JP4711617B2 - Organic electroluminescence device - Google Patents

Description

  The present invention relates to an organic electroluminescent element (organic EL element) having high luminance, high luminous efficiency, and excellent durability.

  The organic EL element is composed of a light-emitting layer or a counter electrode sandwiching a plurality of organic layers including a light-emitting layer. The organic EL element has a light emission from excitons generated by recombination of electrons injected from the cathode and holes injected from the anode in the light emitting layer, or other molecules generated by energy transfer from the excitons. It is an element for obtaining light emission using any one of light emitted from excitons.

Although an invention related to a phosphorescent organic EL device using a metal complex as a host material has been disclosed (see Patent Document 1), its luminous efficiency and durability are not yet sufficient, and it shows further higher luminous brightness and luminous efficiency. At present, the development of a device having excellent durability is eagerly desired.
JP 2002-305083 A

  Accordingly, an object of the present invention is to provide a light-emitting element that exhibits high light emission luminance and light emission efficiency and is excellent in durability.

一般式（ＩＩ）中、Ｑ^２はピリジン環、ピラジン環、又はピリミジン環を表す。Ｘ^２は−ＮＲ^２３−を表す。Ｒ^２３はアリール基を表す。Ｚ^２はベンゼン環を表す。Ｍ^２はＢｅ^２＋、Ｍｇ^２＋、Ａｌ^３＋、Ｚｎ^２＋、Ｇａ^３＋、又はＣｕ^２＋を表す。ｎ^２は１以上の整数を表す。Ｌ^２は配位子を表し、ｍ^２は０以上の整数を表す。
〔２〕
一般式（ＩＩ）で表される化合物は、発光層中における含有率が５０％〜９９．９質量％である〔１〕に記載の有機電界発光素子。
〔３〕
前記有機電界発光素子における有機層が塗布法により形成されたことを特徴とする〔１〕又は〔２〕に記載の有機電界発光素子。
なお、本発明は特許請求の範囲に記載された構成を有するが、以下、その他についても
参考のため記載した。 The object has been achieved by the following.
[1]
An organic electroluminescent device having at least one organic layer including a light emitting layer between a pair of electrodes, wherein the light emitting layer is represented by an orthometalated complex as a phosphorescent material and the following general formula (II) An organic electroluminescent device containing at least one compound.

In the general formula (II), ^{Q 2} represents a pyridine ring, a pyrazine ring, or a pyrimidine ring. X ² represents —NR ²³ —. R ²³ represents an aryl group. Z ² represents a benzene ring. M ² represents Be ²⁺ , Mg ²⁺ , Al ³⁺ , Zn ²⁺ , Ga ³⁺ , or Cu ²⁺ . n ² represents an integer of 1 or more. L ² represents a ligand, and m ² represents an integer of 0 or more.
[2]
The compound represented by the general formula (II) is the organic electroluminescence device according to [1], in which the content in the light emitting layer is 50% to 99.9% by mass .
[3 ]
The organic electroluminescent element according to [1] or [2], wherein the organic layer in the organic electroluminescent element is formed by a coating method.
In addition, although this invention has the structure described in the claim, the following was also described for reference.

  According to the present invention, when a metal complex having a specific structure of the present invention is used as a host material in a light-emitting layer, a light-emitting element that exhibits high emission luminance, high external quantum efficiency, and excellent durability can be provided. In addition, since the metal complex of the present invention can be subjected to a coating process, the production method of the light emitting layer is simple, the energy required for production can be omitted compared with the vapor deposition method, and the man-hours are reduced. Have.

  The organic EL device of the present invention will be described in detail. The organic EL device of the present invention is an organic electroluminescent device having at least one organic layer including a light emitting layer between a pair of electrodes, and the light emitting layer includes a phosphorescent material (phosphorescent material) and a general formula. This is an organic EL device containing at least one compound represented by (I) or the general formula (V). In addition to the light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a protective layer, and the like may be disposed between the pair of electrodes. It may have other functions.

In the organic EL device of the present invention, the compound represented by formula (I) or formula (V) preferably functions as a host material. The host material is a material other than the light emitting material (phosphorescent material in the present invention) among the materials forming the light emitting layer, and has the following various functions (the above various functions):
A function of dispersing and holding the light emitting material (phosphorescent material in the present invention) in the layer;
The function of receiving holes from the anode and hole transport layer,
The ability to receive electrons from the cathode, electron transport layer, etc.
The function of transporting holes and / or electrons,
The ability to provide a field for recombination of holes and electrons,
At least one of a function of transferring the energy of excitons generated by recombination to the light emitting material and a function of transporting holes and / or electrons to the light emitting material;
Means a material having

  Among the various functions described above, the material is preferably a material having at least one function of transporting holes and / or electrons and transferring exciton energy generated by recombination to the light emitting material. More preferably, the material has one function. Further, the compounds represented by the general formulas (I) to (V) have various functions other than the function of transporting holes and / or electrons and the function of transferring the energy of excitons generated by recombination to the light emitting material. May be combined.

  The compound represented by the general formulas (I) to (V) is preferably a main component in the light emitting layer, and more preferably a main component in order to function as a host material. More specifically, the content of the compound represented by the general formulas (I) to (V) in the light emitting layer is preferably 50% to 99.9% by mass, and 60% to 99% by mass. It is more preferable.

  The host material is preferably highly stable against electrochemical oxidation and reduction because it can be electrochemically oxidized or reduced when performing the above functions. In other words, those in which the oxidizing species (eg radical cation species) and reducing species (eg radical anion species) are very stable are preferred. In addition, when recombination is performed in the host material, first, excitons of the host material are generated. Therefore, the excited state of the host material is preferably stable without causing decomposition or thermal deactivation. This also means that a host material that is stable to light is preferable. In addition, in organic EL elements, the destruction of the film due to heat generation during driving and the decomposition of the material are major factors of deterioration, so the host material is also a material that is not decomposed by heat and can hold an amorphous film that is stable to high temperatures. It is preferable.

  As described above, the host material is preferably extremely stable with respect to light, heat, and electrochemical oxidation-reduction, and when a host material that satisfies these is used, the durability of the light-emitting element is greatly improved. Can be expected.

  In consideration of the durability of the light emitting device, the glass transition temperature (Tg) of the compounds of the general formulas (I) to (V) in the present invention is preferably 130 ° C. or higher and 400 ° C. or lower, more preferably 135 ° C. The temperature is 400 ° C. or lower, more preferably 140 ° C. or higher and 400 ° C. or lower, particularly preferably 150 ° C. or higher and 400 ° C. or lower, and most preferably 160 ° C. or higher and 400 ° C. or lower. Here, Tg can be confirmed by thermal measurement such as differential scanning calorimetry (DSC) and differential thermal analysis (DTA), X-ray diffraction (XRD), observation with a polarizing microscope, and the like.

  The compounds of the general formulas (I) to (V) in the present invention are metal complexes (synonymous with the metal complexes of the present invention), and are preferably host materials. The metal species of the metal complex is not particularly limited, but is preferably a metal in the second to fourth periods, more preferably Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, more preferably Li, Be, Na, Mg, Al, Ti, Fe, Co, Ni, Cu, Zn, Ga, and more preferably Be. Mg, Al, Fe, Ni, Cu, and Zn, more preferably Be, Mg, Al, Cu, and Zn, and particularly preferably Al and Zn.

  The metal complex of the present invention may be a so-called binuclear complex having a plurality of metal ions in the same molecule. Moreover, the binuclear complex which consists of multiple types of metals may be sufficient. Moreover, you may have multiple types of ligand. The metal complex of the present invention is preferably a neutral metal complex.

A preferred first form of the organic EL device of the present invention is a form containing a compound represented by formula (I) in the light emitting layer, and preferably functions as a host material. In the general formula (I), X ¹¹ represents a nitrogen atom or C—R ¹¹ . X ¹² represents a nitrogen atom or C—R ¹² . R ¹¹ and R ¹² represent an aryl group or a group that is linked to form a heterocycle. X ¹³ represents an oxygen atom, a sulfur atom, —C (R ¹³ ) R ¹⁴ — or —NR ¹⁵ —. R ¹³ , R ¹⁴ and R ¹⁵ each represents a hydrogen atom or a substituent. Z ¹ represents an atomic group necessary for forming a 5-membered ring or a 6-membered ring. M ¹ represents a metal ion. n ¹ represents an integer of 1 or more. L ¹ represents a ligand, and m ¹ represents an integer of 0 or more.

The compound represented by formula (I) will be described in detail. X ¹¹ represents a nitrogen atom or C—R ¹¹ , and X ¹² represents a nitrogen atom or C—R ¹² . R ¹¹ and R ^{12 each} represents an aryl group or an atomic group necessary for connecting R ¹¹ and R ¹² to form a heterocycle.

When R ¹¹ and R ¹² represent an aryl group, examples of the aryl group include a phenyl group, a naphthyl group, a pyridyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a thienyl group, a furyl group, and a pyrrolyl group. A phenyl group and a pyridyl group, more preferably a phenyl group.

When R ¹¹ and R ¹² are linked to form a heterocyclic ring, the formed heterocyclic ring includes pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiophene ring, furan ring, pyrrole ring, imidazole ring. , An oxazole ring, a thiazole ring, a triazole ring, and the like, preferably a pyridine ring, a pyrazine ring, and a pyrimidine ring, more preferably a pyridine ring and a pyrazine ring, and still more preferably a pyridine ring. When R ¹¹ and R ¹² are linked to form a heterocycle, the heterocycle may form a condensed ring with another ring.

The aryl group represented by R ^11, R ^12, each of the heterocycle and R ¹¹ and R ¹² is formed by connecting may further have a substituent group, include substituent group A.

(Substituent group A)
An alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n- Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, For example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, For example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 2 carbon atoms). Particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, etc.), a substituted carbonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, especially Preferably it has 1 to 12 carbon atoms, such as acetyl, benzoyl, methoxycarbonyl, phenyloxycarbonyl, dimethylaminocarbonyl, phenylaminocarbonyl, etc.), amino group (preferably having 0 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include dimethylamino, methylcarbonylamino, ethylsulfonylamino, dimethylaminocarbonylamino group, phthalimide group, and the like, and sulfonyl groups (preferably. 1 to 20 carbon atoms, more preferably 1 to carbon atoms 6, particularly preferably having 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfo group, carboxyl group, heterocyclic group (aliphatic heterocyclic group, aromatic heterocyclic group. , An oxygen atom, a sulfur atom, or a nitrogen atom, preferably 1 to 50 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as imidazolyl, pyridyl, furyl, Piperidyl, morpholino, benzoxazolyl, triazolyl group, etc.), hydroxy group, alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, a methoxy group, a benzyloxy group, etc.), an aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 carbon atoms). To 16, particularly preferably 6 to 12, and examples thereof include a phenoxy group and a naphthyloxy group. ), Halogen atoms (preferably fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), thiol groups, alkylthio groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 1 carbon atoms). 12 such as a methylthio group, and an arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, and particularly preferably 6 to 12 carbon atoms, such as a phenylthio group). ), Cyano group, silyl group (preferably having 0 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 18 carbon atoms, such as trimethylsilyl group, triphenylsilyl group, t-butyldiphenyl And a silyl group).

X ¹³ represents an oxygen atom, a sulfur atom, —C (R ¹³ ) R ¹⁴ , — or —NR ¹⁵ —. R ¹³ , R ¹⁴ and R ¹⁵ each represents a hydrogen atom or a substituent. As the substituent represented by R ^13, R ^14, those described as substituent groups for substituting a heterocyclic group in which an aryl group represented by ^{R 11, R 12, R 11} , R 12 is formed by connecting Is applicable. R ¹³ and R ¹⁴ are preferably a hydrogen atom, an alkyl group or an aryl group, more preferably a hydrogen atom or an alkyl group, and still more preferably an alkyl group.

Examples of the substituent represented by R ¹⁵ include substituent group B.

(Substituent group B)
An alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n- Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, For example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, For example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 2 carbon atoms). Particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, etc.), a substituted carbonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, especially Preferably it is C1-C12, for example, acetyl, benzoyl, methoxycarbonyl, phenyloxycarbonyl, dimethylaminocarbonyl, phenylaminocarbonyl, etc.), a substituted sulfonyl group (preferably C1-C20, more). Preferably it is C1-C16, Most preferably, it is C1-C12, for example, a mesyl, tosyl etc. are mentioned), a heterocyclic group (an aliphatic heterocyclic group, an aromatic heterocyclic group. Preferably. , An oxygen atom, a sulfur atom, or a nitrogen atom, preferably 1 to 50 carbon atoms, more preferably carbon 30, particularly preferably 2 to 12 carbon atoms, for example imidazolyl, pyridyl, furyl, piperidyl, morpholino, benzoxazolyl, triazolyl group and the like.), And the like. R ¹⁵ is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, more preferably an alkyl group or an aryl group, and still more preferably an aryl group.

Z ¹ represents an atomic group necessary for forming a 5-membered ring or a 6-membered ring, including an atom to which the dotted line shown in the formula is bonded. Ring containing Z ¹ is as may (substituent may have a substituent substituted on the heterocyclic group aryl group or R ^11, R ¹² represented by R ^11, R ¹² is formed by connecting Those listed as substituents can be applied.) Further, they may be condensed with other rings.

Examples of the ring containing Z ¹ include cyclopentene, cyclohexene, benzene, naphthalene, anthracene, phenanthrene, pyrene, perylene, pyridine, quinoline, furan, thiophene, pyrazine, pyrimidine, thiazole, benzothiazole, naphthothiazole, oxazole, benzo Examples thereof include oxazole, naphthoxazole, isoxazole, selenazole, benzoselenazole, naphthselenazole, imidazole, benzimidazole, naphthimidazole, isoquinoline, pyrazole, triazole and the like. The ring containing Z ¹ is preferably an aromatic ring. For example, benzene, naphthalene, anthracene, pyridine, thiophene, pyrazine, and pyrimidine are preferable, benzene and naphthalene are more preferable, and benzene is more preferable.

M ¹ represents a metal ion. The metal ion is not particularly limited, but is preferably a metal ion included in the second to fourth periods of the periodic table (long period type), more preferably a divalent or trivalent metal ion, More preferred are Be ²⁺ , Mg ²⁺ , Al ³⁺ , Zn ²⁺ , Ga ³⁺ and Cu ²⁺ , and particularly preferred are Al ³⁺ , Zn ²⁺ and Ga ³⁺ .

L ¹ represents a monodentate or multidentate ligand. Examples of the ligand include halogen ions (for example, Cl ⁻ , Br ⁻ , I ^{− and the} like), perchlorate ions, and alkoxy ions (preferably having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5, for example, methoxy ion, ethoxy ion, isopropoxy ion, acetylacetonate ion and the like, aryloxy ion (preferably having 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms, still more preferably 6). -8, for example, phenoxy ion, quinolinol ion, 2- (2-hydroxyphenyl) benzoazole ion, etc.), silyloxy ion (preferably having 3-20 carbon atoms, more preferably 11-20, For example, triphenylsilyloxy ion and the like), nitrogen-containing heterocycle ( Preferably, it has 1 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, more preferably 3 to 8 carbon atoms such as phenanthrene and bipyridyl, and acyloxy ions (preferably 1 to 20 carbon atoms, more preferably 2 to 2 carbon atoms). 10, more preferably 3 to 8 and examples thereof include acetoxy ions and the like, ether compounds (preferably having 2 to 20 carbon atoms, particularly preferably 3 to 10 and further preferably 3 to 8, and tetrahydrofuran and the like. And hydroxy ions and the like. More preferred are alkoxy ions, aryloxy ions, and silyloxy ions, and particularly preferred are aryloxy ions.

n ¹ represents an integer of 1 or more, and m ¹ represents an integer of 0 or more. The preferred range of n ¹ and m ¹ varies depending on the metal ion and is not particularly limited, but n ¹ is preferably ¹ to 4, more preferably 1 to 3, and particularly preferably 2 or 3. m ¹ is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0. The combination of the numbers of n ¹ and m ¹ is preferably a combination of numbers in which the compound represented by the general formula (I) becomes a neutral complex.

The compound represented by the general formula (I) is preferably a compound represented by the general formula (II). In the general formula (II), Q ² represents an atomic group necessary for forming a heterocycle, including an atom to which the dotted line shown in the formula is bonded. X ² represents an oxygen atom, a sulfur atom, —C (R ²¹ ) R ²² — or —NR ²³ —. R ²¹ , R ²² and R ²³ represent a hydrogen atom or a substituent. Z ² represents an atomic group necessary for forming a 5-membered ring or a 6-membered ring, including the atom to which the dotted line shown in the formula is bonded. M ² represents a metal ion. n ² represents an integer of 1 or more. L ² represents a ligand, and m ² represents an integer of 0 or more.

Q ² represents an atomic group necessary for forming a heterocycle. Q ² is preferably an atomic group necessary for forming a 5-membered or 6-membered heterocycle, and is preferably an atomic group necessary for forming a 5-membered or 6-membered nitrogen-containing heterocycle. More preferred. The heterocycle formed by Q ² is preferably one containing a nitrogen atom, an oxygen atom or a sulfur atom. For example, a pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiophene ring, furan ring, pyrrole ring, Examples include an imidazole ring, an oxazole ring, a thiazole ring, and a triazole ring, preferably a pyridine ring, a pyrazine ring, and a pyrimidine ring, more preferably a pyridine ring and a pyrazine ring, and still more preferably a pyridine ring. Q ² is a substituent as may (substituent group which may have a substituent substituted on the heterocyclic group aryl group or R ¹¹ is represented by R ^11, R ^12, R ¹² is formed by connecting The above can be applied), and may be condensed with other rings.

X ² , R ²¹ , R ²² , R ²³ , Z ² , M ² , L ² , n ² , and m ² are X ¹³ , R ¹³ , R ¹⁴ , R ¹⁵ , Z ¹ , in general formula (I), respectively. M ^1, is L ^1, n ^1, m ¹ synonymous, and preferred ranges are also the same.

The compound represented by the general formula (II) is preferably a compound represented by the general formula (III). In the general formula (III), Q ³ represents an atomic group necessary for forming a 6-membered nitrogen-containing heterocycle including the atom to which the dotted line shown in the formula is bonded. The 6-membered nitrogen-containing heterocycle is preferably a pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring or triazine ring, preferably a pyridine ring, pyrazine ring or pyrimidine ring, more preferably a pyridine ring or pyrazine ring. More preferably a pyridine ring. X ³ represents an oxygen atom, a sulfur atom, —C (R ³¹ ) R ³² — or —NR ³³ —. R ³¹ , R ³² and R ³³ represent a hydrogen atom or a substituent. R ³⁴ , R ³⁵ , R ³⁶ and R ³⁷ represent a hydrogen atom or a substituent. M ³ represents a metal ion. n ³ represents an integer of 1 or more. L ³ represents a ligand, and m ³ represents an integer of 0 or more.

Q ³ , X ³ , R ³¹ , R ³² , R ³³ , M ³ , L ³ , n ³ , and m ³ are respectively Q ² in general formula (II) and X ¹³ , R ^{13 in} general formula (I). , R ¹⁴ , R ¹⁵ , M ¹ , L ¹ , n ¹ , m ¹ , and the preferred range is also the same.

R ³⁴ , R ³⁵ , R ³⁶ and R ³⁷ represent a hydrogen atom or a substituent. These substituents may be bonded to each other to form a condensed ring. As the substituent, those exemplified as the substituent substituted on the aryl group represented by R ¹¹ and R ¹² in the general formula (I) and the heterocyclic group formed by linking R ¹¹ and R ¹² can be applied. . R ³⁴ , R ³⁵ , R ³⁶ and R ³⁷ are preferably a hydrogen atom, alkyl group, aryl group, cyano group, fluoro group, perfluoro-substituted alkyl group, heterocyclic group, amino group, alkoxy group, aryloxy group, R ^{34 to} R ³⁶ are bonded to each other to form a condensed ring, more preferably a hydrogen atom, an alkyl group, a fluoro group, or a perfluoro-substituted alkyl group, and still more preferably a hydrogen atom, an alkyl group, or a fluoro group. Particularly preferred is a hydrogen atom.

The compound represented by the general formula (III) is preferably a compound represented by the general formula (IV). In the general formula (IV), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁷ and R ⁴⁸ represent a hydrogen atom or a substituent. M ⁴ represents a divalent or trivalent metal ion. n ⁴ represents an integer of 1-3. L ⁴ represents a ligand, and m ⁴ represents an integer of 0 to 2.

R ⁴¹ , R ⁴² and R ⁴³ each represents a hydrogen atom or a substituent. These substituents may be bonded to each other to form a condensed ring. As the substituent, those exemplified as the substituent substituted on the aryl group represented by R ¹¹ and R ¹² in the general formula (I) and the heterocyclic group formed by linking R ¹¹ and R ¹² can be applied. . R ⁴¹ , R ⁴² and R ⁴³ are preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a fluoro group, a perfluoro-substituted alkyl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, R ^{34 to} R ³⁶ are bonded to each other to form a condensed ring, more preferably a hydrogen atom or an alkyl group, and still more preferably a hydrogen atom.

R ⁴⁵ , R ⁴⁶ , R ⁴⁷ , R ⁴⁸ , R ⁴⁴ , M ⁴ , L ⁴ , n ⁴ , and m ⁴ are R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , general formula (III) in general formula (III), respectively. It is synonymous with R ¹⁵ , M ¹ , L ¹ , n ¹ and m ^{1 in} I), and the preferred range is also the same.

  Specific examples of the compounds represented by the general formulas (I) to (IV) are listed below, but the present invention is not limited thereto.

A preferred second form of the organic EL device of the present invention is a form containing a compound represented by the general formula (V) in the light emitting layer, and preferably functions as a host material. In the general formula (V), R ⁵³ represents a hydrogen atom or a substituent. X ⁵¹ represents a nitrogen atom or C—R ⁵¹ . X ⁵² represents a nitrogen atom or C—R ⁵² . R ⁵¹ and R ⁵² represent a hydrogen atom or a substituent. Z ⁵ represents an atomic group necessary for forming a 5-membered ring or a 6-membered ring, including the atom to which the dotted line shown in the formula is bonded. M ⁵ represents a metal ion. n ⁵ represents an integer of 1 or more. L ⁵ represents a ligand, and m ⁵ represents an integer of 0 or more.

R ⁵³ represents a hydrogen atom or a substituent. As the substituent, those exemplified as the substituent substituted on the aryl group represented by R ¹¹ and R ¹² in the general formula (I) and the heterocyclic group formed by linking R ¹¹ and R ¹² can be applied. . R ⁵³ is preferably a hydrogen atom, an alkyl group, an aryl group, or an aromatic heterocyclic group, more preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and further preferably an aryl group.

X ⁵¹ represents a nitrogen atom or C—R ⁵¹ , and X ⁵² represents a nitrogen atom or C—R ⁵² . R ⁵¹ and R ⁵² represent a hydrogen atom or a substituent. R ⁵¹ and R ⁵² may combine with each other to form a 5-membered or 6-membered heterocyclic group, aryl group, or heteroaryl group. As the substituent, those exemplified as the substituent substituted on the aryl group represented by R ¹¹ and R ¹² in the general formula (I) or the heterocyclic group formed by linking R ¹¹ and R ¹² are applied. it can. R ⁵¹ and R ⁵² are preferably a hydrogen atom, an alkyl group, an aryl group, an aromatic heterocyclic group, a group that is bonded to each other to form an aromatic hydrocarbon ring, or a group that is bonded to each other to form an aromatic heterocyclic group. More preferably a hydrogen atom, an alkyl group, an aryl group, a group that is bonded to each other to form an aromatic hydrocarbon ring, a group that is bonded to each other to form an aromatic heterocyclic group, and more preferably a hydrogen atom An atom, an aryl group, or a group that is bonded to each other to form an aromatic heterocycle.

Z ⁵ , M ⁵ , L ⁵ , n ⁵ and m ⁵ have the same meanings as Z ¹ , M ¹ , L ¹ , n ¹ and m ¹ in the general formula (I), respectively, and preferred ranges are also the same.

  Specific examples of the compound represented by the general formula (V) are listed below, but the present invention is not limited thereto.

  The organic EL device of the present invention utilizes light emission from an excited triplet state using a phosphorescent material as a guest material in the light emitting layer. Light emission from the excited triplet state is synonymous with phosphorescence emission. Hereinafter, the phosphorescent material is referred to as “phosphorescent material”. The light emitting device of the present invention contains at least one phosphorescent material. The phosphorescent material used in the present invention is not particularly limited, but a transition metal complex is preferable. The central metal of the transition metal complex is not particularly limited, but is preferably iridium, platinum, rhenium, or ruthenium, more preferably iridium or platinum, and particularly preferably iridium. Among the transition metal complexes, orthometalated complexes are preferable, and orthocarbometalated complexes are preferable. Orthometalated Complex is “Organic Metal Fundamentals and Applications” written by Yamamoto Akio, pages 150 and 232, Hankabosha (1982) and “Photochemistry and Photophysics of Coordination Compound” by H. Yersin, It is a general term for a group of compounds described in pages 71 to 77 and pages 135 to 146, Springer-Verlag (1987) and the like.

  The light emitting element of the present invention is characterized in that the light emitting layer contains a phosphorescent material as a light emitting material and a metal complex material as a host material. The phosphorescent material may be used alone or in combination of two or more, and the host material may be used alone or in combination of two or more.

  In the organic EL device of the present invention, it is preferable that the light emitting layer is composed of only a phosphorescent material and the compounds represented by the general formulas (I) to (V). The content ratio (mass ratio) of the compound represented by the general formulas (I) to (V) and the phosphorescent material in the light emitting layer is preferably 50:50 to 99.99: 0.01, 70: 30-99.9: 0.1 is more preferable, and 80: 20-99: 1 is further more preferable.

  The phosphorescent material preferably has a phosphorescent quantum yield of 20 ° C. or higher of 70% or higher, more preferably 80% or higher, and still more preferably 85% or higher.

  Examples of the phosphorescent material include US 6303231 B1, US 6097147, WO 00/57676, WO 00/70655, WO 01/08230, WO 01/39234 A2, WO 01/41512 A1, WO 02/02714 A2, and WO 02. / 15645 A1, Japanese Patent Application Laid-Open No. 2001-247859, Japanese Patent Application No. 2000-33561, Japanese Patent Application No. 2001-189539, Japanese Patent Application No. 2001-248165, Japanese Patent Application No. 2001-339684, Japanese Patent Application No. 2001-239281, Japanese Patent Application No. 2001-219909, EP 12112257 JP 2002-226495, JP 2002-234894, JP 2001-247659, JP 2001-298470, JP 2002-173684, JP 2002-203678, JP 2002-203 679 et al., Nature, 395, 151 (1998), Applied Physics Letters, 75, 4 (1999), Polymer Preprints, 41, 770 (2000), Journal of American Chemical. Those described in non-patent literature such as Society, 123, 4304 (2001), Applied Physics Letters, 79, 2082 (1999) can be suitably used.

  There are no particular limitations on the system, driving method, mode of use, etc. of the light emitting device of the present invention.

  The method for forming the organic compound layer in the light emitting device of the present invention is not particularly limited, and resistance heating vapor deposition, electrophotography, electron beam, sputtering, molecular lamination, coating (spray coating, dip coating, impregnation) Method, roll coat method, gravure coat method, reverse coat method, roll brush method, air knife coat method, curtain coat method, spin coat method, flow coat method, bar coat method, micro gravure coat method, air doctor coat, blade coat Methods, squeeze coating methods, transfer roll coating methods, kiss coating methods, cast coating methods, extrusion coating methods, wire bar coating methods, screen coating methods, etc.), inkjet methods, printing methods, transfer methods, and the like. Among these, the resistance heating vapor deposition method, the coating method, and the transfer method are preferable in consideration of the characteristics of the element, the ease of manufacture, the cost, and the like. When the light-emitting element has a stacked structure of two or more layers, it can be manufactured by combining the above methods.

  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, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N-vinylcarbazole). , Hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicon resin and the like.

  The light-emitting device of the present invention includes at least a light-emitting layer, but may additionally have a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, etc. as these organic layers. Each layer may be provided with other functions. Details of each layer will be described below.

  The material of the hole injection layer and the hole transport layer has any one of the function of injecting holes from the anode, the function of transporting holes, and the function of blocking electrons injected from the cathode. Specific examples include carbazole, imidazole, triazole, oxazole, oxadiazole, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic Tertiary amine compounds, styrylamines, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organic metals Complex, transition metal Body, or derivatives of the above compounds.

  The film 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 500 nm. . 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.

  The material for the electron injection layer and the electron transport layer may be any material that has any one of the function of injecting electrons from the cathode, the function of transporting electrons, and the function of blocking holes injected from the anode. . Specific examples thereof include, for example, triazole, triazine, oxazole, oxadiazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, silole, naphthaleneperylene, and the like. Aromatic metal tetracarboxylic anhydrides, phthalocyanines, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, various metal complexes represented by metal complexes having benzoxazole or benzothiazole as ligands, or derivatives of the above compounds Can be mentioned.

  Although the film thickness of an electron injection layer and an electron carrying layer is not specifically limited, The thing of the range of 1 nm-5 micrometers is preferable normally, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm. The electron injection layer and the electron transport layer may have a single layer structure made of one or more of the above-described materials, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

  The light emitting layer in the present invention contains at least one phosphorescent material and at least one metal complex, but a plurality of other materials may be used in combination. Examples of materials used in the light emitting layer include benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, coumarin, perylene, perinone, oxadiazole, aldazine, pyralidine, and cyclopentadiene. Bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, styrylamine, aromatic dimethylidin compounds, polythiophene, polyphenylene, polyphenylene vinylene, and other polymer compounds, or derivatives of the above compounds.

  The light emitting layer may be a single layer or a multilayer of two or more layers. When there are a plurality of light emitting layers, each layer may emit different light emission colors. Even when there are a plurality of light emitting layers, each light emitting layer is preferably composed only of a phosphorescent material and a metal complex. Although the film thickness of a light emitting layer is not specifically limited, Usually, the thing of the range of 1 nm-5 micrometers is preferable, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm.

As the material for the protective layer, any material may be used as long as it has a function of preventing the material that promotes device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychloro Trifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer, and a copolymer main chain A fluorine-containing copolymer having a cyclic structure, a water-absorbing substance having a water absorption rate of 1% or more, Examples include moisture-proof substances having a water content of 0.1% or less. There is no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation ions) Plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, ink jet method, printing method, transfer method, and electrophotographic method can be applied.

  The anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used, preferably Is 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), metals such as gold, silver, chromium and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as laminates, copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and mixtures and laminates of these with ITO, It is a conductive metal oxide, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like. Although the film thickness of the anode can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 500 nm.

  As the anode, a layer formed on a soda-lime glass, non-alkali glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. However, when glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating vapor deposition method, an ion plating method, a chemical reaction method (sol-gel method, etc.), a spray method, etc. A film is formed by a method such as dipping, thermal CVD, plasma CVD, or ITO dispersion coating. The anode can be subjected to cleaning and other treatments to lower the drive voltage of the element and increase the light emission efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment, etc. are effective.

  The cathode supplies electrons to the electron injection layer, the electron transport layer, the light emitting layer, etc., and the adhesion, ionization potential, stability, etc. between the cathode and the adjacent layer such as the electron injection layer, electron transport layer, light emitting layer, etc. Selected in consideration of As a material for the cathode, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples include alkali metals (for example, Li, Na, K, Cs, etc.) or fluorides thereof, Alkaline earth metal (eg, Mg, Ca, etc.) or fluorides thereof, gold, silver, lead, aluminum, sodium-potassium alloy, or a mixed metal thereof, lithium-aluminum alloy, or a mixed metal thereof, magnesium-silver alloy Or a mixed metal thereof, or a rare earth metal such as indium or ytterbium, preferably a material having a work function of 4 eV or less, more preferably aluminum, a lithium-aluminum alloy, or a mixed metal thereof, a magnesium-silver alloy Or a mixed metal thereof. The film 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, still more preferably 100 nm to 1 μm. A method such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, or a coating method is used for producing the cathode, and a metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. Furthermore, a plurality of metals can be vapor-deposited simultaneously to form an alloy electrode, or a previously prepared alloy may be vapor-deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

  The organic layer of the light-emitting element of the present invention preferably has a three-layer structure of a hole transport layer, a light-emitting layer, and an electron transport layer, or a four-layer structure provided with a hole block layer.

  The light-emitting element of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer / organic layer, etc. It is possible to improve light extraction efficiency and external quantum efficiency.

  The light-emitting element of the present invention may be a so-called top emission type in which light emission is extracted from the anode side.

  The substrate used in the light-emitting device of the present invention is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, and polyethersulfone. , Polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon, polytetrafluoroethylene-polyethylene copolymer, and the like.

  The light emitting layer of the organic electroluminescent element of the present invention may have at least one laminated structure. The number of stacked layers is preferably 2 or more and 50 or less, more preferably 4 or more and 30 or less, and still more preferably 6 or more and 20 or less.

  The thickness of each layer constituting the stack is not particularly limited, but is preferably 0.2 nm or more and 20 nm or less, more preferably 0.4 nm or more and 15 nm or less, further preferably 0.5 nm or more and 10 nm or less, and particularly preferably 1 nm or more and 5 nm or less. .

  The light emitting layer of the organic electroluminescent element of the present invention may have a plurality of domain structures. The light emitting layer may have another domain structure. The diameter of each domain is preferably from 0.2 nm to 10 nm, more preferably from 0.3 nm to 5 nm, further preferably from 0.5 nm to 3 nm, particularly preferably from 0.7 nm to 2 nm.

  The organic EL element of the present invention can be suitably used for display elements, displays, backlights, electrophotography, illumination light sources, recording light sources, exposure light sources, reading light sources, signs, signboards, interiors, optical communications, and the like.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

(Comparative Example 1)
The cleaned ITO substrate is put in a vapor deposition apparatus, and TPD (N, N′-diphenyl-N, N′-di (m-tolyl) benzidine) is vapor-deposited by 50 nm, and Alq and Ir (ppy) ₃ are 17 thereon. The film was deposited at a mass ratio of 1 to 36 nm, and the compound a was further deposited to 36 nm. A patterned mask (with a light emission area of 4 mm × 5 mm) was placed on the obtained organic thin film, and after 3 nm of lithium fluoride was deposited, 60 nm of aluminum was deposited to prepare an organic EL device of Comparative Example 1.

Using the source measure unit 2400 manufactured by Toyo Technica, the obtained organic EL element was applied with a constant DC voltage to emit light, and the luminance was measured by Topcon's luminance meter BM-8. The emission wavelength and CIE chromaticity coordinates were expressed in Hamamatsu. Measurement was performed using a spectrum analyzer PMA-11 manufactured by Photonics. As a result, green light emission having a CIE chromaticity of (x, y) = (0.324, 0.557), an emission peak wavelength of 530 nm, a maximum luminance of 1300 cd / m ² , and an external quantum efficiency of 0.22 is obtained. %Met.

(Comparative Example 2)
An organic EL device of Comparative Example 2 was produced in the same manner as Comparative Example 1 except that the following compound CBP was used instead of Alq. As a result of evaluating the organic EL device of Comparative Example 2 in the same manner as in Comparative Example 1, green light emission with CIE chromaticity of (x, y) = (0.276, 0.630) and emission peak wavelength of 516 nm was obtained. The maximum luminance was 27000 cd / m ² and the external quantum efficiency was 12.7%.

(Comparative Example 3)
In the same manner as in Comparative Example 1 except that the following compound H-4 (compound (H-4) described in paragraph No. [0034] of JP-A-2002-305083) is used instead of Alq, The organic EL element of Example 3 was produced. As a result of evaluating the organic EL device of Comparative Example 3 in the same manner as in Comparative Example 1, green light emission with CIE chromaticity of (x, y) = (0.286, 0.624) and emission peak wavelength of 522 nm was obtained. The maximum luminance was 21000 cd / m ² and the external quantum efficiency was 11.4%.

An organic EL device of Example 1 was produced in the same manner as Comparative Example 1 except that Exemplified Compound 1 was used instead of Alq. As a result of evaluating the organic EL device of Example 1 in the same manner as in Comparative Example 1, green light emission having a CIE chromaticity of (x, y) = (0.320, 0.615) and an emission peak wavelength of 524 nm was obtained. The maximum luminance was 83000 cd / m ² and the external quantum efficiency was 19.7%.

An organic EL device of Example 2 was produced in the same manner as Comparative Example 1 except that Example Compound 2 was used instead of Alq. As a result of evaluating the organic EL device of Example 2 in the same manner as in Comparative Example 1, green light emission with CIE chromaticity of (x, y) = (0.300, 0.621) and emission peak wavelength of 517 nm was obtained. The maximum luminance was 53000 cd / m ² and the external quantum efficiency was 23.1%.

  From the results of Examples 1 and 2 and Comparative Examples 1 to 3, in the phosphorescent organic EL device, when the metal complex of the present invention is used as a host material, the luminance and efficiency are superior to those of conventional organic EL devices. It turns out that an organic EL element is obtained.

An organic EL device of Example 3 was produced in the same manner as in Comparative Example 1 except that Exemplified Compound 4 was used instead of Alq. As a result of evaluating the organic EL device of Example 3 in the same manner as in Comparative Example 1, green light emission with CIE chromaticity of (x, y) = (0.300, 0.631) and emission peak wavelength of 517 nm was obtained. The maximum luminance was 64000 cd / m ² and the external quantum efficiency was 23.9%.

An organic EL device of Example 4 was produced in the same manner as Comparative Example 1 except that Exemplified Compound 21 was used in place of Alq. As a result of evaluating the organic EL device of Example 4 in the same manner as in Comparative Example 1, green light emission having a CIE chromaticity of (x, y) = (0.299, 0.619) and an emission peak wavelength of 518 nm was obtained. The maximum luminance was 46000 cd / m ² and the external quantum efficiency was 18.8%.

The cleaned ITO substrate is put in a vapor deposition apparatus, and TPD (N, N′-diphenyl-N, N′-di (m-tolyl) benzidine) is deposited to a thickness of 50 nm. On this, exemplary compound 1, exemplary compound 2 and Ir ( ppy) ₃ was evaporated at a mass ratio of 9: 9: 1 to 36 nm, and further compound a was evaporated to 36 nm thereon. A patterned mask (with a light emitting area of 4 mm × 5 mm) was placed on the obtained organic thin film, lithium fluoride was deposited to 3 nm, and then aluminum was deposited to 60 nm to produce an organic EL device of Example 5. As a result of evaluating the organic EL device of Example 5 in the same manner as in Comparative Example 1, green light emission with a CIE chromaticity of (x, y) = (0.304, 0.630) and an emission peak wavelength of 516 nm was obtained. The maximum luminance was 72000 cd / m ² and the external quantum efficiency was 20.5%.

  From the results of Examples 1 to 5 and Comparative Examples 1 to 3, in the phosphorescent organic EL device, when the metal complex of the present invention is used as a host material, the luminance and efficiency are superior to those of conventional organic EL devices. It turns out that an organic EL element is obtained.

  In the organic EL elements of Examples 1 to 5 and Comparative Example 2, when the luminance half time combined with the initial luminance was measured, the organic EL element of Comparative Example 2 was 8 hours. The organic EL device was 85 hours, the organic EL device of Example 2 was 79 hours, the device of Example 3 was 111 hours, the device of Example 4 was 59 hours, and the device of Example 5 was 144 hours.

  From the results of Example 6 above, it can be seen that when the metal complex material of the present invention is used in the phosphorescent organic EL device, an organic EL device having excellent driving durability can be obtained.

On the cleaned ITO substrate, Baytron P (PEDOT-PSS (polyethylenedioxythiophene-polystyrenesulfonic acid dope) dispersion / manufactured by Bayer) was applied by spin coating, and then vacuum-heated and dried at 100 ° C. for 1 hour. A hole injection layer (film thickness of about 50 nm) was laid. On top of this, 10 mg of polycarbonate resin Z, 25 mg of Exemplified Compound 1 and ₃ mg of Ir (ppy) ₃ were dissolved in 3 mL of dichloroethane by spin coating (2000 rpm for 30 seconds). The total thickness of the organic layer was 150 nm. A cathode was vapor-deposited in the same manner as in Comparative Example 1 to produce an organic EL device of Example 7. As a result of evaluating the organic EL device of Example 7 in the same manner as in Comparative Example 1, green light emission with CIE chromaticity of (x, y) = (0.304, 0.630) and emission peak wavelength of 516 nm was obtained. The maximum luminance was 23500 cd / m ² and the external quantum efficiency was 14.9%.

  From the result of Example 7, it was found that the phosphorescent organic EL device using the metal complex of the present invention as a host material can obtain a light-emitting device with high luminance and high efficiency even when the device is manufactured by a coating process. .

Claims (3)

An organic electroluminescent device having at least one organic layer including a light emitting layer between a pair of electrodes, wherein the light emitting layer is represented by an orthometalated complex as a phosphorescent material and the following general formula (II) An organic electroluminescent device containing at least one compound.

In the general formula (II), ^{Q 2} represents a pyridine ring, a pyrazine ring, or a pyrimidine ring. X ² represents —NR ²³ —. R ²³ represents an aryl group. Z ² represents a benzene ring. M ² represents Be ²⁺ , Mg ²⁺ , Al ³⁺ , Zn ²⁺ , Ga ³⁺ , or Cu ²⁺ . n ² represents an integer of 1 or more. L ² represents a ligand, and m ² represents an integer of 0 or more.   The organic electroluminescent element according to claim 1, wherein the compound represented by the general formula (II) has a content in the light emitting layer of 50% to 99.9% by mass. The organic electroluminescence device according to claim 1 or 2, characterized in that the organic layer in the organic light emitting device is formed by a coating method.