescent hybrid white light emitting element, or a simple type having a single light emitting unit. A tandem type having a plurality of light emitting units may be used, and among them, a phosphorescent type is preferable. Here, the “light emitting unit” refers to a minimum unit that includes one or more organic layers, one of which is a light emitting layer, and can emit light by recombination of injected holes and electrons.

Accordingly, typical element configurations of simple organic EL elements include the following element configurations.
(1) Anode / light emitting unit / cathode The above light emitting unit may be a laminated type having a plurality of phosphorescent light emitting layers and fluorescent light emitting layers. In that case, the light emitting unit is generated by a phosphorescent light emitting layer between the light emitting layers. In order to prevent the excitons from diffusing into the fluorescent light emitting layer, a space layer may be provided. A typical layer structure of the light emitting unit is shown below.
(A) Hole transport layer / light emitting layer (/ electron transport layer)
(B) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer (/ electron transport layer)
(C) Hole transport layer / phosphorescent layer / space layer / fluorescent layer (/ electron transport layer)
(D) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(E) Hole transport layer / first phosphorescent light emitting layer / space layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(F) Hole transport layer / phosphorescent layer / space layer / first fluorescent layer / second fluorescent layer (/ electron transport layer)
(G) Hole transport layer / electron barrier layer / light emitting layer (/ electron transport layer)
(H) Hole transport layer / light emitting layer / hole barrier layer (/ electron transport layer)
(I) Hole transport layer / fluorescent light emitting layer / triplet barrier layer (/ electron transport layer)

Each phosphorescent or fluorescent light-emitting layer may have a different emission color. Specifically, in the laminated light emitting layer (d), hole transport layer / first phosphorescent light emitting layer (red light emitting) / second phosphorescent light emitting layer (green light emitting) / space layer / fluorescent light emitting layer (blue light emitting) / Examples include a layer configuration such as an electron transport layer.
An electron barrier layer may be appropriately provided between each light emitting layer and the hole transport layer or space layer. Further, a hole blocking layer may be appropriately provided between each light emitting layer and the electron transport layer. By providing an electron barrier layer or a hole barrier layer, electrons or holes can be confined in the light emitting layer, the recombination probability of charges in the light emitting layer can be increased, and the lifetime can be improved.

The following element structure can be mentioned as a typical element structure of a tandem type organic EL element.
(2) Anode / first light emitting unit / intermediate layer / second light emitting unit / cathode Here, as the first light emitting unit and the second light emitting unit, for example, the same light emitting unit as that described above is selected independently. can do.
The intermediate layer is generally called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, or an intermediate insulating layer, and has electrons in the first light emitting unit and holes in the second light emitting unit. A known material structure to be supplied can be used.

FIG. 1 is a schematic view showing a layer structure of an embodiment of the organic EL device of the present invention.
The organic EL element 1 has a configuration in which an anode 20, a hole transport zone 30, a light emitting layer 40, an electron transport zone 50, and a cathode 60 are laminated on a substrate 10 in this order. The hole transport zone 30 refers to an organic layer sandwiched between the anode 20 and the light emitting layer 40, and means, for example, a hole transport layer, a hole injection layer, an electron barrier layer, or the like. Similarly, the electron transport zone 50 refers to an organic layer sandwiched between the cathode 60 and the light emitting layer 40, and means, for example, an electron transport layer, an electron injection layer, a hole barrier layer, or the like. The barrier layer can confine electrons and holes in the light emitting layer 40 and increase the probability of exciton generation in the light emitting layer 40. These need not be formed, but preferably one or more layers are formed. In this element, the organic thin film layer is each organic layer provided in the hole transport zone 30, each light emitting layer 40, and each organic layer provided in the electron transport zone 50. Among these organic thin film layers, at least one layer contains the organic EL element material of the present invention.
The content of this material with respect to one organic thin film layer containing the organic EL element material of the present invention is preferably 1 to 100% by weight.

In this specification, a host combined with a fluorescent dopant is referred to as a fluorescent host, and a host combined with a phosphorescent dopant is referred to as a phosphorescent host. The fluorescent host and the phosphorescent host are not distinguished only by the molecular structure. That is, the phosphorescent host means a material constituting a phosphorescent light emitting layer containing a phosphorescent dopant, and does not mean that it cannot be used as a material constituting a fluorescent light emitting layer. The same applies to the fluorescent host.

(substrate)
The organic EL element of the present invention is produced on a translucent substrate. The light-transmitting substrate is a substrate that supports the organic EL element, and is preferably a smooth substrate having a light transmittance in the visible region of 400 nm to 700 nm of 50% or more. Specifically, a glass plate, a polymer plate, etc. are mentioned. Examples of the glass plate include those using soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz and the like as raw materials. Examples of the polymer plate include those using polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like as raw materials.

(anode)
The anode of the organic EL element plays a role of injecting holes into the hole transport layer or the light emitting layer, and it is effective to use a material having a work function of 4.5 eV or more. Specific examples of the anode material include indium tin oxide alloy (ITO), tin oxide (NESA), indium zinc oxide, gold, silver, platinum, copper, and the like. The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. When light emitted from the light emitting layer is extracted from the anode, it is preferable that the transmittance of light in the visible region of the anode is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. The film thickness of the anode depends on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 10 nm to 200 nm.

(cathode)
The cathode plays a role of injecting electrons into the electron injection layer, the electron transport layer or the light emitting layer, and is preferably formed of a material having a small work function. The cathode material is not particularly limited, and specifically, indium, aluminum, magnesium, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-lithium alloy, aluminum-scandium-lithium alloy, magnesium-silver alloy and the like can be used. Similarly to the anode, the cathode can be produced by forming a thin film by a method such as vapor deposition or sputtering. Moreover, you may take out light emission from the cathode side as needed.

(Light emitting layer)
An organic layer having a light emitting function, and when a doping system is employed, includes a host material and a dopant material. At this time, the host material mainly has a function of encouraging recombination of electrons and holes and confining excitons in the light emitting layer, and the dopant material efficiently emits excitons obtained by recombination. It has a function.
In the case of a phosphorescent element, the host material mainly has a function of confining excitons generated by the dopant in the light emitting layer.

Here, the light emitting layer employs, for example, a double host (also referred to as host / cohost) that adjusts the carrier balance in the light emitting layer by combining an electron transporting host and a hole transporting host. The light emitting layer preferably contains a first host material and a second host material, and the first host material is preferably the organic EL device material of the present invention.
Moreover, you may employ | adopt the double dopant from which each dopant light-emits by putting in 2 or more types of dopant materials with a high quantum yield. Specifically, a mode in which yellow emission is realized by co-evaporating a host, a red dopant, and a green dopant to make the light emitting layer common is used.

The above light-emitting layer is a laminate in which a plurality of light-emitting layers are stacked, so that electrons and holes are accumulated at the light-emitting layer interface, and the recombination region is concentrated at the light-emitting layer interface to improve quantum efficiency. Can do.
The ease of injecting holes into the light emitting layer may be different from the ease of injecting electrons, and the hole transport ability and electron transport ability expressed by the mobility of holes and electrons in the light emitting layer may be different. May be different.

The light emitting layer can be formed by a known method such as a vapor deposition method, a spin coating method, or an LB method (Langmuir Broadgett method). The light emitting layer can also be formed by thinning a solution obtained by dissolving a binder such as a resin and a material compound in a solvent by a spin coating method or the like.
The light emitting layer is preferably a molecular deposited film. The molecular deposited film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidifying from a material compound in a solution state or a liquid phase state. The thin film (molecular accumulation film) formed by the LB method can be classified by the difference in the aggregation structure and the higher-order structure, and the functional difference resulting therefrom.

The dopant material is selected from known fluorescent dopants exhibiting fluorescent emission or phosphorescent dopants exhibiting phosphorescent emission.
The fluorescent dopant is selected from fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, fluorene derivatives, boron complexes, perylene derivatives, oxadiazole derivatives, anthracene derivatives, chrysene derivatives, and the like. Preferably, a fluoranthene derivative, a pyrene derivative, and a boron complex are used.

The phosphorescent dopant (phosphorescent material) that forms the light emitting layer is a compound that can emit light from the triplet excited state, and is not particularly limited as long as it emits light from the triplet excited state, but Ir, Pt, Os, Au, Cu, An organometallic complex containing at least one metal selected from Re and Ru and a ligand is preferable. The ligand preferably has an ortho metal bond. A metal complex containing a metal atom selected from Ir, Os and Pt is preferred in that the phosphorescent quantum yield is high and the external quantum efficiency of the light emitting device can be further improved, and an iridium complex, an osmium complex, or a platinum complex. Are more preferable, iridium complexes and platinum complexes are more preferable, and orthometalated iridium complexes are particularly preferable.

The content of the phosphorescent dopant in the light emitting layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is preferably 0.1 to 70% by mass, more preferably 1 to 30% by mass. If the phosphorescent dopant content is 0.1% by mass or more, sufficient light emission can be obtained, and if it is 70% by mass or less, concentration quenching can be avoided.

The phosphorescent host is a compound having a function of efficiently emitting the phosphorescent dopant by efficiently confining the triplet energy of the phosphorescent dopant in the light emitting layer. The organic EL device material of the present invention is suitable as a phosphorescent host. The light emitting layer may contain 1 type of organic EL element material of this invention, and may contain 2 or more types of organic EL element material of this invention.

When the organic EL device material of the present invention is used as the host material of the light emitting layer, the emission wavelength of the phosphorescent dopant material contained in the light emitting layer is not particularly limited. Among these, at least one of the phosphorescent dopant materials contained in the light emitting layer preferably has an emission wavelength peak of 430 nm to 700 nm, and more preferably 440 nm to 650 nm. By using the compound of the present invention as a host material and doping a phosphorescent dopant material having such an emission wavelength to form a light emitting layer, a long-life organic EL device can be obtained.

In the organic EL device of the present invention, a compound other than the material for the organic EL device of the present invention can be appropriately selected as the phosphorescent host according to the purpose.
The organic EL device material of the present invention and other compounds may be used in combination as a phosphorescent host material in the same light emitting layer, and when there are a plurality of light emitting layers, the phosphorescent host of one of the light emitting layers. The material for an organic EL device of the present invention may be used as a material, and a compound other than the material for an organic EL device of the present invention may be used as a phosphorescent host material for another light emitting layer. Moreover, the organic EL device material of the present invention can be used for organic layers other than the light emitting layer. In that case, a compound other than the organic EL device material of the present invention is used as the phosphorescent host of the light emitting layer. May be.

Specific examples of compounds other than the organic EL device material of the present invention and suitable as a phosphorescent host include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrins Compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidene derivatives And metal complexes of heterocyclic tetracarboxylic anhydrides, phthalocyanine derivatives, 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands Various metal complexes such as polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, etc. Examples thereof include polymer compounds. A phosphorescent host may be used independently and may use 2 or more types together. Specific examples include the following compounds.

When the light emitting layer contains the first host material and the second host material, the organic EL element material of the present invention is used as the first host material, and the organic EL element material other than the organic EL element material of the present invention is used as the second host material. A compound may be used. In the present invention, the terms “first host material” and “second host material” mean that the plurality of host materials contained in the light emitting layer have different structures from each other. It is not specified by the material content.
It does not specifically limit as said 2nd host material, It is a compound other than the organic EL element material of this invention, and the same thing as the above-mentioned compound as a compound suitable as a phosphorescent host is mentioned. As the second host material, a compound having no cyano group is preferable. The second host is preferably a carbazole derivative, arylamine derivative, fluorenone derivative, or aromatic tertiary amine compound.

The thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 7 to 50 nm, and still more preferably 10 to 50 nm. When the thickness is 5 nm or more, it is easy to form a light emitting layer, and when the thickness is 50 nm or less, an increase in driving voltage can be avoided.

(Electron donating dopant)
The organic EL device of the present invention preferably has an electron donating dopant in the interface region between the cathode and the light emitting unit. According to such a configuration, it is possible to improve the light emission luminance and extend the life of the organic EL element. Here, the electron donating dopant means a material containing a metal having a work function of 3.8 eV or less, and specific examples thereof include alkali metals, alkali metal complexes, alkali metal compounds, alkaline earth metals, alkaline earths. Examples thereof include at least one selected from metal complexes, alkaline earth metal compounds, rare earth metals, rare earth metal complexes, rare earth metal compounds, and the like.

Examples of the alkali metal include Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV), Cs (work function: 1.95 eV), and the like. A function of 2.9 eV or less is particularly preferable. Of these, K, Rb, and Cs are preferred, Rb and Cs are more preferred, and Cs is most preferred. Examples of alkaline earth metals include Ca (work function: 2.9 eV), Sr (work function: 2.0 eV to 2.5 eV), Ba (work function: 2.52 eV), and the like. The thing below 9 eV is especially preferable. Examples of rare earth metals include Sc, Y, Ce, Tb, Yb, and the like, and those having a work function of 2.9 eV or less are particularly preferable.

Examples of the alkali metal compound include alkali oxides such as Li ₂ O, Cs ₂ O, and K ₂ O, and alkali halides such as LiF, NaF, CsF, and KF, and LiF, Li ₂ O, and NaF are preferable. Examples of the alkaline earth metal compound include BaO, SrO, CaO, and Ba _x Sr _1-x O (0 <x <1), Ba _x Ca _1-x O (0 <x <1) mixed with these. BaO, SrO, and CaO are preferable. The rare earth metal _{_{_{_{compound, YbF 3, ScF 3, ScO}}}} 3, Y 2 O 3, Ce 2 O 3, GdF 3, TbF 3 and the _{_{like, YbF 3, ScF 3, TbF}} 3 are preferable.

The alkali metal complex, alkaline earth metal complex, and rare earth metal complex are not particularly limited as long as each metal ion contains at least one of an alkali metal ion, an alkaline earth metal ion, and a rare earth metal ion. The ligands include quinolinol, benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyl oxazole, hydroxyphenyl thiazole, hydroxydiaryl thiadiazole, hydroxydiaryl thiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, Hydroxyfulborane, bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene, β-diketones, azomethines, and derivatives thereof are preferred, but are not limited thereto.

As an addition form of the electron donating dopant, it is preferable to form a layered or island shape in the interface region. As a forming method, while depositing an electron donating dopant by resistance heating vapor deposition, an organic compound (light emitting material or electron injecting material) that forms an interface region is simultaneously deposited, and the electron donating dopant is dispersed in the organic compound. Is preferred. The dispersion concentration is organic compound: electron donating dopant = 100: 1 to 1: 100, preferably 5: 1 to 1: 5 in molar ratio.

In the case where the electron donating dopant is formed in a layered form, after forming the light emitting material or the electron injecting material, which is an organic layer at the interface, in a layered form, the reducing dopant is vapor-deposited by a resistance heating vapor deposition method. .1 nm to 15 nm. When the electron donating dopant is formed in an island shape, after forming the light emitting material and the electron injecting material, which are organic layers at the interface, in an island shape, the electron donating dopant is deposited by resistance heating vapor deposition alone, preferably The island is formed with a thickness of 0.05 nm to 1 nm.
In the organic EL device of the present invention, the ratio of the main component to the electron donating dopant is preferably the main component: electron donating dopant = 5: 1 to 1: 5 in a molar ratio of 2: 1 to 1: 2. More preferably.

(Electron transport layer)
The electron transport layer is an organic layer formed between the light emitting layer and the cathode, and has a function of transporting electrons from the cathode to the light emitting layer. When the electron transport layer is composed of a plurality of layers, an organic layer close to the cathode may be defined as an electron injection layer. The electron injection layer has a function of efficiently injecting electrons from the cathode into the organic layer unit.

As the electron transporting material used for the electron transporting layer, an aromatic heterocyclic compound containing one or more heteroatoms in the molecule is preferably used, and a nitrogen-containing ring derivative is particularly preferable. The nitrogen-containing ring derivative is preferably an aromatic ring having a nitrogen-containing 6-membered ring or 5-membered ring skeleton, or a condensed aromatic ring compound having a nitrogen-containing 6-membered ring or 5-membered ring skeleton.

The thickness of the electron transport layer is not particularly limited, but is preferably 1 nm to 100 nm.
Moreover, it is preferable to use an insulator or a semiconductor as an inorganic compound in addition to the nitrogen-containing ring derivative as a component of the electron injection layer that can be provided adjacent to the electron transport layer. If the electron injection layer is made of an insulator or a semiconductor, current leakage can be effectively prevented and the electron injection property can be improved.

As such an insulator, it is preferable to use at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is preferable in that the electron injection property can be further improved. Specifically, preferable alkali metal chalcogenides include, for example, Li ₂ O, K ₂ O, Na ₂ S, Na ₂ Se, and Na ₂ O, and preferable alkaline earth metal chalcogenides include, for example, CaO, BaO. , SrO, BeO, BaS and CaSe. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

Further, as a semiconductor, an oxide, nitride, or oxynitride containing at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and Zn. One kind alone or a combination of two or more kinds of products may be mentioned. In addition, the inorganic compound constituting the electron injection layer is preferably a microcrystalline or amorphous insulating thin film. If the electron injection layer is composed of these insulating thin films, a more uniform thin film is formed, and pixel defects such as dark spots can be reduced. Examples of such inorganic compounds include alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides.

When such an insulator or semiconductor is used, the preferred thickness of the layer is about 0.1 nm to 15 nm. Further, the electron injection layer in the present invention is preferable even if it contains the above-mentioned electron donating dopant.

(Hole transport layer)
An organic layer formed between the light emitting layer and the anode, and has a function of transporting holes from the anode to the light emitting layer. When the hole transport layer is composed of a plurality of layers, an organic layer close to the anode may be defined as a hole injection layer. The hole injection layer has a function of efficiently injecting holes from the anode into the organic layer unit. The organic EL device material of the present invention is also suitable as a hole injection layer and a hole transport layer.

As another material for forming the hole transport layer, an aromatic amine compound, for example, an aromatic amine derivative represented by the following formula (H) is preferably used.

In the formula ^{(H), Ar 1 ~ Ar} 4 is a substituted or an aromatic hydrocarbon group or fused aromatic hydrocarbon group unsubstituted ring carbon atoms 6 to 50, a substituted or unsubstituted ring atoms of 5 to 50 aromatic heterocyclic groups or condensed aromatic heterocyclic groups, or a group in which these aromatic hydrocarbon groups or condensed aromatic hydrocarbon groups and aromatic heterocyclic groups or condensed aromatic heterocyclic groups are bonded.
In the formula (H), L represents a substituted or unsubstituted aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted ring forming atom number of 5 to 50. Represents an aromatic heterocyclic group or a condensed aromatic heterocyclic group.

Specific examples of the compound of formula (H) are shown below.

An aromatic amine represented by the following formula (J) is also preferably used for forming the hole transport layer.

In the formula (J), the definitions of Ar ¹ to Ar ³ are the same as the definitions of Ar ¹ to Ar ^{4 in} the formula (H). Specific examples of the compound of formula (J) are shown below, but are not limited thereto.

The hole transport layer of the organic EL device of the present invention may have a two-layer structure of a first hole transport layer (anode side) and a second hole transport layer (cathode side).
The thickness of the hole transport layer is not particularly limited, but is preferably 10 to 200 nm.

In the organic EL device of the present invention, a layer containing an acceptor material may be bonded to the anode side of the hole transport layer or the first hole transport layer. This is expected to reduce drive voltage and manufacturing costs.
As the acceptor material, a compound represented by the following formula (K) is preferable.

(In the formula (K), R ₂₁ to R ₂₆ may be the same as or different from each other, and each independently represents a cyano group, —CONH ₂ , a carboxyl group, or —COOR ₂₇ (R ₂₇ is a group having 1 to 20 carbon atoms) Represents an alkyl group or a cycloalkyl group having 3 to 20 carbon atoms, provided that one or more pairs of R ₂₁ and R ₂₂ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ are combined together. A group represented by —CO—O—CO— may be formed.)
Examples of R ₂₇ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, and a cyclohexyl group.
The thickness of the layer containing the acceptor material is not particularly limited, but is preferably 5 to 20 nm.

(N / p doping)
In the hole transport layer and the electron transport layer described above, as described in Japanese Patent No. 3695714, the carrier injection ability is improved by doping the donor material (n) and acceptor material (p). Can be adjusted.
A typical example of n doping is a method of doping a metal such as Li or Cs into an electron transport material, and a typical example of p doping is F ₄ TCNQ (2, 3, 5, 6) as a hole transport material. -Tetrafluor-7,7,8,8-tetracyanoquinodimethane) and the like.

(Space layer)
For example, when the fluorescent layer and the phosphorescent layer are laminated, the space layer is a fluorescent layer for the purpose of adjusting the carrier balance so that excitons generated in the phosphorescent layer are not diffused into the fluorescent layer. It is a layer provided between the layer and the phosphorescent light emitting layer. In addition, the space layer can be provided between the plurality of phosphorescent light emitting layers.
Since the space layer is provided between the light emitting layers, a material having both electron transport properties and hole transport properties is preferable. In order to prevent diffusion of triplet energy in the adjacent phosphorescent light emitting layer, the triplet energy is preferably 2.6 eV or more. Examples of the material used for the space layer include the same materials as those used for the above-described hole transport layer.

(Barrier layer)
The organic EL device of the present invention preferably has a barrier layer such as an electron barrier layer, a hole barrier layer, or a triplet barrier layer in a portion adjacent to the light emitting layer. Here, the electron barrier layer is a layer that prevents electrons from leaking from the light emitting layer to the hole transport layer, and the hole barrier layer is a layer that prevents holes from leaking from the light emitting layer to the electron transport layer. is there.
The triplet barrier layer prevents the triplet excitons generated in the light emitting layer from diffusing into the surrounding layers, and confins the triplet excitons in the light emitting layer, thereby transporting electrons other than the light emitting dopant of the triplet excitons. It has a function of suppressing energy deactivation on the molecules of the layer.

When providing the triplet barrier layer, the phosphorescent devices, triplet energy E ^{T d} of the phosphorescent dopant in the light emitting layer _and the triplet energy of the compound used as a triplet barrier layer and E ^{^T} _TB, E ^T _d < If the energy magnitude relationship of E ^T _TB is satisfied, the triplet exciton of the phosphorescent dopant is confined (cannot move to other molecules) and the energy deactivation path other than light emission on the dopant is interrupted. It is assumed that light can be emitted with high efficiency. However, even if the relationship of E ^T _d <E ^T _TB is satisfied, if this energy difference ΔE ^T = E ^T _TB −E ^T _d is small, under the environment of room temperature, which is the actual element driving environment, , endothermically triplet excitons overcame this energy difference Delta] E ^T by thermal energy near is considered to be possible to move to another molecule. In particular, in the case of phosphorescence emission, the exciton lifetime is longer than that of fluorescence emission, so that the influence of the endothermic exciton transfer process is likely to appear. The energy difference ΔE ^T is preferably as large as possible relative to the thermal energy at room temperature, more preferably 0.1 eV or more, and particularly preferably 0.2 eV or more. On the other hand, in the fluorescent element, the organic EL element material of the present invention can be used as a triplet barrier layer having a TTF element structure described in International Publication WO2010 / 134350A1.

In addition, the electron mobility of the material constituting the triplet barrier layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of electric field strength of 0.04 to 0.5 MV / cm. As a method for measuring the electron mobility of an organic material, several methods such as the Time of Flight method are known. Here, the electron mobility is determined by impedance spectroscopy.
The electron injection layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of electric field strength of 0.04 to 0.5 MV / cm. This facilitates the injection of electrons from the cathode into the electron transport layer, and also promotes the injection of electrons into the adjacent barrier layer and the light emitting layer, thereby enabling driving at a lower voltage.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

Example 1 Synthesis of Compound 7 (1) Synthesis of Intermediate 1

In a three-necked flask, 5.51 g (30 mmol) of 4-Bromo-1,2-phenylenediamine, 7.00 g (33 mmol) of 2-Dibenzofuranyl boronic acid, 8.29 g (60 mmol) of K ₂ CO ₃ , 30 mL of water, Pd (OAc) ₂ 135 mg (0.6 mmol), Tri (o-tolyl) phosphine 365 mg (1.2 mmol), and 1,2-dimethyloxyne 60 mL were added and refluxed for 8 hours under a nitrogen atmosphere. After completion of the reaction, it was cooled to room temperature. The mixture was extracted with dichloromethane using a separatory funnel, dried over anhydrous magnesium sulfate, and filtered. The crude product obtained by concentrating the filtrate was purified by silica gel column chromatography (dichloromethane: ethyl acetate = 8: 2) to obtain Intermediate 1.
Yield 6.75g
Yield 82%

(2) Synthesis of intermediate 2

In a three-necked flask, 5.00 g (18.2 mmol) of Intermediate 1 and Iodobenzene 8.92. g (43.7 mmol), sodium tert-butoxide 5.25 g (54.6 mmol), tris (dibenzylideneacetone) dipalladium 165 mg (0.18 mmol), 1,1′-bis (diphenylphosphino) ferrocene 200 mg (0 .36 mmol) and 182 mL of toluene were added and refluxed for 6 hours under a nitrogen atmosphere. After completion of the reaction, the reaction mixture was cooled to room temperature and filtered using celite. The filtrate was concentrated, and the resulting crude product was purified by silica gel column chromatography (hexane: dichloromethane = 1: 1) to obtain Intermediate 2.
Yield 2.64 g
Yield 34%

(3) Synthesis of compound 7

In a three-necked flask equipped with a Dean-Stark trap, Intermediate 2. 1.28 g (3 mmol), 2-Dibenzofuranyl boronic acid 0.70 g (3.3 mmol), 1,8-diazabicyclo [5.4.0] -7-undecene 91 mg (0.6 mmol) and 45 mL of toluene were added, and the mixture was refluxed for 8 hours while dehydrating under a nitrogen atmosphere using a Dean-Stark trap. After completion of the reaction, the mixture was cooled to room temperature and diluted by adding 200 mL of toluene. The origin impurity component was removed from this solution through a silica gel short column. The crude product obtained by concentrating this solution was recrystallized three times with a toluene: methanol mixed solvent to obtain Compound 7.
Yield 1.07g
Yield 59%

The compound was identified by FD-MS and ¹ H-NMR.
¹ H-NMR (400 MHz, CD ₂ Cl ₂ ): δ = 7.18 (d, 1H), 7.25-7.54 (m, 19H), 7.55-7.61 (m, 2H), 7.63-7.71 (m, 2H), 7.78 (s, 1H), 8.02 (d, 1H), 8.13 (d, 1H)
FD-MS measurement data Theoretical value: 602 Actual value: 602

Comparative Example 1: Synthesis of Comparative Example Compound E1

A compound similar to (3) of Example 1 except that N, N ′-(Diphenyl) -2-phenylenediamine, 2-Dibenzofuranyl boronic acid was used instead of Intermediate 2 instead of Intermediate 2, and Phenyl boronic acid was used instead of Intermediate 2. E1 was synthesized.
Yield 0.70g
Yield 67%

The compound was identified by FD-MS and ¹ H-NMR.
^{_{1 H-NMR (400MHz, CD}} 2 Cl 2): δ = 6.96-7.06 (m, 4H), 7.09 (t, 2H), 7.13-7.23 (m, 3H), 7.28-7.36 (m, 6H), 7.39-7.46 (m, 4H)
FD-MS measurement data Theoretical value: 346 Actual value: 346

Comparative Example 2: Synthesis of Comparative Example Compound E2

Journal of the American Chemical Society 1959, vol. 81, p. Comparative Example Compound E2 was synthesized according to the method described in 2681-2683.

Comparative Example 3: Synthesis of Comparative Example Compound E3

Comparative Example Compound E3 was synthesized in the same manner as (3) of Example 1 except that 3,3′-diaminobenzidine was used as the starting material instead of Intermediate 2.
Yield 1.72g
Yield 61%

The compound was identified by FD-MS and ¹ H-NMR.
¹ H-NMR (400 MHz, DMSO-d ₆ ): δ = 7.14 (q, 4H), 7.33 (s, 2H), 7.48 (t, 2H), 7.57 (t, 2H) , 7.75 (d, 2H), 7.80 (d, 2H), 8.10 (t, 4H), 8.69 (s, 2H), 9.25 (d, 4H)
FD-MS measurement data Theoretical value: 566 Actual value: 566

<Cyclic voltammetry measurement>
The following compounds synthesized in Example 1 and Comparative Example 1 were subjected to cyclic voltammetry measurement to evaluate electrochemical oxidation characteristics.

(Cyclic voltammetry measurement method)
Cyclic voltammetry was measured using an Electrochemical Analyzer 630B manufactured by ALS as an apparatus under the following conditions and measurement procedures.
[Measurement condition]
electrode:
Working electrode: Glassy carbon Reference electrode: Ag / Ag +
Counter electrode: Pt
Electrolyte: Tetrabutylammonium perchlorate Measurement solvent: N, N-dimethylformamide Measurement atmosphere: Nitrogen potential Scan rate: Range of 0.005 V / sec to 0.1 V / sec

[Measurement procedure]
(1) An electrolyte and 10 mL of dimethylformamide are placed in a measurement cell (for 10 mL) so that the electrolyte concentration is about 0.1 M, and nitrogen gas is bubbled from a thin tube inserted into the solution for 5 minutes to uniformly dissolve.
(2) An electrode (working electrode, reference electrode, counter electrode) is set in the measurement cell. The working electrode is used after being polished with an alumina powder abrasive just before use.
(3) 10 mg of the measurement substrate is added to the measurement solution, and nitrogen gas is bubbled through the thin tube inserted into the solution for 5 minutes to uniformly dissolve it.
(4) The nitrogen gas bubbling tubule is pulled up from the solution liquid level, and the nitrogen gas flow is continued so that the inside of the measurement cell is in a nitrogen gas atmosphere, and then measurement is performed using an Electrochemical Analyzer 630B manufactured by ALS.

(Cyclic voltammetry measurement data)
The cyclic voltammetry measurement data of Compound 7 is shown in FIG. From FIG. 2, it can be read that reversible oxidation waves are shown, and it can be seen that Compound 7 has high electrochemical oxidation stability.
The cyclic voltammetry measurement data of Comparative Example Compound E1 is shown in FIG. From FIG. 3, it can be seen that an irreversible oxidation wave is shown, and it can be seen that Compound E1 has low electrochemical oxidation stability.

Example 2: Synthesis of compound (20) (1) Synthesis of intermediate (1)

In a three-necked flask, 16.35 g (50 mmol) of Bis (4-bromophenyl) amine, 2-Dibenzofuranyl boronic acid 22.26. g (105 mmol), 27.64 g (200 mmol) of K ₂ CO ₃ , 100 mL of water, 225 mg (1 mmol) of Pd (OAc) _2, 609 mg ( ₂ mmol) of Tri (o-tolyl) phosphine, 100 mL of 1,2-dimethylethane, The mixture was refluxed for 8 hours under a nitrogen atmosphere. After completion of the reaction, it was cooled to room temperature. The mixture was extracted with dichloromethane using a separatory funnel, dried over anhydrous magnesium sulfate, and filtered. The filtrate was passed through a silica gel short column to remove the origin impurities. Thereafter, 100 mL of methanol was added and ultrasonic cleaning was performed for 10 minutes, and the sample was collected by filtration. This was vacuum-dried at 50 degreeC for 6 hours, and the intermediate body (1) was obtained.
Yield 20.90g
Yield 83%

(2) Synthesis of intermediate (2)

In the atmosphere, 20.90 g (41.7 mmol) of intermediate (1) and 250 mL of N, N-dimethylformamide were placed in a three-necked flask to dissolve intermediate (1). A solution of 15.14 g (85.07 mmol) of N-bromosuccinimide dissolved in 42 mL of N, N-dimethylformamide was added dropwise thereto at room temperature over 15 minutes, and then stirred at room temperature for 18 hours. After completion of the reaction, the sample solution was poured into 300 mL of water, and the deposited sample was collected by filtration. Methanol 200mL was added to this, ultrasonically washed for 10 minutes, and filtered. This was heated and dissolved in 1.5 L of dioxane, and after cooling to room temperature, the origin impurities were removed through a silica gel short column before the sample was precipitated. After the solution was concentrated, 300 mL of methanol was added, and the mixture was refluxed and stirred for 3 hours. After returning to room temperature, the solution was collected by filtration. Intermediate (2) was obtained by vacuum-drying at 50 ° C. for 8 hours.
Yield 21.10 g
Yield 77%

(3) Synthesis of intermediate (3)

Intermediate necked flask (2) 6.59g (10mmol), 2,6- dimethylaniline 9.69 g (80 mmol), sodium chromatography tert butoxide _{_{5.77g (60mmol), Pd 2 (}} dba) 3 366mg (0.4mmol) , 464 mg (1.6 mmol) of Tri-tert-butylphosphonium Tetrafluoroborate and 100 mL of toluene were added, and the mixture was refluxed for 9 hours under a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was cooled to room temperature, diluted with 200 mL of toluene, and filtered using celite. The filtrate was passed through a silica gel short column to remove the origin impurities, and then concentrated. This was purified by silica gel chromatography (developing solvent toluene: hexane = 8: 2) and concentrated. The precipitated sample was ultrasonically washed with 150 mL of a toluene: hexane = 1: 1 mixed solvent for 10 minutes and collected by filtration. This was vacuum-dried at 50 ° C. for 6 hours to obtain an intermediate (3).
Yield 8.35g
Yield 56%

(4) Synthesis of compound (20)

In a three-necked flask, 6.08 g (8.22 mmol) of intermediate (3) and 164 mL of dehydrated tetrahydrofuran were added to dissolve intermediate (3). This was cooled to 0 ° C., and 15.8 mL (25.15 mmol) of n-butyllithium 1.59 M hexane solution was added dropwise over 5 minutes. At this time, the solution quickly turned dark red. After stirring at 0 ° C. for 15 minutes, 1.17 g (8.22 mmol) of boron trifluoride diethyl ether complex dissolved in 16 mL of dehydrated tetrahydrofuran was added dropwise over 10 minutes. Then, it was made to stir at room temperature for 16 hours.
After completion of the reaction, the solvent was removed by an evaporator and dried. To this, 600 mL of toluene was added and refluxed in a nitrogen atmosphere to dissolve the sample. After cooling to room temperature, the sample was not precipitated, but the solution was passed through a silica gel short column to remove the origin impurities. This was concentrated and dried, and the precipitated sample was ultrasonically washed with ethyl acetate for 5 minutes. The sample was refluxed for 2 hours under a nitrogen atmosphere, cooled to room temperature, and collected by filtration. This was vacuum-dried at 50 ° C. for 6 hours to obtain a compound (20).
Yield 3.50g
Yield 57%

The compound was identified by FD-MS and ¹ H-NMR.
^{_{1 H-NMR (400MHz, CD}} 2 Cl 2): δ = 2.05-2.12 (s, 12H), 6.89 (d, 2H), 7.04-7.17 (m, 6H), 7.37 (t, 2H), 7.43-7.62 (m, 8H), 7.62-7.68 (m, 2H), 7.82 (d, 2H), 8.02 (d, 2H), 8.12 (d, 2H)
FD-MS measurement data Theoretical value: 747 Actual value: 747

The lowest excited triplet energy and ionization potential of the compounds of Examples 1 and 2 and Comparative Examples 1 to 3 were measured by the following methods. The results are shown in Table 1.

(1) Triplet energy (E ^T )
The measurement was performed using a commercially available apparatus F-4500 (manufactured by Hitachi). Each compound was dissolved in an EPA solvent (diethyl ether: isopentane: ethanol = 5: 5: 5 (volume ratio), each solvent was a spectroscopic grade) (sample 10 μmol / liter) to prepare a sample for phosphorescence measurement. The phosphorescence measurement sample placed in the quartz cell was cooled to 77 (K), and the phosphorescence measurement sample was irradiated with excitation light, and the phosphorescence intensity was measured while changing the wavelength.
The conversion formula of triplet energy (E ^T ) is as follows.
E ^T (eV) = 1239.85 / λ _ph
In the formula, “λ _ph ” (unit: nm) draws a tangent line to the rising edge of the phosphorescence spectrum on the short wavelength side when the phosphorescence spectrum is represented with the phosphorescence intensity on the vertical axis and the wavelength on the horizontal axis. , The wavelength value of the intersection of the tangent and the baseline.

(2) Ionization potential A thin film of the measurement compound was formed on the ITO substrate by a vacuum deposition method or a coating method, and the measurement was performed using a commercially available atmospheric photoelectron spectrometer AC-3 (manufactured by Riken Keiki Co., Ltd.).

Example 3
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum evaporation apparatus, and first, the compound HI1 is formed with a thickness of 20 nm on the surface on which the ITO electrode line is formed so as to cover the ITO electrode line. Subsequently, compound HT1 was deposited by resistance heating with a thickness of 60 nm, and thin films were sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a hole transport layer, respectively.

Next, on the hole transport layer, Compound 7 and Compound BD1 were simultaneously deposited by resistance heating to form a thin film having a thickness of 50 nm. At this time, the compound BD1 was vapor-deposited so that the mass ratio was 20% with respect to the total mass of the compound 7 and the compound BD1. The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, in which the compound 7 functions as a host and the compound BD1 functions as a light emitting dopant.
Next, a thin film having a thickness of 10 nm was formed on the phosphorescent light emitting layer by resistance heating vapor deposition of Compound B1. This thin film functions as a hole blocking layer. The film formation rate was 1.2 liter / s.

Next, a thin film having a thickness of 10 nm was formed on the hole barrier layer by resistance heating vapor deposition of the compound ET1. The film formation rate was 1 Å / s. This film functions as an electron injection layer.
Next, LiF having a film thickness of 1.0 nm was deposited on the electron injection layer at a film formation rate of 0.1 Å / s.
Next, metallic aluminum was vapor-deposited on the LiF film at a deposition rate of 8.0 Å / s to form a metal cathode with a film thickness of 80 nm to obtain an organic EL element.

About the obtained organic EL element, the element performance (half life (time until a brightness | luminance falls to 50% of initial light emission luminance)) when driving at constant current as initial light emission luminance of 1000 cd / m ² was evaluated.

Comparative Example 4
An organic EL device was prepared and evaluated in the same manner as in Example 3 except that Compound E3 was used as the host of the phosphorescent light emitting layer instead of Compound 7. The results are shown in Table 2. The “half life (relative%)” is a relative ratio when the half life of the element of Example 3 is 100%.

From Table 2, it can be seen that when the compound of the present invention is used as a host of the phosphorescent layer, a long-life organic EL device can be provided.

Example 4
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum evaporation apparatus, and first, the compound HI1 is formed with a thickness of 20 nm on the surface on which the ITO electrode line is formed so as to cover the ITO electrode line. Subsequently, compound HT1 was deposited by resistance heating with a thickness of 60 nm, and thin films were sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a hole transport layer, respectively.

Next, on the hole transport layer, the compound (20) and the compound BD1 were simultaneously deposited by resistance heating to form a thin film having a thickness of 50 nm. At this time, the compound BD1 was vapor-deposited so that the mass ratio was 20% with respect to the total mass of the compound (20) and the compound BD1. The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, in which the compound (20) functions as a host and the compound BD1 functions as a light emitting dopant.
Next, a thin film having a thickness of 10 nm was formed on the phosphorescent light emitting layer by resistance heating vapor deposition of Compound B1. This thin film functions as a hole blocking layer. The film formation rate was 1.2 liter / s.

Comparative Example 5
An organic EL device was prepared and evaluated in the same manner as in Example 4 except that compound E3 was used as the host of the phosphorescent light emitting layer instead of compound (20). The results are shown in Table 3. The “half life (relative%)” is a relative ratio when the half life of the element of Example 4 is 100%.

From Table 3, it can be seen that when the compound of the present invention is used as a host of the phosphorescent layer, a long-life organic EL device can be provided.

Example 5: Synthesis of compound 12

Compound 12 was synthesized in the same manner as (3) of Example 1 except that 8- (N-Carbazolyl) dibenzofuran-2-boronic acid was used as the starting material instead of 2-Dibenzofuranyl boronic acid.
Yield 0.69g
Yield 30%

The compound was identified by FD-MS and ¹ H-NMR.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 7.18 (1H, d), 7.32-7.47 (22H, m), 7.54-7.58 (3H, m), 7. 62-7.65 (1H, m), 7.69-7.72 (2H, m), 7.79 (1H, d), 7.96-8.00 (1H, m), 8.07 ( 1H, d), 8.17-8.20 (2H, m)
FD-MS measurement data Theoretical value: 767 Actual value: 767

Example 6 Synthesis of Compound 15 (1) Synthesis of Intermediate 11

In a three-necked flask, 9-Phenyl-9H, 9′H- [3,3 ′] bicarbazolyl 4.1 g (10 mmol), 1-Bromo-3,4-dichlorobenzene, 2.7 g (12 mmol), trans-1,2-cyclohexanediamine 0.11 g (1 mmol), 0.2 g (1 mmol) of copper iodide, 6.4 g (30 mmol) of tripotassium phosphate and 30 ml of xylene were added and refluxed for 24 hours under a nitrogen atmosphere. After completion of the reaction, it was cooled to room temperature. The crude product obtained by concentrating the solvent was purified by silica gel column chromatography (toluene: hexane = 1: 1) to obtain 3.6 g of intermediate 11.
Yield 3.60g
Yield 65%

(2) Synthesis of intermediate 12

Three-necked flask Intermediate 11 5.5g (10mmol), palladium acetate _{_{0.22g (1mmol), P (t}} -Bu) 3 -HBF 4 0.44g (1.5mmol), t-BuONa 2.88g (30mmol) Then, 20 ml of aniline was added and refluxed for 4 hours under a nitrogen atmosphere. After completion of the reaction, it was cooled to room temperature. The crude product obtained by diluting with toluene and filtering off insolubles and then concentrating the solvent was purified by silica gel column chromatography (dichloromethane: hexane = 1: 2) to obtain 3.6 g of intermediate 12. It was.
Yield 4.00g
Yield 60%

(3) Synthesis of compound 15

Compound 15 was synthesized in the same manner as in (3) of Example 1, except that phenylboronic acid was used instead of 2-Dibenzofuranyl boronic acid, and intermediate 12 was used instead of intermediate 2.
Yield 0.79g
Yield 35%

The compound was identified by FD-MS and ¹ H-NMR.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 7.10-7.52 (28H, m), 7.62-7.69 (3H, m), 7.74-7.78 (2H, m ), 8.20-8.25 (2H, m), 8.43-8.46 (2H, m)
FD-MS measurement data Theoretical value: 752 Actual value: 752

Example 7: Synthesis of Compound 73
(1) Synthesis of intermediate 13

Intermediate 13 was synthesized in the same manner as (1) of Example 6 except that Carbazole was used instead of 9-Phenyl-9H, 9′H- [3,3 ′] bicarbazolyl as the starting material.
Yield 1.40g
Yield 45%

(2) Synthesis of intermediate 14

Intermediate 14 was synthesized in the same manner as (2) of Example 6 except that intermediate 13 was used instead of intermediate 11.
Yield 3.40g
Yield 80%

(3) Synthesis of compound 73

Compound 73 was synthesized in the same manner as (3) of Example 1 except that Intermediate 14 was used instead of Intermediate 2.
Yield 0.59g
Yield 33%

The compound was identified by FD-MS and ¹ H-NMR.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 7.17-7.53 (24H, m), 7.61-7.64 (1H, m), 7.72 (1H, d), 8. 13 (2H, d)
FD-MS measurement data Theoretical value: 601 Actual value: 601

The triplet energy and ionization potential of the compounds synthesized in Examples 5, 6, and 7 were measured by the above methods. The results are shown in Table 4.

Example 8
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum evaporation apparatus, and first, the compound HI1 is formed with a thickness of 20 nm on the surface on which the ITO electrode line is formed so as to cover the ITO electrode line. Subsequently, compound HT1 was deposited by resistance heating with a thickness of 60 nm, and thin films were sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a hole transport layer, respectively.

Next, on the hole transport layer, Compound 7 and Compound BD1 were simultaneously deposited by resistance heating to form a thin film having a thickness of 40 nm. At this time, the compound BD1 was vapor-deposited so that the mass ratio was 20% with respect to the total mass of the compound 7 and the compound BD1. The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, in which the compound 7 functions as a host and the compound BD1 functions as a light emitting dopant.
Next, a thin film having a thickness of 5 nm was formed on the phosphorescent light emitting layer by resistance heating vapor deposition of Compound 7. This thin film functions as a hole blocking layer. The film formation rate was 1.2 liter / s.

Next, a compound having a thickness of 25 nm was formed on the hole barrier layer by resistance heating vapor deposition of the compound ET1. The film formation rate was 1 Å / s. This film functions as an electron injection layer.
Next, LiF having a film thickness of 1.0 nm was deposited on the electron injection layer at a film formation rate of 0.1 Å / s.
Next, metallic aluminum was vapor-deposited on the LiF film at a deposition rate of 8.0 Å / s to form a metal cathode with a film thickness of 80 nm to obtain an organic EL element.

Example 9
An organic EL device was obtained in the same manner as in Example 8, except that Compound 12 was used instead of Compound 7.

Example 10
An organic EL device was obtained in the same manner as in Example 8 except that Compound 15 was used instead of Compound 7.

Example 11
An organic EL device was obtained in the same manner as in Example 8 except that Compound 73 was used instead of Compound 7.

Comparative Example 6
An organic EL device was produced in the same manner as in Example 8 except that Compound E2 was used instead of Compound 7, but E2 had a very low vapor deposition temperature and could not form a uniform thin film. It was not possible to produce an organic EL device capable of measuring
Comparative Example 7
An organic EL device was obtained in the same manner as in Example 8 except that Compound E3 was used instead of Compound 7.

About the obtained organic EL element, it was made to light-emit by constant current drive, the brightness | luminance and the current density were measured, and the voltage in the current density of 1 mA / cm < ² >, and luminous efficiency (external quantum efficiency) were calculated | required. Further, the half life at an initial luminance of 1,000 cd / m ² (the time for the luminance to decrease to 50% of the initial emission luminance) was determined. The results are shown in Table 5.
The “half life (relative%)” is a relative ratio when the half life of the device of Example Y-1 is 100%.

From the results shown in Table 5, it can be seen that when the compound of the present invention is used as the host material of the phosphorescent light emitting layer, an organic EL device having a low voltage, high efficiency, and long life can be provided. Further, it also functions as a hole barrier layer material, and is found to be useful.

Example 12
A glass substrate with a 130 nm-thick ITO electrode line (manufactured by Geomatec) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes.
The glass substrate with the ITO electrode line after the cleaning is mounted on the substrate holder of the vacuum evaporation apparatus, and first, the compound HI1 is formed with a thickness of 20 nm on the surface on which the ITO electrode line is formed so as to cover the ITO electrode line. Then, compound HT1 was deposited by resistance heating with a thickness of 50 nm, and a thin film was sequentially formed. The film formation rate was 1 Å / s. These thin films function as a hole injection layer and a first hole transport layer, respectively.

Next, a thin film having a thickness of 10 nm was formed on the hole transport layer by resistance heating vapor deposition of compound 73. This thin film functions as a second hole transport layer. Further, Compound B1 and Compound BD1 were simultaneously deposited by resistance heating to form a thin film having a thickness of 40 nm. At this time, the compound BD1 was vapor-deposited so that the mass ratio was 20% with respect to the total mass of the compound 7 and the compound BD1. The film formation rates were 1.2 Å / s and 0.3 Å / s, respectively. This thin film functions as a phosphorescent light emitting layer, in which the compound 7 functions as a host and the compound BD1 functions as a light emitting dopant.
Next, a thin film having a thickness of 5 nm was formed on the phosphorescent light emitting layer by resistance heating vapor deposition of Compound 7. This thin film functions as a hole blocking layer. The film formation rate was 1.2 liter / s.

Comparative Example 8
An organic EL device was obtained in the same manner as in Example 12 except that the compound E3 was used instead of the compound 73.
About the obtained organic EL element, it was made to light-emit by constant current drive, the brightness | luminance and the current density were measured, and the voltage in the current density of 1 mA / cm < ² >, and luminous efficiency (external quantum efficiency) were calculated | required. Further, the half life at an initial luminance of 1,000 cd / m ² (the time for the luminance to decrease to 50% of the initial emission luminance) was determined. The results are shown in Table 6.
The “half life (relative%)” is a relative ratio when the half life of the element of Example 12 is 100%.

From the results shown in Table 6, it can be seen that when the compound of the present invention is used as the hole transport layer material, an organic EL device with high efficiency and long life can be provided.

Since the compound of the present invention has high electrochemical oxidation stability, it is extremely useful as a material for organic electronics elements.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
All the contents of the Japanese application specification that is the basis of the priority of Paris in this application are incorporated herein.

Claims

A benzodiazaborol compound represented by formula (1).

(Where
A 1 and A 2 are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group,
A substituted or unsubstituted sulfone group, or a single bond,
A 3 is,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms,
A fluoro group,
A cyano group or a single bond,
A 1 and A 3 , or A 2 and A 3 may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A 1 , A 2 , and A 3 are not bonded to each other to form the following ring in which three diazaborol rings are condensed.

Ring Q fused with the diazaborol ring is
A substituted or unsubstituted benzene ring,
A substituted or unsubstituted benzene ring in which at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic aromatic ring having 5 to 24 ring atoms is condensed And
n is an integer from 1 to 6,
When n is 1, L does not exist,
when n is 2 to 6, L is a linking group that bridges between any of Q, A 1 , A 2 , and A 3 , or a single bond;
When n is 2 to 6, n, Q, A 1 , A 2 , and A 3 may be the same as or different from each other.
However,
(I) When n is 1 and Q is an unsubstituted benzene ring,
(Ii) when n is 2 to 6, Q is an unsubstituted benzene ring, and L is a single bond, when the unsubstituted benzene rings Q are bonded to each other by a single bond L, And (iii) When n is 2 to 6 and Q is an unsubstituted benzene ring, any of A 1 , A 2 or A 3 is bonded by L. )
The benzodiazaborol compound according to claim 1, which is represented by the formula (I-1).

(Where
A 1 and A 2 are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group,
A substituted or unsubstituted sulfone group, or a single bond,
A 3 is,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl sulfide group having 1 to 20 carbon atoms,
A substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms,
A fluoro group,
A cyano group or a single bond,
A 1 and A 3 , or A 2 and A 3 may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A 1 and A 3 , or A 2 and A 3 are not bonded to each other to form the following 5-membered ring.
The ring Q condensed with the diazaborol ring has at least one substituent R, and may further have an optional substituent, a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted ring A heteroaromatic ring is condensed with at least one benzene ring which may further have an optional substituent,
Substituent R is
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
a substituted or unsubstituted unsaturated aliphatic hydrocarbon group having 2 to 20 carbon atoms bonded by an atom having sp 2 hybrid orbital property,
a substituted or unsubstituted ring-formed unsaturated aliphatic hydrocarbon ring group having 3 to 20 carbon atoms bonded by an atom having sp 2 hybrid orbital property,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted cycloalkoxy group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted amino group,
Substituted or unsubstituted boryl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted alkylsulfide group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylsulfide group having 6 to 30 ring carbon atoms,
n is an integer from 1 to 6,
When n is 1, L does not exist,
when n is 2 to 6, L is a linking group that bridges between any of Q, A 1 , A 2 , and A 3 , or a single bond;
When n is 2 to 6, n, Q, A 1 , A 2 , and A 3 may be the same as or different from each other. )
The benzodiazaborol compound according to claim 1 or 2, having a basic skeleton selected from the group consisting of the following structural formulas (I-2) to (I-14).

(Wherein A 1 to A 3 , L, and n are as defined in the formula (1)).
X is each independently an oxygen atom, a nitrogen atom, or a sulfur atom. )
In the case where A 1 and A 3 or A 2 and A 3 are bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of a diazaborol skeleton, the following structural formulas (I-15) and ( The benzodiazaborol compound according to any one of claims 1 to 3, which has a basic skeleton selected from the group consisting of I-16).

(Wherein A 1 , A 2 , Q, L, and n are as defined in Formula (1) above).
The L linking group is an ether group, a thioether group, a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaromatic ring group having 6 to 30 ring atoms, The benzodiazaborol compound according to any one of claims 1 to 4, which is a substituted or unsubstituted amino group.
The benzodiazaborol compound according to any one of claims 1 to 5, wherein n is 1 or 2.
A 1 , A 2 , and A 3 are each independently a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms. The benzodiazaborol compound according to any one of claims 1 to 6, which is an aromatic ring group.
A 1 , A 2 , and A 3 are each independently substituted or unsubstituted phenyl group, substituted or unsubstituted tolyl group, substituted or unsubstituted xylyl group, substituted or unsubstituted mesityl group, substituted Or an unsubstituted biphenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted triphenylenine group, a substituted or unsubstituted m-terphenyl group, a substituted or unsubstituted dibenzo The benzodiazaborol compound according to claim 7, which is a furanyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted carbazolyl group.
When Q is a benzene ring having a substituent R, the substituent R is a substituted or unsubstituted phenyl group, a substituted or unsubstituted o-biphenyl group, a substituted or unsubstituted m-biphenyl group, substituted or unsubstituted Substituted p-biphenyl group, substituted or unsubstituted m-terphenyl group, substituted or unsubstituted p-terphenyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted phenanthryl group, substituted or unsubstituted The benzodiazaborol according to claim 1, which is a triphenylenine group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted carbazolyl group. Compound.
When Q is a substituted or unsubstituted aromatic ring, or a benzene ring fused with a substituted or unsubstituted heteroaromatic ring, the condensed ring containing the benzene ring is a substituted or unsubstituted phenanthrene, substituted or unsubstituted The benzodiazaborol according to any one of claims 1 to 9, which is substituted triphenylene, substituted or unsubstituted fluorene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, or substituted or unsubstituted carbazole. Compound.
The benzodiazaborol compound according to claim 1 represented by formula (II-1).

[Where:
A 11 and A 12 are each independently
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group, or a substituted or unsubstituted sulfone group,
A 11 and A 12 may be bonded to each other to form a 5- to 7-membered ring including a nitrogen atom and a boron atom of the benzodiazaborol skeleton.
However, A 11 and A 12 are not bonded to each other to form the following 5-membered ring.

Rings Q 1 and Q 2 fused with the diazaborol ring are each independently
A substituted or unsubstituted benzene ring,
A substituted or unsubstituted benzene ring in which at least one substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic aromatic ring having 5 to 24 ring atoms is condensed It is.
n 2 is an integer of 1 to 6,
When n 2 is 1, L 2 is not present,
When n 2 is 2 to 6, L 2 is a linking group that bridges between any of Q 1 , Q 2 , A 11 , and A 12 , or a single bond,
When n 2 is 2 to 6, n 2 Q 1 , Q 2 , A 11 , and A 12 may be the same as or different from each other. ]
The benzodiazaborol compound according to claim 11 represented by formula (II-2).

[Where:
A 11 and A 12 are as defined in Formula (II-1),
R 1 to R 8 are each independently
Hydrogen atom,
A substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms,
A substituted or unsubstituted alkyl group having 3 to 20 carbon atoms,
A substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms,
A substituted or unsubstituted silyl group,
A substituted or unsubstituted phosphino group,
A substituted or unsubstituted phosphine oxide group,
A substituted or unsubstituted sulfoxide group, or a substituted or unsubstituted sulfone group,
Adjacent groups of R 1 to R 8 may be bonded to form a ring. ]
A 11 and A 12 are each independently
The benzodiazabo according to claim 11 or 12, which is a substituted or unsubstituted aromatic ring group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaromatic ring group having 5 to 30 ring atoms. Roll compound.
A 11 and A 12 are each independently
A substituted or unsubstituted phenyl group,
A substituted or unsubstituted biphenyl group,
A substituted or unsubstituted terphenyl group,
A substituted or unsubstituted fluorenyl group,
A substituted or unsubstituted pyridinyl group,
A substituted or unsubstituted pyrimidinyl group,
A substituted or unsubstituted triazinyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted azadibenzofuranyl group,
A substituted or unsubstituted azadibenzothiophenyl group,
A substituted or unsubstituted azacarbazolyl group,
The benzodiazaborol compound according to any one of claims 11 to 13, which is selected from the group consisting of a substituted or unsubstituted benzimidazolyl group and a substituted or unsubstituted imidazolyl group.
1 or 2 of R 1 to R 8 are each independently
A substituted or unsubstituted phenyl group,
A substituted or unsubstituted biphenyl group,
A substituted or unsubstituted terphenyl group,
A substituted or unsubstituted fluorenyl group,
A substituted or unsubstituted pyridinyl group,
A substituted or unsubstituted pyrimidinyl group,
A substituted or unsubstituted triazinyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted carbazolyl group,
A substituted or unsubstituted azadibenzofuranyl group,
A substituted or unsubstituted azadibenzothiophenyl group,
A substituted or unsubstituted azacarbazolyl group,
A group selected from the group consisting of a substituted or unsubstituted benzimidazolyl group and a substituted or unsubstituted imidazolyl group,
The benzodiazaborol compound according to any one of claims 12 to 14, wherein the other R 1 to R 8 are hydrogen atoms.
An organic electroluminescent device material comprising the benzodiazaborol compound according to any one of claims 1 to 15.
The organic electroluminescent element which has one or more organic thin film layers containing a light emitting layer between a cathode and an anode, and at least 1 layer of the said organic thin film layer contains the material for organic electroluminescent elements of Claim 16 .
The organic electroluminescent element according to claim 17, wherein the light emitting layer contains the material for an organic electroluminescent element.
19. The light-emitting layer contains a phosphorescent material, and the phosphorescent material is an orthometalated complex of metal atoms selected from iridium (Ir), osmium (Os), and platinum (Pt). Organic electroluminescence element.
The organic electroluminescence device according to any one of claims 17 to 19, wherein the organic electroluminescence device has a hole transport zone between the light emitting layer and the anode, and the hole transport zone contains the material for an organic electroluminescence device.
The organic electroluminescence device according to any one of claims 17 to 19, wherein the organic electroluminescence device has an electron transport zone between the light emitting layer and the anode, and the electron transport zone contains the material for the organic electroluminescence device.