JP2011037838A - Benzofluorene compound, material for luminous layer and organic electroluminescent device using the compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a benzofluorene compound exhibiting excellent performances by application to, e.g. an organic electroluminescent device. <P>SOLUTION: There is provided the benzofluorene compound, wherein a benzene ring condensed to a 5-membered ring is substituted with diphenylamino. In the benzofluorene compound, substituted silyl is substituted at the p-position with respect to the phenyl. One example (1-20) thereof is shown. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a benzofluorene compound, a light emitting layer material using the compound, and an organic electroluminescent device.

  The organic electroluminescent element is a self-luminous light emitting element and is expected as a light emitting element for display or illumination. 2. Description of the Related Art Conventionally, display devices using light emitting elements that emit electroluminescence have been studied variously because they can save power and can be thinned. Further, organic electroluminescent elements made of organic materials can be easily reduced in weight and size. Therefore, it has been actively studied. In particular, the development of organic materials with light emission characteristics such as blue, which is one of the three primary colors of light, and organic materials that have charge transporting ability (such as semiconductors and superconductors) such as holes and electrons The development of materials has been actively studied regardless of whether it is a high molecular compound or a low molecular compound.

  An organic electroluminescent element has a structure which consists of a pair of electrode which consists of an anode and a cathode, and the one layer or several layer which is arrange | positioned between the said pair of electrodes and contains an organic compound. The layer containing an organic compound includes a light-emitting layer and a charge transport / injection layer that transports or injects charges such as holes and electrons, and various organic materials have been developed as the organic compound (for example, International Publication No. 2004/061047, International Publication No. 2004/061048 (Special Table No. 2006-512395), International Publication No. 2005/056633 (see Patent Documents 1, 2, and 3). However, only the polymer compound of benzofluorene is disclosed in the examples of these patent documents. Further, for example, International Publication No. 2003/051092 pamphlet (Japanese Patent Publication No. 2005-513713) discloses a dibenzofluorene compound having an aryl-substituted amino (see Patent Document 4). However, only the structural formula is disclosed in the document, and its specific characteristics are not reported. In addition, International Publication No. 2007/108666 pamphlet shows a compound in which a trimethylsilyl group is substituted for phenyl in an aryl derivative such as pyrene or chrysene having a diphenylamino group (see Patent Document 5). However, the literature does not report specific examples and effects of introducing a trimethylsilyl group.

International Publication No. 2004/061047 Pamphlet International Publication No. 2004/061048 (Special Publication 2006-512395) International Publication No. 2005/056633 Pamphlet International Publication No. 2003/051092 (Special Publication 2005-513713 Publication) International Publication No. 2007/108666 Pamphlet

  However, an organic electroluminescent device having sufficient performance with respect to the device life and the like has not been obtained yet even if the organic material described above is used. Under such circumstances, it has been desired to develop an organic electroluminescent device having higher performance in terms of device lifetime, that is, a compound capable of obtaining the device.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a benzofluorene compound represented by the following general formula (1) and succeeded in the production thereof. In addition, it has been found that an organic electroluminescent device improved in device lifetime and the like can be obtained by arranging an organic electroluminescent device by arranging a layer containing this benzofluorene compound between a pair of electrodes. Completed.

  That is, the present invention provides the following benzofluorene compounds.

[1] A benzofluorene compound represented by the following general formula (1).
(Where
R ¹ and R ² are each independently hydrogen, optionally substituted alkyl, substituted silyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted cycloalkyl. Or fluorine,
m and n are each independently an integer of 1 to 5,
Each R ³ is independently hydrogen, optionally substituted alkyl, optionally substituted aryl or optionally substituted heteroaryl, and two R ^3s combine to form a ring; You may,
However, at least one of the maximum 20 R ¹ and R ² is a para-substituted substituted silyl, and at least one hydrogen in the benzofluorene compound represented by the formula (1) is substituted with deuterium. May be. )

[2] The benzofluorene compound according to the above [1], represented by the following general formula (1 ′).
(Where
R ¹ and R ² are each independently hydrogen, optionally substituted alkyl or substituted silyl;
n is each independently an integer of 1 to 5,
Each R ³ is independently hydrogen, optionally substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl;
However, at least one of the maximum 12 R ¹ and R ² is a para-substituted substituted silyl, and at least one hydrogen in the benzofluorene compound represented by the formula (1 ′) is substituted with deuterium. It may be. )

[3] R ¹ is each independently substituted silyl;
Each R ² is independently hydrogen, optionally substituted alkyl or substituted silyl;
n is each independently an integer of 1 to 5, and
Each R ³ is independently hydrogen, optionally substituted alkyl, or optionally substituted aryl;
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound described in [2] above.

[4] R ¹ and R ² are each independently substituted silyl;
n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms, and
The substituents for R ¹ , R ² and R ³ are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons or aryl having 6 to 16 carbons,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound described in [2] above.

[5] R ^{1 s} are each independently substituted silyl;
Each R ² is independently an optionally substituted alkyl having 1 to 24 carbon atoms;
n is 1 or 2,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms,
The substituents for R ¹ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
The substituents in R ² are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons, aryl having 6 to 16 carbons, or fluorine; and
The substituents for R ³ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound described in [2] above.

[6] R ¹ is each independently substituted silyl;
R ² is hydrogen;
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms,
The substituents in R ¹ are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons or aryl having 6 to 16 carbons; and
The substituents for R ³ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound described in [2] above.

[7] R ¹ is each independently substituted silyl;
Each R ² is independently a para-substituted substituted silyl, n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons, and
The substituents for R ¹ , R ² and R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl. is there,
The benzofluorene compound described in [4] above.

[8] R ¹ is each independently substituted silyl;
Each R ² is independently a meta-substituted substituted silyl, n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons, and
The substituents for R ¹ , R ² and R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl. is there,
The benzofluorene compound described in [4] above.

[9] R ¹ is each independently substituted silyl;
R ² is each independently a para-substituted or meta-substituted alkyl having 1 to 12 carbon atoms which may be substituted, n is 1 or 2,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons;
The substituents in R ¹ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl;
The substituents at R ² are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl, naphthyl or fluorine; and
The substituents in R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl.
The benzofluorene compound described in [5] above.

[10] Each R ¹ is independently substituted silyl;
R ² is hydrogen, and at least one of the hydrogens may be substituted with deuterium;
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons;
The substituents in R ¹ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl; and
The substituents in R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl.
The benzofluorene compound described in [6] above.

[11] R ¹ is each independently trimethylsilyl, triethylsilyl or dimethylmono-t-butylsilyl;
Each R ² is independently a para-substituted, trimethylsilyl, triethylsilyl or dimethylmono tert-butylsilyl, n is 1, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound described in [4] above.

[12] R ¹ is each independently trimethylsilyl, triethylsilyl or dimethylmono-t-butylsilyl;
Each R ² is independently meta-substituted, trimethylsilyl, triethylsilyl or dimethylmono tert-butylsilyl, n is 1, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound described in [4] above.

[13] R ¹ is each independently trimethylsilyl, triethylsilyl or dimethylmono-t-butylsilyl;
R ² is para-substituted or meta-substituted, methyl, ethyl, i-propyl or t-butyl, n is 1 or 2, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound described in [5] above.

[14] R ¹ is each independently trimethylsilyl, triethylsilyl or dimethylmono-t-butylsilyl;
R ² is hydrogen and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound described in [6] above.

[15] A material for a light emitting layer of a light emitting device, the material for a light emitting layer containing the benzofluorene compound according to any one of [1] to [14].

[16] An organic electroluminescence device comprising a pair of electrodes composed of an anode and a cathode, and a light emitting layer disposed between the pair of electrodes and containing the light emitting layer material described in [15] above.

[17] Furthermore, it has an electron transport layer and / or an electron injection layer arranged between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer is a quinolinol-based metal complex, The organic electroluminescence device according to [16] above, which contains at least one selected from the group consisting of a pyridine derivative, a phenanthroline derivative, a borane derivative, and a benzimidazole derivative.

[18] The electron transport layer and / or the electron injection layer further includes an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, or an alkaline earth. Containing at least one selected from the group consisting of metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes The organic electroluminescent element as described in [17] above.

[19] A display device comprising the organic electroluminescent element as described in any one of [16] to [18].

[20] An illumination device comprising the organic electroluminescent element as described in any one of [16] to [18].

  According to a preferred embodiment of the present invention, for example, a benzofluorene compound having excellent characteristics as a light emitting layer material can be provided. Moreover, the organic electroluminescent element improved about characteristics, such as element lifetime, can be provided.

  The benzofluorene compound of the present invention will be described in detail. The benzofluorene compound according to the present invention is a benzofluorene compound represented by the general formula (1).

1. Benzofluorene compound represented by the general formula (1) First, the benzofluorene compound represented by the general formula (1) will be described.

The “alkyl” of the “optionally substituted alkyl” in R ¹ , R ² and R ³ of the general formula (1) may be either a straight chain or a branched chain, for example, having 1 to 24 carbon atoms Examples thereof include straight chain alkyl or branched chain alkyl having 3 to 24 carbon atoms. Preferred “alkyl” is alkyl having 1 to 18 carbons (branched alkyl having 3 to 18 carbons). More preferable “alkyl” is alkyl having 1 to 12 carbons (branched alkyl having 3 to 12 carbons). More preferable “alkyl” is alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). Particularly preferred “alkyl” is alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

  Specific examples of “alkyl” include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1 -Methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2 -Propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-hept Decyl, n- octadecyl, such as n- eicosyl, and the like.

Examples of “aryl” of “optionally substituted aryl” in R ¹ , R ² and R ³ of the general formula (1) include aryl having 6 to 30 carbon atoms. Preferred “aryl” is aryl having 6 to 16 carbon atoms, more preferably aryl having 6 to 12 carbon atoms.

  Specific examples of “aryl” include monocyclic aryl phenyl, (o-, m-, p-) tolyl, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-) xylyl, mesityl, (o-, m-, p-) cumenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, fused bicyclic aryl Certain (1-, 2-) naphthyl, tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o- Terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl -4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-ter Enyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), a condensed tricyclic aryl, acenaphthylene- (1-, 3- , 4-, 5-) yl, fluorene- (1-, 2-, 3-, 4-, 9-) yl, phenalen- (1-, 2-) yl, (1-, 2-, 3-, 4-, 9-) phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'- Phenyl-m-terphenyl-4-yl, m-quaterphenyl), triphenylene- (1-, 2-) yl which is a fused tetracyclic aryl, pyrene- (1-, 2-, 4-) yl, Naphtacene- (1-, 2-, 5-) yl, pericyclic, a fused pentacyclic aryl Emissions - (1-, 2-, 3-) yl, pentacene - (1-, 2-, 5-, 6-) yl, and the like.

Particularly preferred “aryl” in R ¹ , R ² and R ³ are phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl and phenanthryl. Among these, phenyl, 4-biphenylyl, 1-naphthyl, 2- Naphthyl is preferred.

Examples of “heteroaryl” of “optionally substituted heteroaryl” in R ¹ , R ² and R ³ of the general formula (1) include heteroaryl having 2 to 30 carbon atoms. Preferred “heteroaryl” is heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, particularly preferably carbon. It is a heteroaryl having a number of 2 to 10.
Examples of the “heteroaryl” include a heterocyclic group containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom, such as an aromatic heterocyclic group. Can be given.

  Examples of the “heterocyclic group” include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, Benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothazinyl, phenazinyl, etc. Imidazolyl, pyridyl, carbazolyl and the like are preferable.

  Examples of the `` aromatic heterocyclic group '' include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, Benzofuranyl, isobenzofuranyl, benzo [b] thienyl, indolyl, isoindolyl, 1H-indazolyl, benzoimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl , Purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phena Cycloalkenyl, phenoxathiinyl, thianthrenyl, etc. indolizinyl, and the like, thienyl, imidazolyl, pyridyl, such as carbazolyl are preferable.

Examples of “cycloalkyl” of “optionally substituted cycloalkyl” in R ¹ and R ² of the general formula (1) include cycloalkyl having 3 to 12 carbon atoms. Preferred “cycloalkyl” is cycloalkyl having 3 to 10 carbon atoms. More preferred “cycloalkyl” is cycloalkyl having 3 to 8 carbon atoms. More preferred “cycloalkyl” is cycloalkyl having 3 to 6 carbon atoms.

  Specific examples of “cycloalkyl” include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

As the “substituted silyl” in R ¹ and R ² of the general formula (1), three hydrogens in the silyl group are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t- Examples thereof include those substituted with butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl.

  Specific examples of the “substituted silyl” include trimethylsilyl, triethylsilyl, tripropylsilyl, trii-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethyl. Silyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldi Propylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldii-propylsilyl, ethyldii-propylsilyl , Butyl di i- propyl silyl, sec- butyl di i- propyl silyl include trialkylsilyl such as t- butyldi i- propyl silyl. In addition, phenyldimethylsilyl, phenyldiethylsilyl, phenyldi-t-butylsilyl, methyldiphenylsilyl, ethyldiphenylsilyl, propyldiphenylsilyl, i-propyldiphenylsilyl, butyldiphenylsilyl, sec-butyldiphenylsilyl, t-butyldiphenylsilyl, tri And phenylsilyl.

Examples of the substituent of “optionally substituted” in R ¹ , R ² and R ³ of the general formula (1) include alkyl, cycloalkyl, aryl, and fluorine. Preferred examples of these are as follows: R ¹ , R ² and R ³ are each described in the “alkyl” column, R ¹ and R ² are described in the “cycloalkyl” column, R ¹ , R ² and R ³ are “aryl”. The one explained in the column is given.

R ¹ , R ² and R ³ preferably have no “substituent”, but when having a substituent, specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, n-heptyl, n-octyl, t-octyl, n-nonyl, n-decyl, n-undecyl, n- Alkyl such as dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl; cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl; phenyl, Aryls such as biphenylyl, naphthyl, terphenylyl, phenanthryl; Alkylaryl such as methylphenyl, ethylphenyl, s-butylphenyl, t-butylphenyl, 1-methylnaphthyl, 2-methylnaphthyl, 1,6-dimethylnaphthyl, 2,6-dimethylnaphthyl, 4-t-butylnaphthyl And fluorine. The number of substituents is, for example, the maximum possible number of substitution, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

Moreover, all or part of the hydrogen atoms in R ¹ , R ² and R ³ may be deuterium.

R ¹ and R ² may be the same or different, but R ¹ and R ² are preferably the same. Moreover, although two R < ³ > may be the same or different, it is preferable that two R < ³ > is the same. Two R ³ may be bonded to form a ring. As a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, or indene is spiro-condensed to the 5-membered ring of the fluorene skeleton. You may do it.

What is important in the present invention is that at least one of the maximum 20 R ¹ and R ² in the general formula (1) is selected as a para-substituted substituted silyl group. Para-substitution refers to substitution in the phenyl group of the diphenylamino group in the general formula (1) at the para position based on the nitrogen bond position. Similarly, meta substitution means substitution at the phenyl group with a meta position based on the nitrogen bond position.

  Preferably, each of the two diphenylamino groups in the benzofluorene compound is para-substituted by two substituted silyl groups (a total of four para-substituted silyl groups in the compound). Further, preferably, each of the two diphenylamino groups in the benzofluorene compound is para-substituted by one substituted silyl group (a total of two para-substituted silyl groups in the compound). In addition, when one substituted silyl group is para-substituted one by one on each of two diphenylamino groups in the benzofluorene compound, each of the remaining two phenyl groups to which the substituted silyl group is not bonded includes, for example, an alkyl group. May be substituted, each may be unsubstituted, or each substituted silyl group may be meta-substituted.

Further, all or a part of the hydrogen atoms in the benzofluorene skeleton and the phenyl group of the diphenylamino group constituting the benzofluorene compound represented by the general formula (1) may be deuterium. When deuterated, the hydrogen atom in the phenyl group of the diphenylamino group is preferably deuterated, and among the phenyl groups of the diphenylamino group, a phenyl group in which R ¹ or R ² are all hydrogen (ie, More preferably, the hydrogen atom in the unsubstituted phenyl group) is deuterated.

  Specific examples of the compound represented by the general formula (1) include compounds represented by the general formula (1 ′), and specific examples include, for example, the following formulas (1-1) to ( 1-96). Among the following compounds, in particular, the following formula (1-1), formula (1-3), formula (1-5), formula (1-6), formula (1-20), formula (1-25), Formula (1-26), Formula (1-29), Formula (1-30), Formula (1-32), Formula (1-40), Formula (1-60), Formula (1-62), Formula (1-80), Formula (1-88), Formula (1-91), Formula (1-94), Formula (1-100), Formula (1-101), Formula (1-102), Formula ( 1-103) and the compounds represented by formula (1-110) are preferred.

2. Production method of benzofluorene compound As represented by the general formula (1), a compound in which two diphenylamino groups are bonded to a benzofluorene skeleton is obtained by utilizing an existing reaction such as Buchwald-Hartwig reaction or Ullmann reaction. Can be manufactured.

The Buchwald-Hartwig reaction is a method of coupling an aromatic halide and a primary aromatic amine or a secondary aromatic amine using a palladium catalyst or a copper catalyst in the presence of a base. Specific examples of the reaction route for obtaining the compound represented by the general formula (1) by this method are as follows (Schemes 1 to 3). For the method of synthesizing the aromatic halide described in Scheme 1, for example, International Publication No. 2005/056633 pamphlet is helpful. In addition, the reaction shown in the first stage of Scheme 1 is Suzuki coupling, and the reaction can be performed by alternately exchanging the X group and the Y group in the two compounds to be reacted. Further, in this first stage reaction, Negishi coupling can be used instead of Suzuki coupling. In this case, a zinc chloride complex is used instead of boronic acid or boronic acid ester as the compound having Y group. . In the case of this Negishi coupling, the reaction can be carried out even if the X group and the Y group are alternately exchanged (that is, using a zinc chloride complex of naphthalene) in the same manner as described above. Furthermore, in Scheme 1, in order to form a five-membered ring after the coupling reaction, a raw material in which —COOR is substituted next to carbon to be coupled to the benzene ring is used, but the 2-position of the naphthalene ring ( It is also possible to use a raw material in which -COOR is substituted on the side of the carbon to be coupled. R ¹ , R ² and R ^{3 in} each scheme correspond to those used in the general formula (1), respectively.

Specific examples of the palladium catalyst used in this reaction include tetrakis (triphenylphosphine) palladium (0): Pd (PPh ₃ ) ₄ , bis (triphenylphosphine) palladium (II) dichloride: PdCl ₂ (PPh ₃ ) ₂ , Palladium (II) acetate: Pd (OAc) ₂ , tris (dibenzylideneacetone) dipalladium (0): Pd ₂ (dba) ₃ , tris (dibenzylideneacetone) dipalladium (0) chloroform complex: Pd ₂ (dba) ₃ · CHCl ₃ , bis (dibenzylideneacetone) palladium (0): Pd (dba) ₂ and the like.

  In order to accelerate the reaction, a phosphine compound may be added to these palladium compounds in some cases. Specific examples of the phosphine compound include tri (t-butyl) phosphine, tricyclohexylphosphine, 1- (N, N-dimethylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (N, N -Dibutylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (methoxymethyl) -2- (di-t-butylphosphino) ferrocene, 1,1'-bis (di-t-butylphosphino) ) Ferrocene, 2,2′-bis (di-t-butylphosphino) -1,1′-binaphthyl, 2-methoxy-2 ′-(di-t-butylphosphino) -1,1′-binaphthyl, 1, 1'-bis (diphenylphosphino) ferrocene, bis (diphenylphosphino) binaphthyl, 4-dimethylaminophenyl di-t-butylphosphine, phenyldi-t-butylphosphine Fin, and the like.

  Specific examples of the base used in this reaction are sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, sodium t-butoxide, sodium acetate, phosphoric acid. Tripotassium, potassium fluoride, etc.

  Furthermore, specific examples of the solvent used in this reaction are benzene, toluene, xylene, N, N-dimethylformamide, tetrahydrofuran, diethyl ether, t-butylmethyl ether, 1,4-dioxane, methanol, ethanol, Isopropyl alcohol and the like. These solvents can be appropriately selected according to the structures of the aromatic halide, triflate, aromatic boronic acid ester and aromatic boronic acid to be reacted. A solvent may be used independently and may be used as a mixed solvent.

  The Ullman reaction is a method of coupling an aromatic halide and a primary aromatic amine or a secondary aromatic amine using a copper catalyst in the presence of a base. Specific examples of the copper catalyst used in the Ullman reaction include copper powder, copper chloride, copper bromide or copper iodide. Moreover, the specific example of the base used by this reaction can be selected from the same thing as Buchwald-Hartwig reaction. Furthermore, specific examples of the solvent used in the Ullman reaction include nitrobenzene, dichlorobenzene, N, N-dimethylformamide and the like.

In addition, as represented by the general formula (1), a compound in which two diphenylamino groups are bonded to a benzofluorene skeleton can also be produced using the following reaction (Schemes 4 and 5). Note that the reaction shown in the first stage of Scheme 4 and Scheme 5 is Suzuki coupling, and the reaction can be performed by alternately exchanging the X group and the Y group in the two compounds to be reacted. Further, in this first stage reaction, Negishi coupling can be used instead of Suzuki coupling. In this case, a zinc chloride complex is used instead of boronic acid or boronic acid ester as the compound having Y group. . In the case of this Negishi coupling, the reaction can be carried out even if the X group and the Y group are alternately exchanged (that is, using a zinc chloride complex of diphenylamino-substituted naphthalene) as described above. Note that R ¹ , R ² and R ³ in each scheme correspond to those used in the general formula (1), respectively.

  In addition, the benzofluorene compound according to the present invention includes those in which at least a part of hydrogen is substituted with deuterium. Such a compound can be obtained by using a raw material in which a desired portion is deuterated. Can be synthesized in the same manner as described above.

3. Organic Electroluminescent Device The benzofluorene compound according to the present invention can be used as a material for an organic electroluminescent device, for example.
The organic electroluminescent element according to this embodiment will be described in detail based on the drawings. FIG. 1 is a schematic cross-sectional view showing an organic electroluminescent element according to this embodiment.

<Structure of organic electroluminescence device>
An organic electroluminescent device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, and a hole injection layer 103. A hole transport layer 104 provided on the light emitting layer 105, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, and an electron transport layer 106. And the cathode 108 provided on the electron injection layer 107.

  The organic electroluminescent element 100 is manufactured in the reverse order, for example, the substrate 101, the cathode 108 provided on the substrate 101, the electron injection layer 107 provided on the cathode 108, and the electron injection layer. An electron transport layer 106 provided on 107, a light-emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light-emitting layer 105, and a hole transport layer 104 A structure including the hole injection layer 103 provided above and the anode 102 provided on the hole injection layer 103 may be employed.

  Not all of the above layers are necessary, and the minimum structural unit is composed of the anode 102, the light emitting layer 105, and the cathode 108, and the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection are included. The layer 107 is an arbitrarily provided layer. Moreover, each said layer may consist of a single layer, respectively, and may consist of multiple layers.

  As an aspect of the layer constituting the organic electroluminescence device, in addition to the above-described configuration aspect of “substrate / anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode”, "Substrate / anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode", "substrate / Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ”,“ substrate ” / Anode / light emitting layer / electron transport layer / electron injection layer / cathode ”,“ substrate / anode / hole transport layer / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / hole transport layer / light emitting layer / “Electron transport layer / cathode”, “substrate / anode / hole injection layer / light emitting layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / light emitting layer / electron transport” Layer / cathode ”,“ substrate / anode / hole injection layer / hole transport layer / light emitting layer / cathode ”,“ substrate / anode / hole injection layer / light emitting layer / cathode ”,“ substrate / anode / hole transport ” Layer / light emitting layer / cathode ”,“ substrate / anode / light emitting layer / electron transport layer / cathode ”,“ substrate / anode / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / light emitting layer / cathode ” An aspect may be sufficient.

<Substrate in organic electroluminescence device>
The substrate 101 serves as a support for the organic electroluminescent device 100, and usually quartz, glass, metal, plastic, or the like is used. The substrate 101 is formed into a plate shape, a film shape, or a sheet shape according to the purpose. For example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone and the like are preferable. In the case of a glass substrate, soda lime glass, non-alkali glass, or the like is used, and the thickness only needs to be sufficient to maintain the mechanical strength. The upper limit value of the thickness is, for example, 2 mm or less, preferably 1 mm or less. The glass material is preferably alkali-free glass because it is better to have less ions eluted from the glass. However, soda lime glass with a barrier coat such as SiO ₂ is also commercially available, so it can be used. it can. Further, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one surface in order to improve the gas barrier property, and a synthetic resin plate, film or sheet having a low gas barrier property is used as the substrate 101. When used, it is preferable to provide a gas barrier film.

<Anode in organic electroluminescence device>
The anode 102 serves to inject holes into the light emitting layer 105. When the hole injection layer 103 and / or the hole transport layer 104 are provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these layers. .

  Examples of the material for forming the anode 102 include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), etc.), halogenated compounds. Examples thereof include metals (such as copper iodide), copper sulfide, carbon black, ITO glass, and nesa glass. Examples of the organic compound include polythiophene such as poly (3-methylthiophene), conductive polymer such as polypyrrole and polyaniline, and the like. In addition, it can select suitably from the substances currently used as an anode of an organic electroluminescent element, and can use it.

  The resistance of the transparent electrode is not particularly limited as long as a current sufficient for light emission of the light emitting element can be supplied, but it is desirable that the resistance is low from the viewpoint of power consumption of the light emitting element. For example, an ITO substrate of 300Ω / □ or less functions as an element electrode. However, since it is now possible to supply a substrate of about 10Ω / □, for example, 100-5Ω / □, preferably 50-5Ω. It is particularly desirable to use a low resistance product of / □. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of 100 to 300 nm.

<Hole injection layer and hole transport layer in organic electroluminescence device>
The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating and mixing one kind or two or more kinds of hole injection / transport materials or a mixture of the hole injection / transport material and the polymer binder. Is done. In addition, an inorganic salt such as iron (III) chloride may be added to the hole injection / transport material to form a layer.

  As a hole injection / transport material, it is necessary to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied. The hole injection efficiency is high, and the injected holes are transported efficiently. It is desirable to do. For this purpose, it is preferable to use a substance that has a low ionization potential, a high hole mobility, excellent stability, and is less likely to generate trapping impurities during production and use.

  As a material for forming the hole injection layer 103 and the hole transport layer 104, in a photoconductive material, a compound conventionally used as a charge transport material for holes, a p-type semiconductor, and a hole injection of an organic electroluminescent element are used. Any known material used for the layer and the hole transport layer can be selected and used. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis (N-allylcarbazole) or bis (N-alkylcarbazole), triarylamine derivatives (aromatic tertiary class). Polymer having amino in main chain or side chain, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-di (3-methylphenyl) -4 , 4'-diaminobiphenyl, N, N'-diphenyl-N, N'-dinaphthyl-4,4'-diaminobiphenyl (hereinafter abbreviated as NPD), N, N'-diphenyl-N, N'- Di (3-methylphenyl) -4,4′-diphenyl-1,1′-diamine, N, N′-dinaphthyl-N, N′-diphenyl Triphenylamine derivatives such as 4,4′-diphenyl-1,1′-diamine, 4,4 ′, 4 ″ -tris (3-methylphenyl (phenyl) amino) triphenylamine, starburst amine derivatives, and stilbene Derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, heterocyclic compounds such as benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, porphyrin derivatives, polysilanes, etc. Polycarbonate, styrene derivatives, polyvinyl carbazole, and polysilane having a body in the side chain are preferable, but any compound that forms a thin film necessary for manufacturing a light-emitting element, can inject holes from the anode, and can further transport holes. Especially limited No.

  It is also known that the conductivity of organic semiconductors is strongly influenced by the doping. Such an organic semiconductor matrix material is composed of a compound having a good electron donating property or a compound having a good electron accepting property. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping of electron donor materials. (For example, the document “M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (22), 3202-3204 (1998)”) and the document “J. Blochwitz, M Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (6), 729-731 (1998)). These generate so-called holes by an electron transfer process in an electron donating base material (hole transport material). Depending on the number and mobility of holes, the conductivity of the base material varies considerably. Known matrix substances having hole transporting properties include, for example, benzidine derivatives (TPD and the like), starburst amine derivatives (TDATA and the like), and specific metal phthalocyanines (particularly zinc phthalocyanine ZnPc and the like). 2005-167175).

<Light emitting layer in organic electroluminescent element>
The light emitting layer 105 emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound that emits light by being excited by recombination of holes and electrons (a light-emitting compound), can form a stable thin film shape, and is in a solid state It is preferable that the compound exhibits a high emission (fluorescence and / or phosphorescence) efficiency.

  The light emitting layer may be either a single layer or a plurality of layers, each formed of a light emitting material (host material, dopant material), which may be a mixture of a host material and a dopant material or a host material alone. Or either. That is, in each layer of the light emitting layer, only the host material or the dopant material may emit light, or both the host material and the dopant material may emit light. Each of the host material and the dopant material may be one kind or a plurality of combinations. The dopant material may be included in the host material as a whole, or may be included partially. The amount of dopant used varies depending on the dopant and may be determined according to the characteristics of the dopant. The standard of the amount of the dopant used is preferably 0.001 to 50% by weight, more preferably 0.1 to 10% by weight, and further preferably 1 to 5% by weight of the entire light emitting material. As a doping method, it can be formed by a co-evaporation method with a host material, but it may be pre-mixed with the host material and then simultaneously deposited.

  The host material is not particularly limited, but has previously been known as a light emitter, such as fused ring derivatives such as anthracene and pyrene, metal chelated oxinoid compounds such as tris (8-quinolinolato) aluminum, bis Bisstyryl derivatives such as styryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, thiadiazolopyridine derivatives, pyrrolopyrrole In derivatives and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives are preferably used.

  In addition, as a host material, it can select and use suitably from the compound etc. which were described in the chemical industry June, 2004 issue page 13, and the reference cited up.

  The amount of the host material used is preferably 50 to 99.999% by weight of the entire light emitting material, more preferably 80 to 99.95% by weight, and still more preferably 90 to 99.9% by weight.

  Moreover, as a dopant material, the benzofluorene compound of the said General formula (1) can be used, and especially following formula (1-1), Formula (1-3), Formula (1-5), Formula (1) -6), formula (1-20), formula (1-25), formula (1-26), formula (1-29), formula (1-30), formula (1-32), formula (1- 40), formula (1-60), formula (1-62), formula (1-80), formula (1-88), formula (1-91), formula (1-94), formula (1-100) ), The formula (1-101), the formula (1-102), the formula (1-103), and the compound represented by the formula (1-110) are preferably used. The amount of the benzofluorene compound represented by the general formula (1) used as a dopant material is preferably 0.001 to 50% by weight, more preferably 0.05 to 20% by weight, based on the entire luminescent material. More preferably, it is 0.1 to 10% by weight. As a doping method, it can be formed by a co-evaporation method with a host material, but it may be pre-mixed with the host material and then simultaneously deposited.

  Other dopant materials can be used at the same time. The other dopant material is not particularly limited, and a known compound can be used, and can be selected from various materials according to a desired emission color. Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopylene, dibenzopyrene and rubrene, benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, Bisstyryl derivatives such as oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives and distyrylbenzene derivatives Kaihei 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278) Isobenzofuran derivatives such as diazaindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di (2-methylphenyl) isobenzofuran, di (2-trifluoromethylphenyl) isobenzofuran, phenylisobenzofuran, Dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzoimidazolylcoumarin derivatives , Coumarin derivatives such as 3-benzoxazolyl coumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives , Oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2, 5-thiadiazolopyrene derivatives, pyromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, and deazaflavin derivatives.

  Illustratively for each color light, blue to blue-green dopant materials include naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene and other aromatic hydrocarbon compounds and derivatives thereof, furan, pyrrole, thiophene, silole, Aromatic heterocyclic compounds such as 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene And its derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, imidazole, thiazole, thiadiazole, cal Azole derivatives such as sol, oxazole, oxadiazole, triazole and metal complexes thereof, and N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1′- Examples thereof include aromatic amine derivatives represented by diamine.

  Examples of green to yellow dopant materials include coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and naphthacene derivatives such as rubrene, and the above blue The compound which introduce | transduced the substituent which enables long wavelength, such as aryl, heteroaryl, aryl vinyl, amino, and cyano to the compound illustrated as a blue-green dopant material is also mentioned as a suitable example.

  Further, examples of the orange to red dopant material include naphthalimide derivatives such as bis (diisopropylphenyl) perylenetetracarboxylic imide, perinone derivatives, rare earth complexes such as Eu complexes having acetylacetone, benzoylacetone and phenanthroline as ligands, 4 -(Dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone Derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, phenoxazones Substituents that enable longer wavelengths such as aryl, heteroaryl, arylvinyl, amino, and cyano are added to the compounds exemplified as the above-mentioned blue to blue-green and green to yellow dopant materials. The introduced compound is also a suitable example. Furthermore, a phosphorescent metal complex having iridium represented by tris (2-phenylpyridine) iridium (III) or platinum as a central metal is also a suitable example.

  As the dopant material suitable for the light emitting layer material of the present invention, among the above-mentioned dopant materials, the benzofluorene compound represented by the general formula (1) is most suitable. , Borane derivatives, amine-containing styryl derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, iridium complexes or platinum complexes are preferred.

Examples of perylene derivatives include 3,10-bis (2,6-dimethylphenyl) perylene, 3,10-bis (2,4,6-trimethylphenyl) perylene, 3,10-diphenylperylene, 3,4- Diphenylperylene, 2,5,8,11-tetra-t-butylperylene, 3,4,9,10-tetraphenylperylene, 3- (1'-pyrenyl) -8,11-di (t-butyl) perylene 3- (9′-anthryl) -8,11-di (t-butyl) perylene, 3,3′-bis (8,11-di (t-butyl) perylenyl), and the like.
JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, Perylene derivatives described in JP-A No. 2000-34234, JP-A No. 2001-267075, JP-A No. 2001-217077 and the like may be used.

Examples of the borane derivatives include 1,8-diphenyl-10- (dimesitylboryl) anthracene, 9-phenyl-10- (dimesitylboryl) anthracene, 4- (9′-anthryl) dimesitylborylnaphthalene, 4- (10 ′). -Phenyl-9'-anthryl) dimesitylborylnaphthalene, 9- (dimesitylboryl) anthracene, 9- (4'-biphenylyl) -10- (dimesitylboryl) anthracene, 9- (4 '-(N-carbazolyl) phenyl) -10- (Dimesitylboryl) anthracene and the like.
Moreover, you may use the borane derivative described in the international publication 2000/40586 pamphlet.

  Examples of the amine-containing styryl derivative include N, N, N ′, N′-tetra (4-biphenylyl) -4,4′-diaminostilbene, N, N, N ′, N′-tetra (1-naphthyl). -4,4'-diaminostilbene, N, N, N ', N'-tetra (2-naphthyl) -4,4'-diaminostilbene, N, N'-di (2-naphthyl) -N, N' -Diphenyl-4,4'-diaminostilbene, N, N'-di (9-phenanthryl) -N, N'-diphenyl-4,4'-diaminostilbene, 4,4'-bis [4 "-bis ( Diphenylamino) styryl] -biphenyl, 1,4-bis [4′-bis (diphenylamino) styryl] -benzene, 2,7-bis [4′-bis (diphenylamino) styryl] -9,9-dimethylfluorene , 4, 4 ' Examples thereof include bis (9-ethyl-3-carbazovinylene) -biphenyl, 4,4′-bis (9-phenyl-3-carbazovinylene) -biphenyl, etc. JP-A 2003-347056 and JP-A 2001- An amine-containing styryl derivative described in Japanese Patent No. 307884 may be used.

Examples of the aromatic amine derivative include N, N, N, N-tetraphenylanthracene-9,10-diamine, 9,10-bis (4-diphenylamino-phenyl) anthracene, and 9,10-bis (4- Di (1-naphthylamino) phenyl) anthracene, 9,10-bis (4-di (2-naphthylamino) phenyl) anthracene, 10-di-p-tolylamino-9- (4-di-p-tolylamino-1) -Naphthyl) anthracene, 10-diphenylamino-9- (4-diphenylamino-1-naphthyl) anthracene, 10-diphenylamino-9- (6-diphenylamino-2-naphthyl) anthracene, [4- (4-diphenyl) Amino-phenyl) naphthalen-1-yl] -diphenylamine, [4- (4-diphenylamino-phenyl) Naphthalen-1-yl] -diphenylamine, [6- (4-diphenylamino-phenyl) naphthalen-2-yl] -diphenylamine, 4,4′-bis [4-diphenylaminonaphthalen-1-yl] biphenyl, 4, 4'-bis [6-diphenylaminonaphthalen-2-yl] biphenyl, 4,4 "-bis [4-diphenylaminonaphthalen-1-yl] -p-terphenyl, 4,4" -bis [6-diphenyl Aminonaphthalen-2-yl] -p-terphenyl and the like.
Moreover, you may use the aromatic amine derivative described in Unexamined-Japanese-Patent No. 2006-156888.

Examples of the coumarin derivative include coumarin-6 and coumarin-334.
Moreover, you may use the coumarin derivative described in Unexamined-Japanese-Patent No. 2004-43646, Unexamined-Japanese-Patent No. 2001-76876, and Unexamined-Japanese-Patent No. 6-298758.

Examples of the pyran derivative include the following DCM and DCJTB.
Also, JP 2005-126399, JP 2005-097283, JP 2002-234892, JP 2001-220577, JP 2001-081090, and JP 2001-052869. Alternatively, pyran derivatives described in the above may be used.

Examples of the iridium complex include Ir (ppy) _{3 described} below.
Further, the iridium complexes described in JP-A-2006-089398, JP-A-2006-080419, JP-A-2005-298483, JP-A-2005-097263, JP-A-2004-111379, etc. It may be used.

Examples of the platinum complex include the following PtOEP.
Further, the platinum complexes described in JP-A-2006-190718, JP-A-2006-128634, JP-A-2006-093542, JP-A-2004-335122, JP-A-2004-331508, etc. It may be used.

  In addition, as a dopant, it can select and use suitably from the compound etc. which were described in the chemical industry June, 2004 issue page 13, and the reference cited up.

<Electron injection layer and electron transport layer in organic electroluminescence device>
The electron injection layer 107 plays a role of efficiently injecting electrons moving from the cathode 108 into the light emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are each formed by laminating and mixing one or more electron transport / injection materials or a mixture of the electron transport / injection material and the polymer binder.

  The electron injecting / transporting layer is a layer that administers electrons injected from the cathode and further transports electrons. It is desirable that the electron injecting electrons have high efficiency and efficiently transport the injected electrons. For this purpose, it is preferable to use a substance that has a high electron affinity, a high electron mobility, excellent stability, and is unlikely to generate trapping impurities during production and use. However, considering the transport balance between holes and electrons, if the role of effectively preventing the holes from the anode from flowing to the cathode side without recombination is mainly played, the electron transport capability is much higher. Even if it is not high, the effect of improving the luminous efficiency is equivalent to that of a material having a high electron transport capability. Therefore, the electron injection / transport layer in this embodiment may include a function of a layer that can efficiently block the movement of holes.

  Materials used for the electron transport layer and the electron injection layer include compounds conventionally used as electron transport compounds in photoconductive materials, and known compounds used for the electron injection layer and the electron transport layer of organic electroluminescent elements. Any of these can be selected and used.

  Specifically, pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, thiophene derivatives, thiadiazole derivatives, quinoxaline derivatives, quinoxaline Derivative polymers, benzazole compounds, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, imidazopyridine derivatives, borane derivatives, benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, aldazine derivatives, carbazole derivatives, indole derivatives, Examples thereof include phosphorus oxide derivatives and bisstyryl derivatives. In addition, oxadiazole derivatives (1,3-bis [(4-t-butylphenyl) 1,3,4-oxadiazolyl] phenylene, etc.), triazole derivatives (N-naphthyl-2,5-diphenyl-1,3, etc.) 4-triazole etc.), benzoquinoline derivatives (2,2′-bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene etc.), benzimidazole derivatives (tris (N-phenylbenzimidazole) -2-yl) benzene), bipyridine derivatives, terpyridine derivatives (1,3-bis (4 ′-(2,2 ′: 6′2 ″ -terpyridinyl)) benzene, etc.), naphthyridine derivatives (bis (1-naphthyl) ) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide, etc.) These materials are But it used but may be used in admixture with different materials.

  In addition, metal complexes having electron-accepting nitrogen can also be used, such as hydroxyazole complexes such as quinolinol-based metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. can give. These materials can be used alone or in combination with different materials.

  Among the materials described above, quinolinol metal complexes, bipyridine derivatives, phenanthroline derivatives, borane derivatives or benzimidazole derivatives are preferable.

The quinolinol-based metal complex is a compound represented by the following general formula (E-1).
In the formula, R ^{1 to} R ⁶ are hydrogen or a substituent, M is Al, Ga, Be, or Zn, and n is an integer of 2 or 3.

  Specific examples of the quinolinol-based metal complex include tris (8-quinolinolato) aluminum, tris (4-methyl-8-quinolinolato) aluminum, tris (5-methyl-8-quinolinolato) aluminum, tris (3,4-dimethyl- 8-quinolinolato) aluminum, tris (4,5-dimethyl-8-quinolinolato) aluminum, tris (4,6-dimethyl-8-quinolinolato) aluminum, bis (2-methyl-8-quinolinolato) (phenolate) aluminum, bis (2-methyl-8-quinolinolato) (2-methylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (3-methylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (4- Methyl phenolate) alumini Bis (2-methyl-8-quinolinolato) (2-phenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (3-phenylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (4-Phenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,3-dimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,6-dimethylphenolate) aluminum Bis (2-methyl-8-quinolinolato) (3,4-dimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (3,5-dimethylphenolate) aluminum, bis (2-methyl-8) -Quinolinolate) (3,5-di-t-butylphenolate) alumini Bis (2-methyl-8-quinolinolato) (2,6-diphenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,4,6-triphenylphenolato) aluminum, bis (2 -Methyl-8-quinolinolato) (2,4,6-trimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,4,5,6-tetramethylphenolato) aluminum, bis (2- Methyl-8-quinolinolato) (1-naphtholato) aluminum, bis (2-methyl-8-quinolinolato) (2-naphtholato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (2-phenylphenolato) aluminum Bis (2,4-dimethyl-8-quinolinolate) (3-phenylphenola) G) Aluminum, bis (2,4-dimethyl-8-quinolinolato) (4-phenylphenolate) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolate) aluminum, bis ( 2,4-dimethyl-8-quinolinolato) (3,5-di-t-butylphenolate) aluminum, bis (2-methyl-8-quinolinolato) aluminum-μ-oxo-bis (2-methyl-8-quinolinolato) ) Aluminum, bis (2,4-dimethyl-8-quinolinolato) aluminum-μ-oxo-bis (2,4-dimethyl-8-quinolinolato) aluminum, bis (2-methyl-4-ethyl-8-quinolinolato) aluminum -Μ-oxo-bis (2-methyl-4-ethyl-8-quinolinolato) aluminum Bis (2-methyl-4-methoxy-8-quinolinolato) aluminum-μ-oxo-bis (2-methyl-4-methoxy-8-quinolinolato) aluminum, bis (2-methyl-5-cyano-8- Quinolinolato) aluminum-μ-oxo-bis (2-methyl-5-cyano-8-quinolinolato) aluminum, bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum-μ-oxo-bis (2- Methyl-5-trifluoromethyl-8-quinolinolato) aluminum, bis (10-hydroxybenzo [h] quinoline) beryllium and the like.

The bipyridine derivative is a compound represented by the following general formula (E-2).
In the formula, G represents a simple bond or an n-valent linking group, and n is an integer of 2 to 8. Carbon atoms that are not used for bonding of pyridine-pyridine or pyridine-G may be substituted.

Examples of G in the general formula (E-2) include the following structural formulas. In addition, R in the following structural formula is each independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl.

  Specific examples of the pyridine derivative include 2,5-bis (2,2′-bipyridyl-6-yl) -1,1-dimethyl-3,4-diphenylsilole, 2,5-bis (2,2′- Bipyridyl-6-yl) -1,1-dimethyl-3,4-dimesitylsilole, 2,5-bis (2,2′-bipyridyl-5-yl) -1,1-dimethyl-3,4 Diphenylsilole, 2,5-bis (2,2′-bipyridyl-5-yl) -1,1-dimethyl-3,4-dimesitylsilole 9,10-di (2,2′-bipyridyl-6- Yl) anthracene, 9,10-di (2,2′-bipyridyl-5-yl) anthracene, 9,10-di (2,3′-bipyridyl-6-yl) anthracene, 9,10-di (2, 3'-bipyridyl-5-yl) anthracene, 9,10-di (2,3 -Bipyridyl-6-yl) -2-phenylanthracene, 9,10-di (2,3'-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (2,2'-bipyridyl-6) -Yl) -2-phenylanthracene, 9,10-di (2,2'-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (2,4'-bipyridyl-6-yl)- 2-Phenylanthracene, 9,10-di (2,4′-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (3,4′-bipyridyl-6-yl) -2-phenylanthracene 9,10-di (3,4'-bipyridyl-5-yl) -2-phenylanthracene, 3,4-diphenyl-2,5-di (2,2'-bipyridyl-6-yl) thiophene, 3, , 4-Diphenyl 2,5-di (2,3′-bipyridyl-5-yl) thiophene, 6′6 ″ -di (2-pyridyl) 2,2 ′: 4 ′, 4 ″: 2 ″, 2 ″ ′-quater Examples include pyridine.

The phenanthroline derivative is a compound represented by the following general formula (E-3-1) or (E-3-2).
In the formula, R ^{1 to} R ⁸ are hydrogen or a substituent, adjacent groups may be bonded to each other to form a condensed ring, G represents a simple bond or an n-valent linking group, and n represents 2 It is an integer of ~ 8. Examples of G in the general formula (E-3-2) include the same ones as described in the bipyridine derivative column.

  Specific examples of the phenanthroline derivative include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di (1,10-phenanthroline- 2-yl) anthracene, 2,6-di (1,10-phenanthroline-5-yl) pyridine, 1,3,5-tri (1,10-phenanthroline-5-yl) benzene, 9,9′-difluor -Bis (1,10-phenanthroline-5-yl), bathocuproin, 1,3-bis (2-phenyl-1,10-phenanthroline-9-yl) benzene and the like.

  In particular, the case where a phenanthroline derivative is used for an electron transport layer and an electron injection layer will be described. In order to obtain stable light emission over a long period of time, a material excellent in thermal stability and thin film formation is desired, and among the phenanthroline derivatives, the substituent itself has a three-dimensional structure, Those having a three-dimensional structure by steric repulsion with an adjacent substituent or those having a plurality of phenanthroline skeletons linked to each other are preferred. Further, when linking a plurality of phenanthroline skeletons, a compound containing a conjugated bond, a substituted or unsubstituted aromatic hydrocarbon, or a substituted or unsubstituted aromatic heterocycle in the linking unit is more preferable.

The borane derivative is a compound represented by the following general formula (E-4), and is disclosed in detail in JP-A-2007-27587.
In which R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl or an optionally substituted aryl, X is an optionally substituted arylene, and Y is a substituted And optionally substituted aryl having 16 or less carbon atoms, substituted boryl, or optionally substituted carbazole, and n is each independently an integer of 0 to 3.

Among the compounds represented by the general formula (E-4), the compounds represented by the following general formula (E-4-1), and further the following general formulas (E-4-1-1) to (E-4) The compound represented by -1-4) is preferred. Specific examples include 9- [4- (4-Dimesitylborylnaphthalen-1-yl) phenyl] carbazole, 9- [4- (4-Dimesitylborylnaphthalen-1-yl) naphthalen-1-yl. Carbazole and the like.
In which R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl or an optionally substituted aryl, and R ²¹ and R ²² are each independently a hydrogen, It is at least one of alkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocyclic ring, or cyano, and X ¹ is an optionally substituted arylene having 20 or less carbon atoms. Each n is independently an integer from 0 to 3, and each m is independently an integer from 0 to 4.

In each formula, R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

Among the compounds represented by the general formula (E-4), a compound represented by the following general formula (E-4-2), and a compound represented by the following general formula (E-4-2-1) Is preferred.
In which R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl or an optionally substituted aryl, X ¹ is an optionally substituted arylene having 20 or less carbon atoms, And n is an integer of 0-3 each independently.

In which R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

Among the compounds represented by the above general formula (E-4), the compound represented by the following general formula (E-4-3), and the following general formula (E-4-3-1) or (E-4 The compound represented by -3-2) is preferable.
In which R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl or an optionally substituted aryl, X ¹ is an optionally substituted arylene having 10 or less carbon atoms, Y ¹ is an optionally substituted aryl having 14 or less carbon atoms, and n is each independently an integer of 0 to 3.

In each formula, R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

The benzimidazole derivative is a compound represented by the following general formula (E-5).
In the formula, Ar ^{1 to} Ar ³ are each independently hydrogen or aryl having 6 to 30 carbon atoms which may be substituted. In particular, a benzimidazole derivative which is anthryl optionally substituted with Ar ¹ is preferable.

  Specific examples of the aryl having 6 to 30 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, acenaphthylene-1-yl, acenaphthylene-3-yl, acenaphthylene-4-yl, acenaphthylene-5-yl, and fluorene-1- Yl, fluoren-2-yl, fluoren-3-yl, fluoren-4-yl, fluoren-9-yl, phenalen-1-yl, phenalen-2-yl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-anthryl, 2-anthryl, 9-anthryl, fluoranthen-1-yl, fluoranthen-2-yl, fluoranthen-3-yl, fluoranthen-7-yl, fluoranthen-8-yl, Triphenylene-1-yl, triphenylene-2-yl, pyreth -1-yl, pyren-2-yl, pyren-4-yl, chrysen-1-yl, chrysen-2-yl, chrysen-3-yl, chrysen-4-yl, chrysen-5-yl, chrysene-6 -Yl, naphthacene-1-yl, naphthacene-2-yl, naphthacene-5-yl, perylene-1-yl, perylene-2-yl, perylene-3-yl, pentacene-1-yl, pentasen-2-yl , Pentacene-5-yl and pentacene-6-yl.

  Specific examples of the benzimidazole derivative include 1-phenyl-2- (4- (10-phenylanthracen-9-yl) phenyl) -1H-benzo [d] imidazole, 2- (4- (10- (naphthalene-2) -Yl) anthracen-9-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole, 2- (3- (10- (naphthalen-2-yl) anthracen-9-yl) phenyl) -1- Phenyl-1H-benzo [d] imidazole, 5- (10- (naphthalen-2-yl) anthracen-9-yl) -1,2-diphenyl-1H-benzo [d] imidazole, 1- (4- (10 -(Naphthalen-2-yl) anthracen-9-yl) phenyl) -2-phenyl-1H-benzo [d] imidazole, 2- (4- (9,10-di (naphthalene) 2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole, 1- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl ) -2-phenyl-1H-benzo [d] imidazole, 5- (9,10-di (naphthalen-2-yl) anthracen-2-yl) -1,2-diphenyl-1H-benzo [d] imidazole is there.

  The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As this reducing substance, various substances can be used as long as they have a certain reducing ability. For example, alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkali From the group consisting of earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes At least one selected can be suitably used.

  Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV) or Cs (1.95 eV), and Ca (2. 9eV), Sr (2.0 to 2.5 eV) or Ba (2.52 eV), and alkaline earth metals such as those having a work function of 2.9 eV or less are particularly preferable. Among these, a more preferable reducing substance is an alkali metal of K, Rb or Cs, more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or the electron injection layer, the luminance of the organic EL element can be improved and the lifetime can be extended. Further, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable. Particularly, a combination containing Cs, such as Cs and Na, Cs and K, Cs and Rb, or A combination of Cs, Na and K is preferred. By containing Cs, the reducing ability can be efficiently exhibited, and by adding to the material for forming the electron transport layer or the electron injection layer, the luminance of the organic EL element can be improved and the lifetime can be extended.

<Cathode in organic electroluminescence device>
The cathode 108 serves to inject electrons into the light emitting layer 105 through the electron injection layer 107 and the electron transport layer 106.

  The material for forming the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but the same material as that for forming the anode 102 can be used. Among them, metals such as tin, magnesium, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or alloys thereof (magnesium-silver alloy) , Magnesium-indium alloys, aluminum-lithium alloys such as lithium fluoride / aluminum) are preferred. Lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective for increasing the electron injection efficiency and improving device characteristics. However, these low work function metals are often often unstable in the atmosphere. In order to improve this point, for example, a method is known in which an organic layer is doped with a small amount of lithium, cesium or magnesium and a highly stable electrode is used. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, it is not limited to these.

  Furthermore, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, and inorganic materials such as silica, titania and silicon nitride, polyvinyl alcohol, vinyl chloride Lamination of hydrocarbon polymer compounds and the like is a preferred example. The method for producing these electrodes is not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam, sputtering, ion plating, and coating.

<Binder that may be used in each layer>
The materials used for the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer can form each layer alone, but as a polymer binder, polyvinyl chloride, polycarbonate, Polystyrene, poly (N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polysulfone, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin , Dispersed in solvent-soluble resins such as polyurethane resin, curable resins such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, etc. To be possible.

<Method for producing organic electroluminescent element>
Each layer constituting the organic electroluminescent element is formed by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, printing method, spin coating method or cast method, coating method, etc. It can be formed by using a thin film. The film thickness of each layer thus formed is not particularly limited and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a crystal oscillation type film thickness measuring device or the like. When a thin film is formed using a vapor deposition method, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, and the like. Deposition conditions generally include boat heating temperature +50 to + 400 ° C., vacuum degree 10 ⁻⁶ to 10 ⁻³ Pa, deposition rate 0.01 to 50 nm / sec, substrate temperature −150 to + 300 ° C., film thickness 2 nm to 5 μm. It is preferable to set appropriately within the range.

  Next, as an example of a method for producing an organic electroluminescent device, an organic electric field composed of an anode / hole injection layer / hole transport layer / a light emitting layer composed of a host material and a dopant material / electron transport layer / electron injection layer / cathode. A method for manufacturing a light-emitting element will be described. A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to produce an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-evaporated to form a thin film to form a light emitting layer. An electron transport layer and an electron injection layer are formed on the light emitting layer, and a thin film made of a cathode material is formed by vapor deposition. By forming it as a cathode, a target organic electroluminescent element can be obtained. In the preparation of the organic electroluminescence device described above, the order of preparation may be reversed, and the cathode, electron injection layer, electron transport layer, light emitting layer, hole transport layer, hole injection layer, and anode may be fabricated in this order. Is possible.

  When a DC voltage is applied to the organic electroluminescent device thus obtained, the anode may be applied with a positive polarity and the cathode with a negative polarity. When a voltage of about 2 to 40 V is applied, the organic electroluminescent device is transparent or translucent. Luminescence can be observed from the electrode side (anode or cathode, and both). The organic electroluminescence device emits light when a pulse current or an alternating current is applied. The alternating current waveform to be applied may be arbitrary.

<Application examples of organic electroluminescent devices>
The present invention can also be applied to a display device provided with an organic electroluminescent element or a lighting device provided with an organic electroluminescent element.
A display device or an illuminating device including an organic electroluminescent element can be manufactured by a known method such as connecting the organic electroluminescent element according to the present embodiment and a known driving device, such as direct current driving, pulse driving, or alternating current. It can be driven by appropriately using a known driving method such as driving.

  Examples of the display device include a panel display such as a color flat panel display, and a flexible display such as a flexible color organic electroluminescence (EL) display (for example, JP-A-10-335066 and JP-A-2003-321546). Gazette, Japanese Patent Application Laid-Open No. 2004-281086, etc.). Examples of the display method of the display include a matrix and / or segment method. Note that the matrix display and the segment display may coexist in the same panel.

  A matrix means a pixel in which pixels for display are two-dimensionally arranged such as a lattice or a mosaic, and displays a character or an image with a set of pixels. The shape and size of the pixel are determined by the application. For example, a square pixel with a side of 300 μm or less is usually used for displaying images and characters on a personal computer, monitor, TV, and a pixel with a side of mm order for a large display such as a display panel. become. In monochrome display, pixels of the same color may be arranged. However, in color display, red, green, and blue pixels are displayed side by side. In this case, there are typically a delta type and a stripe type. The matrix driving method may be either a line sequential driving method or an active matrix. The line-sequential driving has an advantage that the structure is simple. However, the active matrix may be superior in consideration of the operation characteristics, so that it is necessary to properly use it depending on the application.

  In the segment system (type), a pattern is formed so as to display predetermined information, and a predetermined region is caused to emit light. For example, the time and temperature display in a digital clock or a thermometer, the operation state display of an audio device or an electromagnetic cooker, the panel display of an automobile, and the like can be mentioned.

  Examples of the illuminating device include an illuminating device such as indoor lighting, a backlight of a liquid crystal display device, and the like (for example, Japanese Patent Application Laid-Open Nos. 2003-257621, 2003-277741, and 2004-119211). Etc.) The backlight is used mainly for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. In particular, as a backlight for liquid crystal display devices, especially personal computers for which thinning is an issue, considering that conventional methods are made of fluorescent lamps and light guide plates, it is difficult to reduce the thickness. The backlight using the light emitting element according to the embodiment is thin and lightweight.

<Synthesis example of benzofluorene compound>
Hereinafter, the compound represented by the formula (1-20), the formula (1-25), the formula (1-26), the formula (1-60), the formula (1-62) and the compound (A ) And (B) will be described.

<Synthesis Example of Compound Represented by Formula (1-20)>

Under a nitrogen atmosphere, 22.9 g of 1-bromo-4- (trimethylsilyl) benzene and 10.7 g of p-toluidine are dissolved in 150 ml of dehydrated toluene, 45 mg of palladium acetate, 12.5 g of sodium t-butoxide, and tris (t-butyl) ) 1.2 g of phosphine was added and heated at 100 ° C. for 8 hours. After the reaction, water was added, the organic layer and the aqueous layer were separated with a separatory funnel, and the organic layer was concentrated. The crude product was purified with a silica gel short column (solvent: toluene) and then dried under heat and vacuum (90 ° C., 0.01 kPa) to obtain 20.7 g (yield 81%) of the following compound.

  Under a nitrogen atmosphere, 5.3 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [C] fluorene and 5.7 g of the compound synthesized above were dissolved in 30 ml of dehydrated toluene, and 22 mg of palladium acetate, sodium t- 2.4 g of butoxide and 0.060 g of tris (t-butyl) phosphine were added and heated at 80 ° C. for 1 hour. After the reaction, the catalyst was removed by purification with a silica gel short column (solvent: toluene). Thereafter, the crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 7/3 (volume ratio)), and then sublimation purification was performed to obtain the target compound represented by the formula (1-20). 5.0 g (yield 57%) was obtained.

The structure of the compound represented by formula (1-20) was confirmed by MS spectrum and NMR measurement.
APCI-MS: m / z 876 [M + 2H] ^+
1 H-NMR (CDCl ₃ ) σ 8.70 (d, 1H), 8.11 (d, 1H), 7.99 (d, 1H), 7.52 (t, 1H, J = 8 Hz), 7. 33-6.84 (m, 30H), 2.31 (s, 3H), 2.24 (s, 3H), 0.24 (s, 9H), 0.20 (s, 9H).

<Synthesis Example of Compound Represented by Formula (1-25)>

Under a nitrogen atmosphere, 4.7 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [c] fluorene and 2.4 g of 4-isopropylaniline are dissolved in 30 ml of dehydrated toluene, and bis (dibenzylideneacetone) palladium 52 mg , Sodium t-butoxide 2.3 g, and tris (t-butyl) phosphine 0.055 g were added and heated at 50 ° C. for 2 hours. Thereafter, 4.1 g of 1-bromo-4- (trimethylsilyl) benzene, 10 mg of palladium acetate, and 2.3 g of sodium t-butoxide were added and heated at 80 ° C. for 4 hours.
After the reaction, 100 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain the target compound represented by formula (1-25) by 2. 5 g (yield 30%) was obtained.

The structure of the compound represented by the formula (1-25) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.70 (d, 1H), 8.15 (d, 1H), 8.03 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 37-6.88 (m, 30H), 2.87 (m, 2H), 1.22 (d, 6H), 1.23 (d, 6H) 0.25 (s, 9H), 0.21 ( s, 9H).

<Synthesis Example of Compound Represented by Formula (1-26)>

Under a nitrogen atmosphere, 22.9 g of 1-bromo-4- (trimethylsilyl) benzene and 14.9 g of pt-butylaniline are dissolved in 150 ml of dehydrated toluene, and 67 mg of palladium acetate, 12.5 g of sodium tert-butoxide, and tris ( t-Butyl) phosphine (1.8 g) was added and the mixture was heated at 100 ° C. for 4 hours. After the reaction, water was added, and the organic layer and the aqueous layer were separated with a separatory funnel. The organic layer was collected and purified with a silica gel short column (solvent: toluene), and then heated and dried under vacuum (100 ° C., 0.01 kPa) to obtain 23.4 g (yield 79%) of the following compound.

  Under a nitrogen atmosphere, 5.3 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [C] fluorene and 6.5 g of the compound synthesized above were dissolved in 30 ml of dehydrated toluene, and 22 mg of palladium acetate, sodium t- 2.4 g of butoxide and 0.060 g of tris (t-butyl) phosphine were added and heated at 60 ° C. for 4 hours. After cooling at room temperature, the precipitate was filtered and washed with methanol and water. Thereafter, the crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 4/1 (volume ratio)) and then purified by sublimation to obtain the target compound represented by formula (1-26). 5.4 g (56% yield) was obtained.

The structure of the compound represented by the formula (1-26) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.70 (d, 1H), 8.15 (d, 1H), 8.02 (d, 1H), 7.50 (t, 1H, J = 8 Hz), 7. 37-6.90 (m, 30H), 1.30 (d, 6H), 1.26 (d, 6H), 0.24 (s, 9H), 0.20 (s, 9H).

<Synthesis Example of Compound Represented by Formula (1-60)>

Under a nitrogen atmosphere, 5.0 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [c] fluorene and 1.7 g of aniline were dissolved in 30 ml of dehydrated toluene, 52 mg of bis (dibenzylideneacetone) palladium, sodium t -2.3 g of butoxide and 0.055 g of tris (t-butyl) phosphine were added and heated at 50 ° C. for 2 hours. Thereafter, 4.1 g of 1-bromo-4- (trimethylsilyl) benzene, 10 mg of palladium acetate, and 2.3 g of sodium t-butoxide were added and heated at 80 ° C. for 4 hours.
After the reaction, 100 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain the desired compound represented by the formula (1-60) by 2. 5 g (yield 32%) was obtained.

The structure of the compound represented by the formula (1-60) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.70 (d, 1H), 8.18 (d, 1H), 8.02 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 37-6.92 (m, 31H), 0.25 (s, 9H), 0.21 (s, 9H).

<Synthesis Example of Compound Represented by Formula (1-62)>
Under a nitrogen atmosphere, 9.5 g of 5,9-dibromo-7,7-dimethyl-7H-benzo [C] fluorene and 4.5 g of aniline are dissolved in 80 ml of dehydrated toluene, 140 mg of bis (dibenzylideneacetone) palladium, sodium t -7.0 g of butoxide and 0.15 g of tris (t-butyl) phosphine were added and heated at 50 ° C. for 2 hours. After the reaction, 11 g of 1-bromo-4- (trimethylsilyl) benzene, 27 mg of palladium acetate, and 7.0 g of sodium t-butoxide were added and heated at 80 ° C. for 4 hours.
100 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain the desired compound represented by the formula (1-62) by 3. 1 g (yield 18%) was obtained.

The structure of the compound represented by the formula (1-62) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.68 (d, 1H), 8.15 (d, 1H), 8.05 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 45-6.94 (m, 32H), 1.41 (s, 6H), 0.27 (s, 9H), 0.22 (s, 9H).

<Synthesis Example of Comparative Example Compound (A)>

Under a nitrogen atmosphere, 2.5 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [c] fluorene and 1.6 g of diphenylamine are dissolved in 100 ml of dehydrated xylene, 1.5 mg of palladium acetate, sodium t-butoxide 0 .98 g and tri (t-butyl) phosphine 14 mg were added and refluxed for 4 hours.
After the reaction, 100 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 3/1 (volume ratio)) and then purified by sublimation to obtain 450 mg of the desired comparative compound (A) (yield: 13%). )Obtained.

The structure of the comparative compound (A) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ = 8.70 (d, 1H), 8.16 (d, 1H), 8.02 (d, 1H), 7.56 (t, 1H), 7.37- 7.34 (m, 2H), 7.58 to 6.86 (m, 32H).

<Synthesis Example of Comparative Example Compound (B)>

Under a nitrogen atmosphere, 5.0 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [C] fluorene and 1.7 g of aniline are dissolved in 30 ml of dehydrated toluene, 52 mg of bis (dibenzylideneacetone) palladium, sodium t -2.3 g of butoxide and 0.055 g of tris (t-butyl) phosphine were added and heated at 50 ° C. for 2 hours. After the reaction, 4.1 g of 1-bromo-3- (trimethylsilyl) benzene, 10 mg of palladium acetate, and 2.3 g of sodium t-butoxide were added and heated at 80 ° C. for 4 hours.
After the reaction, 100 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain 0.3 g (yield 4) of the desired comparative compound (B). %)Obtained.

The structure of the comparative compound (B) was confirmed by MS spectrum and NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.70 (d, 1H), 8.18 (d, 1H), 8.04 (d, 1H), 7.57 (t, 1H, J = 8 Hz), 7. 38-6.85 (m, 31H), 0.17 (s, 9H), 0.10 (s, 9H).

<Synthesis Example of Compound Represented by Formula (1-100)>

  Under a nitrogen atmosphere, 8.0 g of 5,9-dibromo-7,7-dimethyl-7H-benzo [C] fluorene and 5.7 g of p-methylaniline hydrochloride are dissolved in 200 ml of dehydrated toluene to obtain bis (dibenzylideneacetone). 115 mg of palladium, 15 g of sodium t-butoxide, and 0.160 g of 4- (dimethylamino) phenyl) bis-t-butylphosphine were added and heated at 80 ° C. for 2 hours. After the reaction, 10 g of 1-bromo-4- (trimethylsilyl) benzene was added and heated at 80 ° C. for 4 hours. 100 ml of water was added thereto, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with alumina (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain 6.9 g of a compound represented by the formula (1-100) (yield). 46%).

The structure of the compound represented by the formula (1-100) was confirmed by NMR measurement.
¹ H-NMR (Toluene-d8) σ 8.67 (d, 1H), 8.30 (d, 1H), 8.00 (d, 1H), 7.52 (t, 1H, J = 8 Hz), 7 .42-6.83 (m, 20H), 2.13 (s, 3H), 2.06 (s, 3H), 1.16 (s, 6H), 0.24 (s, 9H),. 20 (s, 9H).

<Synthesis Example of Compound Represented by Formula (1-101)>

  Under a nitrogen atmosphere, 8.9 g of 5,9-dibromo-7,7-dimethyl-7H-benzo [C] fluorene and 6.7 g of pt-butylaniline are dissolved in 60 ml of dehydrated toluene, and bis (dibenzylideneacetone) 140 mg of palladium, 8.5 g of sodium t-butoxide, and 0.155 g of tris (t-butyl) phosphine were added and heated at 50 ° C. for 2 hours. After the reaction, 10 g of 1-bromo-4- (trimethylsilyl) benzene, 27 mg of palladium acetate, 8.5 g of sodium t-butoxide and 0.073 g of tris (t-butyl) phosphine were added and heated at 80 ° C. for 4 hours. It was. 100 ml of water was added thereto, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with alumina (solvent: heptane / toluene = 5/1 (volume ratio)) and then purified by sublimation to obtain 8.7 g of a compound represented by the formula (1-101) 44%).

The structure of the compound represented by the formula (1-101) was confirmed by NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.67 (d, 1H), 8.15 (d, 1H), 8.07 (d, 1H), 7.54 (t, 1H, J = 8 Hz), 7. 46-6.96 (m, 20H), 1.42 (s, 6H), 1.33 (s, 9H), 1.28 (s, 9H) 0.26 (s, 9H), 0.21 ( s, 9H).

<Synthesis Example of Compound Represented by Formula (1-102)>

  Under a nitrogen atmosphere, 4.8 g of 5,9-dibromo-7,7-dimethyl-7H-benzo [C] fluorene and 2.9 g of 2,5-dimethylaniline are dissolved in 100 ml of dehydrated toluene, and bis (dibenzylideneacetone) 140 mg of palladium, 4.6 g of sodium t-butoxide, and 0.190 g of 4- (dimethylamino) phenyl) bis-t-butylphosphine were added and heated at 60 ° C. for 2 hours. After the reaction, 5.5 g of 1-bromo-4- (trimethylsilyl) benzene, 70 mg of bis (dibenzylideneacetone) palladium, 2.3 g of sodium t-butoxide, and 4- (dimethylamino) phenyl) bis t-butylphosphine 10g was added and it heated at 80 degreeC for 4 hours. 100 ml of water was added thereto, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 5/1 (volume ratio)), and then sublimation purification was performed to obtain 3.1 g (yield) of the compound represented by the formula (1-102). 18%).

The structure of the compound represented by the formula (1-102) was confirmed by NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.68 (d, 1H), 8.15 (d, 1H), 8.05 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 44-6.60 (m, 18H), 2.24 (s, 3H), 2.18 (s, 3H), 1.42 (s, 6H), 0.27 (s, 9H), 0.22 (S, 9H).

<Synthesis Example of Compound Represented by Formula (1-5)>

First, in a nitrogen atmosphere, 27.1 g of 1-bromo-4- (triethylsilyl) benzene and 4.8 g of benzylamine are dissolved in 150 ml of dehydrated toluene, and 100 mg of palladium acetate, 11.2 g of sodium t-butoxide, and tris (t -Butyl) phosphine 0.27g was added and it heated at 90 degreeC for 4 hours. After the reaction, ethyl acetate and water were added. The organic layer was separated from the aqueous layer with a separatory funnel, and the organic layer was concentrated. The crude product was purified by a silica gel column (solvent: heptane / toluene = 9/1 (volume ratio)) to obtain 17.2 g (yield 78%) of a compound having the following structure.

Next, 16.9 g of this compound was added to a mixture of 1.6 g of formic acid and 3.4 g of triethylamine in ice-cooled ethanol, and after purging with nitrogen, palladium carbon Pd / C (10 wt%) was added. And heated to reflux. A small amount of ethanol solution of formic acid was added little by little so that the reaction solution would not become basic, and Pd / C (10 wt%) was added when the reaction did not proceed. After completion of the reaction, the product was purified with a basic alumina column (solvent: toluene / heptane = 1: 4 to 1: 2 by gradually changing the volume ratio), and 9.0 g of a compound having the following structure (yield 69%) Got.

  Finally, 0.9 g of this compound and 0.5 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [C] fluorene are dissolved in 10 ml of dehydrated toluene under a nitrogen atmosphere, and 2 mg of palladium acetate, sodium t -0.25 g of butoxide and 6 mg of tris (t-butyl) phosphine were added and heated at 60 ° C for 1 hour. 100 ml of toluene and 100 ml of water were added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to alumina column purification (solvent: heptane alone was changed gradually to heptane / toluene = 9/1 (volume ratio)), and then sublimation purification was performed. 0.7 g (yield 70%) of the compound obtained.

The structure of the compound represented by the formula (1-5) was confirmed by NMR measurement.
¹ H-NMR (CDCl ₃ ) σ8.71 (d, 1H), 8.19 (d, 1H), 8.00 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 37-6.95 (m, 30H), 0.97 (t, 18H, J = 8Hz), 0.93 (t, 18H, J = 8Hz), 0.77 (q, 12H, J = 8Hz), 0.73 (q, 12H, J = 8 Hz).

<Synthesis Example of Compound Represented by Formula (1-6)>

First, 10 g of 4,4′-diiododiphenylamine, 10 g of t-butyldimethylsilane, 18.4 g of ethyldiisopropylamine, 0.26 g of palladium acetate, and 2- (di-t-butylphosphino) biphenyl 0 in a nitrogen atmosphere. To 71 g, 50 ml of dehydrated N-methylpyrrolidone was added and stirred at room temperature for 4 hours. After the reaction, toluene and water were added. The organic layer was separated from the aqueous layer with a separatory funnel, and the organic layer was concentrated. The crude product was purified with an alumina column (solvent: heptane / toluene = 9/1 (volume ratio)), and a disilyl compound (bis (4- (t-butyldimethylsilyl) phenyl) amine) having the following left structure: 5.5 g (yield 58%) and 2.8 g (yield 41%) of a monosilyl compound (4- (t-butyldimethylsilyl) -N-phenylaniline) having the following right structure were obtained.

  Next, in a nitrogen atmosphere, 3.0 g of the disilyl compound and 1.4 g of 5,9-dibromo-7,7-dimethyl-7H-benzo [C] fluorene are dissolved in 20 ml of dehydrated toluene, and 11 mg of palladium acetate, sodium 860 mg of t-butoxide and 30 mg of tris (t-butyl) phosphine were added and heated at 60 ° C. for 1 hour. 100 ml of toluene and 100 ml of water were added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was purified by alumina column purification (solvent: heptane alone was changed gradually to heptane / toluene = 95/5 (volume ratio)), and then purified by sublimation, and expressed by the formula (1-6). 2 g of the compound obtained (yield 56%).

The structure of the compound represented by the formula (1-6) was confirmed by NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.69 (d, 1 H), 8.15 (d, 1 H), 8.04 (d, 1 H), 7.56 (t, 1 H, J = 8 Hz), 7. 47-7.05 (m, 20H), 1.41 (s, 6H), 0.90 (s, 18H), 0.86 (s, 18H), 0.26 (s, 12H), 0.22 (S, 12H).

<Synthesis Example of Compound Represented by Formula (1-103)>

First, 10 g of 4,4′-diiododiphenylamine, 10 g of t-butyldimethylsilane, 18.4 g of ethyldiisopropylamine, 0.26 g of palladium acetate, and 2- (di-t-butylphosphino) biphenyl 0 in a nitrogen atmosphere. To 71 g, 50 ml of dehydrated N-methylpyrrolidone was added and stirred at room temperature for 4 hours. After the reaction, toluene and water were added. The organic layer was separated from the aqueous layer with a separatory funnel, and the organic layer was concentrated. The crude product was purified with an alumina column (solvent: heptane / toluene = 9/1 (volume ratio)), and 5.5 g (yield 58%) of a disilyl compound having the following left structure and the following right structure. 2.8 g (yield 41%) of monosilyl compound was obtained.

  Next, in a nitrogen atmosphere, 2.8 g of the monosilyl compound and 2.0 g of 5,9-dibromo-7,7-diphenyl-7H-benzo [C] fluorene are dissolved in 20 ml of dehydrated toluene, and bis (dibenzylideneacetone). ) 25 mg of palladium, 1.9 g of sodium t-butoxide, and 35 mg of 4- (dimethylamino) phenyl) bis-t-butylphosphine were added and heated at 80 ° C. for 5 hours. 20 ml of water was added, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with alumina (solvent: heptane / toluene = 4/1 (volume ratio)), followed by sublimation purification to obtain 1.7 g (yield) of the compound represented by the formula (1-103). 42%).

The structure of the compound represented by the formula (1-103) was confirmed by NMR measurement.
¹ H-NMR (CDCl ₃ ) σ 8.69 (d, 1 H), 8.15 (d, 1 H), 8.04 (d, 1 H), 7.55 (t, 1 H, J = 8 Hz), 7. 44-6.74 (m, 22H), 1.40 (s, 6H), 0.90 (s, 9H), 0.86 (s, 9H), 0.26 (s, 6H), 0.21 (S, 6H).

<Synthesis Example of Compound Represented by Formula (1-110)>

  Under a nitrogen atmosphere, 12 g of 5,9-diiodo-7,7-dimethyl-7H-benzo [C] fluorene and aniline-2,3,4,5,6-d5 (5.0 g) are dissolved in 200 ml of dehydrated toluene. , 290 mg of bis (dibenzylideneacetone) palladium, 15 g of sodium t-butoxide, and 350 mg of 4- (dimethylamino) phenyl) bist-butylphosphine were added and heated at 60 ° C. for 1 hour. After the reaction, 12 g of 1-bromo-4- (trimethylsilyl) benzene was added and heated at 90 ° C. for 2 hours. 100 ml of water was added thereto, and the organic layer was washed with water using a separatory funnel. After removing the aqueous layer, the organic layer was collected and concentrated by a rotary evaporator to obtain a crude product. The crude product was subjected to column purification with alumina (solvent: heptane / toluene = 4/1 (volume ratio)), and then recrystallized from heptane. This was further sublimated and purified by formula (1-110). 8.1 g (yield 46%) of the represented compound was obtained.

The structure of the compound represented by Formula (1-110) was confirmed by NMR measurement.
¹ H-NMR (CHCl ₃ ) σ8.88 (d, 1H), 8.16 (d, 1H), 8.05 (d, 1H), 7.56 (t, 1H, J = 8 Hz), 7. 45 (s, 1H), 7.41-7.01 (m, 12H), 1.41 (s, 6H), 0.27 (s, 9H), 0.22 (s, 9H).

  By appropriately selecting the starting compound, other benzofluorene compounds can be synthesized by a method according to the above synthesis example.

<Characteristics when used in electroluminescent devices>
Examples 1-4 and Comparative Examples 1 and 2, to prepare an electroluminescent device according to Example 5 and Comparative Example 3, respectively 1000 cd / ^{m 2} during light emission characteristics in a voltage (V), and current density (mA / cm ² ), luminous efficiency (lm / W), current efficiency (cd / A), EL emission wavelength (nm), external quantum efficiency (%), and then a luminance of 2000 cd / m ² is obtained. The time (time) during which the luminance was maintained at 50% or more of the initial luminance when driven at a constant current at a current density was measured. Hereinafter, Examples 1 to 4 and Comparative Examples 1 and 2, and Example 5 and Comparative Example 3 will be described in detail.

Table 1 below shows the material configuration of each layer in the produced electroluminescent elements according to Examples 1 to 4 and Comparative Examples 1 and 2 and Example 5 and Comparative Example 3. In all cases, the cathode was composed of lithium fluoride / aluminum.

In Table 1, the compound (1-20), the compound (1-25), the compound (1-26), the compound (1-62) or the compound (1-60) is represented by the above formula (1-20), It is a compound represented by (1-25), Formula (1-26), Formula (1-62), or Formula (1-60). In Table 1, “CuPc” is copper phthalocyanine, “NPD” is N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine, and compound (A) is N ⁵ , N ⁵ , N ^9. , N ⁹ , 7,7-Hexaphenyl-7H-benzo [C] fluorene-5,9-diamine, compound (B) is N ⁵ , N ⁹ -bis (3-trimethylsilylphenyl) -N ⁵ , N ⁹ , 7,7-tetraphenyl-7H-benzo [C] fluorene-5,9-diamine, compound (C) is 9-phenyl-10- [6- (1,1 ′; 3,1 ″) terphenyl- 5′-yl] naphthalen-2-yl] anthracene, compound (D) is 5,5 ′-(2-phenylanthracene-9,10-diyl) di-2,2′-bipyridine, It has a structure.

<Example 1>
A glass substrate of 26 mm × 28 mm × 0.7 mm on which ITO was deposited to a thickness of 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus, a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, a molybdenum vapor deposition boat containing compound (C), Molybdenum deposition boat containing compound (1-20), molybdenum deposition boat containing compound (D), molybdenum deposition boat containing lithium fluoride, and tungsten deposition boat containing aluminum Attached.

Depressurize the vacuum chamber to 5 × 10 ⁻⁴ Pa, heat the vapor deposition boat containing CuPc, deposit CuPc to a film thickness of 70 nm, and form a hole injection layer. The evaporation boat was heated to deposit NPD so as to have a film thickness of 30 nm to form a hole transport layer. Next, the molybdenum vapor deposition boat containing the compound (C) and the molybdenum vapor deposition boat containing the compound (1-20) are heated to emit light by co-deposition of both compounds to a film thickness of 35 nm. A layer was formed. At this time, the dope concentration of the compound (1-20) was about 5% by weight. Next, the evaporation boat containing the compound (D) was heated, and the compound (D) was evaporated to a film thickness of 15 nm to form an electron transport layer. The above deposition rate was 0.01-1 nm / sec.

  Thereafter, the vapor deposition boat containing lithium fluoride is heated to deposit lithium fluoride at a vapor deposition rate of 0.003 to 0.1 nm / second so that the film thickness becomes 0.5 nm, and then vapor deposition containing aluminum. The organic EL element was obtained by heating the boat and depositing aluminum at a deposition rate of 0.01 to 10 nm / second so as to have a film thickness of 100 nm.

Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.39 V, the current density was 11 mA / cm ² , the luminous efficiency was 6.45 (lm / W), The current efficiency is 9.02 cd / A, the external quantum efficiency is 7.02% (emission wavelength: 465 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The time to maintain was 550 hours.

<Example 2>
An organic EL device was obtained by the method according to Example 1 except that the compound (1-20) used as the dopant of the light emitting layer in Example 1 was replaced with the compound (1-25). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.15 V, the current density was 11 mA / cm ² , the luminous efficiency was 7.14 (lm / W), The current efficiency is 9.44 cd / A, the external quantum efficiency is 7.24% (emission wavelength: 465 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The time to maintain was 550 hours.

<Example 3>
An organic EL device was obtained by the method according to Example 1 except that the compound (1-20) used as the dopant for the light emitting layer in Example 1 was replaced with the compound (1-26). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.20 V, the current density was 11 mA / cm ² , the luminous efficiency was 7.10 (lm / W), The current efficiency is 9.50 cd / A, the external quantum efficiency is 7.58% (emission wavelength: 465 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 650 hours.

<Example 4>
An organic EL device was obtained by the method according to Example 1 except that the compound (1-20) used as the dopant of the light emitting layer in Example 1 was replaced with the compound (1-62). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.31 V, the current density was 14 mA / cm ² , the light emission efficiency was 5.08 (lm / W), The current efficiency is 6.97 cd / A, the external quantum efficiency is 7.25% (emission wavelength: 460 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 290 hours.

<Comparative Example 1>
An organic EL device was obtained by the method according to Example 1 except that the compound (1-20) used as the dopant of the light emitting layer in Example 1 was changed to the compound (A). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.41 V, the current density was 13 mA / cm ² , the luminous efficiency was 5.43 (lm / W), The current efficiency is 7.61 cd / A, the external quantum efficiency is 7.03% (light emission wavelength: 460 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 250 hours.

<Comparative Example 2>
An organic EL device was obtained by the method according to Example 1 except that the compound (1-20) used as the dopant of the light emitting layer in Example 1 was replaced with the compound (B). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.55 V, the current density was 14 mA / cm ² , the light emission efficiency was 5.02 (lm / W), The current efficiency is 7.27 cd / A, the external quantum efficiency is 6.48% (emission wavelength: 460 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The time to maintain was 220 hours.

<Example 5>
A glass substrate of 26 mm × 28 mm × 0.7 mm on which ITO was deposited to a thickness of 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus, a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, a molybdenum vapor deposition boat containing compound (C), Molybdenum deposition boat containing compound (1-60), molybdenum deposition boat containing compound (D), molybdenum deposition boat containing lithium fluoride, and tungsten deposition boat containing aluminum Attached.

Depressurize the vacuum chamber to 5 × 10 ⁻⁴ Pa, heat the vapor deposition boat containing CuPc, deposit CuPc to a film thickness of 100 nm, and form a hole injection layer. The evaporation boat was heated to deposit NPD so as to have a film thickness of 30 nm to form a hole transport layer. Next, the molybdenum vapor deposition boat containing the compound (C) and the molybdenum vapor deposition boat containing the compound (1-60) are heated to emit light by co-deposition of both compounds to a film thickness of 35 nm. A layer was formed. At this time, the dope concentration of the compound (1-60) was about 5% by weight. Next, the evaporation boat containing the compound (D) was heated, and the compound (D) was evaporated to a film thickness of 15 nm to form an electron transport layer. The above deposition rate was 0.01-1 nm / second.

  Thereafter, the vapor deposition boat containing lithium fluoride is heated to deposit lithium fluoride at a vapor deposition rate of 0.003 to 0.1 nm / second so that the film thickness becomes 0.5 nm, and then vapor deposition containing aluminum. The organic EL element was obtained by heating the boat and depositing aluminum at a deposition rate of 0.01 to 10 nm / second so as to have a film thickness of 100 nm.

Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.34 V, the current density was 12 mA / cm ² , the emission efficiency was 5.95 (lm / W), The current efficiency is 8.22 cd / A, the external quantum efficiency is 7.24% (emission wavelength: 460 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 350 hours.

<Comparative Example 3>
An organic EL device was obtained by the method according to Example 3 except that the compound (1-60) used as the dopant for the light emitting layer in Example 3 was replaced with the compound (A). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.35 V, the current density was 13 mA / cm ² , the emission efficiency was 5.53 m / W, and the current efficiency was 7 .66 cd / A, external quantum efficiency of 7.24% (emission wavelength: 460 nm), and the time during which the luminance is maintained at 50% or more of the initial luminance when driven at a constant current at a current density at which a luminance of 2000 cd / m ² is obtained. Was 230 hours.

Table 2 below summarizes the performance evaluation of the electroluminescent elements according to Examples 1 to 4 and Comparative Examples 1 and 2 and Example 5 and Comparative Example 3 described above.

Moreover, the electroluminescent element which concerns on Examples 6-9 was produced, and the voltage (V), current density (mA / cm < ² >), luminous efficiency (lm / W), electric current which are the characteristics at the time of 1000 cd / m < ² > light emission, respectively. Measurement of efficiency (cd / A), EL emission wavelength (nm), external quantum efficiency (%), and then the luminance is the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ² The time (hours) for maintaining 50% or more of was measured. Hereinafter, Examples 6 to 9 will be described in detail.

Table 3 below shows the material configuration of each layer in the electroluminescent elements according to the produced Examples 6 to 9. In all cases, the cathode was composed of lithium fluoride / aluminum.

  In Table 3, the compound (1-100), the compound (1-101), the compound (1-102), or the compound (1-5) has the above formula (1-100), formula (1-101), and formula, respectively. (1-102) or a compound represented by formula (1-5). Further, “CuPc”, “NPD”, compound (C) and compound (D) in Table 3 are the same as those shown in Table 1, respectively.

<Example 6>
A glass substrate of 26 mm × 28 mm × 0.7 mm on which ITO was deposited to a thickness of 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus, a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, a molybdenum vapor deposition boat containing compound (C), Molybdenum vapor deposition boat containing compound (1-100), molybdenum vapor deposition boat containing compound (D), molybdenum vapor deposition boat containing lithium fluoride, and tungsten vapor deposition boat containing aluminum Attached.

Depressurize the vacuum chamber to 5 × 10 ⁻⁴ Pa, heat the vapor deposition boat containing CuPc, deposit CuPc to a film thickness of 70 nm, and form a hole injection layer. The evaporation boat was heated to deposit NPD so as to have a film thickness of 30 nm to form a hole transport layer. Next, the molybdenum vapor deposition boat containing the compound (C) and the molybdenum vapor deposition boat containing the compound (1-100) were heated to emit light by co-deposition of both compounds to a film thickness of 35 nm. A layer was formed. At this time, the dope concentration of the compound (1-100) was about 5% by weight. Next, the evaporation boat containing the compound (D) was heated, and the compound (D) was evaporated to a film thickness of 15 nm to form an electron transport layer. The above deposition rate was 0.01-1 nm / sec.

  Thereafter, the vapor deposition boat containing lithium fluoride is heated to deposit lithium fluoride at a vapor deposition rate of 0.003 to 0.1 nm / second so as to have a film thickness of 1 nm, and then the vapor deposition boat containing aluminum Was heated and aluminum was deposited at a deposition rate of 0.01 to 10 nm / second to obtain a film thickness of 100 nm to obtain an organic EL device.

Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.40 V, the current density was 13 mA / cm ² , the emission efficiency was 5.50 (lm / W), The current efficiency is 7.70 cd / A, the external quantum efficiency is 6.81% (emission wavelength: 463 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The time to maintain was 305 hours.

<Example 7>
An organic EL device was obtained by the method according to Example 6 except that the compound (1-100) used as the dopant for the light emitting layer in Example 6 was replaced with the compound (1-101). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.62 V, the current density was 13 mA / cm ² , the emission efficiency was 5.21 (lm / W), The current efficiency is 7.65 cd / A, the external quantum efficiency is 7.31% (emission wavelength 462 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 510 hours.

<Example 8>
An organic EL device was obtained by the method according to Example 6 except that the compound (1-100) used as the dopant for the light emitting layer in Example 6 was replaced with the compound (1-102). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.31 V, the current density was 12 mA / cm ² , the emission efficiency was 5.90 (lm / W), The current efficiency is 8.10 cd / A, the external quantum efficiency is 7.45% (emission wavelength 462 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The maintenance time was 310 hours.

<Example 9>
An organic EL device was obtained by the method according to Example 6 except that the compound (1-100) used as the dopant of the light emitting layer in Example 6 was replaced with the compound (1-5). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 4.25 V, the current density was 12 mA / cm ² , the emission efficiency was 6.22 (lm / W), The current efficiency is 8.41 cd / A, the external quantum efficiency is 8.15% (emission wavelength: 463 nm), and the luminance is 50% or more of the initial luminance when driven at a constant current at a current density that provides a luminance of 2000 cd / m ^2. The time to maintain was 240 hours.

Table 4 below summarizes the performance evaluation of the electroluminescent elements according to Examples 6 to 9 described above.

In addition, electroluminescent devices according to Example 10 and Comparative Example 4 were produced, and voltage (V), current density (mA / cm ² ), and luminous efficiency (lm / W), which are characteristics at 1000 cd / m ² emission, respectively. , Measurement of current efficiency (cd / A), measurement of EL emission wavelength (nm), external quantum efficiency (%), and then brightness when driven at constant current at a current density at which a brightness of 2000 cd / m ² is obtained. The time (time) for maintaining 80% or more of the initial luminance was measured. Hereinafter, Example 10 and Comparative Example 4 will be described in detail.

Table 5 below shows the material configuration of each layer in the electroluminescent elements according to the produced Examples 10 and 11 and Comparative Example 4. In all cases, the cathode was composed of a quinolinolato lithium / magnesium-silver alloy.

  In Table 5, the compound (1-110) and the compound (1-62) are compounds represented by the above formula (1-110) and the above formula (1-62), respectively. Further, “NPD”, compound (A) and compound (D) in Table 5 are the same as those shown in Table 1, respectively. Further, the compound (E) in Table 5 is N4, N4′-diphenyl-N4, N4′-bis (9-phenyl-9H-carbazol-3-yl)-[1,1′-biphenyl] -4,4 ′. -Diamine, and the compound (F) is 9,10-di (naphthalen-1-yl) anthracene, each having the following chemical structure.

<Example 10>
A glass substrate of 26 mm × 28 mm × 0.7 mm on which ITO was deposited to a thickness of 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus, a molybdenum vapor deposition boat containing the compound (E), a molybdenum vapor deposition boat containing the NPD, and a molybdenum vapor deposition containing the compound (F). Boat, molybdenum deposition boat containing compound (1-110), molybdenum deposition boat containing compound (D), molybdenum deposition boat containing 8-quinolinolatolithium, and magnesium-silver A tungsten vapor deposition boat containing an alloy was attached.

The vacuum chamber is depressurized to 5 × 10 ⁻⁴ Pa, the evaporation boat containing the compound (E) is heated, and the compound (E) is evaporated to a film thickness of 40 nm to form a hole injection layer. Then, the evaporation boat containing NPD was heated, and NPD was evaporated to a film thickness of 30 nm to form a hole transport layer. Next, the molybdenum vapor deposition boat containing the compound (F) and the molybdenum vapor deposition boat containing the compound (1-110) are heated to emit light by co-deposition of both compounds to a film thickness of 35 nm. A layer was formed. At this time, the dope concentration of the compound (1-110) was about 5% by weight. Next, the evaporation boat containing the compound (D) was heated, and the compound (D) was evaporated to a film thickness of 15 nm to form an electron transport layer. The above deposition rate was 0.01-1 nm / sec.

  Thereafter, the evaporation boat containing 8-quinolinolatolithium is heated to deposit 8-quinolinolatolithium at a deposition rate of 0.003 to 0.1 nm / second so as to have a film thickness of 1 nm. The organic EL element was obtained by heating the vapor deposition boat containing a magnesium-silver alloy, and vapor-depositing a MgAg alloy with the vapor deposition rate of 0.01-10 nm / sec so that it might become a film thickness of 100 nm.

Using the ITO electrode as the anode and the 8-quinolinolatolithium / magnesium-silver alloy electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 5.10 V, the current density was 15 mA / cm ² , and the luminous efficiency was 4.06. (Lm / W), current efficiency of 6.58 cd / A, external quantum efficiency of 6.89% (emission wavelength: 458 nm), and initial brightness when driven at constant current at a current density that provides a brightness of 2000 cd / m ² The time for maintaining 80% or more of the luminance was 200 hours.

<Example 11>
An organic EL device was obtained by the method according to Example 10 except that the compound (1-110) used as the dopant for the light emitting layer in Example 10 was replaced with the compound (1-62). Using the ITO electrode as the anode and the 8-quinolinolatolithium / magnesium-silver alloy electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 5.09 V, the current density was 15 mA / cm ² , and the luminous efficiency was 4.19. (Lm / W), current efficiency of 6.49 cd / A, external quantum efficiency of 6.68% (emission wavelength: 458 nm), and initial brightness when driven at constant current at a current density that provides a brightness of 2000 cd / m ² The time for maintaining 80% or more of the luminance was 160 hours.

<Comparative example 4>
An organic EL device was obtained by the method according to Example 10 except that the compound (1-110) used as the dopant of the light emitting layer in Example 10 was changed to the compound (A). Using the ITO electrode as the anode and the 8-quinolinolatolithium / magnesium-silver alloy electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 5.05 V, the current density was 14 mA / cm ² , and the luminous efficiency was 4.48. (Lm / W), current efficiency is 7.20 cd / A, external quantum efficiency is 6.44% (emission wavelength: 460 nm), and the luminance is initial when driven at a constant current at a current density at which a luminance of 2000 cd / m ² is obtained. The time for maintaining 80% or more of the luminance was 130 hours.

Table 6 below summarizes the performance evaluation of the electroluminescent elements according to Examples 10 and 11 and Comparative Example 4 described above.

  According to a preferred aspect of the present invention, it is possible to provide an organic electroluminescent element having an excellent element lifetime, a display device including the same, a lighting device including the same, and the like.

It is a schematic sectional drawing which shows the organic electroluminescent element which concerns on this embodiment.

DESCRIPTION OF SYMBOLS 100 Organic electroluminescent element 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims (20)

A benzofluorene compound represented by the following general formula (1).
(Where
R ¹ and R ² are each independently hydrogen, optionally substituted alkyl, substituted silyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted cycloalkyl. Or fluorine,
m and n are each independently an integer of 1 to 5,
Each R ³ is independently hydrogen, optionally substituted alkyl, optionally substituted aryl or optionally substituted heteroaryl, and two R ^3s combine to form a ring; You may,
However, at least one of the maximum 20 R ¹ and R ² is a para-substituted substituted silyl, and at least one hydrogen in the benzofluorene compound represented by the formula (1) is substituted with deuterium. May be. ) The benzofluorene compound according to claim 1, which is represented by the following general formula (1 ').
(Where
R ¹ and R ² are each independently hydrogen, optionally substituted alkyl or substituted silyl;
n is each independently an integer of 1 to 5,
Each R ³ is independently hydrogen, optionally substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl;
However, at least one of the maximum 12 R ¹ and R ² is a para-substituted substituted silyl, and at least one hydrogen in the benzofluorene compound represented by the formula (1 ′) is substituted with deuterium. It may be. ) Each R ¹ is independently substituted silyl;
Each R ² is independently hydrogen, optionally substituted alkyl or substituted silyl;
n is each independently an integer of 1 to 5, and
Each R ³ is independently hydrogen, optionally substituted alkyl, or optionally substituted aryl;
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound according to claim 2. R ¹ and R ² are each independently substituted silyl;
n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms, and
The substituents for R ¹ , R ² and R ³ are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons or aryl having 6 to 16 carbons,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound according to claim 2. Each R ¹ is independently substituted silyl;
Each R ² is independently an optionally substituted alkyl having 1 to 24 carbon atoms;
n is 1 or 2,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms,
The substituents for R ¹ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
The substituents in R ² are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons, aryl having 6 to 16 carbons, or fluorine; and
The substituents for R ³ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound according to claim 2. Each R ¹ is independently substituted silyl;
R ² is hydrogen;
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 24 carbon atoms or optionally substituted aryl having 6 to 30 carbon atoms,
The substituents in R ¹ are each independently alkyl having 1 to 24 carbons, cycloalkyl having 3 to 12 carbons or aryl having 6 to 16 carbons; and
The substituents for R ³ are each independently alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 16 carbon atoms,
At least one hydrogen in four phenyl groups bonded to two nitrogens of the benzofluorene compound may be substituted with deuterium;
The benzofluorene compound according to claim 2. Each R ¹ is independently substituted silyl;
Each R ² is independently a para-substituted substituted silyl, n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons, and
The substituents for R ¹ , R ² and R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl. is there,
The benzofluorene compound according to claim 4. Each R ¹ is independently substituted silyl;
Each R ² is independently a meta-substituted substituted silyl, n is 1,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons, and
The substituents for R ¹ , R ² and R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl. is there,
The benzofluorene compound according to claim 4. Each R ¹ is independently substituted silyl;
R ² is each independently a para-substituted or meta-substituted alkyl having 1 to 12 carbon atoms which may be substituted, n is 1 or 2,
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons;
The substituents in R ¹ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl;
The substituents at R ² are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl, naphthyl or fluorine; and
The substituents in R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl.
The benzofluorene compound according to claim 5. Each R ¹ is independently substituted silyl;
R ² is hydrogen, and at least one of the hydrogens may be substituted with deuterium;
Each R ³ is independently hydrogen, optionally substituted alkyl having 1 to 12 carbons or optionally substituted aryl having 6 to 16 carbons;
The substituents in R ¹ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl; and
The substituents in R ³ are each independently methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, biphenylyl or naphthyl.
The benzofluorene compound according to claim 6. Each R ¹ is independently trimethylsilyl, triethylsilyl or dimethylmono t-butylsilyl;
Each R ² is independently a para-substituted, trimethylsilyl, triethylsilyl or dimethylmono tert-butylsilyl, n is 1, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound according to claim 4. Each R ¹ is independently trimethylsilyl, triethylsilyl or dimethylmono t-butylsilyl;
Each R ² is independently meta-substituted, trimethylsilyl, triethylsilyl or dimethylmono tert-butylsilyl, n is 1, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound according to claim 4. Each R ¹ is independently trimethylsilyl, triethylsilyl or dimethylmono t-butylsilyl;
R ² is para-substituted or meta-substituted, methyl, ethyl, i-propyl or t-butyl, n is 1 or 2, and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound according to claim 5. Each R ¹ is independently trimethylsilyl, triethylsilyl or dimethylmono t-butylsilyl;
R ² is hydrogen and
Each R ³ is independently methyl, ethyl, propyl, phenyl, biphenylyl or naphthyl;
The benzofluorene compound according to claim 6.   A material for a light emitting layer of a light emitting element, the material for a light emitting layer containing the benzofluorene compound according to any one of claims 1 to 14.   An organic electroluminescence device comprising a pair of electrodes composed of an anode and a cathode, and a light emitting layer disposed between the pair of electrodes and containing the light emitting layer material according to claim 15.   Furthermore, it has an electron transport layer and / or an electron injection layer disposed between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer includes a quinolinol-based metal complex, a pyridine derivative, The organic electroluminescent device according to claim 16, comprising at least one selected from the group consisting of a phenanthroline derivative, a borane derivative and a benzimidazole derivative.   The electron transport layer and / or the electron injection layer may further include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, or an alkaline earth metal. The material contains at least one selected from the group consisting of halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes. 18. The organic electroluminescent device according to item 17.   A display device comprising the organic electroluminescent element according to claim 16.   The illuminating device provided with the organic electroluminescent element in any one of Claims 16 thru | or 18.