JP2009267244A - Organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroluminescent element which has high luminous efficiency and superior durability. <P>SOLUTION: The organic electroluminescent element has an organic layer including at least a light-emitting layer between a pair of electrodes, the organic layer containing a compound expressed by general formula (I). In general formula (I), M represents a bivalent metal ion. Z<SP>11</SP>represents a nitrogen atom or phosphorus atom. Z<SP>12</SP>and Z<SP>13</SP>each represents an atom selected from among a carbon atom, a nitrogen atom, and a phosphorus atom. A<SP>10</SP>to A<SP>19</SP>are each independently C-R or N. R is a hydrogen atom or substituent. Y<SP>11</SP>to Y<SP>13</SP>are each an atom selected to form a five-membered aromatic heterocycle together with Z11 and a carbon atom. L<SP>1</SP>is a bivalent coupling group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent device (hereinafter also referred to as “organic EL device” or “device”) that can emit light by converting electric energy into light, and particularly has excellent luminescent properties and durability. It relates to an element.

  Organic electroluminescent elements (organic EL elements) are actively researched and developed because they can emit light with high brightness when driven at a low voltage. An organic electroluminescent element has an organic layer between a pair of electrodes, and electrons injected from the cathode and holes injected from the anode recombine in the organic layer, and the generated exciton energy is used for light emission. To do.

In recent years, the use of phosphorescent light emitting materials has led to higher efficiency of devices. Known phosphorescent materials include iridium complexes and platinum complexes (see, for example, Patent Documents 1 and 2).
As other phosphorescent materials, metal complexes having a tridentate or higher multidentate ligand are known (see, for example, Patent Documents 3 to 6).

On the other hand, as an organic EL element using a deuterated material, a technique described in Patent Document 7 is known. It is described that excellent light emission characteristics and thermal stability can be obtained by using the deuterated material described in Patent Document 7.
US Pat. No. 6,303,238 International Publication No. 00/57676 Pamphlet International Publication No. 04/108857 Pamphlet JP 2005-310733 A JP 2006-261623 A WO05 / 42444 pamphlet International Publication No. 02/47440 Pamphlet

In the field of organic EL devices, development of phosphorescent materials having higher efficiency and higher durability is desired.
An object of the present invention is to provide an organic electroluminescent device having high luminous efficiency and excellent durability.

  As a result of investigations to solve the above problems, the present inventors have found that a ligand that forms a complex with a divalent metal ion is a 5-membered ring neutral ligand and a 6-membered ring anionic ligand. A tetradentate formed by linking a bidentate ligand consisting of a bidentate ligand consisting of a 6-membered neutral ligand and a 6-membered anionic ligand at a specific site It has been found that an organic electroluminescent device containing a metal complex as a ligand in an organic layer solves the above problem. That is, the above problem can be solved by the following means.

[1] An organic electroluminescent element having an organic layer including at least a light emitting layer between a pair of electrodes, wherein the organic layer contains a compound represented by the following general formula (I): Light emitting element.

(In general formula (I), M represents a divalent metal ion. Z ¹¹ represents a nitrogen atom or a phosphorus atom. Z ¹² and Z ¹³ represent an atom selected from a carbon atom, a nitrogen atom, and a phosphorus atom. , When Z ¹² is a carbon atom, Z ¹³ represents a nitrogen atom or a phosphorus atom, and when Z ¹² is a nitrogen atom or a phosphorus atom, Z ¹³ represents a carbon atom, and the bond between M and Z ¹¹ is a coordinate bond And a bond between M and Z ^{12 to} Z ¹³ represents a coordination bond or a covalent bond, A ^{10 to} A ¹⁹ each independently represents C—R or N. R represents a hydrogen atom or a substituent. Y ^{11 to} Y ¹³ are atoms selected so as to form a 5-membered aromatic heterocycle together with Z ¹¹ and a carbon atom, and L ¹ represents a divalent linking group.
[2] The organic electroluminescent element as described in [1] above, wherein M is platinum ion.
[3] The organic electroluminescent element as described in [1] or [2] above, wherein Z ¹¹ and Z ¹³ are nitrogen atoms, and Z ¹² is a carbon atom.
[4] The organic electroluminescent element as described in any one of [1] to [3], wherein L ¹ is a divalent linking group composed of a single atom which may have a substituent.
[5] The organic electroluminescence device as described in any one of [1] to [4], wherein two of Y ^{11 to} Y ¹³ are carbon atoms.
[6] The organic electroluminescence according to any one of [1] to [5], wherein the compound represented by the general formula (I) is a compound represented by the following general formula (II): element.

(In the general formula (II), A ^{20 to} A ²⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. L ² represents a single atom which may have a substituent. Y ²¹ to Y ²³ are atoms selected from a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom so as to form a 5-membered aromatic heterocycle together with the nitrogen atom and the carbon atom. In the case of a carbon atom and a nitrogen atom, they may have a substituent.)
[7] The organic electroluminescent element as described in any one of [1] to [6], wherein the light emitting layer contains a compound represented by the general formula (I).
[8] The organic electroluminescent element as described in any one of [1] to [7], wherein the compound represented by the general formula (I) is contained in an organic layer between the light emitting layer and the cathode.
[9] The organic electroluminescent element as described in any one of [1] to [8], wherein the compound represented by the general formula (I) is contained in an organic layer between the light emitting layer and the anode.
[10] The organic electroluminescent element as described in any one of [1] to [9] above, wherein a material having at least one deuterium atom is contained in at least one of the organic layers.
[11] The organic electric field according to [10], wherein the material having at least one deuterium atom is a material containing either a carbazole skeleton or an indole skeleton having at least one deuterium atom. Light emitting element.

  Since the organic electroluminescent device of the present invention is excellent in external quantum efficiency and durability, display device, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source, sign, signboard, interior, It can be suitably used for optical communication and the like.

Hereinafter, preferred embodiments of the organic EL element according to the present invention will be described.
The organic EL device according to the present invention has an organic layer including at least a light emitting layer between a pair of electrodes. The organic layer may be a layer made of only an organic compound or a layer containing both an organic compound and an inorganic compound. The organic layer may include a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a hole block layer, an electron block layer, an exciton block layer and the like in addition to the light emitting layer. Each layer may have other functions. Each layer may be formed of a plurality of layers.

  As an aspect of stacking the organic layers, an aspect in which the hole transport layer, the light emitting layer, and the electron transport layer are stacked in this order from the anode side is preferable. Furthermore, a charge blocking layer or the like may be provided between the hole transport layer and the light-emitting layer and / or between the light-emitting layer and the electron transport layer. A hole injection layer may be provided between the anode and the hole transport layer, and an electron injection layer may be provided between the cathode and the electron transport layer.

At least one of the organic layers contains the metal complex represented by the general formula (I).
The function of the metal complex represented by the general formula (I) is not limited, and can be used as a light-emitting material, a host material, an exciton block material, a charge block material, or a charge transport material. Of these, the use as a light emitting material, a host material, and a charge transport material is more preferable, the use as a light emitting material and a host material is still more preferable, and the use as a light emitting material is most preferable.

  Moreover, the layer containing the compound represented by the general formula (I) can be contained in any of the organic layers described above. As a preferred embodiment, the compound represented by the general formula (I) is contained in the light emitting layer, contained in the organic layer between the light emitting layer and the cathode, or contained in the organic layer between the light emitting layer and the anode. Is mentioned.

When the compound represented by the general formula (I) is contained in the light emitting layer, it is more preferably contained in the light emitting layer as the light emitting material or the host material, and further preferably contained in the light emitting layer as the light emitting material, It is particularly preferable that it is contained in the light emitting layer together with at least one kind of host material.
When contained in the light emitting layer as a light emitting material, the content of the compound represented by the general formula (I) is preferably in the range of 0.1% by mass to 50% by mass with respect to the total mass of the light emitting layer. From the viewpoint of durability and external quantum efficiency, the range of 1% by mass to 50% by mass is more preferable, and the range of 2% by mass to 40% by mass is more preferable.

When the compound represented by the general formula (I) is contained in the organic layer located between the light emitting layer and the cathode, it is contained in the electron transport layer, the electron injection layer, the exciton block layer, the hole block layer, etc. There is a case. When contained in these layers, it can be used together with an electron transporting material described later.
When included in the electron transport layer and the electron injection layer, the content thereof is preferably in the range of 0.1% by mass to 99% by mass with respect to the total mass of the compound forming the layer, and has durability and external quantum efficiency. In view of the above, the range of 5% by mass to 70% by mass is more preferable, and the range of 5% by mass to 45% by mass is more preferable.
When used as an exciton blocking layer or a hole blocking layer, the content thereof is preferably in the range of 30% by mass to 100% by mass with respect to the total mass of the compound forming the layer, and is 50 from the viewpoint of external quantum efficiency. The range of mass% to 100 mass% is more preferable, and the range of 70 mass% to 100 mass% is more preferable.

The compound represented by the general formula (I) is contained in a hole injection layer, a hole transport layer, an exciton block layer, an electron block layer, etc. May be included. When contained in these layers, it can be used together with a hole transporting material described later.
When included in the hole injection layer and the hole transport layer, the content thereof is preferably in the range of 0.1% by mass to 99% by mass with respect to the total compound mass forming the layer. From the viewpoint of quantum efficiency, the range of 5% by mass to 70% by mass is more preferable, and the range of 5% by mass to 45% by mass is more preferable.
When used as an exciton block layer or an electron block layer, the content is preferably in the range of 30% by mass to 100% by mass with respect to the total mass of the compound forming the layer, and 50% from the viewpoint of external quantum efficiency. % To 100% by mass is more preferable, and 70% to 100% by mass is more preferable.

The compound represented by formula (I) will be described.
In the general formula (I), a coordination bond is a bond formed by a neutral ligand having no charge and a metal, such as a lone pair of electrons on the nitrogen atom of an azole or pyrizone. It is to be combined. The covalent bond is a bond formed by a metal having a monovalent negative charge and a metal, for example, an anionic state in which hydrogen ions (H ⁺ ) are dissociated from C—H bonds or N—H bonds. This is a bond formed by the atom and metal.

In general formula (I), M represents a divalent metal ion. Z ¹¹ represents a nitrogen atom or a phosphorus atom. Z ¹² and Z ¹³ represent an atom selected from a carbon atom, a nitrogen atom, and a phosphorus atom. When Z ¹² is a carbon atom, Z ¹³ represents a nitrogen atom or a phosphorus atom, and Z ¹² represents a nitrogen atom or a phosphorus atom. In the case, Z ¹³ represents a carbon atom. The bond between M and Z ¹¹ represents a coordination bond, and the bond between M and Z ^{12 to} Z ¹³ represents a coordination bond or a covalent bond. A ^{10 to} A ¹⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. Y ^{11 to} Y ¹³ are atoms selected so as to form a 5-membered aromatic heterocycle together with Z ¹¹ and a carbon atom. L ¹ represents a divalent linking group.

  M represents a divalent metal ion. Although it does not specifically limit as a bivalent metal ion, Platinum ion, palladium ion, nickel ion, ruthenium ion, copper ion, zinc ion etc. are mentioned, Platinum ion, palladium ion, copper ion, zinc ion are preferred, platinum ion Copper ions are more preferable, and platinum ions are particularly preferable.

Z ¹¹ represents a nitrogen atom or a phosphorus atom, and is preferably a nitrogen atom.
Z ¹² and Z ¹³ are selected from a carbon atom, a nitrogen atom, and a phosphorus atom. When Z ¹² is a carbon atom, Z ¹³ represents a nitrogen atom or a phosphorus atom, and when Z ¹² is a nitrogen atom or a phosphorus atom, Z ¹³ represents a carbon atom. Z ¹² is preferably a carbon atom or a nitrogen atom, and more preferably a carbon atom. Z ¹³ is preferably a nitrogen atom or a phosphorus atom, and more preferably a nitrogen atom.

A ^{10 to} A ¹⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. The substituent represented by R can be arbitrarily selected from the substituent groups A listed below.
Substituent group A:
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as a methyl group, ethyl group, iso-propyl group, tert-butyl group, n- Octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, especially Preferably it is C2-C10, for example, a vinyl group, an allyl group, 2-butenyl group, 3-pentenyl group etc.), an alkynyl group (preferably C2-C30, more preferably C2-C2). To 20, particularly preferably 2 to 10 carbon atoms, such as a propargyl group and a 3-pentynyl group), an aryl group (preferably The number of carbon atoms is 6 to 30, more preferably 6 to 20, and particularly preferably 6 to 12, and examples thereof include a phenyl group, a p-methylphenyl group, a naphthyl group, and an anthranyl group.), An amino group (Preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, and particularly preferably 0 to 10 carbon atoms. For example, amino group, methylamino group, dimethylamino group, diethylamino group, dibenzylamino group, diphenyl Amino group, ditolylamino group, etc.), alkoxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy group, ethoxy group, Butoxy group, 2-ethylhexyloxy group, etc.), aryloxy group (preferably having 6 to 30 carbon atoms, more preferred) Or having 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy group, 1-naphthyloxy group, 2-naphthyloxy group, etc.), heterocyclic oxy group (preferably carbon The number is 1 to 30, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms. Examples thereof include a pyridyloxy group, a pyrazyloxy group, a pyrimidyloxy group, a quinolyloxy group, and the like, and an acyl group (preferably. C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, an acetyl group, a benzoyl group, a formyl group, a pivaloyl group etc. are mentioned), an alkoxycarbonyl group (preferably). Has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 12 carbon atoms. Examples thereof include a rubonyl group and an ethoxycarbonyl group. ), An aryloxycarbonyl group (preferably having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonyl group), an acyloxy group ( Preferably it has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include an acetoxy group and a benzoyloxy group.

An acylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include an acetylamino group and a benzoylamino group), an alkoxycarbonylamino group (Preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably carbon 7 to 30, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group), a sulfonylamino group (preferably 1 to 30 carbon atoms, More preferably, it has 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms. Amino group, benzenesulfonylamino group, etc.), sulfamoyl group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group, methyl A sulfamoyl group, a dimethylsulfamoyl group, a phenylsulfamoyl group, etc.), a carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to carbon atoms). For example, carbamoyl, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, etc.), alkylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably carbon number). 1 to 12, and examples thereof include a methylthio group and an ethylthio group. An arylthio group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenylthio group), a heterocyclic thio group (preferably carbon atoms). 1-30, more preferably 1-20 carbon atoms, particularly preferably 1-12 carbon atoms, such as pyridylthio group, 2-benzimidazolylthio group, 2-benzoxazolylthio group, 2-benzthiazolyl group. A luthio group, etc.),

A sulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl group, tosyl group, etc.), sulfinyl group (preferably carbon 1-30, more preferably 1-20 carbon atoms, particularly preferably 1-12 carbon atoms such as methanesulfinyl group and benzenesulfinyl group), ureido group (preferably 1-30 carbon atoms). , More preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido group, methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably 1 to 1 carbon atom). 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a diethylphosphoric acid amide group, a phenylphosphoric acid group Hydroxy group, mercapto group, halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group , Hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom, Is an imidazolyl group, pyridyl group, quinolyl group, furyl group, thienyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, carbazolyl group, azepinyl group, etc.), silyl group ( Preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 2 carbon atoms. For example, a trimethylsilyl group, a triphenylsilyl group, etc.), a silyloxy group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, A trimethylsilyloxy group, a triphenylsilyloxy group, etc.), a phosphoryl group (for example, a diphenylphosphoryl group, a dimethylphosphoryl group, etc.).

When Z ¹² is a nitrogen atom and A ^{11 to} A ¹³ are CR, when Z ¹³ is a nitrogen atom and A ^{17 to} A ¹⁹ and A ¹⁰ are CR, A ¹² and A ¹⁸ R is preferably a hydrogen atom, alkyl group, aryl group, amino group, alkoxy group, aryloxy group, fluorine atom or cyano group, more preferably a hydrogen atom, amino group, alkoxy group, aryloxy group or fluorine atom. And particularly preferably a hydrogen atom or a fluorine atom, and R in A ¹¹ , A ¹³ , A ¹⁷ , A ¹⁹ , A ¹⁰ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group , Fluorine atom, cyano group, more preferably hydrogen atom, amino group, alkoxy group, aryloxy group, fluorine atom, particularly preferably hydrogen atom. It is a child.

When Z ¹² is a carbon atom and A ^{11 to} A ¹³ are C—R, Z ¹³ is a carbon atom and A ^{17 to} A ¹⁹ , A ¹⁰ is C—R, and A ¹⁴ to When A ¹⁶ is C—R, R of A ¹² , A ¹⁵ and A ¹⁸ is preferably a hydrogen atom, an alkyl group, a polyfluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, A cyano group, more preferably a hydrogen atom, a polyfluoroalkyl group, an alkyl group, an aryl group, a fluorine atom, or a cyano group, and particularly preferably a hydrogen atom, a polyfluoroalkyl group, or a cyano group. R represented by A ¹¹ , A ¹³ , A ¹⁴ , A ¹⁶ , A ¹⁷ , A ¹⁹ is preferably a hydrogen atom, an alkyl group, a polyfluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, A cyano group, more preferably a hydrogen atom, a polyfluoroalkyl group, a fluorine atom or a cyano group, and particularly preferably a hydrogen atom or a fluorine atom. R represented by A ¹⁰ is preferably a hydrogen atom or a fluorine atom, more preferably a hydrogen atom.

A nitrogen atom among A ^{10 to} A ¹⁹ is preferably selected from A ¹² , A ¹³ , A ¹⁵ , A ¹⁶ , A ¹⁸ , and A ^19, and is selected from A ¹² , A ¹⁵ , and A ¹⁸ . Is more preferable, and it is particularly preferable that Z ¹² is selected from A ¹² and A ^{15 in} the case where the carbon atom is Z ¹² .

When adjacent ones of A ^{11 to} A ¹³ , A ^{14 to} A ¹⁶ , A ^{17 to} A ¹⁹ , and A ¹⁰ are CR, the adjacent CR Rs are connected to each other to form a ring. You may do it. When a ring is formed, a condensed ring structure is formed at the positions of A ¹¹ and A ¹² , A ¹² and A ¹³ , A ¹⁴ and A ¹⁵ , A ¹⁵ and A ¹⁶ , A ¹⁷ and A ¹⁸ , A ¹⁸ and A ^19. It is more preferable that a condensed ring structure is formed at the positions A ¹¹ and A ¹² , A ¹⁴ and A ¹⁵ , A ¹⁷ and A ¹⁸ , and it is compressed at the positions A ¹¹ and A ¹² , A ¹⁷ and A ^18. It is particularly preferred to form a ring structure. As the condensed ring structure, for example, a 5-membered ring, a 6-membered ring, a 7-membered ring structure and the like can be formed, and a 5-membered ring and a 6-membered ring structure are preferable.
Examples of the 5-membered ring structure include cyclopentene ring, cyclopentadiene ring, furan ring, thiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxazole ring, isoxazole ring, oxadiazole ring, thiazole ring, pyrrolidine ring, silole Rings and the like can be formed.
As the 6-membered ring structure, a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a piperidine ring, a pyran ring, a dihydropyran ring, and the like can be formed.
The ring structure may be condensed with another ring structure. Among these condensed ring structures, those condensed with a 5-membered ring structure include indene ring, indole ring, benzofuran ring, benzothiophene ring, silole ring, and those condensed with a 6-membered ring structure include benzene ring, A pyridine ring and a pyrazine ring are preferable, an indene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a benzene ring and a pyridine ring are more preferable, and an indole ring, a benzofuran ring, a benzothiophene ring and a benzene ring are particularly preferable.
The above ring structure may have a substituent. Examples of the substituent include the substituent group A.

Y ^{11 to} Y ¹³ are atoms that may have a substituent selected so as to form a 5-membered aromatic heterocycle together with Z ¹¹ and a carbon atom. For example, when one of Y ^{11 to} Y ¹³ is a nitrogen atom, an oxygen atom, a sulfur atom, or a phosphorus atom, the other two can be arbitrarily selected from a carbon atom, a nitrogen atom, and a phosphorus atom. Moreover, all of Y ^{11 to} Y ¹³ may be a nitrogen atom or a phosphorus atom.
That is, examples of specific combinations of (Y ¹¹ , Y ¹² , Y ¹³ ) include the following.
(O, C, C), (S, C, C), (P, C, C), (N, C, C),
(C, O, C), (C, S, C), (C, P, C), (C, N, C),
(C, C, O), (C, C, S), (C, C, P), (C, C, N),
(O, N, C), (S, N, C), (P, N, C), (N, N, C),
(O, C, N), (S, C, N), (P, C, N), (N, C, N),
(N, C, N), (S, N, N), (P, N, N), (N, N, N),
(N, O, C), (N, S, C), (N, P, C),
(C, O, N), (C, S, N), (C, P, N), (C, N, N),
(N, O, N), (N, S, N), (N, P, N),
(N, C, O), (N, C, S), (N, C, P),
(C, N, O), (C, N, S), (C, N, P),
(N, N, O), (N, N, S), (N, N, P)

Among the ^above, when considering the stability of the heterocyclic 5-membered aromatic containing Y 11 ^{to Y 13,} it is preferable two of Y 11 ^{to Y 13} is a carbon atom. That is,
(O, C, C), (S, C, C), (N, C, C),
(C, O, C), (C, S, C), (C, N, C),
(C, C, O), (C, C, S), (C, C, N)
A combination of
(O, C, C), (S, C, C), (N, C, C),
(C, O, C), (C, S, C), (C, N, C),
Is more preferred,
(O, C, C), (S, C, C), (N, C, C)
The combination of is particularly preferable.

^{Further, Y 11} and ^{Y 12,} or at the position of ^{Y 12} and ^{Y 13,} may form a condensed ring structure. Examples of specific combinations of (Y ¹¹ , Y ¹² , Y ¹³ ) that can form a condensed ring structure include
(O, C, C), (S, C, C), (N, C, C),
(C, C, O), (C, C, S), (C, C, N),
(C, N, C), (C, N, N), (N, C, N)
Is mentioned.

As the condensed ring structure,
(O, C, C), (S, C, C), (N, C, C),
(C, C, O), (C, C, S), (C, C, N)
In the case of this combination, it can take the same structure as the above-mentioned condensed ring structure containing two carbon atoms in the condensed ring portion, and the preferred range of the structure is also the same. Also,
(N, C, C), (C, C, N), (C, N, C), (C, N, N), (N, C, N)
With respect to the combination, the condensed ring structure is an azacyclohexadiene structure containing a nitrogen atom in the condensed ring portion. (For example, QB50CN-56 described later.)

If Y ¹¹ to Y ¹³ has a substituent, the substituent can be applied to those exemplified as the substituent group A.
When Y ^{11 to} Y ¹³ are nitrogen atoms, the substituent is preferably an alkyl group, an aryl group, an acyl group, a heterocyclic group, or a silyl group, more preferably an alkyl group, an aryl group, or a heterocyclic group, an alkyl group, An aryl group is particularly preferred. As the alkyl group, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an n-octyl group, an n-decyl group, an n-hexadecyl group, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, and a 1-adamantyl group are preferable. , A methyl group, an isopropyl group, a tert-butyl group, a cyclohexyl group, and a 1-adamantyl group are more preferable, and a methyl group and a tert-butyl group are particularly preferable. As the aryl group, a phenyl group, a p-methylphenyl group, a 1-naphthyl group, a 2-naphthyl group, and a 9-anthranyl group are preferable, and a phenyl group, a p-methylphenyl group, a 1-naphthyl group, and a 2-naphthyl group are preferable. More preferred is a phenyl group.
In the case where Y ^{11 to} Y ¹³ are carbon atoms, the substituent is the same as the substituent R in the case where Z ¹¹ is a nitrogen atom and A ^{11 to} A ¹³ is C—R. The same.

L ¹ represents a divalent linking group. Examples of the divalent linking group represented by L ¹ include alkylene groups (methylene, ethylene, propylene, etc.), arylene groups (phenylene, naphthalenediyl), heteroarylene groups (pyridinediyl, thiophenediyl, etc.), imino groups (- NR-) (such as phenylimino group), oxy group (-O-), thio group (-S-), phosphinidene group (-PR-) (such as phenylphosphinidene group), silylene group (-SiRR'-) (Dimethylsilylene group, diphenylsilylene group, etc.), or a combination thereof. These linking groups may further have a substituent.

L ¹ is preferably an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group, or a silylene group, and more preferably a monoatomic divalent linking group that may have a substituent. Are a methylene group, an imino group, an oxy group, a thio group and a silylene group, more preferably a methylene group and an imino group.
The methylene group is more preferably a disubstituted methylene group, more preferably a dimethylmethylene group, a diethylmethylene group, a diisobutylmethylene group, a dibenzylmethylene group, an ethylmethylmethylene group, a methylpropylmethylene group, an isobutylmethylmethylene group, A diphenylmethylene group, a methylphenylmethylene group, a cyclohexanediyl group, a cyclopentanediyl group, a fluorenediyl group, and a fluoromethylmethylene group, particularly preferably a dimethylmethylene group, a diphenylmethylene group, and a cyclohexanediyl group.
The imino group is more preferably an alkylimino group or an arylimino group, and more preferably a methylimino group, an isopropylimino group, a tert-butylimino group, a 1-adamantylimino group, a phenyl group, an o-tolyl group (2 -Methylphenyl group), xylyl group, mesityl group, 4-tert-butylphenyl group, 3,5-di (tert-butyl) phenyl group, more preferably tert-butylimino group, 1-adamantylimino group, A phenyl group, a mesityl group, and a 3,5-di (tert-butyl) phenyl group, particularly preferably a tert-butylimino group and a phenyl group.

  The compound represented by the general formula (I) is preferably a compound represented by the general formula (II).

In the general formula (II), A ^{20 to} A ²⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. Y ^{21 to} Y ²³ represent an atom selected from a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom so as to form a 5-membered aromatic heterocycle together with the nitrogen atom and the carbon atom. May have a substituent. L ² represents a monoatomic divalent linking group which may have a substituent.

The general formula (II) will be described.
A ^{20 to} A ²⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. The A ²¹ to A ^26, have the same meanings as ^A 14 ^{to A 16} in Formula (I), and preferred ranges are also the same. A ^{27 to} A ²⁹ and A ²⁰ are respectively synonymous with A ^{17 to} A ¹⁹ and A ^{10 in} the case where Z ¹³ in the general formula (I) is a nitrogen atom, and the preferred ranges are also the same. .

Y ^{21 to} Y ²³ represent an atom selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom so as to form a 5-membered aromatic heterocycle together with the nitrogen atom and the carbon atom. In some cases, it may have a substituent. Y < ²¹ > -Y < ²³ > is synonymous with the case where Y < ¹¹ > -Y < ¹³ > in the said general formula (I) is a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom, and its preferable range is also the same.

L ² represents a monoatomic divalent linking group which may have a substituent. L ² is synonymous with the case where L ¹ in the general formula (I) is a monoatomic divalent linking group, and the preferred range is also the same.

  Hereinafter, although the specific example of a compound represented by general formula (I) is shown, this invention is not limited to these.

In the following specific examples, the compound represented by the general formula (I) is represented by the general formula (0) composed of the partial structures Q ^{1 to} Q ⁴ , the linking group L, and the divalent metal ion M shown below. And

That, ^{Q 1} is a partial structure group QB50CN, ^{Q 2} is a partial structure group QT60CN and QT61CC, ^{Q 3} is a partial structure group QT61CC, ^{Q 4} is selected from the partial structure group QB61CC and QB60CN, as a combination,
(QB50CN, QT60CN, QT61CC, QB61CC),
(QB50CN, QT61CC, QT61CC, QB60CN)
It is.
In the following partial structure groups, M and L correspond to M and L in the general formula (0), respectively. Q is, Q in the [partial structure represented by Q ^1] represents Q ^2, Q in the [partial structure represented by Q ^2] represents Q ^1, the partial structure represented by [Q ³ the Q in] represents Q ^4, Q in the partial structure] represented by [Q ⁴ are representative of the Q ^3.

[Partial structure represented by Q ^1]
The partial structure group QB50CN is shown below.

[Partial structure represented by Q ^2]
The partial structure group QT60CN is shown below.

[Partial structure represented by Q ^2] and [partial structure represented by Q ^3]
The partial structure group QT61CC is shown below.

[Partial structure represented by Q ^4]
The partial structure group QB61CC is shown below.

  The partial structure group QB60CN is shown below.

A group of linking groups L is shown below.
In the following examples, Q represents Q ² or Q ³ in the general formula (0).

Specific combinations of the compounds of the present invention consisting of Q ¹ , Q ² , Q ³ , Q ⁴ , L and M (that is, specific examples of the compound represented by the general formula (I)) are shown in the following table. Although what is described is illustrated, it is not limited to these.
In the following table, for example, in compound 1-1, Q ¹ in the above general formula (I) represents QB50CN-1, Q ² represents QT60CN-1, Q ³ represents QT61CC-1, and Q ⁴ represents QB61CC-1, L represents L-1, M represents Pt, and means a compound represented by the following general formula.

The compound represented by the general formula (I) may be a low molecular compound, an oligomer compound, or a polymer compound, but is preferably a low molecular compound.
In the case of a polymer compound, the weight average molecular weight (polystyrene conversion) is preferably 1000 to 5000000, more preferably 2000 to 1000000, and still more preferably 3000 to 100,000. In the case of a polymer compound, the structure represented by the general formula (I) may be contained in the polymer main chain or in the polymer side chain. In the case of the polymer compound, it may be a homopolymer compound or a copolymer compound.

The compound represented by the general formula (I) can be synthesized by a known synthesis method. Specifically, it is obtained by reacting a compound serving as a ligand with a metal source in the presence or absence of a solvent, in the presence or absence of a base, at room temperature or below or under heating according to a known method. It is done.
As a known method, Journal of Organic Chemistry 53, 786, (1988), GR Newkome et al.), Page 789, left line 53 to right line 7, line 790, left line 18 line The method described in line 38, page 790, the method described in lines 19-30 of the right column, Chemische Berichte 113, 2749 (1980), H. Lexy et al.), The method described in page 2752, lines 26-35. Etc.

  Examples of the metal source include platinum chloride, platinum bromide, platinum acetylacetonate, potassium chloroplatinate, palladium chloride, sodium chloropalladate, copper acetate, copper acetylacetonate, dichloro (N, N, N ′, N '-Tetramethylenediamine) zinc, zinc acetate, etc. can be used.

  When using a solvent, for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, a sulfoxide solvent, water or the like is used. be able to. More specifically, acetonitrile, benzonitrile, acetic acid, ethanol, methoxyethanol, glycerol, water, and a mixed solvent thereof can be used.

  When a base is used, various bases of inorganic compounds or organic compounds can be used. For example, sodium methoxide, t-butoxy potassium, triethylamine, potassium carbonate and the like can be used.

The reaction temperature of the reaction varies depending on the activity of the reaction, and can be performed in the range of −30 ° C. to 400 ° C. Preferably, it is 0 degreeC-350 degreeC, and 25 degreeC-250 degreeC is more preferable. In addition, when heating, the method of heating with a microwave other than a normal heating means can also be used.
The reaction time varies depending on the activity of the reaction raw materials, and can usually be carried out in the range of 1 hour to 3 days. Preferably, it is 1 hour to 12 hours, more preferably 1 hour to 8 hours, and particularly preferably 1 hour to 4 hours.

  In addition, additives that promote the reaction (silver trifluoromethanesulfonate, pyridine, triethylamine, etc.) may be added. The reaction may be performed in the presence of an inert gas (nitrogen gas, argon gas, etc.).

  It is preferable to use a material having at least one deuterium atom for the organic layer. The durability can be further improved by using a material having at least one deuterium atom.

  The material having at least one deuterium atom may be contained in any organic layer, but the hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer, exciton blocking layer, charge It is preferably contained in one or more of the block layers, more preferably contained in one or more of the light emitting layer, exciton blocking layer, and charge blocking layer, and contained in the light emitting layer. More preferably, it is preferably contained as a host material in the light emitting layer.

  The material having at least one deuterium atom may be an organic material, an inorganic material, or both, but is preferably an organic material.

An organic material having at least one deuterium atom is a ratio of a deuterium atom to a hydrogen atom at a position where a hydrogen atom or deuterium atom in the organic material can be bonded (number of deuterium atoms: number of hydrogen atoms). ) In the range of 100: 0 to 1:99. Here, the position at which a hydrogen atom or deuterium atom can be bonded may be in any range from at least one specific position to the entire position in one molecule. In other words, the said ratio is synonymous with the ratio (deuteration rate) which a deuterium atom occupies in the sum total of the position where a hydrogen atom or a deuterium atom can couple | bond together.
Therefore, the state of the above ratio can be realized by simultaneously using a compound containing deuterium at the position and a compound not containing deuterium at an appropriate ratio.

  The composition range of deuterium atoms and hydrogen atoms is preferably 100: 0 to 5:95, more preferably 100: 0 to 50:50, and particularly preferably 100: 0 to 80:20.

  Examples of the organic material having at least one deuterium atom include, but are not limited to, compounds described in International Publication No. 02/47440 pamphlet.

  Preferable organic materials having at least one deuterium atom are materials containing nitrogen atoms. Among materials containing a nitrogen atom, a material containing a tertiary amine skeleton, a carbazole skeleton or an indole skeleton is preferred, a material containing a carbazole skeleton or an indole skeleton is more preferred, and a material containing a carbazole skeleton is particularly preferred.

  Examples of the material having at least one deuterium atom and containing a carbazole skeleton or an indole skeleton include the following.

  Next, each element constituting the organic EL element will be described.

<Organic layer>
The organic layer includes at least a light emitting layer and may be composed of a single layer or a plurality of layers. When composed of a plurality of layers, as the organic layer other than the light emitting layer, as described above, a hole transport layer, an electron transport layer, a hole block layer, an electron block layer, a hole injection layer, an electron injection layer, etc. Each layer is mentioned.

-Formation of organic layer-
Each layer constituting the organic layer can be suitably formed by any of a dry film forming method such as a vapor deposition method and a sputtering method, a transfer method, and a printing method.

-Light emitting layer-
The light-emitting layer receives holes from the anode, the hole injection layer, or the hole transport layer when an electric field is applied, receives electrons from the cathode, the electron injection layer, or the electron transport layer, and recombines holes and electrons. It is a layer which has the function to provide and to emit light. The light emitting layer may be a single layer or may be formed of two or more layers. In the case of two or more layers, each layer may emit light with different emission colors.

  The light emitting layer may be composed of only the light emitting material, or may be a mixed layer of the host material and the light emitting material.

Here, the host material is a material other than the light emitting material among the materials constituting the light emitting layer, and functions to disperse the light emitting material and hold it in the layer, and receive holes from the anode, the hole transport layer, and the like. Function, function to receive electrons from cathode, electron transport layer, etc., function to transport holes and / or electrons, function to provide recombination field of holes and electrons, and emit energy of excitons generated by recombination It means a material having at least one of a function of transferring to a material and a function of transporting holes and / or electrons to a light emitting material.
The host material is preferably a charge transport material. The host material may be one kind or two or more kinds. For example, an electron transporting host material and a hole transporting host material may be used in combination. Furthermore, the light emitting layer may include a material that does not have charge transporting properties and does not emit light.

  More specifically, the host material has a carbazole skeleton, a diarylamine skeleton, a pyridine skeleton, a pyrazine skeleton, a triazine skeleton, an arylsilane skeleton, The materials exemplified in the sections of hole injection layer, hole transport layer, electron injection layer, and electron transport layer can be used.

As the luminescent material, the compound represented by the general formula (I) can be used. Further, as other light emitting materials, the following fluorescent light emitting materials and / or phosphorescent light emitting materials can be used.
<Fluorescent material>
Fluorescent materials generally include benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, coumarin, pyran, perinone, oxadiazole, aldazine, pyralidine, cyclopentadiene. Bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compounds, condensed polycyclic aromatic compounds (such as anthracene, phenanthroline, pyrene, perylene, rubrene, or pentacene), 8- Various metal complexes represented by quinolinol metal complexes, pyromethene complexes and rare earth complexes, polythiophene, polyphenylene, polyphenylene vinylene and other poly Over compounds, organic silane, and the like, and their derivatives.

<Phosphorescent material>
In general, examples of phosphorescent materials include complexes containing transition metal atoms or lanthanoid atoms.
For example, the transition metal atom is not particularly limited, but preferably includes ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper, and platinum, and more preferably rhenium, iridium. And platinum, more preferably iridium and platinum.
Examples of the lanthanoid atom include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Among these lanthanoid atoms, neodymium, europium, and gadolinium are preferable.

Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Examples include ligands described in Yersin's "Photochemistry and Photophysics of Coordination Compounds" published by Springer-Verlag 1987, Akio Yamamoto "Organic Metal Chemistry-Fundamentals and Applications-" .
Specific ligands are preferably halogen ligands (preferably chlorine ligands), nitrogen-containing heterocyclic ligands (eg, phenylpyridine, benzoquinoline, quinolinol, bipyridyl, phenanthroline, etc.), diketones Ligand (for example, acetylacetone), carboxylic acid ligand (for example, acetic acid ligand), carbon monoxide ligand, isonitrile ligand, cyano ligand, more preferably nitrogen-containing Heterocyclic ligand. The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

  Preferable specific examples of the phosphorescent material include the following. It is particularly preferable to use the following compound and the compound represented by the general formula (I) in combination as a light emitting material.

  The light-emitting material is generally contained in an amount of 0.1% to 50% by mass based on the total mass of the compound forming the light-emitting layer, but is contained in an amount of 1% to 50% by mass from the viewpoint of durability and external quantum efficiency. It is preferable that the content is 2 to 40% by mass.

  Although the thickness of a light emitting layer is not specifically limited, Usually, it is preferable that they are 1 nm-500 nm, it is more preferable that they are 5 nm-200 nm, and it is still more preferable that they are 10 nm-100 nm.

-Hole injection layer, hole transport layer-
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. Specifically, the hole injection layer and the hole transport layer are carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamines. Derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, organosilane derivatives, carbon In addition, a layer containing various metal complexes represented by an Ir complex having phenylazole or phenylazine as a ligand is preferable.
The thicknesses of the hole injection layer and the hole transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the hole transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the hole injection layer is preferably 0.1 nm to 200 nm, more preferably 0.5 nm to 100 nm, and still more preferably 1 nm to 100 nm.
The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. .

-Electron injection layer, electron transport layer-
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. Specifically, the electron injection layer and the electron transport layer are triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, Carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, aromatic tetracarboxylic anhydrides such as naphthalene and perylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands It is preferably a layer containing various metal complexes typified by metal complexes, organosilane derivatives, and the like.

The thicknesses of the electron injection layer and the electron transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the electron transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and still more preferably 0.5 nm to 50 nm.
The electron injection layer and the electron 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.

-Hole blocking layer-
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
Examples of organic compounds constituting the hole blocking layer include aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4- Aluminum complexes such as phenylphenolate (abbreviated as BAlq), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10- phenanthroline derivatives such as phenanthroline (abbreviated as BCP)) and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm.
The hole blocking 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.

<Anode>
The anode usually only needs to have a function as an electrode for supplying holes to the organic layer, and there is no particular limitation on the shape, structure, size, etc., depending on the use and purpose of the light-emitting element, It can select suitably from well-known electrode materials. As described above, the anode is usually provided as a transparent anode.

  Suitable examples of the material for the anode include metals, alloys, metal oxides, conductive compounds, and mixtures thereof. Specific examples of the anode material include conductive metals such as tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Metals such as oxides, gold, silver, chromium, nickel, and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, polyaniline, polythiophene, polypyrrole, etc. Organic conductive materials, and a laminate of these and ITO. Among these, conductive metal oxides are preferable, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like.

  The anode is composed of, for example, a wet method such as a printing method and a coating method, a physical method such as a vacuum deposition method, a sputtering method, and an ion plating method, and a chemical method such as a CVD and a plasma CVD method. It can be formed on the substrate according to a method appropriately selected in consideration of suitability with the material to be processed. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like.

  There is no restriction | limiting in particular as a formation position of an anode, According to the use and objective of a light emitting element, it can select suitably. Is preferably formed on the substrate. In this case, the anode may be formed on the entire one surface of the substrate, or may be formed on a part thereof.

  The patterning for forming the anode may be performed by chemical etching such as photolithography, or may be performed by physical etching using a laser, or by vacuum deposition or sputtering with a mask overlapped. It may be performed by a lift-off method or a printing method.

  The thickness of the anode can be appropriately selected depending on the material constituting the anode and cannot be generally defined, but is usually about 10 nm to 50 μm, and preferably 50 nm to 20 μm.

The resistance value of the anode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less. When the anode is transparent, it may be colorless and transparent or colored and transparent. In order to take out light emission from the transparent anode side, the transmittance is preferably 60% or more, and more preferably 70% or more.

  The transparent anode is detailed in Yutaka Sawada's “New Development of Transparent Electrode Film”, published by CMC (1999), and the matters described here can be applied to the present invention. In the case of using a plastic substrate having low heat resistance, a transparent anode formed using ITO or IZO at a low temperature of 150 ° C. or lower is preferable.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light-emitting element. The electrode material can be selected as appropriate.

  Examples of the material constituting the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Specific examples include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, magnesium. -Rare earth metals such as silver alloys, indium, ytterbium, and the like. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.

Among these, as a material constituting the cathode, an alkali metal or an alkaline earth metal is preferable from the viewpoint of electron injecting property, and a material mainly composed of aluminum is preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, an alloy of aluminum and 0.01 to 10% by mass of alkali metal or alkaline earth metal, or a mixture thereof (for example, lithium-aluminum alloy, magnesium-aluminum alloy, etc.) Say.

  The materials for the cathode are described in detail in JP-A-2-15595 and JP-A-5-121172, and the materials described in these publications can also be applied in the present invention.

  There is no restriction | limiting in particular about the formation method of a cathode, According to a well-known method, it can carry out. For example, the cathode described above is configured from a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, or a chemical method such as CVD or plasma CVD method. It can be formed according to a method appropriately selected in consideration of suitability with the material. For example, when a metal or the like is selected as the cathode material, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  Patterning when forming the cathode may be performed by chemical etching such as photolithography, physical etching by laser, or the like, or by vacuum deposition or sputtering with the mask overlaid. It may be performed by a lift-off method or a printing method.

There is no restriction | limiting in particular in the cathode formation position, You may form in the whole on an organic layer, and may be formed in the part.
Further, a dielectric layer made of an alkali metal or alkaline earth metal fluoride or oxide may be inserted between the cathode and the organic layer with a thickness of 0.1 to 5 nm. This dielectric layer can also be regarded as a kind of electron injection layer. The dielectric layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

The thickness of the cathode can be appropriately selected depending on the material constituting the cathode and cannot be generally defined, but is usually about 10 nm to 5 μm, and preferably 50 nm to 1 μm.
Further, the cathode may be transparent or opaque. The transparent cathode can be formed by depositing a thin cathode material to a thickness of 1 to 10 nm and further laminating a transparent conductive material such as ITO or IZO.

<Protective layer>
The entire organic EL element may be protected by a protective layer.
As a material contained in the protective layer, any material may be used as long as it has a function of preventing materials that promote 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 nitrides such as SiN _x and SiN _x O _y , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , polyethylene, polypropylene, polymethyl Monomer mixture containing methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene and at least one comonomer A copolymer obtained by copolymerization of a copolymer having a cyclic structure in the copolymer main chain. Copolymer, 1% by weight of the water absorbing water absorption material, water absorption of 0.1% or less of moisture-proof material, and the like.

  The method for forming the protective layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency) Excited ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, transfer method can be applied.

<Board>
The electrode and the organic layer can be formed on a substrate.
The substrate is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. Specific examples include zirconia-stabilized yttrium (YSZ), inorganic materials such as glass, polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, and polycycloolefin. , Organic materials such as norbornene resin and poly (chlorotrifluoroethylene).
For example, when glass is used as the substrate, alkali-free glass is preferably used as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what applied barrier coats, such as a silica. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

  There is no restriction | limiting in particular about the shape of a board | substrate, a structure, a magnitude | size, It can select suitably according to the use, purpose, etc. of a light emitting element. In general, the shape of the substrate is preferably a plate shape. The substrate structure may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members.

  The substrate may be colorless and transparent or colored and transparent, but is preferably colorless and transparent in that it does not scatter or attenuate light emitted from the light emitting layer.

The substrate can be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
As a material for the moisture permeation preventive layer (gas barrier layer), inorganic materials such as silicon nitride and silicon oxide are preferably used. The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.
When a thermoplastic substrate is used, a hard coat layer, an undercoat layer, or the like may be further provided as necessary.

<Sealing container>
The organic EL device of the present invention may seal the entire device using a sealing container.
Moreover, you may enclose a water | moisture-content absorber or an inert liquid in the space between a sealing container and an organic EL element. Although it does not specifically limit as a moisture absorber, For example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, calcium chloride, magnesium chloride, copper chloride Cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, magnesium oxide and the like. The inert liquid is not particularly limited, and examples thereof include fluorinated solvents such as paraffins, liquid paraffins, perfluoroalkanes, perfluoroamines, perfluoroethers, chlorinated solvents, and silicone oils. It is done.

<Driving method>
The organic EL device of the present invention obtains light emission by applying a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. be able to.
Regarding the driving method of the organic EL device of the present invention, each of JP-A-2-148687, JP-A-6-301355, JP-A-5-290080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-2441047. The driving methods described in the publications, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429 and 6023308, and the like can be applied.

<Application>
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.

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

[Examples 1-1 to 1-20, Comparative Examples 1-1 to 1-20]
<Examples 1-1 to 1-20: Production of organic EL elements A-1 to 20>
A glass substrate having a 2.5 cm square and 0.5 mm thick ITO film (manufactured by Geomat Co., Ltd., surface resistance 10 Ω / □) is placed in a cleaning container, and ultrasonically cleaned in 2-propanol for 30 minutes. UV-ozone treatment was performed. On the transparent anode (ITO film), the following organic layers were sequentially deposited according to the following table by vacuum deposition.
In addition, the vapor deposition rate in a present Example is 0.1-2 nm / sec unless there is particular notice. The deposition rate was measured using a quartz resonator. The film thicknesses described below were also measured using a crystal resonator.

Hole injection layer: Hole injection material (HI) film thickness 10nm
Hole transport layer: Hole transport material (HT) film thickness 40nm
Light emitting layer: mixed material film thickness 30 nm of host material (H) 92 mass%, light emitting material (EM) 8 mass%
Hole blocking layer: Hole blocking material (HB) film thickness 5nm
Electron transport layer: Electron transport material (ET) film thickness 10nm
Electron injection layer: Electron injection material (EI) film thickness 1nm

  Finally, 0.1 nm of lithium fluoride and 100 nm of metal aluminum were deposited in this order to form a cathode. Without exposing it to the atmosphere, put it in a glove box substituted with argon gas, and seal it using a stainless steel sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.) Organic EL elements A-1 to 20 were obtained.

  The structure of the hole injection material (HI) HI-1 to 4 is shown below.

  The structure of the hole transport material (HT) HT-1 to 7 is shown below.

  The structures of the host material (H) H-1 to 13 are shown below.

  The structure of the light emitting material (EM) is shown below.

  The structure of the hole blocking material (HB) HB-1 and 2 is shown below.

  The structures of electron transport materials (ET) ET-1 and ET-2 are shown below.

  The structure of the electron injection material (EI) EI-1 is shown below.

<Comparative Examples 1-1 to 1-20: Production of Organic EL Elements A-1 ′ to 20 ′>
In the organic EL elements A-1 to A-20, the organic EL element A-1 ′ to the organic EL elements A-1 to 20 are the same as the organic EL elements A-1 to A-20 except that the light emitting material (EM) is changed to the compound 0-1 shown below. 20 'was produced.

<Evaluation of organic EL element>
The organic EL element obtained above was evaluated for the following items.
(1) EL external quantum yield Using a source measure unit 2400 type manufactured by Toyo Technica, a direct current constant voltage was applied to the organic EL element to emit light. The EL external quantum yield was calculated from the front luminance at 100 cd / m ² .

(2) Drive durability The organic EL element is set in the OLED test system ST-D type manufactured by Tokyo System Development Co., Ltd., and is driven in constant current mode under the condition of a positive constant current of 0.4 mA. Time (time until the luminance is reduced to 50% of the initial luminance) was determined.

  The above results are summarized in the following table. The following table shows the results of the organic EL elements A-1 to A-20 as relative values with the organic EL elements A-1 'to 20' of the comparative example being taken as 100.

  From the above results, it is shown that the compound represented by the general formula (I) has an effect in improving the efficiency and luminance half-life in the organic EL device, and is used for a material containing a deuterium atom. Was shown to have a particularly noticeable improvement effect.

[Examples 2-1 to 2-4, Comparative examples 2-1 and 2]
<Production and Evaluation of Organic EL Elements B-0 to B-5>
According to the following table | surfaces, organic EL element B-0-5 was produced and evaluated by the same method as organic EL element A-1 except having selected the material used for each layer. In the following table | surface, the external quantum yield of each element is shown by the relative value which set the external quantum yield of organic EL element B-0 to 100.

  The structure of EM-1 is shown below.

  From the above results, it was shown that the compound represented by the general formula (I) has a remarkable effect in improving the external quantum yield when used in the hole blocking layer.

[Examples 3-1, 2 and Comparative Examples 3-1, 2]
<Production and Evaluation of Organic EL Elements C-0 to C3>
According to the following table | surfaces, except having selected the material added to a light emitting layer other than a host material and a light emitting material, and the material used for each layer, organic EL element C-0-3 was carried out by the same method as organic EL element A-1. Made and evaluated. In the following table | surface, the external quantum yield of each element is shown by the relative value which set the external quantum yield of the organic EL element C-0 to 100.

  The structure of EM-2 is shown below.

  From the above results, it was shown that the addition of the compound represented by the general formula (I) to the light emitting layer together with the iridium complex has a remarkable effect in improving the external quantum yield.

[Examples 4-1 to 3, Comparative Examples 4-1 and 2]
<Production and Evaluation of Organic EL Elements D-0 to 4>
The same as the organic electroluminescent element A-1, except that an electron blocking layer having a thickness of 5 nm is provided between the hole transport layer and the light emitting layer, and the electron blocking material (EB) used for each layer is selected according to the following table. The organic electroluminescent elements D-0 to D-4 were prepared and evaluated by the method. In the following table | surface, the external quantum yield of each element is shown by the relative value which set the external quantum yield of the organic EL element D-0 to 100.

  The structure of EM-3 is shown below.

  From the above results, it was shown that the use of the compound represented by the general formula (I) for the electron blocking layer has a remarkable effect on the improvement of the external quantum yield.

[Examples 5-1 to 3, Comparative Examples 5-1 to 3]
<Production and Evaluation of Organic EL Elements E-0 to 5>
Organic electroluminescent elements E-0 to E-5 were prepared and evaluated in the same manner as the organic electroluminescent element A-1, except that materials used for each layer were selected according to the following table. In the following table, the luminance half time of each element is shown as a relative value with the luminance half time of the organic EL element E-0 as 100.

  The structure of ET-1 'is shown below.

  From the above results, it was shown that the compound represented by the general formula (I) has a particularly remarkable effect in improving the luminance half-life when used with a material containing a deuterium atom.

Claims (11)

An organic electroluminescent device having an organic layer including at least a light emitting layer between a pair of electrodes, wherein the organic layer contains a compound represented by the following general formula (I).

(In general formula (I), M represents a divalent metal ion. Z ¹¹ represents a nitrogen atom or a phosphorus atom. Z ¹² and Z ¹³ represent an atom selected from a carbon atom, a nitrogen atom, and a phosphorus atom. , When Z ¹² is a carbon atom, Z ¹³ represents a nitrogen atom or a phosphorus atom, and when Z ¹² is a nitrogen atom or a phosphorus atom, Z ¹³ represents a carbon atom, and the bond between M and Z ¹¹ is a coordinate bond And a bond between M and Z ^{12 to} Z ¹³ represents a coordination bond or a covalent bond, A ^{10 to} A ¹⁹ each independently represents C—R or N. R represents a hydrogen atom or a substituent. Y ^{11 to} Y ¹³ are atoms selected so as to form a 5-membered aromatic heterocycle together with Z ¹¹ and a carbon atom, and L ¹ represents a divalent linking group.   The organic electroluminescent device according to claim 1, wherein M is platinum ion. Z ¹¹ and Z ¹³ is a nitrogen atom, an organic electroluminescence device according to claim 1 or 2, characterized in that Z ¹² is a carbon atom. The organic electroluminescent element according to claim 1, wherein L ¹ is a divalent linking group composed of a single atom which may have a substituent. 5. The organic electroluminescent element according to claim 1, wherein two of Y ^{11 to} Y ¹³ are carbon atoms. The organic electroluminescent element according to claim 1, wherein the compound represented by the general formula (I) is a compound represented by the following general formula (II).

(In the general formula (II), A ^{20 to} A ²⁹ each independently represent C—R or N. R represents a hydrogen atom or a substituent. L ² represents a single atom which may have a substituent. Y ²¹ to Y ²³ are atoms selected from a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom so as to form a 5-membered aromatic heterocycle together with the nitrogen atom and the carbon atom. In the case of a carbon atom and a nitrogen atom, they may have a substituent.)   The organic electroluminescent element according to any one of claims 1 to 6, wherein the light-emitting layer contains a compound represented by the general formula (I).   The organic electroluminescent element according to claim 1, wherein the compound represented by the general formula (I) is contained in an organic layer between the light emitting layer and the cathode.   The organic electroluminescent element according to any one of claims 1 to 8, wherein the compound represented by the general formula (I) is contained in an organic layer between the light emitting layer and the anode.   The organic electroluminescent element according to any one of claims 1 to 9, wherein a material having at least one deuterium atom is contained in at least one of the organic layers.   The organic electroluminescent element according to claim 10, wherein the material having at least one deuterium atom is a material containing either a carbazole skeleton or an indole skeleton having at least one deuterium atom.