JP2002308837A - New compound and light-emitting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound having good hole transportability and, simultaneously, excellent durability, and an light-emitting device having high luminace and excellent durability containing the same by using the light-emitting device into which the compound is incorporated. SOLUTION: The compound is represented by formula (1) (wherein X is a hole transporting group; Y is a divalent connecting group or a mere bond; Z is a group of >=3 atoms capable of forming a ring structure; R is a hydrogen atom or a substituent; at least one of the group having substituted the site contiguous to the site at which X is connected to Y and R is a group other than a hydrogen atom; and R may be connected to Z to form a ring structure), and the light-emitting device comprises the compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel compound having a hole transporting property, and a light emitting device using the same.

[0002]

2. Description of the Related Art At present, research and development on various display elements are active. Among them, an organic electroluminescence (EL) element, which can obtain high-luminance light emission at a low voltage, is attracting attention as a promising display element. ing. For example, an EL element that forms an organic thin film by vapor deposition of an organic compound is known (Applied Phy
sics Letters, 51, p. 913-, (1987)). The organic electroluminescent device described in the document has a laminated structure of an electron transporting material and a hole transporting material, and its light emitting characteristics are greatly improved as compared with a conventional single-layer type device. Examples of hole transport materials used in this stacked device include triarylamine derivatives represented by TPD (N, N'-di-m-tolyl-N, N'-diphenylbenzidine), pyrrole, carbazole Π-electron-rich aromatic compounds such as thiophene and thiophene are known as excellent hole transport materials. However, these compounds have high crystallinity, and it has been found that an organic electroluminescent device using these compounds as a hole transport material has a problem in raw storage stability. As a means for solving this problem, in the case of a triarylamine derivative, a technique of introducing a condensed polycyclic aromatic group or using a compound group with improved symmetry is disclosed in Appl.Phys.Lett. 56, 799 (1990), Polymer Pr
eprints (ACS) 349 (1997). In addition, the same study was conducted for nitrogen-containing heterocyclic compounds such as carbazole derivatives, and a technique for polymerizing the same was disclosed in Appl.Phys.Lett.
63, page 2627 (1993) and the like. The inventors also
Techniques for improving the storage and driving durability of the organic electroluminescent device derived from the hole transport material have been studied so far.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to develop a compound having good hole transporting ability and excellent durability, and to use the compound in a light emitting device, whereby the luminance is improved. An object of the present invention is to develop a light-emitting element that is high and has excellent element durability.

[0004]

Means for Solving the Problems The present invention has been achieved by a compound described in the following item 12 and a light emitting device containing the compound.

1) A compound represented by the general formula (1). General formula (1)

[0006]

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X is a hole transporting group. Y is a divalent linking group or a simple bond. Z is an atomic group capable of forming three or more cyclic structures. R represents a hydrogen atom or a substituent. At least one of R and R substituted at the position adjacent to the site where X is connected to Y is a group other than a hydrogen atom. R may be linked to Z to form a cyclic structure. 2) The compound according to the above 1), wherein X in the general formula (1) is a diarylamino group. 3) The compound according to the above 1), wherein X in the general formula (1) is a group containing a triarylamine.
4) The compound according to 1) above, wherein X in the general formula (1) is a group containing a condensed or non-condensed π-electron-rich aromatic heterocycle. 5) The compound according to any one of 1) to 4) above, wherein Y in the general formula (1) is a mere bond. 6) wherein 1 in the general formula (1) is an arylene group or a heteroarylene group;
The compound according to any one of 4). 7) The compound according to any one of 1) to 4) above, wherein Y in the general formula (1) is a bond connecting X and Z via one atom. 8) a ring formed by Z in the general formula (1) (Z,
The ring formed by the carbon to which R is bonded and the carbon to which Y is bonded) is an aromatic ring or a heteroaromatic ring, Compound. 9) The general formula (1) according to any one of the above 1) to 8).
The compound which has two or more partial structural units which can be represented by these in one molecule. 10) A light-emitting device material, which is a compound according to any one of the above 1) to 9). 11) A light emitting device comprising at least one compound according to any one of the above 1) to 9). 12) The light emitting device according to the above item 11), wherein at least one light emitting material capable of emitting light from triplet excitons is used as the light emitting material. 13) The light emitting device according to 11) or 12), wherein at least one of the organic layers is formed by coating.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION First, the compound represented by the general formula (1) will be described. The compound represented by the general formula (1) is a compound having a structure in which a hole transporting group is substituted with a cyclic structure directly or via a divalent linking group. Among them, compounds having a cyclic structure or a structure substituted with a cyclic structure having a substituent other than a hydrogen atom at a position adjacent to the site where X bonds to Y (ortho position) are particularly preferred. However, when Y is a simple bond, X is directly bonded to the cyclic structure. First, X, which is a group having a hole transporting property, will be described. X represents a group having a hole transporting property.

With respect to groups having a hole transporting property, compounds having various structures having such groups are known in the art. For example, a compound having a primary to tertiary nitrogen atom, that is, an amine derivative, may be mentioned first. Among them,
An amine substituted with an aromatic hydrocarbon or a heteroaromatic compound is preferable, and among them, a tertiary amine compound in which all of the substituents are an aromatic hydrocarbon or a heteroaromatic compound is particularly preferable. Therefore, X is preferably a group having a diarylamino group or a triarylamine. The following can be mentioned:
An electron-rich heteroaromatic compound. Examples thereof include a 5-membered heteroaromatic in which one heteroatom is included in the ring structure, and compounds of the type in which the heteroatoms are condensed with each other or with an aromatic hydrocarbon.
Examples thereof include pyrrole, thiophene, furan, indole, carbazole, benzothiophene, benzofuran, dibenzothiophene, dibenzofuran, indolizine and the like. Further, a compound having a nitrogen atom, such as a hydrazone compound, a pyrazolone compound, a hydroxylamine compound, or an alkoxyamine compound, can also be used as the compound having a hole transporting group.

[0010] Among these electron-rich aromatic compounds, carbazole derivatives are particularly preferably used. When carbazole is used as the group represented by X, the substitution position may be any of the 1- to 9-positions, but the 3- or 9-position is preferred. Y is a divalent linking group or a simple bond. Examples of the linking group include an arylene group, an alkylene group, an ether group, a thioether group, an ester group, an amide group, a sulfonamide group, a urethane group, a ureido group, a carbonate group, and the like. It is an arylene group, an alkylene group or an ether group, particularly preferably a mere bond, a methylene group or an ether group.

Z represents an atomic group forming a cyclic structure. The atoms forming the skeleton of the ring used here are carbon, nitrogen,
It is composed of oxygen, sulfur, selenium, etc.
8, preferably a 5- or 6-membered aromatic or heteroaromatic ring. Z can also be condensed with an atom group having another ring structure. Examples of the aromatic ring include benzene, xylene, toluene, naphthalene, anthracene, and pyrene. Further, as the heteroaromatic ring, pyrrole, pyrazole, imidazole, pyridine,
Examples include triazole, tetrazole, pyridazine, pyrimidine, oxazole, isoxazole, thiazole, isothiazole, oxadiazole and the like. Further, as another ring formed by condensing with a group of atoms of the structure, a benzo-fused 5-membered heterocyclic ring (for example, benzopyrazole,
Benzoimidazole, benzoxazole, benzothiazole, etc.) and condensed heterocyclic rings (eg, imidazopyridine, pyrazoloimidazole, etc.).

R represents a hydrogen atom or a substituent. However, the present invention is characterized in that at least one of the positions adjacent to the site linked to Y of X and / or R is substituted with a substituent other than a hydrogen atom. Here, as a substituent other than a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a cyano group, a formyl group, a substituted or unsubstituted alkyl group (preferably having 1 to 30 carbon atoms) , More preferably 1 to 15 carbon atoms
It is. For example, a methyl group, a t-butyl group, a cyclohexyl group and the like can be mentioned. ), Alkenyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms, for example, vinyl group, 1-propenyl group, 1-buten-2-yl group, cyclohexen-1-yl group, etc. ), And
Alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms, such as ethynyl group and 1-propynyl group), and aryl group (preferably having 6 to 30 carbon atoms, more preferably Has 6 to 15 carbon atoms, such as phenyl, tolyl, xylyl, naphthyl,
Examples include a biphenylyl group and a pyrenyl group. ), A heterocyclic group (preferably a 5- or 6-membered ring, which may be condensed with another ring. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. 30, more preferably 2 to 15. For example,
Examples include a pyridyl group, a piperidyl group, an oxazolyl group, an oxadiazolyl group, a tetrahydrofuryl group, and a thienyl group. ), Primary to tertiary amino groups (amino group, alkylamino group, arylamino group, dialkylamino group,
Diarylamino group, alkylarylamino group, heterocyclic amino group, bisheterocyclic amino group and the like. It is preferably a tertiary amino group, and has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms. For example, a dimethylamino group, a diphenylamino group, a phenylnaphthylamino group and the like can be mentioned. ), An imino group (a group represented by —CR ₁₁ NRNR ₁₂ or —N = CR ₁₃ R ₁₄ , wherein R _{11 to} R ₁₄ are a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryl It is a group selected from an oxy group and a primary to tertiary amino group, preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, and an alkoxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 30 carbon atoms). Has 1 to 15 carbon atoms, for example, a methoxy group,
Examples include an ethoxy group and a cyclohexyloxy group. ), An aryloxy group (preferably having 6 to 30 carbon atoms,
More preferably, it has 6 to 15 carbon atoms. For example, a phenoxy group, a 1-naphthoxy group, a 4-phenylphenoxy group and the like can be mentioned. ), Alkylthio group (preferably carbon number
It has 1 to 30, more preferably 1 to 15 carbon atoms. For example, a methylthio group, an ethylthio group, a cyclohexylthio group and the like can be mentioned. ), An arylthio group (preferably having carbon atoms
It has 6 to 30, more preferably 6 to 15 carbon atoms. For example,
Examples include a phenylthio group and a tolylthio group. ),
Carbonamido group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an acetamido group,
Examples include a benzoylamide group and an N-methylbenzoylamide group. ), A sulfonamide group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example,
Methanesulfonamide group, benzenesulfonamide group,
and p-toluenesulfonamide group. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, a dimethylcarbamoyl group,
Phenylcarbamoyl group, diphenylcarbamoyl group,
And a dioctylcarbamoyl group. ), A sulfamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an unsubstituted sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, A diphenylsulfamoyl group, a dioctylsulfamoyl group, etc.), an alkylcarbonyl group (preferably having 1 to 3 carbon atoms).
It has 0, more preferably 1 to 15 carbon atoms. For example, an acetyl group, a propionyl group, a butyroyl group, a lauroyl group and the like can be mentioned. ), An arylcarbonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as a benzoyl group and a naphthoyl group), an alkylsulfonyl group (preferably having 1 to 3 carbon atoms).
It has 0, more preferably 1 to 15 carbon atoms. Examples include a methanesulfonyl group and an ethanesulfonyl group. ), An arylsulfonyl group (preferably having 6 to 3 carbon atoms)
It has 0, more preferably 6 to 15 carbon atoms. For example, a benzenesulfonyl group, a p-toluenesulfonyl group, a 1-naphthalenesulfonyl group and the like can be mentioned. ), An alkoxycarbonyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms; for example, a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc.), an aryloxycarbonyl group ( It preferably has 6 to 30 carbon atoms, more preferably 6 to 15 carbon atoms, such as a phenoxycarbonyl group and a 1-naphthoxycarbonyl group.), An alkylcarbonyloxy group (preferably 1 to 30 carbon atoms, More preferably 1 to 15 carbon atoms
It is. For example, an acetoxy group, a propionyloxy group, a butyroyloxy group and the like can be mentioned. ), An arylcarbonyloxy group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as a benzoyloxy group and a 1-naphthoyloxy group), a urethane group (preferably having It has a number of 1 to 30, more preferably 1 to 15. For example, a methoxycarbonamide group, a phenoxycarbonamide group, a methylaminocarbonamide group and the like can be mentioned, and a ureido group (preferably 1 to 30 carbon atoms). And more preferably 1 to 15 carbon atoms.
For example, a methylaminocarbonamide group, a dimethylaminocarbonamide group, a diphenylaminocarbonamide group and the like can be mentioned. ), A carbonate group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, such as a methoxycarbonyloxy group and a phenoxycarbonyloxy group). Among them, an alkyl group, an aryl group, an alkoxy group, and an aryloxy group are preferable, and an alkyl group and an aryl group are particularly preferable.

R may be linked to Z to form a cyclic structure. The group represented by X, Y, Z can be substituted with various substituents other than a hydrogen atom. Examples thereof include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom), a cyano group, a formyl group, or a substituted or unsubstituted alkyl group (preferably having 1 to 30 carbon atoms, more preferably The number is 1 to 15. For example, a methyl group,
Examples include a t-butyl group and a cyclohexyl group. ), An alkenyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms. For example, a vinyl group, 1-
Propenyl group, 1-buten-2-yl group, cyclohexene-1-
And an yl group. ), An alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 15 carbon atoms, such as an ethynyl group and a 1-propynyl group), and an aryl group (preferably having 6 to 30 carbon atoms). More preferably, it has 6 to 15. For example, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenylyl group, a pyrenyl group and the like can be mentioned, and a heterocyclic group (preferably a 5- or 6-membered ring). The hetero atom includes, for example, a nitrogen atom, an oxygen atom and a sulfur atom, preferably having 2 to 30 carbon atoms, and more preferably having 2 to 15 carbon atoms. A pyridyl group, a piperidyl group, an oxazolyl group, an oxadiazolyl group, a tetrahydrofuryl group, a thienyl group, and the like.)
To tertiary amino group (amino group, alkylamino group, arylamino group, dialkylamino group, diarylamino group, alkylarylamino group, heterocyclic amino group, bisheterocyclic amino group, etc .; preferably a tertiary amino group; It has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms.
For example, a dimethylamino group, a diphenylamino group, a phenylnaphthylamino group and the like can be mentioned. ), An imino group (a group represented by -CR ₁₁ = NR ₁₂ or -N = CR ₁₃ R ₁₄ , wherein R
_{11 to} R ₁₄ are groups selected from a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, and a primary to tertiary amino group. Preferably 1 to 30 carbon atoms,
More preferably, it has 1 to 15 carbon atoms. ), An alkoxy group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms)
It is. For example, a methoxy group, an ethoxy group, a cyclohexyloxy group and the like can be mentioned. ), An aryloxy group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms)
It is. For example, a phenoxy group, a 1-naphthoxy group, a 4-phenylphenoxy group and the like can be mentioned. ), An alkylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms. Examples thereof include a methylthio group, an ethylthio group, and a cyclohexylthio group), and an arylthio group (preferably having 6 carbon atoms). -30, more preferably 6-15 carbon atoms, such as a phenylthio group and a tolylthio group.) A carbonamide group (preferably 1-30 carbon atoms, more preferably 1-15 carbon atoms).
For example, an acetamide group, a benzoylamide group, an N-methylbenzoylamide group and the like can be mentioned. ), A sulfonamide group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, a methanesulfonamide group,
Examples include a benzenesulfonamide group and a p-toluenesulfonamide group. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group,
Examples include a dimethylcarbamoyl group, a phenylcarbamoyl group, a diphenylcarbamoyl group, and a dioctylcarbamoyl group. ), A sulfamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, an unsubstituted sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, A diphenylsulfamoyl group, a dioctylsulfamoyl group, etc.), an alkylcarbonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 30 carbon atoms).
It is 15. For example, an acetyl group, a propionyl group, a butyroyl group, a lauroyl group and the like can be mentioned. ), An arylcarbonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms, such as a benzoyl group and a naphthoyl group), an alkylsulfonyl group (preferably having 1 to 30 carbon atoms). , More preferably 1 to 15 carbon atoms
It is. Examples include a methanesulfonyl group and an ethanesulfonyl group. ), An arylsulfonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms; examples thereof include a benzenesulfonyl group, a p-toluenesulfonyl group, and a 1-naphthalenesulfonyl group), and alkoxy. Carbonyl group (preferably having 1 carbon atom
-30, more preferably 1-15 carbon atoms. For example, a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group and the like can be mentioned. ), An aryloxycarbonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms. For example, a phenoxycarbonyl group, 1
-Naphthoxycarbonyl group and the like. ), An alkylcarbonyloxy group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, for example, an acetoxy group, a propionyloxy group, a butyroyloxy group, etc.), an arylcarbonyloxy group (preferably Has 6 to 30 carbon atoms, more preferably 6 to 15 carbon atoms.
Examples include a benzoyloxy group and a 1-naphthoyloxy group. ), Urethane group (preferably having 1 to 3 carbon atoms)
It has 0, more preferably 1 to 15 carbon atoms. For example, a methoxycarbonamide group, a phenoxycarbonamide group, a methylaminocarbonamide group and the like can be mentioned. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. Examples thereof include a methylaminocarbonamide group, a dimethylaminocarbonamide group, and a diphenylaminocarbonamide group). And a carbonic ester group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, such as a methoxycarbonyloxy group and a phenoxycarbonyloxy group).

The partial structural unit represented by the general formula (1) functions effectively in the present invention, but a compound having two or more of these partial structural units in one molecule can be particularly preferably used.

In the present invention, the above-mentioned partial structural unit (repeating unit) is defined as follows.

[0016]

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In the formula, parentheses indicate a repeating unit, and R,
X, Y, and Z have the same meanings as in formula (1). n is 1
Is an integer greater than or equal to. In the formula 1, an n-valent single atom (n
), Or the repeating units may be bonded to each other.

Further, the compound represented by the general formula (1) may form a polymer compound having the exemplified structure in a part of its repeating unit. In this case, X, Y, and Z contain a polymerizable group such as an ethylenically unsaturated bond, or a polymerizable group such as a carboxyl group, an amino group, or an ester group that causes polycondensation, and the group is polymerized. Thus, the polymer may be formed, or the precursor of the compound represented by the general formula (1) may form the polymer while forming the compound skeleton of the general formula (1).

Regarding the compound represented by the general formula (1), a compound having a structure finally exhibiting a function can be used as it is, regardless of whether it is a low molecular weight or a high molecular weight. The precursor may be used in an organic electroluminescent device, and after or during the construction of the device, a physical or chemical post-treatment may be used to guide the final structure.
When used as a low molecular weight compound, the molecular weight is preferably in the range of 200 to 5,000, preferably 300 to 2,000. When used as a polymer compound, the average molecular weight (Mw)
Preferably 2000 to 100000, preferably 5000 to 100
000 range.

The compound represented by the general formula (1) can be synthesized by a known method. In the following, examples of typical synthetic schemes are disclosed, followed by specific examples of the compounds of the present invention. The present invention is of course not limited by this specific example.

[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[Synthesis of Compound HT-2] In a 3000 ml three-necked flask equipped with a thermometer and a reflux condenser, 167 g (1.0 mol) of carbazole, 1,3,5-trisbromomethyl-2,4,6 -120 g (0.3 mol) of trimethylbenzene, 56 g (1.0 mol) of potassium hydroxide, 10 g of tetrabutylammonium bromide, 1000 ml of toluene and 300 ml of water were charged, and the mixture was reacted under reflux conditions for 5 hours while stirring using a stirring blade.
Crystals precipitated as the reaction proceeded. After completion of the reaction, the reaction mixture was cooled, and the precipitate was filtered and washed with water and methanol. The crude crystals were recrystallized from a mixed solvent of chloroform / ethanol to obtain 167 g of Compound HT-2 crystals.

When the compound of the present invention is used as a material for a light-emitting device, the light-emitting device emits light from a singlet exciton, light from a triplet exciton, or light from both. Although it can be used as a material, the effect is exhibited particularly in combination with a light emitting material including light emission from a triplet exciton.

The luminescent material used in the present invention is preferably at least one of an orthometalated metal complex and a porphyrin metal complex which are phosphorescent compounds.
Orthometallated metal complexes are more preferably used.

The orthometalated metal complex used in the present invention will be described. The ortho-metalated metal complex is described in, for example, "Organic Metal Chemistry-Fundamentals and Applications-", p.
Shokabosha, written by Akio Yamamoto 1982, Photochemis
try and Photophysics of Coordination Compounds '' p
71-p77, p135-p146 Springer-Verlag H. Yersin 19
It is a general term for a group of compounds described in 1987 and the like.
As the central metal of the metal complex, any transition metal can be used. In the present invention, among them, rhodium, platinum, gold, iridium, ruthenium, palladium and the like can be preferably used. Of these, iridium is more preferred. The specific description and the compound examples of the ortho-metalated metal complex are described in Japanese Patent Application No. 2000-254171, paragraphs 0152 to 0180.

The valence of the metal of the orthometalated metal complex is not particularly limited, but trivalent is preferred when iridium is used. The ligand of the orthometalated metal complex is not particularly limited as long as it can form an orthometallated metal complex. For example, an aryl group-substituted nitrogen-containing aromatic hetero ring derivative (the substitution position of an aryl group is on a carbon adjacent to a nitrogen-containing aromatic hetero ring nitrogen atom, and examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, Examples of the nitrogen-containing aromatic heterocycle include pyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, quinoxaline, phthalazine, quinazoline, naphthyridine, cinnoline, perimidine, phenanthroline, pyrrole, imidazole, and pyrazole. , Oxazole, oxadiazole, triazole,
Thiadiazole, benzimidazole, benzoxazole, benzothiazole, phenanthridine and the like),

Heteroaryl group-substituted nitrogen-containing aromatic heterocyclic derivative (the substitution position of the heteroaryl group is on the carbon adjacent to the nitrogen-containing aromatic heterocyclic nitrogen atom. Group, thiophenyl group, furyl group, etc.), 7,8-benzoquinoline derivative, phosphinoaryl derivative, phosphinoheteroaryl derivative, phosphinoxyaryl derivative, phosphinoxyhetero An aryl derivative, an aminomethylaryl derivative, an aminomethylheteroaryl derivative and the like can be mentioned. Of these, aryl-substituted nitrogen-containing aromatic heterocyclic derivatives, heteroaryl-substituted nitrogen-containing aromatic heterocyclic derivatives, and 7,8-benzoquinoline derivatives are preferable, and phenylpyridine derivatives, thiophenylpyridine derivatives, and 7,8-benzoquinoline Derivatives are more preferred, thiophenylpyridine derivatives,
7,8-Benzoquinoline derivatives are more preferred.

The porphyrin metal complex used in the present invention is preferably a platinum complex, more preferably a divalent platinum complex.

As a light-emitting element in which light emission from a triplet exciton is observed, an iridium complex (Ir (ppy) ₃ : Tris-Ortho-
Metalated Complex of Iridium (III) with 2-Phenylpyr
Green light-emitting devices utilizing light emission from idine) have been reported (Applied Physics Letters 75, 4 (1999)). It has been reported that this device achieved an external quantum yield of 8%, surpassing the external quantum yield of 5%, which was said to be the limit of the conventional device.

Next, a light emitting device containing the compound of the present invention will be described. The method for forming the organic layer of the light-emitting element containing the compound of the present invention is not particularly limited, but methods such as resistance heating evaporation, electron beam, sputtering, molecular lamination, coating, printing, and ink-jet methods. Is used, and resistance heating evaporation and a coating method are preferable in terms of production. The compound of the present invention can be formed by an evaporation method and an organic layer forming method by a coating method.

The light emitting device of the present invention is a device in which a light emitting layer or a plurality of organic compound thin films including the light emitting layer is formed between a pair of anode and cathode electrodes. , An electron injection layer, an electron transport layer, a protective layer, and the like, and each of these layers may have another function. Various materials can be used for forming each layer.

The anode supplies holes to the hole injection layer, the hole transport layer, the light emitting layer, etc., and may be made of a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof. It is preferable that the material has a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, and nickel, and those metals and conductive metal oxides. Mixtures or laminates, inorganic conductive substances such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, and the like. Oxides,
In particular, ITO is preferable in terms of productivity, high conductivity, transparency, and the like. The thickness of the anode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda lime glass, an alkali-free glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass in order to reduce ions eluted from the glass. Further, when soda lime glass is used, it is preferable to use a glass coated with a barrier coat such as silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. When glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used for manufacturing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (such as a sol-gel method), and a dispersion of indium tin oxide are used. The film is formed by a method such as coating. The anode can be cleaned or otherwise treated to lower the device's drive voltage,
It is also possible to increase the luminous efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment and the like are effective. The cathode supplies electrons to the electron injection layer, the electron transport layer, the light-emitting layer, and the like. The cathode, the adhesion between the negative electrode such as the electron injection layer, the electron transport layer, and the light-emitting layer, the ionization potential, and stability. Is taken into consideration. As the material of the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples thereof include alkali metals (eg, Li, Na,
K, Cs, etc.) and their fluorides, oxides, alkaline earth metals (eg, Mg, Ca, etc.) and their fluorides, oxides, gold, silver, lead, alnium, sodium-potassium alloys or mixed metals thereof, Examples thereof include a lithium-aluminum alloy or a mixed metal thereof, a magnesium-silver alloy or a mixed metal thereof, and rare earth metals such as indium and ytterbium, and preferably have a work function of 4 eV.
The following materials are preferable, and aluminum, a lithium-aluminum alloy or a mixed metal thereof, a magnesium-silver alloy or a mixed metal thereof are more preferable. The cathode can have not only a single-layer structure of the compound and the mixture, but also a stacked structure including the compound and the mixture. The thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and further preferably 100 nm.
nm to 1 μm. A method such as an electron beam method, a sputtering method, a resistance heating evaporation method, or a coating method is used for manufacturing the cathode, and a metal can be evaporated alone or two or more components can be simultaneously evaporated. Further, an alloy electrode can be formed by depositing a plurality of metals at the same time, or an alloy prepared in advance may be deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The material of the light emitting layer is capable of injecting holes from an anode or a hole injection layer or a hole transport layer when applying an electric field, and also capable of injecting electrons from a cathode or an electron injection layer or an electron transport layer. Any material can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of providing a field of recombination of holes and electrons to emit light. For example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives, perinone derivatives, oxadiazole derivatives, aldazine derivatives , Metal complexes and rare earth complexes of pyrrolidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidin compounds, 8-quinolinol derivatives Representative metal complexes, ortho-metalated complexes, etc., polythiophene, polyphenylene, polyphenylenevinylene And the like of the polymer compound. The thickness of the light-emitting layer is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm,
It is more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. The method for forming the light emitting layer is not particularly limited, but includes resistance heating evaporation, electron beam, sputtering, molecular lamination, coating (spin coating, casting, dip coating, etc.),
A method such as an LB method, a printing method, and an ink-jet method is used, and a resistance heating evaporation and a coating method are preferable.

The material of the hole injection layer and the hole transport layer has a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. Should be fine. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, and styryl anthracene derivatives , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds,
Examples thereof include poly (N-vinylcarbazole) derivatives, aniline-based copolymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene. The thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 5 μm.
00 nm. The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the hole injection layer and the hole transport layer include a vacuum deposition method, an LB method, an inkjet method, and a method in which the hole injection and transport agent is dissolved or dispersed in a solvent and coated (spin coating, casting, Dip coating method) and a printing method. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resins, ketone resins, phenoxy resins, polyamides, ethyl cellulose, vinyl acetate, ABS resins, polyurethanes, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins, silicone resins, and the like.

The material of the electron injecting layer and the electron transporting layer is not limited as long as it has a function of injecting electrons from the cathode, a function of transporting electrons, or a function of blocking holes injected from the anode. Good. The thickness of the electron injecting layer and the electron transporting layer is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-mentioned materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the electron injecting layer and the electron transporting layer include a vacuum deposition method, an LB method, an ink jet method, and a method in which the electron injecting and transporting agent is dissolved or dispersed in a solvent and coated (spin coating method, casting method, dip coating method). And the like, and a printing method. In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified in the case of the hole injection transport layer can be applied.

As the material of the protective layer, any material may be used as long as it has a function of preventing a substance which promotes element deterioration such as moisture and oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ , G
eO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3,
Metal oxides such as TiO ₂ , MgF ₂ , LiF, AlF ₃ ,
CaF _2, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, poly-dichloro-difluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, A copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, A moisture-proof substance having a water absorption of 0.1% or less can be used. There is no particular limitation on the method of forming the protective layer, for example, a vacuum evaporation method,
Sputtering method, reactive sputtering method, MBE
(Molecular beam epitaxy) method, cluster ion beam method,
An ion plating method, a plasma polymerization method (high-frequency excitation ion plating method), a plasma CVD method, a laser CVD method, a thermal CVD method, a gas source CVD method, a coating method, an inkjet method, and a printing method can be applied.

[0046]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. (Example 1) ITO on a 25 mm x 25 mm x 0.7 mm glass substrate
Film formed with a thickness of 150 nm (Tokyo Sanyo Vacuum Co., Ltd.)
Was used as a transparent support substrate. After etching and washing the transparent support substrate, about 10 nm of copper phthalocyanine was deposited. next
TPD (N, N'-bis (3-methylphenyl) -N, N'-diphenylbenzidine) about 40 nm, and Alq (tris (8-hydroxyquinolinato) aluminum) about 60 nm as the third layer
Were sequentially deposited in a vacuum of 10 ⁻³ to 10 ⁻⁴ Pa at a substrate temperature of room temperature. A mask patterned on the organic thin film (a mask having a light-emitting area of 5 mm x 5 mm) is installed, and magnesium: silver = 10: 1 is co-deposited at 250 nm in a vapor deposition apparatus, and then silver is 300 nm
Was deposited to produce an element 101. For element 101, TP
EL devices 102 to 108 having exactly the same composition as 101 were produced except that two comparative compounds and five compounds of the present invention were used instead of D. Using a source measure unit 2400 manufactured by Toyo Technica, a DC constant voltage is applied to the EL element to emit light, and the brightness is measured by a luminance meter BM-8 manufactured by Topcon Corporation.The emission wavelength is measured by a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. It measured using. The emission spectrum is λ
Analogs with max in the range 525-530 nm were obtained. Table 1 shows the results of measuring the maximum value of the external quantum efficiency of light emission and the maximum light emission intensity calculated from the light emission energy obtained by integrating the entire light emission spectrum region and the power consumption at that time.

[0047]

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[0048]

[Table 1]

Further, these elements were sealed in an autoclave replaced with argon gas, and heated at 85 ° C. for 1 hour.
Table 2 shows the results of the same luminance measurement and light emission surface observation after storage for 0 days.

[0050]

[Table 2]

As is evident from the results of Tables 1 and 2, in the devices 101 to 103 using the comparative compounds, the luminous performance immediately after the device production was the same as that of the compound of the present invention, but the performance after storage was greatly reduced. Resulting in. In contrast, it can be seen that the compound of the present invention has high luminous performance even after storage.

(Example 2) Copper phthalocyanine was vapor-deposited to a thickness of about 10 nm on an ITO glass substrate etched and washed in the same manner as in Example 1. On top of this, TPD of about 40 nm as a second layer, and CBP and triplet exciton light emitting material TL-1 as a third layer in a molar ratio of 9
While co-evaporating at a ratio of 5: 5, about 25 nm, and about 40 nm of TIMP as a fourth layer were sequentially evaporated and laminated in a vacuum of 10 ⁻³ to 10 ⁻⁴ Pa at a substrate temperature of room temperature. A mask patterned on an organic thin film (a mask with a light-emitting area of 5 mm x 5 mm)
Is installed, and magnesium: silver = 10: 1 250n in the vapor deposition device
After co-evaporation of m, 300 nm of silver was evaporated to produce an element 201.

[0053]

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EL devices 202 to 208 having exactly the same composition as 201 were prepared except that two comparative compounds and five compounds of the present invention were used instead of CBP.

[0055]

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The light emission of the device manufactured in the same manner as in Example 1 was measured. The emission spectrum shows that λmax is 530 for all samples.
A similar shape with a range of nm to 535 nm was obtained. Table 3 shows the results of measuring the maximum value of the external quantum efficiency of light emission and the maximum light emission intensity in the same manner as in Example 1.

[0057]

[Table 3]

These elements were sealed in an autoclave replaced with argon gas as in Example 1, and
Table 4 shows the results of similar luminance measurement and light emission surface observation after storage for 10 days under a heating condition of ° C.

[0059]

[Table 4]

As is clear from the results of Tables 3 and 4, in the devices 201 to 203 using the comparative compounds, the luminous performance immediately after the device was prepared was equivalent to that of the compound of the present invention, but the performance after storage was greatly reduced. Resulting in. On the other hand, similarly to Example 1, it is understood that the compound of the present invention has high luminous performance even after storage.

Example 3 A poly [(3,4-ethylenedioxy) -2,5-thiophene] polystyrene sulfonic acid dispersion (Bayer) was placed on an ITO glass substrate etched and washed in the same manner as in Example 1. (Baytron P, 1.3% solid content), spin dried at 150 ° C for 2 hours,
A coating layer of nm was formed. On top of this, poly (N-
Vinylcarbazole (PVK) 20mg, CBP 20mg, PBD (2-
(4'-t-butylphenyl) -5- (4 ''-(phenyl) phenyl) -1,3,4-oxadiazole) 12 mg, TL as luminescent material
A solution of 11 mg in 2 ml of 1,2-dichloroethane was spin-coated. The thickness of this coating film was about 120 nm.
A mask patterned on an organic thin film (light emitting area is 5mm
A mask having a size of × 5 mm) was set, and magnesium: silver = 10: 1 was co-deposited at 250 nm in a vapor deposition apparatus, and then 300 nm of silver was vapor-deposited to produce an element 301. EL devices 302 to 306 having exactly the same composition as 301 except that two comparative compounds and three compounds of the present invention were used instead of CBP for device 301.
The light emission of the device manufactured in the same manner as in Example 1 was measured. As for the emission spectra, all samples had similar shapes having λmax in the range of 530 nm to 535 nm. Table 5 shows the results of measuring the maximum value of the external quantum efficiency of light emission and the maximum light emission intensity in the same manner as in Example 1.

[0062]

[Table 5]

Further, these elements were sealed in an autoclave replaced with argon gas as in Example 1, and
Table 10 shows the results of similar luminance measurement and light emission surface observation after storage for 10 days under a heating condition of ° C.

[0064]

[Table 6]

As is clear from the results of Tables 5 and 6, in the devices 301 to 303 using the comparative compound, the luminous performance immediately after the device was prepared was equivalent to that of the compound of the present invention, but the performance after storage was greatly reduced. Resulting in. On the other hand, similarly to Example 1, it is understood that the compound of the present invention has high luminous performance even after storage.

[0066]

The compound of the present invention has good hole transporting ability and excellent durability, and by using the compound, a light emitting device having high luminance and excellent device durability can be obtained. Was.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07D 333/76 C07D 333/76 4H006 471/04 104 471/04 104A 4H049 C07F 7/10 C07F 7/10 S 4H050 15/00 15/00 E C09K 11/06 690 C09K 11/06 690 H05B 33/14 H05B 33/14 A 33/22 33/22 DF term (reference) 3K007 AB02 AB05 AB11 EB00 4C034 DM01 DU12 4C037 SA02 4C065 AA03 BB04 CC01 DD01 EE02 HH06 JJ01 KK02 LL01 PP03 4C204 BB05 CB25 DB01 EB01 FB16 GB01 4H006 AA01 AA03 AB92 BU46 4H049 VN01 VP01 VQ60 VR24 4H050 AA01 AA03 AB92 WB11 WB14

Claims (7)

[Claims] 1. A compound represented by the general formula (1). General formula (1) X is a hole transporting group. Y is a divalent linking group or a simple bond. Z is an atomic group capable of forming three or more cyclic structures. R represents a hydrogen atom or a substituent. X is
Of the group and R substituted at the position adjacent to the site linked to Y,
At least one is a group other than a hydrogen atom. R may be linked to Z to form a cyclic structure. 2. In the formula (1), X is any one of a group containing a diarylamino group and a triarylamine or a group containing a condensed or non-condensed π-electron-rich aromatic heterocycle. A compound according to claim 1. 3. The method according to claim 1, wherein Y in the general formula (1) is represented by any one of a mere bond, an arylene group or a heteroarylene group, and a bond connecting X and Z via one atom. Or the compound according to 2. 4. The compound according to claim 1, wherein the ring formed by Z in the general formula (1) is an aromatic ring or a heteroaromatic ring. 5. A compound according to claim 1, wherein the compound has two or more partial structural units represented by the general formula (1) in one molecule. (6) a compound according to (1) to (5),
A light-emitting element comprising: 7. The light emitting device according to claim 6, wherein at least one light emitting material capable of emitting light from triplet excitons is used as the light emitting material.