JP2002308855A - New compound and luminescent element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminescent element which has a high luminance and an excellent durability. SOLUTION: A new compound represented by formula (1) (wherein X is a group containing a fused or non-fused, electron-deficient heteroaromatic ring; Yn is a group of atoms capable of forming 3-membered or higher ring structure; Rn is H or a substituent provided at least one Rn is a substituent other than H; n is an integer of 1 or higher; and Rn may be connected to Yn to form a ring structure) is provided. The luminescent element is prepared by using the compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron transporting compound 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, organic electroluminescent (EL) elements are
Since high-luminance light emission can be obtained at a low voltage, it is attracting attention as a promising display element. For example, an EL element that forms an organic thin film by vapor deposition of an organic compound is known (Appli.
ed Physics 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 the electron transporting material used in this stacked device include a light metal complex represented by Alq (tris-8-hydroxy-quinolinato aluminum), oxadiazole, triazole, benzimidazole, benzoxazole, and benzothiazole. Such π-electron deficient aromatic compounds are known as excellent electron transport materials. However, when an π-electron deficient aromatic compound is used as an electron transport material among these compounds, the organic electroluminescent device has a problem in raw storage stability (driving durability and storage durability). Knew. As a means for solving this problem, 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 (199).
0), Polymer Preprints (ACS) 349 (1997). In addition, about technology such as polymerization, App
l. Phys. Lett. 63, 2627 (1993) and the like. The inventors have also studied techniques for improving the deterioration of the raw storage stability (driving durability and storage durability) of the organic electroluminescent device derived from the electron transport material.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to develop a compound having good electron transporting ability and excellent durability, and by using the compound, to obtain a device having high luminance and excellent durability of the device. To develop a light emitting device.

[0004]

The present invention provides the following (1) to
Achieved by (11). (1) A compound represented by the general formula (1). General formula (1)

[0005]

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X represents a group containing a condensed or non-condensed electron-deficient heteroaromatic ring. Yn is an atomic group capable of forming a three- or more-membered ring structure. Rn represents a hydrogen atom or a substituent. At least one of Rn is a substituent other than a hydrogen atom. n is an integer of 1 or more. Rn may be linked to Yn to form a cyclic structure. (2) The compound according to the above (1), wherein X in the general formula (1) is a group containing a condensed or non-condensed nitrogen-containing 6-membered heteroaromatic ring. (3) The compound according to the above (1), wherein X in the general formula (1) is a group containing a fused or non-fused 5-membered heteroaromatic ring containing two or more heteroatoms. (4) X in the general formula (1) is a carbon atom site and Y is
The compound according to any one of the above (1) to (3), which is bonded to n. (5) n in the general formula (1) is 2 or more;
The compound according to any one of the above (1) to (4), wherein two or more of n are substituents other than a hydrogen atom.

(6) Any one of the above (1) to (5), wherein Yn in the general formula (1) is an atomic group capable of forming a cyclic structure of an aromatic ring or a heteroaromatic ring. The compound according to the above. (7) The compound according to any one of the above (1) to (6), wherein the compound has two or more partial structural units represented by the general formula (1) in one molecule. (8) A light-emitting element material, which is the compound according to any one of (1) to (7). (9) A light emitting device comprising at least one compound according to any one of (1) to (7). (10) The light-emitting device according to (9), wherein at least one light-emitting material capable of emitting light from a triplet exciton is used as the light-emitting material. (11) The light-emitting device according to (9) or (10), 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. In the compound represented by the general formula (1), a condensed or non-condensed electron-deficient heteroaromatic ring is substituted with a cyclic structure having a substituent other than a hydrogen atom at a position adjacent to the bonding site (ortho position). Is a compound of the structure
First, X, which is a group containing a condensed or non-condensed electron-deficient heteroaromatic ring, will be described. X is a group containing a condensed or non-condensed electron-deficient heteroaromatic ring. When used for a light-emitting material, X is a group having an electron transporting property.

Examples of the heteroaromatic ring in X include a nitrogen-containing 5-membered heteroaromatic compound having two or more heteroatoms. Examples include pyrazole, imidazole, oxazole, thiazole, triazole (1,2,3- and 1,2,4-), tetrazole, oxadiazole (1,2,4-, 1,2,5- and 1,3,4-), thiadiazole (1,2,4-, 1,2,5- and 1,3,4-), and the like. Compounds condensed with each other or with an aromatic hydrocarbon can be used in the same manner. The following are electron-deficient nitrogen-containing 6-membered heteroaromatic compounds. Examples include pyridine, pyridazine, pyrimidine, pyridazine, triazine and the like. As for these compounds, compounds which are condensed with each other or with aromatic hydrocarbons, 5-membered and 6-membered heteroaromatics can also be used. Examples thereof include quinazoline and quinoxaline.

Further, there may be mentioned complex compounds in which these heterocyclic compounds are coordinated to metal atoms or ions. Examples of complex compounds include compounds in which a heteroatom contained in a heteroaromatic ring or a lawn-pair electron possessed by a substituted anionic substituent is coordinated to a metal (for example, the Alq derivative mentioned above). And compounds in which the π electron of a heteroaromatic ring or an aromatic ring is coordinated to a metal (eg, a metallocene compound), and an orthometalated complex in which a metal is directly bonded to a heteroaromatic ring or an aromatic ring. Can be mentioned. Further, examples of the electron transporting heterocyclic compound having a single hetero atom include silole derivatives. Among these, a nitrogen-containing 5-membered ring heteroaromatic compound having two or more heteroatoms is particularly preferred, and imidazole, oxazole, thiazole, 1,2,4-triazole, 1,3,4-oxadiazole are particularly preferred. Azole and 1,3,4-thiadiazole.

Yn represents an atomic group forming a cyclic structure.
Examples of this include saturated carbocycles such as cyclopropane and cyclobutane, aromatic carbocycles such as benzene and naphthalene, and heterocycles such as pyrrole, pyrazole, imidazole, oxazole, oxadiazole, pyridine and quinazoline. Is preferably 3 to 8, and
Six-membered aromatic or heteroaromatic rings are preferred. Particularly preferred are oxadiazole and imidazole.

Rn represents a hydrogen atom or a substituent. Here, at least one of Rn is a substituent other than a hydrogen atom, and n is an integer of 1 or more and 4 or less. Rn may be linked to X to form a cyclic structure.

Examples of the substituent represented by Rn include:
Halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, formyl group, or substituted or unsubstituted alkyl group (preferably having 1 to carbon atoms)
30, more preferably 1 to 15 carbon atoms. For example,
Examples thereof include a methyl group, a t-butyl group, and a cyclohexyl group. ), An alkenyl group (preferably having 2 to 3 carbon atoms)
0, more preferably 2 to 15 carbon atoms. For example, vinyl group, 1-propenyl group, 1-buten-2-yl group,
And a cyclohexen-1-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 a carbon number of 6 to 15. Examples thereof include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenylyl group, a pyrenyl group and the like, 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 2 to 30 carbon atoms, more preferably 2 to 15 carbon atoms.
It is. For example, pyridyl group, piperidyl group, oxazolyl group, oxadiazolyl group, tetrahydrofuryl group,
And a thienyl group. ), Primary to tertiary amino groups (amino groups, alkylamino groups, arylamino groups, dialkylamino groups, diarylamino groups, alkylarylamino groups, heterocyclic amino groups, bisheterocyclic amino groups, etc., preferably tertiary amino groups) And having 1 to 3 carbon atoms
0, more preferably 1 to 16 carbon atoms. For example, a dimethylamino group, a diphenylamino group, a phenylnaphthylamino group and the like can be mentioned. ), Imino group (—CR ₁₁ ＝
Group represented by NR _12, or -N = CR ₁₃ R _14. Where 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 3 carbon atoms
0, more preferably 1 to 15 carbon atoms. ), An alkoxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, such as a methoxy group, an ethoxy group, and a cyclohexyloxy group), and an aryloxy group (preferably having a carbon number of 1 to 30). 6 to 30, more preferably 6 to 15. For example, a phenoxy group,
Examples thereof include a 1-naphthoxy group and a 4-phenylphenoxy group. ), An alkylthio group (preferably having 1 to 1 carbon atoms)
30, more preferably 1 to 15 carbon atoms. For example,
Examples thereof include a methylthio group, an ethylthio group, and a cyclohexylthio group. ), An arylthio group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms. Examples thereof include a phenylthio group and a tolylthio group.)
Carbonamide group (preferably 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms. Examples thereof include an acetamido group, a benzoylamide group, and an N-methylbenzoylamide group), and a sulfonamide group (preferably Has a carbon number of 1 to 30, more preferably a carbon number of 1 to 15. For example, a methanesulfonamide group, a benzenesulfonamide group, a p-toluenesulfonamide group and the like are mentioned, and a carbamoyl group (preferably a carbon number). 1-3
0, more preferably 1 to 15 carbon atoms. For example, an unsubstituted carbamoyl group, methylcarbamoyl group, dimethylcarbamoyl group, phenylcarbamoyl group, diphenylcarbamoyl group, dioctylcarbamoyl group and the like can be mentioned. ), A sulfamoyl group (preferably having 1 carbon atom)
-30, more preferably 1-15 carbon atoms. Examples include an unsubstituted sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group, diphenylsulfamoyl group, dioctylsulfamoyl group, and the like. ), An alkylcarbonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms. Examples thereof include an acetyl group, a propionyl group, a butyroyl group, and a lauroyl group), and an arylcarbonyl group (preferably). Has 6 or more carbon atoms
30, more preferably 6 to 15 carbon atoms. For example,
Examples include a benzoyl group and a naphthoyl group. ), An alkylsulfonyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. Examples thereof include a methanesulfonyl group and an ethanesulfonyl group).
Arylsulfonyl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms; for example, benzenesulfonyl group, p-toluenesulfonyl group, 1-naphthalenesulfonyl group, etc.), and alkoxycarbonyl group (Preferably has 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms. Examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group.), An aryloxycarbonyl group (preferably having 6 carbon atoms). -30, more preferably 6-15 carbon atoms
It is. For example, a phenoxycarbonyl group, a 1-naphthoxycarbonyl group and the like can be mentioned. ), An alkylcarbonyloxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms. Examples thereof include an acetoxy group, a propionyloxy group, a butyroyloxy group and the like), and 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. ), A urethane group (preferably having 1 carbon atom)
-30, more preferably 1-15 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 1 to 15 carbon atoms. Examples thereof include a methylaminocarbonamide group, a dimethylaminocarbonamide group, and a diphenylaminocarbonamide group). A carbonate group (preferably having 1 to 30 carbon atoms;
More preferably, it has 1 to 15 carbon atoms. For example, a methoxycarbonyloxy group, a phenoxycarbonyloxy group and the like can be mentioned. ). 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. In Rn, n is preferably 2 or more, and particularly preferably 2 to 3. At that time,
It is preferred that two or more of Rn are other than a hydrogen atom.
Regarding the bond between X and Yn, X and Yn may be bonded at a hetero atom site (mainly a nitrogen atom) or at a carbon atom site, but it is preferable that X is bonded to Yn at a carbon atom site. preferable.

Further, a compound having two or more partial structural units represented by the general formula (1) in one molecule is particularly preferably used.

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

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In the formula, parentheses indicate a repeating unit, and X, Y
n and Rn have the same meanings as in the general formula (1). n is an integer of 1 or more. In the formula (1), the bond may be via an n-valent atomic group (n-valent single atom), or the repeating units may be bonded to each other. In the covalent bond between X and Yn (the carbon atom closest to X contained in Yn),
They may be bonded via a linking group, and examples of the linking group include a methylene group and an arylene group.

The group represented by X or Yn 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 from 1 to 15. For example, a methyl group, a t-butyl group, a cyclohexyl group and the like can be mentioned.
30, more preferably 2 to 15 carbon atoms. For example,
Examples include a vinyl group, a 1-propenyl group, a 1-buten-2-yl group, and a cyclohexen-1-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 5 or 6).
It is a membered ring and may be condensed with another ring. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. It preferably has 2 to 30 carbon atoms, more preferably 2 to 15 carbon atoms. For example, a pyridyl group, a piperidyl group,
Examples include an oxazolyl group, an oxadiazolyl group, a tetrahydrofuryl group, and a thienyl group. ), Primary to tertiary amino groups (amino groups, alkylamino groups, arylamino groups, dialkylamino groups, diarylamino groups, alkylarylamino groups, heterocyclic amino groups, bisheterocyclic amino groups, etc., preferably tertiary amino groups) And has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, such as a dimethylamino group, a diphenylamino group, a phenylnaphthylamino group and the like, and an imino group (-C
Group represented by R ₁₁ = NR ₁₂ or -N = CR ₁₃ R _14. Here, R _{11 to} R ₁₄ represent a hydrogen atom, an alkyl group, an aryl group,
Heterocyclic group, alkoxy group, aryloxy group, 1-3
It is a group selected from secondary amino groups. Preferably 1 carbon atom
-30, more preferably 1-15 carbon atoms. ), An alkoxy group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms, such as a methoxy group, an ethoxy group, and a cyclohexyloxy group).
An aryloxy group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 15 carbon atoms; for example, phenoxy group, 1-naphthoxy group, 4-phenylphenoxy group, etc.), and alkylthio group (preferably Has 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, for example, a methylthio group, an ethylthio group, a cyclohexylthio group and the like, and an arylthio group (preferably 6 to 30 carbon atoms, more preferably It has 6 to 15 carbon atoms, such as a phenylthio group and a tolylthio group.
0, more preferably 1 to 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 1 carbon atom)
~ 15. For example, a methanesulfonamide group, a benzenesulfonamide group, a p-toluenesulfonamide group and the like can be mentioned. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms).
For example, an unsubstituted carbamoyl group, methylcarbamoyl group, dimethylcarbamoyl group, phenylcarbamoyl group, diphenylcarbamoyl group, dioctylcarbamoyl group and the like can be mentioned. ), A sulfamoyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, 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 15 carbon atoms. For example, an acetyl group, a propionyl group, a butyroyl group) And an arylcarbonyl group (preferably having 6 carbon atoms).
-30, more preferably 6-15 carbon atoms. Examples include a benzoyl group and a naphthoyl group. ), An alkylsulfonyl group (preferably having 1 to carbon atoms)
30, more preferably 1 to 15 carbon atoms. For example,
Examples include a methanesulfonyl group and an ethanesulfonyl group. ), An arylsulfonyl group (preferably having 6 carbon atoms)
-30, more preferably 6-15 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 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, such as a phenoxycarbonyl group and a 1-naphthoxycarbonyl group), and an alkylcarbonyloxy group (preferably). Has 1 to 30 carbon atoms, more preferably 1 to 15. For example, an acetoxy group, a propionyloxy group, a butyroyloxy group and the like can be mentioned, and an arylcarbonyloxy group (preferably having 6 to 30 carbon atoms). It preferably has 6 to 15 carbon atoms, for example, benzoyloxy group, 1
-Naphthoyloxy group and the like. ), A urethane group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 15 carbon atoms. For example, a methoxycarbonamide group,
Examples include a phenoxycarbonamide group and a methylaminocarbonamide group. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably 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).

Further, the compound represented by the general formula (1) may form a polymer compound having an exemplified structure in a part of its repeating unit. In this case, Y, Rn, Y
n contains 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 to form a polymer. Or the general formula (1)
The precursor of the compound represented by may form a 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 200 to 5000, preferably 300 to 200.
It is in the range of 0. When used as a polymer compound, the average molecular weight (Mw) is preferably from 2,000 to 100.
000, preferably in the range of 5,000 to 100,000.

The compound represented by the general formula (1) can be synthesized by a known method. The general synthesis scheme is disclosed below, followed by specific examples of the compound of the present invention. The present invention is of course not limited by this specific example.

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[0028]

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[0029]

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[0030]

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[Synthesis of Compound ET-2] In a 1000 ml three-necked flask equipped with a thermometer and a reflux condenser, 99 g (0.5 mol) of 2-phenylbenzoic acid was placed.
l), 32.5 g of hydrazine sulfate (0.25 mol
1) 500 g of polyphosphoric acid was charged and the temperature was increased. At first, it was viscous and could not be stirred, but it became possible to stir from around a temperature exceeding 100 ° C. The reaction was carried out at 180 ° C. for 5 hours while stirring using a stirring blade as it was. After completion of the reaction, the reaction mixture was poured into warm water to precipitate crystals. After cooling, the precipitate was filtered and washed with water and methanol. The crude crystals were recrystallized from a mixed solvent of chloroform / ethanol to obtain 72 g of Compound ET-2 crystals.
I got

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, emits light from a triplet exciton, emits light from both, and emits light. 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 when iridium is used, trivalent is preferred. 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),

A 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 heterocycle 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, resistance heating evaporation,
Coating methods are preferred.

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, and the like. A metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof is used. It is possible to use a material having 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 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 can 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, T
metal oxides such as iO ₂ , MgF ₂ , LiF, AlF ₃ , C
aF ₂ metal fluorides such as, 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.

[0047]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. (Example 1) A transparent support substrate was prepared by forming a film of ITO to a thickness of 150 nm on a glass substrate of 25 mm x 25 mm x 0.7 mm (manufactured by Tokyo Sanyo Vacuum Co., Ltd.). After etching and washing this transparent support substrate, about 10 nm of copper phthalocyanine was deposited. TPD (N, N'-bis (3-methylphenyl) -N, N'-diphenylbenzidine) is about 40 nm as the second layer, and Alq (Tris (8
-Hydroxyquinolinato) aluminum) about 20 nm,
DNPB (2,5-bis (1-naphthyl) as the fourth layer
(-1,3,4-oxadiazole)
Vapor deposition and lamination were carried out in a vacuum of 0 ^-3 to 10 ^-4 Pa at a substrate temperature of room temperature. A mask (a mask having a light emitting area of 5 mm × 5 mm) patterned on the organic thin film is installed,
250 nm of magnesium: silver = 10: 1 in a vapor deposition apparatus
After co-evaporation, 300 nm of silver was evaporated, whereby an element 101 was manufactured. With respect to the device 101, except that two comparative compounds and five compounds of the present invention were used instead of DNPB,
EL elements 102 to 108 having exactly the same composition as in Example 1 were produced. 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 luminance is measured by a luminance meter BM-8 manufactured by Topcon Corporation. The emission wavelength is measured by a spectrum analyzer P manufactured by Hamamatsu Photonics.
It was measured using MA-11. As for the emission spectra, all samples had similar shapes having λmax in the range of 525 nm to 530 nm. 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.

[0048]

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[0049]

[Table 1]

These elements were sealed in an autoclave replaced with argon gas, and heated at 85 ° C.
Table 2 shows the results of the same luminance measurement and light emission surface observation after storage for 10 days.

[0051]

[Table 2]

Looking at the results in Tables 1 and 2, in the devices 101 to 103 using the comparative compounds, the luminous performance immediately after the device production was slightly lower than that of the compound of the present invention. However, after storage, the difference in performance is large, and the light emission performance of the sample of the comparative example is greatly reduced. 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, a TPD of about 40 nm as a second layer, and CBP and a triplet light emitting material TL- as a third layer.
About 2 while co-evaporating 1 to a molar ratio of 95: 5.
5 nm, and about 40 nm of TIMP as the fourth layer in order of 1.
Vapor deposition and lamination were carried out in a vacuum of 0 ^-3 to 10 ^-4 Pa at a substrate temperature of room temperature. A mask (a mask having a light emitting area of 5 mm × 5 mm) patterned on the organic thin film is installed,
250 nm of magnesium: silver = 10: 1 in a vapor deposition apparatus
After co-evaporation, 300 nm of silver was evaporated, whereby an element 201 was formed.

[0054]

Embedded image

For the device 201, except that two comparative compounds and five compounds of the present invention were used instead of TIMP,
EL elements 202 to 208 having exactly the same composition as 201 were produced.

[0056]

Embedded image

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 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.

[0058]

[Table 3]

Further, 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 emission surface observation after storage for 10 days under the heating condition of 5 ° C.

[0060]

[Table 4]

As is clear from the results shown in Tables 3 and 4, in the devices 201 to 203 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. 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-) was formed on an ITO glass substrate etched and washed in the same manner as in Example 1.
Ethylenedioxy) -2,5-thiophene] polystyrene sulfonic acid dispersion (manufactured by Bayer: Baytro
nP solid content 1.3%), and then spin-coated.
Vacuum drying was performed at 0 ° C. for 2 hours to form a coating layer having a thickness of 100 nm. On this, as a light emitting layer, 20 mg of poly (N-vinylcarbazole (PVK)), 20 mg of CBP, and PBD
(2- (4′-t-butylphenyl) -5- (4 ″-
A solution prepared by dissolving 12 mg of (phenyl) phenyl) -1,3,4-oxadiazole and 1 mg of TL-1 as a light emitting material in 2 ml of 1,2-dichloroethane was spin-coated. The thickness of this coating film was about 120 nm. A mask (a mask having a light-emitting area of 5 mm × 5 mm) patterned on an organic thin film is provided, and magnesium: silver = 10: 1 is co-deposited at 250 nm in a vapor deposition apparatus, and then 300 nm of silver is vapor-deposited to produce an element 301. did. EL devices 302 to 306 having exactly the same composition as the device 301 except that two comparative compounds and three compounds of the present invention were used instead of the PBD for the device 301.

[0063]

Embedded image

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.

[0065]

[Table 5]

Further, these elements were sealed in an autoclave replaced with argon gas as in Example 1, and
After storage for 10 days under the heating condition of 5 ° C., the results of the same luminance measurement and emission surface observation are shown in Table 6.

[0067]

[Table 6]

As is evident from the results in Tables 5 and 6, in the devices 301 to 303 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 large. Will drop. 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.

[0069]

By containing the compound of the present invention in a light-emitting device, a light-emitting device having durability, excellent emission luminance, and excellent maximum emission external quantum yield was realized.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07D 271/10 C07D 271/10 285/12 401/14 401/14 417/14 417/14 519/00 519 / 00 311 311 C09K 11/06 690 C09K 11/06 690 H05B 33/14 B H05B 33/14 33/22 B 33/22 C07D 285/12 A F-term (reference) 3K007 AB02 AB03 AB04 AB11 CA01 CB01 DA01 DB03 EB00 4C036 AD08 AD20 AD27 4C056 AA01 AB01 AB02 AC02 AC07 AD01 AD03 AE03 CA03 CC01 CD03 FA04 FA08 FB01 FC01 4C063 AA03 AA05 BB01 BB06 CC26 CC67 DD12 DD58 EE10 4C072 AA01 BB02 CC02 CC11 CC16 EE03 U01H01 FF03

Claims (8)

[Claims] 1. A compound represented by the general formula (1). General formula (1) X represents a group containing a condensed or non-condensed electron-deficient heteroaromatic ring. Yn is an atomic group capable of forming a three- or more-membered ring structure. Rn represents a hydrogen atom or a substituent. Rn
Is a substituent other than a hydrogen atom. n is an integer of 1 or more. Rn may be linked to Yn to form a cyclic structure. 2. In the general formula (1), X is a condensed or non-condensed nitrogen-containing 6-membered heteroaromatic ring or a condensed or non-condensed 5-membered heteroaromatic ring containing two or more heteroatoms. 2. A group containing any one of the above.
The compound according to the above. 3. The compound according to claim 1, wherein said X in the general formula (1) is bonded to Yn at a carbon atom site. 4. The compound according to claim 1, wherein n in the general formula (1) is 2 or more, and two or more of Rn are substituents other than a hydrogen atom. Compound. 5. The method according to claim 1, wherein Yn in the general formula (1) is an atomic group capable of forming a cyclic structure of an aromatic ring or a heteroaromatic ring. Compound. 6. The compound according to claim 1, wherein the compound has two or more partial structural units represented by the general formula (1) in one molecule. 7. A light-emitting element comprising at least one compound according to claim 1. Description: 8. The method according to claim 7, wherein at least one light-emitting material capable of emitting light from triplet excitons is used.
The light-emitting element according to any one of the preceding claims.