JP6111162B2 - Benzotriazole derivative, material for organic electroluminescence device, and organic electroluminescence device using the same - Google Patents

Description

  The present invention relates to a benzotriazole derivative, a material for an organic electroluminescence element, and an organic electroluminescence element using the same.

In general, an organic electroluminescence (EL) element is composed of an anode, a cathode, and one or more organic thin film layers sandwiched between the anode and the cathode. When a voltage is applied between both electrodes, electrons from the cathode side and holes from the anode side are injected into the light emitting region, and the injected electrons and holes recombine in the light emitting region to generate an excited state, which is excited. Light is emitted when the state returns to the ground state.
Since organic EL elements can obtain various luminescent colors by using various luminescent materials in the luminescent layer, practical research on displays and the like is actively conducted. In particular, research on light emitting materials of the three primary colors of red, green, and blue is the most active, and intensive research has been conducted with the aim of improving characteristics.

  For example, as materials for organic EL elements, Patent Documents 1 to 4 disclose compounds having a benzotriazole structure. In the field of organic EL devices, development of new material systems is required in order to further improve device performance such as a decrease in driving voltage.

JP 2005-82701 A International Publication No. 2008/096736 International Publication No. 2009/157429 International Publication No. 2004/063159

  An object of this invention is to provide a novel material useful as an organic EL element material, and an organic EL element using the same.

（式中、Ｒ_１〜Ｒ_４は、それぞれ独立に、水素原子又は置換基を表わし、
Ｌは単結合又は連結基であり、
Ａは３環以上の縮環構造を有する基であり、
ｎは１〜４の整数であり、ｍは１〜４の整数である。
ｍが２以上の場合、複数のＡは互いに同一でも異なっていてもよい。
ｎが２以上の場合、複数のＲ_１〜Ｒ_４は互いに同一でも異なっていてもよい。
隣接するＲ_１〜Ｒ_４同士が結合して環構造を形成してもよい。） According to one embodiment of the present invention, a benzotriazole derivative represented by the following formula (1) and an organic electroluminescent element material containing the same are provided.

(Wherein R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent,
L is a single bond or a linking group;
A is a group having a condensed ring structure of 3 or more rings,
n is an integer of 1 to 4, and m is an integer of 1 to 4.
When m is 2 or more, the plurality of A may be the same as or different from each other.
When n is 2 or more, the plurality of R _{1 to} R ₄ may be the same as or different from each other.
Adjacent R _{1 to} R ₄ may be bonded to each other to form a ring structure. )

  ADVANTAGE OF THE INVENTION According to this invention, a novel material useful as an organic EL element material and an organic EL element using the same can be provided.

It is a schematic sectional drawing which shows an example of the organic EL element of this invention.

In the present invention, “carbon number ab” in the expression “substituted or unsubstituted X group having carbon number ab” represents the carbon number when X group is unsubstituted, and X group The number of carbon atoms of the substituent when is substituted is not included.
The “ring-forming carbon” means a carbon atom constituting a saturated ring or an unsaturated ring, and does not include the number of carbon atoms of a substituent bonded to the ring.
“Ring-forming atom” means an atom constituting a saturated ring or an unsaturated ring, and does not include the number of hydrogen atoms and substituent atoms bonded to the ring.

  In the present invention, the “hydrogen atom” includes isotopes having different neutron numbers, that is, light hydrogen (protium), deuterium (deuterium) and tritium (tritium).

Furthermore, an arbitrary substituent when referred to as “substituted or unsubstituted” is an alkyl group having 1 to 50 carbon atoms (preferably 1 to 18 and more preferably 1 to 8); 3 to 50 ring carbon atoms (preferably A cycloalkyl group having 3 to 10, more preferably 3 to 8, and even more preferably 5 or 6; an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18); ring formation An aralkyl group having 7 to 51 carbon atoms (preferably 7 to 30 and more preferably 7 to 20 carbon atoms) having an aryl group having 6 to 50 carbon atoms (preferably 6 to 25, more preferably 6 to 18); an amino group; An alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8), an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18), and a ring Number of atoms formed 5-50 Preferably mono- or di-substituted amino group having a substituent selected from 5 to 24, more preferably 5 to 13) heteroaryl group; 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) ) An alkoxy group having an alkyl group; an aryloxy group having an aryl group having 6 to 50 (preferably 6 to 25, more preferably 6 to 18) ring carbon atoms; 1 to 50 (preferably 1 to 18) carbon atoms , More preferably 1-8) and mono-substituted, di-substituted or tri-substituted having a substituent selected from an alkyl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18). Substituted silyl group; heteroaryl group having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13); 1 to 50 carbon atoms (preferably 1 to 18, more preferably -8) haloalkyl group; halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom); cyano group; nitro group; alkyl having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) A sulfonyl group having a substituent selected from a group and an aryl group having 6 to 50 (preferably 6 to 25, more preferably 6 to 18) ring-forming carbon atoms; 1 to 50 carbon atoms (preferably 1 to 18, more preferably Is a disubstituted phosphoryl group having a substituent selected from an alkyl group having 1 to 8) and an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18); and an alkylsulfonyloxy group Arylsulfonyloxy group; alkylcarbonyloxy group; arylcarbonyloxy group; boron-containing group; zinc-containing group; tin-containing group; Preferred are those selected from the group consisting of a gnesium-containing group; a lithium-containing group; a hydroxy group; an alkyl- or aryl-substituted carbonyl group; a carboxyl group; a vinyl group; a (meth) acryloyl group; an epoxy group; and an oxetanyl group.
These substituents may be further substituted with the above-mentioned arbitrary substituents.

（式中、Ｒ_１〜Ｒ_４は、それぞれ独立に、水素原子又は置換基を表わし、
Ｌは単結合又は連結基であり、
Ａは３環以上の縮環構造を有する基であり、
ｎは１〜４の整数であり、ｍは１〜４の整数である。
ｍが２以上の場合、複数のＡは互いに同一でも異なっていてもよい。
ｎが２以上の場合、複数のＲ_１〜Ｒ_４は互いに同一でも異なっていてもよい。
隣接するＲ_１〜Ｒ_４同士が結合して環構造を形成してもよい。） [Benztriazole derivatives]
The benztriazole derivative which is one embodiment of the present invention is represented by the following formula (1).

(Wherein R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent,
L is a single bond or a linking group;
A is a group having a condensed ring structure of 3 or more rings,
n is an integer of 1 to 4, and m is an integer of 1 to 4.
When m is 2 or more, the plurality of A may be the same as or different from each other.
When n is 2 or more, the plurality of R _{1 to} R ₄ may be the same as or different from each other.
Adjacent R _{1 to} R ₄ may be bonded to each other to form a ring structure. )

In the formula (1), the substituents represented by R _{1 to} R ₄ are each independently preferably selected from the following group (A), more preferably selected from the following group (B). More preferably, those selected from the following group (C) are used.

  The group (A) is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted ring carbon number 6 to 50 aryl groups, substituted or unsubstituted aralkyl groups having 7 to 51 carbon atoms, amino groups, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted aryl groups having 6 to 50 ring carbon atoms A mono- or di-substituted amino group having a substituent selected from a group and a heteroaryl group having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13), substituted or unsubstituted carbon atoms 1 to 50 alkoxy groups, substituted or unsubstituted aryloxy groups having 6 to 50 carbon atoms, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, and substituted or unsubstituted rings Mono-substituted, di- or tri-substituted silyl groups having a substituent selected from aryl groups having 6 to 50 carbon atoms, substituted or unsubstituted heteroaryl groups having 5 to 50 ring atoms, substituted or unsubstituted carbon Substitution selected from a haloalkyl group having 1 to 50, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms and a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms A sulfonyl group having a group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms having a substituent, alkylsulfonyloxy Group, arylsulfonyloxy group, alkylcarbonyloxy group, arylcarbonyloxy group, boron-containing group, zinc-containing group Group consisting of a group, a tin-containing group, a silicon-containing group, a magnesium-containing group, a lithium-containing group, a hydroxy group, an alkyl-substituted or aryl-substituted carbonyl group, a carboxyl group, a vinyl group, a (meth) acryloyl group, an epoxy group, and an oxetanyl group It is.

  The group (B) is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted ring carbon number 6 to 50 aryl groups, substituted or unsubstituted aralkyl groups having 7 to 51 carbon atoms, amino groups, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted aryl groups having 6 to 50 ring carbon atoms A mono- or di-substituted amino group having a substituent selected from a group and a heteroaryl group having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13), substituted or unsubstituted carbon atoms 1 to 50 alkoxy groups, substituted or unsubstituted aryloxy groups having 6 to 50 carbon atoms, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, and substituted or unsubstituted rings Mono-substituted, di- or tri-substituted silyl groups having a substituent selected from aryl groups having 6 to 50 carbon atoms, substituted or unsubstituted heteroaryl groups having 5 to 50 ring atoms, substituted or unsubstituted carbon Substitution selected from a haloalkyl group having 1 to 50, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms and a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms And a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms and a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.

  The group (C) is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted ring carbon number 6 to 50 aryl groups, substituted or unsubstituted aralkyl groups having 7 to 51 carbon atoms, amino groups, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted aryl groups having 6 to 50 ring carbon atoms A mono- or di-substituted amino group having a substituent selected from a group and a heteroaryl group having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13), substituted or unsubstituted carbon atoms 1 to 50 alkoxy groups, substituted or unsubstituted aryloxy groups having 6 to 50 carbon atoms, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, and substituted or unsubstituted rings Mono-substituted, di- or tri-substituted silyl groups having a substituent selected from aryl groups having 6 to 50 carbon atoms, substituted or unsubstituted heteroaryl groups having 5 to 50 ring atoms, substituted or unsubstituted carbon This is a group consisting of a haloalkyl group of 1 to 50, a halogen atom, a cyano group, and a nitro group.

  Examples of the alkyl group having 1 to 50 carbon atoms (preferably 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms) include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. , Isobutyl group, s-butyl group, t-butyl group, pentyl group (including isomer), hexyl group (including isomer), heptyl group (including isomer), octyl group (including isomer), Nonyl group (including isomers), decyl group (including isomers), undecyl group (including isomers), and dodecyl group (including isomers), tridecyl group, tetradecyl group, octadecyl group, tetracosanyl group, tetra Contanyl group etc. are mentioned, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group (including isomers) Hexyl group (including isomers), heptyl group (including isomers), octyl group (including isomers), nonyl group (including isomers), decyl group (including isomers), undecyl group (isomers) ), Dodecyl group (including isomer), tridecyl group, tetradecyl group and octadecyl group are preferred, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s- A butyl group, t-butyl group, pentyl group (including isomer), hexyl group (including isomer), heptyl group (including isomer), and octyl group (including isomer) are more preferable.

  Examples of the cycloalkyl group having 3 to 50 ring carbon atoms (preferably 3 to 10, more preferably 3 to 8, more preferably 5 or 6) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo group. A heptyl group, a cyclooctyl group, an adamantyl group etc. are mentioned, A cyclopentyl group and a cyclohexyl group are preferable.

Examples of the aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25 ring carbon atoms, more preferably 6 to 18 ring carbon atoms) include, for example, a phenyl group, a naphthyl group, a naphthylphenyl group, and a biphenylyl group. , Terphenylyl group, acenaphthylenyl group, anthryl group, benzoanthryl group, aceanthryl group, phenanthryl group, benzophenanthryl group, phenalenyl group, fluorenyl group, 9,9'-spirobifluorenyl group, benzofluorenyl Group, dibenzofluorenyl group, picenyl group, pentaphenyl group, pentacenyl group, pyrenyl group, chrycenyl group, benzocricenyl group, s-indacenyl group, as-indacenyl group, fluoranthenyl group, benzofluoranthenyl group, tetracenyl group , Triphenylenyl group, benzotriphenylenyl group Perylenyl group, coronyl group, dibenzoanthryl group and the like.
The arylene group having 6 to 50 ring carbon atoms (preferably 6 to 25 ring carbon atoms, more preferably 6 to 18 ring carbon atoms) is an arylene group in which a hydrogen atom is removed from the aryl group. Can be mentioned.

  The number of heteroaryl groups having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13 ring atoms) is at least 1, preferably 1 to 5 (more preferably 1 to 3, more preferably (Preferably 1 to 2) heteroatoms such as nitrogen atom, sulfur atom, oxygen atom and phosphorus atom. Examples of the heteroaryl group include pyrrolyl group, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, oxazolyl group, thiazolyl group, pyrazolyl group, isoxazolyl group, isothiazolyl group. Oxadiazolyl group, thiadiazolyl group, triazolyl group, tetrazolyl group, indolyl group, isoindolyl group, benzofuranyl group, isobenzofuranyl group, benzothiophenyl group, isobenzothiophenyl group, indolizinyl group, quinolidinyl group, quinolyl group, isoquinolyl group , Cinnolyl group, phthalazinyl group, quinazolinyl group, quinoxalinyl group, benzimidazolyl group, benzoxazolyl group, benzthiazolyl group, indazolyl group, benzisoxazolyl group, benzine Isothiazolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxazinyl, azatriphenylenyl, diazatriphe Nylenyl, xanthenyl, azacarbazolyl, azadibenzofuranyl, azadibenzothiophenyl, benzofuranobenzothiophenyl, benzothienobenzothiophenyl, dibenzofuranonaphthyl, dibenzothienonaphthyl, and dinaphthothieno A thiophenyl group etc. are mentioned.

  In addition, as a specific example of the heteroaryl group having 5 to 50 ring atoms, a monovalent group obtained by removing one hydrogen atom from any compound represented by the following formula is also preferable.

［式中、Ａは、それぞれ独立に、ＣＲ^２００、又は窒素原子を表し、Ｒ^２００は、それぞれ独立に、水素原子又は置換基を表し、
Ｙは、それぞれ独立に、単結合、Ｃ（Ｒ^２０１）（Ｒ^２０２）、酸素原子、硫黄原子又はＮ（Ｒ^２０３）を表し、
Ｒ^２０１、Ｒ^２０２及びＲ^２０３は、それぞれ独立に、水素原子又は置換基を表わし、ｍは、それぞれ独立に、０又は１を表す。
上記式中、複数のＡは互いに同一でも異なっていてもよく、複数のＹは互いに同一でも異なっていてもよく、複数のｍは互いに同一でも異なっていてもよい。
ｍが０の場合、Ｙは存在しない。］
上記式中における置換基としては、上述のものと同様のものが挙げられる。

[Wherein, A independently represents CR ²⁰⁰ or a nitrogen atom, and R ²⁰⁰ each independently represents a hydrogen atom or a substituent,
Each Y independently represents a single bond, C (R ²⁰¹ ) (R ²⁰² ), an oxygen atom, a sulfur atom or N (R ²⁰³ );
R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represents a hydrogen atom or a substituent, and m independently represents 0 or 1.
In the above formula, a plurality of A may be the same or different from each other, a plurality of Y may be the same or different from each other, and a plurality of m may be the same or different from each other.
When m is 0, Y does not exist. ]
Examples of the substituent in the above formula include the same ones as described above.

Examples of the aralkyl group having 7 to 51 carbon atoms having an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18) include aralkyl groups having the above aryl group.
The alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8), the aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18), and a ring. Examples of the mono-substituted or di-substituted amino group having a substituent selected from 5 to 50 (preferably 5 to 24, more preferably 5 to 13) heteroaryl groups include the above alkyl group, the above aryl group, and the above group. Examples thereof include a mono-substituted or di-substituted amino group having a substituent selected from a heteroaryl group.
Examples of the alkoxy group having an alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) include the above alkoxy groups having an alkyl group.
Examples of the aryloxy group having an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18) include the above aryloxy groups having an aryl group.

It is selected from an alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) and an aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18). Examples of the monosubstituted, disubstituted or trisubstituted silyl group having a substituent include a monosubstituted, disubstituted or trisubstituted silyl group having a substituent selected from the above alkyl group and the above aryl group.
As said C1-C50 (preferably 1-18, more preferably 1-8) haloalkyl group, one or more of the hydrogen atoms of the said alkyl group are halogen atoms (a fluorine atom, a chlorine atom, a bromine atom, iodine). And those substituted by an atom).

From the alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) and the aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18). Examples of the sulfonyl group having a selected substituent include a sulfonyl group having a substituent selected from the above alkyl group and the above aryl group.
From the alkyl group having 1 to 50 carbon atoms (preferably 1 to 18, more preferably 1 to 8) and the aryl group having 6 to 50 ring carbon atoms (preferably 6 to 25, more preferably 6 to 18). Examples of the disubstituted phosphoryl group having a selected substituent include a disubstituted phosphoryl group having a substituent selected from the above alkyl group and the above aryl group.

The ring structure formed by bonding adjacent R _{1 to} R _{4 of the} formula (1) may be a saturated ring or an unsaturated ring.
The saturated ring is preferably an aliphatic hydrocarbon ring having 3 to 50 ring carbon atoms (preferably 3 to 6, more preferably 5 or 6).
As the unsaturated ring, an aromatic hydrocarbon ring having 6 to 50 ring carbon atoms (preferably 6 to 24, more preferably 6 to 18) or 5 to 50 ring atom atoms (preferably Aromatic heterocycles of 5 to 24, more preferably 5 to 13) are preferred.

  Specific examples of the aliphatic hydrocarbon ring having 3 to 50 ring carbon atoms include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, adamantane ring and the like. A pentane ring and a cyclohexane ring are preferred.

  Specific examples of the aromatic hydrocarbon ring having 6 to 50 ring carbon atoms include benzene ring, naphthalene ring, anthracene ring, benzoanthracene ring, phenanthrene ring, benzophenanthrene ring, fluorene ring, benzofluorene ring, dibenzofluorene ring , Picene ring, tetracene ring, pentacene ring, pyrene ring, chrysene ring, benzochrysene ring, s-indacene ring, as-indacene ring, fluoranthene ring, benzofluoranthene ring, triphenylene ring, benzotriphenylene ring, perylene ring, coronene ring And dibenzoanthracene ring.

  Specific examples of the aromatic heterocyclic ring having 5 to 50 ring atoms include pyrrole ring, pyrazole ring, isoindole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, dibenzothiophene ring, isoquinoline ring, cinnoline ring, Quinoxaline ring, phenanthridine ring, phenanthroline ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, imidazopyridine ring, indole ring, indazole ring, benzimidazole ring, quinoline ring, acridine ring, pyrrolidine ring, dioxane Ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan ring, thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, Imidazole ring, a benzimidazole ring, a pyran ring, a dibenzofuran ring, benzo [c] dibenzofuran ring, a purine ring, acridine ring, and the like.

As the linking group for L, at least one of a substituted or unsubstituted aromatic hydrocarbon ring group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aromatic hydrocarbon ring group, A group in which at least one unsubstituted aromatic heterocyclic group is linked is preferable.
As the aromatic hydrocarbon ring group, aryl having 6 to 50 ring carbon atoms (preferably 6 to 25 ring carbon atoms, more preferably 6 to 18 ring carbon atoms) of the substituent represented by R ₁ or the like described above. And a divalent group obtained by removing one hydrogen atom from the group. A monocyclic aromatic hydrocarbon ring group is preferable. Examples thereof include a phenylene group, a biphenylene group, a terphenylene group, and the like.
As the aromatic heterocyclic group, a hydrogen atom from a heteroaryl group having 5 to 50 ring atoms (preferably 5 to 24, more preferably 5 to 13 ring atoms) of the substituent represented by R ₁ or the like described above. And a divalent group in which one is removed. Preferably, it is a monocyclic aromatic heterocyclic group. For example, pyridine, pyrimidine, triazine and the like can be mentioned.

The group having a condensed ring structure of three or more rings represented by A includes an anthracene ring, a benzoanthracene ring, a phenanthrene ring, a benzophenanthrene ring, a fluorene ring, a benzofluorene ring, a dibenzofluorene ring, Picene ring, tetracene ring, pentacene ring, pyrene ring, chrysene ring, benzochrysene ring, s-indacene ring, as-indacene ring, fluoranthene ring, benzofluoranthene ring, triphenylene ring, benzotriphenylene ring, perylene ring, coronene ring, A hydrocarbon ring such as a dibenzoanthracene ring,
Heterocycles such as dibenzothiophene ring, phenanthridine ring, phenanthroline ring, acridine ring, carbazole ring, dibenzofuran ring, benzo [c] dibenzofuran ring are exemplified.
The above condensed ring structure may have a substituent, and examples of the substituent are the same as those for R ₁ described above.

  In one embodiment of the present invention, n in the formula (1) is preferably 1.

In one embodiment of the present invention, in Formula (1), A is preferably a structure (anthracene structure) represented by Formula (2) below.

The compound represented by the formula (1) and having an anthracene structure can also be used as a constituent material of the organic thin film layer constituting the organic EL element. For example, the organic thin film layer (electron transport between the light emitting layer and the cathode) Layer, hole blocking layer, electron injection layer) and light emitting layer.
In the formula (2), R _{11 to} R ₂₀ each independently represents a single bond, a hydrogen atom, or a substituent, and at least one of them is a benztriazole of the formula (1) through a single bond or a linking group L. Bonds to a ring nitrogen atom.
Examples of the substituent are the same as those for R ₁ described above.

  For example, the compound represented by following formula (3) is mentioned.

（式中、Ｒ_１〜Ｒ_４、Ｒ_１１〜Ｒ_２０及びＬは、それぞれ独立に、前記式（１）及び式（２）と同様な基を表わす。式（３）の括弧内の基は、単結合又は連結基Ｌを介してベンズトリアゾール環の窒素原子と結合している。）

(In the formula, R _{1 to} R ₄ , R _{11 to} R ₂₀ and L each independently represent the same groups as those in the formulas (1) and (2). The groups in parentheses in the formula (3) are , Bonded to the nitrogen atom of the benztriazole ring through a single bond or a linking group L.)

（式中、Ｒ_１〜Ｒ_４、Ｒ_１１〜Ｒ_２０及びＬは、それぞれ独立に、前記式（１）及び式（２）と同様な基を表わす。） As one embodiment of the present invention, for example, a compound represented by the following formula (4) is preferable.

(In the formula, R _{1 to} R ₄ , R _{11 to} R _20, and L each independently represent the same group as in the formula (1) and the formula (2)).

Further, R ₂₀ is preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms. Examples of the aryl group and heteroaryl group are the same as those for R ₁ described above.

In one embodiment of the present invention, A is preferably represented by the following formula (5).

The compound represented by the formula (1) and having the structure of the formula (5) is, for example, an organic thin film layer (electron transport layer, hole barrier layer, electron) formed between the cathode or anode electrode and the light emitting layer. Injection layer) and light emitting layer.
In Formula (5), X ₁ represents NR ₂₁ , an oxygen atom (O), or a sulfur atom (S), and R ₂₁ represents a single bond, a hydrogen atom, or a substituent.
A _{21 to} A ₂₈ each independently represent CR ₂₂ or a nitrogen atom N, and R ₂₂ represents a single bond, a hydrogen atom or a substituent. If R ₂₂ is plural, R ₂₂ may be the same or different, may form a bonded is adjacent R ₂₂ together a ring structure.
At least one of A _{21 to} A ₂₈ and X ₁ is bonded to the nitrogen atom of the benztriazole ring of the formula (1) through a single bond or a linking group L.

In the formula (5), examples of the substituent are the same as those for R ₁ described above.
An example of a ring structure formed by bonding adjacent R _{22 to} each other is the same as the ring structure formed by bonding adjacent R _{1 to} R _{4 to} each other.

（式中、Ｒ_１〜Ｒ_４、Ａ_２１〜Ａ_２８、Ｘ_１、及びＬは、それぞれ独立に、前記式（１）及び式（５）と同様な基を表わす。式（６）の括弧内の基は、単結合又は連結基Ｌを介してベンズトリアゾール環の窒素原子と結合している。） Specifically, the compound represented by following formula (6) is mentioned.

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , X ₁ , and L each independently represent the same group as in the formula (1) and the formula (5). The parentheses in the formula (6) The inner group is bonded to the nitrogen atom of the benztriazole ring through a single bond or a linking group L.)

（式中、Ｒ_１〜Ｒ_４、Ａ_２１〜Ａ_２８、及びＬは、それぞれ独立に、前記式（６）と同様な基を表わす。） More specifically, compounds represented by the following formulas (7) and (8) are exemplified.

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , and L each independently represent the same group as in the formula (6).)

（式中、Ｒ_１〜Ｒ_４、Ａ_２１〜Ａ_２８、Ｘ_１、及びＬは、それぞれ独立に、前記式（６）と同様な基を表わす。Ａ_２１〜Ａ_２４のうち１つは、単結合によりＬ又はベンズトリアゾール環の窒素原子と結合している。）

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , X ₁ , and L each independently represent the same group as the formula (6). One of A _{21 to} A ₂₄ is It is bonded to the nitrogen atom of the L or benztriazole ring by a single bond.)

（式中、Ｒ_１〜Ｒ_４、Ａ_２１〜Ａ_２８、Ｘ_１、及びＬは、それぞれ独立に、前記式（８）と同様な基を表わす。Ａ_２３は単結合によりＬ又はベンズトリアゾール環の窒素原子と結合している。）
以下に、式（１）で表される化合物の一例を示す。 Among the compounds represented by the formula (8), a compound represented by the following formula (9) is preferable.

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , X ₁ , and L each independently represent the same group as in the formula (8). A ₂₃ represents L or a benztriazole ring by a single bond. It is bonded to the nitrogen atom of
Below, an example of the compound represented by Formula (1) is shown.

  The manufacturing method of the said benzotriazole derivative is not specifically limited, It can manufacture combining a conventionally well-known synthesis method. For example, those skilled in the art can use and modify known synthesis methods while referring to the examples of the present specification.

[Materials for organic electroluminescence elements]
The material for organic EL devices of the present invention contains a compound represented by the above formula (1). The content of the compound in the organic EL device material is not particularly limited, and may be, for example, 1% by mass or more, preferably 10% by mass or more, and more preferably 50% by mass or more. More preferably, it is 80 mass% or more, 90 mass% or more is especially preferable, and 100 mass% may be sufficient. Examples of materials other than the compound represented by the formula (1) include materials used in a light emitting layer, an electron transport layer, a hole transport layer, and the like described later.
The material for an organic EL device of the present invention is useful as a material in an organic EL device, and can be used as, for example, a host material and a dopant material in a light emitting layer of a fluorescent light emitting unit or a host material in a light emitting layer of a phosphorescent light emitting unit. . In both the fluorescent light emitting unit and the phosphorescent light emitting unit, an anode-side organic thin film layer provided between the anode of the organic EL element and the light emitting layer, or a cathode provided between the cathode of the organic EL element and the light emitting layer. It is also useful as a material for the side organic thin film layer, that is, a material such as a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer.
The “light emitting unit” means a minimum unit that includes one or more organic layers, one of which is a light emitting layer, and can emit light by recombination of injected holes and electrons.

[Organic EL device]
The organic EL device which is one embodiment of the present invention has one or more organic thin film layers containing a light emitting layer between a cathode and an anode, and at least one of the organic thin film layers is a benztriazole derivative or It includes an organic EL element material. The organic EL element which is one embodiment of the present invention can be driven at a low voltage when at least one of the organic thin film layers includes the benztriazole derivative or the organic EL element material described above.
Examples of the organic thin film layer containing the organic EL element material described above include an anode-side organic thin film layer (hole transport layer, hole injection layer, etc.) provided between the anode and the light emitting layer, a light emitting layer, and a cathode. Examples include, but are not limited to, a cathode side organic thin film layer (electron transport layer, electron injection layer, etc.), a space layer, a barrier layer and the like provided between the light emitting layer and the light emitting layer. The above-mentioned organic EL element material may be contained in any of the above layers. For example, the host material or dopant material in the light emitting layer of the fluorescent light emitting unit, the host material in the light emitting layer of the phosphorescent light emitting unit, It can be used as a hole transport layer, an electron transport layer, or the like.

  The organic EL element of the present invention may be a fluorescent or phosphorescent monochromatic light emitting element, a fluorescent / phosphorescent hybrid white light emitting element, or a simple type having a single light emitting unit. A tandem type having a plurality of light emitting units may be used, and among them, a phosphorescent type is preferable.

The following element structure can be mentioned as a typical element structure of a simple type organic EL element.
(1) Anode / light emitting unit / cathode The above light emitting unit may be a laminated type having a plurality of phosphorescent light emitting layers and fluorescent light emitting layers. In that case, the light emitting unit is generated by a phosphorescent light emitting layer between the light emitting layers. In order to prevent the excitons from diffusing into the fluorescent light emitting layer, a space layer may be provided. A typical layer structure of the light emitting unit is shown below.
(A) Hole transport layer / light emitting layer (/ electron transport layer)
(B) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer (/ electron transport layer)
(C) Hole transport layer / phosphorescent layer / space layer / fluorescent layer (/ electron transport layer)
(D) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(E) Hole transport layer / first phosphorescent light emitting layer / space layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(F) Hole transport layer / phosphorescent layer / space layer / first fluorescent layer / second fluorescent layer (/ electron transport layer)
(G) Hole transport layer / electron barrier layer / light emitting layer (/ electron transport layer)
(H) Hole transport layer / light emitting layer / hole barrier layer (/ electron transport layer)
(I) Hole transport layer / fluorescent light emitting layer / triplet barrier layer (/ electron transport layer)

Each phosphorescent or fluorescent light-emitting layer may have a different emission color. Specifically, in the laminated light emitting layer (d), hole transport layer / first phosphorescent light emitting layer (red light emitting) / second phosphorescent light emitting layer (green light emitting) / space layer / fluorescent light emitting layer (blue light emitting) / Examples include a layer configuration such as an electron transport layer.
An electron barrier layer may be appropriately provided between each light emitting layer and the hole transport layer or space layer. Further, a hole blocking layer may be appropriately provided between each light emitting layer and the electron transport layer. By providing an electron barrier layer or a hole barrier layer, electrons or holes can be confined in the light emitting layer, the recombination probability of charges in the light emitting layer can be increased, and the lifetime can be improved.

The following element structure can be mentioned as a typical element structure of a tandem type organic EL element.
(2) Anode / first light emitting unit / intermediate layer / second light emitting unit / cathode Here, as the first light emitting unit and the second light emitting unit, for example, the same light emitting unit as that described above is selected independently. can do.
The intermediate layer is generally called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, or an intermediate insulating layer, and has electrons in the first light emitting unit and holes in the second light emitting unit. A known material structure to be supplied can be used.

  In FIG. 1, schematic structure of an example of the organic EL element of this invention is shown. The organic EL element 1 includes a substrate 2, an anode 3, a cathode 4, and a light emitting unit 10 disposed between the anode 3 and the cathode 4. The light emitting unit 10 includes a light emitting layer 5 including at least one phosphorescent light emitting layer including a phosphorescent host material and a phosphorescent dopant. A hole injection / transport layer 6 or the like may be formed between the light emitting layer 5 and the anode 3, and an electron injection / transport layer 7 or the like may be formed between the light emitting layer 5 and the cathode 4. Further, an electron barrier layer may be provided on the anode 3 side of the light emitting layer 5, and a hole barrier layer may be provided on the cathode 4 side of the light emitting layer 5. Thereby, electrons and holes can be confined in the light emitting layer 5, and the exciton generation probability in the light emitting layer 5 can be increased.

  In this specification, a host combined with a fluorescent dopant is referred to as a fluorescent host, and a host combined with a phosphorescent dopant is referred to as a phosphorescent host. The fluorescent host and the phosphorescent host are not distinguished only by the molecular structure. That is, the phosphorescent host means a material constituting a phosphorescent light emitting layer containing a phosphorescent dopant, and does not mean that it cannot be used as a material constituting a fluorescent light emitting layer. The same applies to the fluorescent host.

(substrate)
The organic EL element of the present invention is produced on a translucent substrate. The light-transmitting substrate is a substrate that supports the organic EL element, and is preferably a smooth substrate having a light transmittance in the visible region of 400 nm to 700 nm of 50% or more. Specifically, a glass plate, a polymer plate, etc. are mentioned. Examples of the glass plate include those using soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz and the like as raw materials. Examples of the polymer plate include those using polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like as raw materials.

(anode)
The anode of the organic EL element plays a role of injecting holes into the hole transport layer or the light emitting layer, and it is effective to use a material having a work function of 4.5 eV or more. Specific examples of the anode material include indium tin oxide alloy (ITO), tin oxide (NESA), indium zinc oxide, gold, silver, platinum, copper, and the like. The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. When light emitted from the light emitting layer is extracted from the anode, it is preferable that the transmittance of light in the visible region of the anode is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. The film thickness of the anode depends on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 10 nm to 200 nm.

(cathode)
The cathode plays a role of injecting electrons into the electron injection layer, the electron transport layer or the light emitting layer, and is preferably formed of a material having a small work function. The cathode material is not particularly limited, and specifically, indium, aluminum, magnesium, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-lithium alloy, aluminum-scandium-lithium alloy, magnesium-silver alloy and the like can be used. Similarly to the anode, the cathode can be produced by forming a thin film by a method such as vapor deposition or sputtering. Moreover, you may take out light emission from the cathode side as needed.

(Light emitting layer)
An organic layer having a light emitting function, and when a doping system is employed, includes a host material and a dopant material. At this time, the host material mainly has a function of encouraging recombination of electrons and holes and confining excitons in the light emitting layer, and the dopant material efficiently emits excitons obtained by recombination. It has a function.
In the case of a phosphorescent element, the host material mainly has a function of confining excitons generated by the dopant in the light emitting layer.

Here, the light emitting layer employs, for example, a double host (also referred to as host / cohost) that adjusts the carrier balance in the light emitting layer by combining an electron transporting host and a hole transporting host. The light emitting layer preferably contains a first host material and a second host material, and the first host material is preferably the organic EL device material of the present invention.
Moreover, you may employ | adopt the double dopant from which each dopant light-emits by putting in 2 or more types of dopant materials with a high quantum yield. Specifically, a mode in which yellow emission is realized by co-evaporating a host, a red dopant, and a green dopant to make the light emitting layer common is used.

The above light-emitting layer is a laminate in which a plurality of light-emitting layers are stacked, so that electrons and holes are accumulated at the light-emitting layer interface, and the recombination region is concentrated at the light-emitting layer interface to improve quantum efficiency. Can do.
The ease of injecting holes into the light emitting layer may be different from the ease of injecting electrons, and the hole transport ability and electron transport ability expressed by the mobility of holes and electrons in the light emitting layer may be different. May be different.

The light emitting layer can be formed by a known method such as a vapor deposition method, a spin coating method, or an LB method (Langmuir Broadgett method). The light emitting layer can also be formed by thinning a solution obtained by dissolving a binder such as a resin and a material compound in a solvent by a spin coating method or the like.
The light emitting layer is preferably a molecular deposited film. The molecular deposition film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidification from a material compound in a solution state or a liquid phase state. Usually, this molecular deposited film can be distinguished from a thin film (molecular accumulation film) formed by the LB method by a difference in aggregated structure, a difference in higher order structure, or a functional difference resulting therefrom.

  The dopant material is selected from known fluorescent dopants exhibiting fluorescent emission or phosphorescent dopants exhibiting phosphorescent emission.

  The phosphorescent dopant (phosphorescent material) that forms the light emitting layer is a compound that can emit light from the triplet excited state, and is not particularly limited as long as it emits light from the triplet excited state, but Ir, Pt, Os, Au, Cu, An organometallic complex containing at least one metal selected from Re and Ru and a ligand is preferable. The ligand preferably has an ortho metal bond. A metal complex containing a metal atom selected from Ir, Os, and Pt is preferable in that the phosphorescent quantum yield is high and the external quantum efficiency of the light emitting device can be further improved, and an iridium complex, an osmium complex, or a platinum complex. Are more preferable, iridium complexes and platinum complexes are more preferable, and orthometalated iridium complexes are particularly preferable.

There is no restriction | limiting in particular in content in the light emitting layer of a phosphorescent dopant, Although it can select suitably according to the objective, For example, 0.1-70 mass% is preferable and 1-30 mass% is more preferable. If the phosphorescent dopant content is 0.1% by mass or more, sufficient light emission can be obtained, and if it is 70% by mass or less, concentration quenching can be avoided.
Specific examples of preferred organometallic complexes as phosphorescent dopants are shown below.

  The phosphorescent host is a compound having a function of efficiently emitting the phosphorescent dopant by efficiently confining the triplet energy of the phosphorescent dopant in the light emitting layer. The organic EL device material of the present invention is suitable as a phosphorescent host. The light emitting layer may contain 1 type of organic EL element material of this invention, and may contain 2 or more types of organic EL element material of this invention.

  When the organic EL device material of the present invention is used as the host material of the light emitting layer, the emission wavelength of the phosphorescent dopant material contained in the light emitting layer is not particularly limited. Among these, at least one of the phosphorescent dopant materials contained in the light emitting layer preferably has a peak emission wavelength of 490 nm to 700 nm, and more preferably 490 nm to 650 nm. As a luminescent color of a light emitting layer, red, yellow, and green are preferable, for example. By using the compound of the present invention as a host material and doping a phosphorescent dopant material having such an emission wavelength to form a light emitting layer, a long-life organic EL device can be obtained.

In the organic EL device of the present invention, a compound other than the material for the organic EL device of the present invention can be appropriately selected as the phosphorescent host according to the purpose.
The organic EL device material of the present invention and other compounds may be used in combination as a phosphorescent host material in the same light emitting layer, and when there are a plurality of light emitting layers, the phosphorescent host of one of the light emitting layers. The material for an organic EL device of the present invention may be used as a material, and a compound other than the material for an organic EL device of the present invention may be used as a phosphorescent host material for another light emitting layer. Moreover, the organic EL device material of the present invention can be used for organic layers other than the light emitting layer. In that case, a compound other than the organic EL device material of the present invention is used as the phosphorescent host of the light emitting layer. May be.

  Specific examples of compounds other than the organic EL device material of the present invention and suitable as a phosphorescent host include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrins Compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidene meta Derivatives, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, metal complexes having benzoxazole and benzothiazole as ligands Various metal complexes Polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, etc. Examples thereof include molecular compounds. A phosphorescent host may be used independently and may use 2 or more types together. Specific examples include the following compounds.

When the light emitting layer contains the first host material and the second host material, the organic EL element material of the present invention is used as the first host material, and the organic EL element material other than the organic EL element material of the present invention is used as the second host material. A compound may be used. In the present invention, the terms “first host material” and “second host material” mean that the plurality of host materials contained in the light emitting layer have different structures from each other. It is not specified by the material content.
It does not specifically limit as said 2nd host material, It is a compound other than the organic EL element material of this invention, and the same thing as the above-mentioned compound as a compound suitable as a phosphorescent host is mentioned. As the second host, carbazole derivatives, arylamine derivatives, fluorenone derivatives, and aromatic tertiary amine compounds are preferable.

  The organic EL device of the present invention may have a light emitting layer containing a fluorescent light emitting material, that is, a fluorescent light emitting layer. As the fluorescent light emitting layer, known fluorescent light emitting materials can be used. The fluorescent material is preferably at least one selected from anthracene derivatives, fluoranthene derivatives, styrylamine derivatives and arylamine derivatives, and more preferably anthracene derivatives and arylamine derivatives. In particular, an anthracene derivative is preferable as the host material, and an arylamine derivative is preferable as the dopant. Specifically, suitable materials described in International Publication No. 2010/134350 and International Publication No. 2010/134352 are selected. The material for an organic EL device of the present invention may be used as a fluorescent light emitting material for the fluorescent light emitting layer or as a host material for the fluorescent light emitting layer.

The ring-forming carbon number of the anthracene derivative as the fluorescent light-emitting material is preferably 26 to 100, more preferably 26 to 80, and still more preferably 26 to 60. More specifically, the anthracene derivative is preferably an anthracene derivative represented by the following formula (10).

(In the above formula (10), Ar ³¹ and Ar ³² are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a heterocyclic group having 5 to 50 ring atoms.
R ^{81 to} R ⁸⁸ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, substituted or unsubstituted A substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted ring carbon number of 6 to 6 50 aryloxy groups, substituted or unsubstituted arylthio groups having 6 to 50 ring carbon atoms, substituted or unsubstituted alkoxycarbonyl groups having 2 to 50 carbon atoms, substituted or unsubstituted silyl groups, carboxyl groups, halogen atoms , A cyano group, a nitro group or a hydroxyl group. )
The aryl group having 6 to 50 ring carbon atoms is preferably an aryl group having 6 to 40 ring carbon atoms, and more preferably an aryl group having 6 to 30 ring carbon atoms.
The heterocyclic group having 5 to 50 ring atoms is preferably a heterocyclic group having 5 to 40 ring atoms, and more preferably a heterocyclic group having 5 to 30 ring atoms.
As said C1-C50 alkyl group, a C1-C30 alkyl group is preferable, a C1-C10 alkyl group is more preferable, and a C1-C5 alkyl group is further more preferable.
As said C1-C50 alkoxy group, a C1-C30 alkoxy group is preferable, A C1-C10 alkoxy group is more preferable, A C1-C5 alkoxy group is more preferable.
The aralkyl group having 7 to 50 carbon atoms is preferably an aralkyl group having 7 to 30 carbon atoms, and more preferably an aralkyl group having 7 to 20 carbon atoms.
The aryloxy group having 6 to 50 ring carbon atoms is preferably an aryloxy group having 6 to 40 ring carbon atoms, and more preferably an aryloxy group having 6 to 30 ring carbon atoms.
The arylthio group having 6 to 50 ring carbon atoms is preferably an arylthio group having 6 to 40 ring carbon atoms, and more preferably an arylthio group having 6 to 30 ring carbon atoms.
As the C2-C50 alkoxycarbonyl group, a C2-C30 alkoxycarbonyl group is preferable, a C2-C10 alkoxycarbonyl group is more preferable, and a C2-C5 alkoxycarbonyl group is more preferable. .
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
In particular, Ar ³¹ and Ar ³² are preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.

Moreover, as an anthracene derivative represented by Formula (10), the anthracene derivative represented by following formula (10-1) is preferable.

(In the above formula (10-1), Ar ³³ is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a heterocyclic group having 5 to 50 ring atoms. R ^{81 to} R ⁸⁸ are R ⁸⁹ is the same as the definition of R ^{81 to} R ^88. a is an integer of 1 to 7.)
R ^{81 to} R ⁸⁸ are preferably the same as described above. Also ^{it preferred} for ^{R 89} is ^also the same as R 81 ^{to R 88.} a is preferably an integer of 1 to 3, and more preferably 1 or 2.
The aryl group having 6 to 50 ring carbon atoms represented by Ar ³³ is preferably an aryl group having 6 to 40 ring carbon atoms, more preferably an aryl group having 6 to 30 ring carbon atoms, and 6 to 6 ring forming carbon atoms. 20 aryl groups are more preferable, and aryl groups having 6 to 12 ring carbon atoms are particularly preferable.

The arylamine derivative as the fluorescent light-emitting material is preferably an aryldiamine derivative, more preferably an aryldiamine derivative containing a pyrene skeleton, and further preferably an aryldiamine derivative containing a pyrene skeleton and a dibenzofuran skeleton.
More specifically, the aryldiamine derivative is preferably an aryldiamine derivative represented by the following formula (11).

(In the formula (11), Ar ^{34 to} Ar ³⁷ are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms. Represents.
L ²¹ represents a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroarylene group having 5 to 50 ring atoms. )
The aryl group having 6 to 50 ring carbon atoms is preferably an aryl group having 6 to 30 ring carbon atoms, more preferably an aryl group having 6 to 20 ring carbon atoms, and an aryl group having 6 to 12 ring carbon atoms. A group is more preferable, and a phenyl group and a naphthyl group are particularly preferable.
The heteroaryl group having 5 to 50 ring atoms is preferably a heteroaryl group having 5 to 40 ring atoms, more preferably a heteroaryl group having 5 to 30 ring atoms, and 5 to 5 ring forming atoms. More preferred are 20 heteroaryl groups. Examples of the heteroaryl group include a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, and the like, and a dibenzofuranyl group is preferable. Preferable substituents for the heteroaryl group include aryl groups having 6 to 30 ring carbon atoms (preferably 6 to 20, more preferably 6 to 12), and more preferably a phenyl group and a naphthyl group.
The arylene group having 6 to 50 ring carbon atoms is preferably an arylene group having 6 to 40 ring carbon atoms, more preferably an arylene group having 6 to 30 ring carbon atoms, and an arylene group having 6 to 20 ring carbon atoms. The group is more preferable, and the pyrenyl group is particularly preferable.

  The thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 7 to 50 nm, and still more preferably 10 to 50 nm. When the thickness is 5 nm or more, it is easy to form a light emitting layer, and when the thickness is 50 nm or less, an increase in driving voltage is avoided.

(Electron donating dopant)
The organic EL device of the present invention preferably has an electron donating dopant in the interface region between the cathode and the light emitting unit. According to such a configuration, it is possible to improve the light emission luminance and extend the life of the organic EL element. Here, the electron donating dopant means a material containing a metal having a work function of 3.8 eV or less, and specific examples thereof include alkali metals, alkali metal complexes, alkali metal compounds, alkaline earth metals, alkaline earths. Examples thereof include at least one selected from metal complexes, alkaline earth metal compounds, rare earth metals, rare earth metal complexes, rare earth metal compounds, and the like.

  Examples of the alkali metal include Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV), Cs (work function: 1.95 eV), and the like. A function of 2.9 eV or less is particularly preferable. Of these, K, Rb, and Cs are preferred, Rb and Cs are more preferred, and Cs is most preferred. Examples of the alkaline earth metal include Ca (work function: 2.9 eV), Sr (work function: 2.0 eV to 2.5 eV), Ba (work function: 2.52 eV), and the like. The thing below 9 eV is especially preferable. Examples of rare earth metals include Sc, Y, Ce, Tb, Yb, and the like, and those having a work function of 2.9 eV or less are particularly preferable.

Examples of the alkali metal compound include alkali oxides such as Li ₂ O, Cs ₂ O, and K ₂ O, and alkali halides such as LiF, NaF, CsF, and KF, and LiF, Li ₂ O, and NaF are preferable. Examples of the alkaline earth metal compound include BaO, SrO, CaO, Ba _x Sr _1-x O (0 <x <1), Ba _x Ca _1-x O (0 <x <1), and the like obtained by mixing these. BaO, SrO, and CaO are preferable. The rare earth metal _{compound, YbF 3, ScF 3, ScO} 3, Y 2 O 3, Ce 2 O 3, GdF 3, TbF 3 and the _{like, YbF 3, ScF 3, TbF} 3 are preferable.

  The alkali metal complex, alkaline earth metal complex, and rare earth metal complex are not particularly limited as long as each metal ion contains at least one of an alkali metal ion, an alkaline earth metal ion, and a rare earth metal ion. The ligands include quinolinol, benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyl oxazole, hydroxyphenyl thiazole, hydroxydiaryl thiadiazole, hydroxydiaryl thiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, Hydroxyfulborane, bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene, β-diketones, azomethines, and derivatives thereof are preferred, but are not limited thereto.

  As an addition form of the electron donating dopant, it is preferable to form a layered or island shape in the interface region. As a forming method, while depositing an electron donating dopant by resistance heating vapor deposition, an organic compound (light emitting material or electron injecting material) that forms an interface region is simultaneously deposited, and the electron donating dopant is dispersed in the organic compound. Is preferred. The dispersion concentration is organic compound: electron-donating dopant = 100: 1 to 1: 100, preferably 5: 1 to 1: 5 in molar ratio.

In the case where the electron donating dopant is formed in a layered form, after forming the light emitting material or the electron injecting material, which is an organic layer at the interface, in a layered form, the reducing dopant is vapor-deposited by a resistance heating vapor deposition method. .1 nm to 15 nm. When the electron donating dopant is formed in an island shape, after forming the light emitting material and the electron injecting material, which are organic layers at the interface, in an island shape, the electron donating dopant is deposited by resistance heating vapor deposition alone, preferably The island is formed with a thickness of 0.05 nm to 1 nm.
In the organic EL device of the present invention, the ratio of the main component to the electron donating dopant is preferably in the molar ratio of main component: electron donating dopant = 5: 1 to 1: 5, and 2: 1 to 1: 2. More preferably.

(Electron transport layer)
The electron transport layer is an organic layer formed between the light emitting layer and the cathode, and has a function of transporting electrons from the cathode to the light emitting layer. When the electron transport layer is composed of a plurality of layers, an organic layer close to the cathode may be defined as an electron injection layer. The electron injection layer has a function of efficiently injecting electrons from the cathode into the organic layer unit. The organic EL device material of the present invention is also suitable as an electron transport layer material for forming an electron transport layer.

In addition to the organic EL device material of the present invention, as the electron transporting material used for the electron transporting layer, an aromatic heterocyclic compound containing one or more heteroatoms in the molecule is preferably used, and particularly a nitrogen-containing ring derivative is used. preferable. The nitrogen-containing ring derivative is preferably an aromatic ring having a nitrogen-containing 6-membered ring or 5-membered ring skeleton, or a condensed aromatic ring compound having a nitrogen-containing 6-membered ring or 5-membered ring skeleton.
As this nitrogen-containing ring derivative, for example, a nitrogen-containing ring metal chelate complex represented by the following formula (A) is preferable.

R ^{2 to} R ⁷ in the formula (A) which is a nitrogen-containing ring metal chelate complex are each independently a hydrogen atom, a deuterium atom, a halogen atom, a hydroxyl group, an amino group, a hydrocarbon group having 1 to 40 carbon atoms, An alkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 50 carbon atoms, an alkoxycarbonyl group, or an aromatic heterocyclic group having 5 to 50 ring carbon atoms, which may be substituted. .

Examples of the halogen atom include fluorine, chlorine, bromine, iodine and the like.
Examples of the amino group which may be substituted include an alkylamino group, an arylamino group and an aralkylamino group.
The alkylamino group and the aralkylamino group are represented as —NQ ¹ Q ² . Q ¹ and Q ² each independently represent an alkyl group having 1 to 20 carbon atoms or an aralkyl group having 1 to 20 carbon atoms. One of Q ¹ and Q ² may be a hydrogen atom or a deuterium atom.
The arylamino group is represented as —NAr ¹ Ar ^2, and Ar ¹ and Ar ² each independently represent a non-condensed aromatic hydrocarbon group or a condensed aromatic hydrocarbon group having 6 to 50 carbon atoms. One of Ar ¹ and Ar ² may be a hydrogen atom or a deuterium atom.

The hydrocarbon group having 1 to 40 carbon atoms includes an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and an aralkyl group.
The alkoxycarbonyl group is represented as —COOY ′, and Y ′ represents an alkyl group having 1 to 20 carbon atoms.
M is aluminum (Al), gallium (Ga) or indium (In), and is preferably In.
L is a group represented by the following formula (A ′) or (A ″).

In formula (A ′), R ^{8 to} R ¹² are each independently a hydrogen atom, a deuterium atom, or a substituted or unsubstituted hydrocarbon group having 1 to 40 carbon atoms, and groups adjacent to each other are cyclic structures May be formed. In the formula (A ″), R ^{13 to} R ²⁷ are each independently a hydrogen atom, a deuterium atom, or a substituted or unsubstituted hydrocarbon group having 1 to 40 carbon atoms, and groups adjacent to each other are An annular structure may be formed.

In the formula (A), the hydrocarbon group having 1 to 40 carbon atoms represented by R ^{8 to} R ¹² and R ^{13 to} R ^{27 in the} formula (A ′) and the formula (A ″) is a nitrogen-containing ring metal chelate complex. The divalent group in the case where R ^{8 to} R ¹² and the groups adjacent to R ^{13 to} R ²⁷ form a cyclic structure is the same as the hydrocarbon group represented by R ^{2 to} R ⁷ of Examples include methylene group, pentamethylene group, hexamethylene group, diphenylmethane-2,2′-diyl group, diphenylethane-3,3′-diyl group, diphenylpropane-4,4′-diyl group and the like.

  As the electron transport compound used for the electron transport layer, 8-hydroxyquinoline or a metal complex of its derivative, an oxadiazole derivative, and a nitrogen-containing heterocyclic derivative are preferable. As a specific example of the metal complex of 8-hydroxyquinoline or a derivative thereof, a metal chelate oxinoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline), for example, tris (8-quinolinol) aluminum is used. Can do. And as an oxadiazole derivative, the following can be mentioned.

In the above formula, Ar ¹⁷ , Ar ¹⁸ , Ar ¹⁹ , Ar ²¹ , Ar ²² and Ar ²⁵ each represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms or a condensed aromatic hydrocarbon group, Ar ¹⁷ and Ar ¹⁸ , Ar ¹⁹ and Ar ²¹ , Ar ²² and Ar ²⁵ may be the same or different. Examples of the aromatic hydrocarbon group or the condensed aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenyl group, an anthranyl group, a perylenyl group, and a pyrenyl group. Examples of these substituents include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a cyano group.

Ar ²⁰ , Ar ²³ and Ar ²⁴ each represent a substituted or unsubstituted divalent aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 50 carbon atoms, and Ar ²³ and Ar ²⁴ are identical to each other. But it can be different. Examples of the divalent aromatic hydrocarbon group or condensed aromatic hydrocarbon group include a phenylene group, a naphthylene group, a biphenylene group, an anthranylene group, a peryleneylene group, and a pyrenylene group. Examples of these substituents include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a cyano group.

  As these electron transfer compounds, those having good thin film forming properties are preferably used. Specific examples of these electron transfer compounds include the following.

  The nitrogen-containing heterocyclic derivative as the electron transfer compound is a nitrogen-containing heterocyclic derivative composed of an organic compound having the following formula, and includes a nitrogen-containing compound that is not a metal complex. Examples thereof include a 5-membered ring or 6-membered ring containing a skeleton represented by the following formula (B) and a structure represented by the following formula (C).

In the formula (C), X represents a carbon atom or a nitrogen atom. Z ₁ and Z ₂ each independently represents an atomic group capable of forming a nitrogen-containing heterocycle.

  The nitrogen-containing heterocyclic derivative is more preferably an organic compound having a nitrogen-containing aromatic polycyclic group consisting of a 5-membered ring or a 6-membered ring. Further, in the case of such a nitrogen-containing aromatic polycyclic group having a plurality of nitrogen atoms, the nitrogen-containing compound having a skeleton in which the above formulas (B) and (C) or the above formula (B) and the following formula (D) are combined. Aromatic polycyclic organic compounds are preferred.

  The nitrogen-containing group of the nitrogen-containing aromatic polycyclic organic compound is selected from, for example, nitrogen-containing heterocyclic groups represented by the following formulae.

  In each of the above formulas, R is an aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 40 carbon atoms, an aromatic heterocyclic group or condensed aromatic heterocyclic group having 3 to 40 carbon atoms, or 1 to 1 carbon atoms. 20 is an alkyl group or an alkoxy group having 1 to 20 carbon atoms, n is an integer of 0 to 5, and when n is an integer of 2 or more, a plurality of R may be the same or different from each other.

Furthermore, preferred specific compounds include nitrogen-containing heterocyclic derivatives represented by the following formula (D1).
HAr-L ¹ -Ar ¹ -Ar ² (D1)
In the formula (D1), HAr is a substituted or unsubstituted nitrogen-containing heterocyclic group having 3 to 40 carbon atoms, and L ¹ is a single bond, substituted or unsubstituted aromatic hydrocarbon having 6 to 40 carbon atoms. A group, a condensed aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group having 3 to 40 carbon atoms or a condensed aromatic heterocyclic group, and Ar ¹ is a substituted or unsubstituted 2 to 6 carbon atom having 2 to 6 carbon atoms. And Ar ² is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 carbon atoms, a condensed aromatic hydrocarbon group, or a substituted or unsubstituted aromatic group having 3 to 40 carbon atoms. It is a heterocyclic group or a condensed aromatic heterocyclic group.

HAr is selected from the following group, for example.

L ¹ in the formula (D1) is selected from the following group, for example.

Ar ¹ in the formula (D1) is selected from, for example, arylanthranyl groups of the following formulas (D2) and (D3).

In Formula (D2) and Formula (D3), R ^{1 to} R ¹⁴ are each independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy having 1 to 20 carbon atoms. Group, aryloxy group having 6 to 40 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 40 carbon atoms, or substituted or unsubstituted aromatic group having 3 to 40 carbon atoms A heterocyclic group or a condensed aromatic heterocyclic group, and Ar ³ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 carbon atoms or a condensed aromatic hydrocarbon group or substituted or unsubstituted carbon atoms having 3 to 3 carbon atoms. 40 aromatic heterocyclic groups or condensed aromatic heterocyclic groups. Further, R ^{1 to} R ⁸ may be nitrogen-containing heterocyclic derivatives each of which is a hydrogen atom or a deuterium atom.

Ar ² in the formula (D1) is selected from the following group, for example.

  In addition to these, the following compounds are also preferably used as the nitrogen-containing aromatic polycyclic organic compound as the electron transfer compound.

In formula (D4), R _{1 to} R ₄ each independently represent a hydrogen atom, a deuterium atom, a substituted or unsubstituted aliphatic group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon number of 3 to 20 An aliphatic cyclic group, a substituted or unsubstituted aromatic ring group having 6 to 50 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 50 carbon atoms, and X ₁ and X ₂ are each independently Represents an oxygen atom, a sulfur atom, or a dicyanomethylene group.

In addition, the following compounds are also preferably used as the electron transfer compound.

In the formula (D5), R ¹ , R ² , R ³ and R ⁴ are the same or different groups, and are an aromatic hydrocarbon group or a condensed aromatic hydrocarbon group represented by the following formula (D6). It is.

In the formula (D6), R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are the same or different from each other, and are a hydrogen atom, a deuterium atom, a saturated or unsaturated alkoxy group having 1 to 20 carbon atoms. Group, a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, an amino group, or an alkylamino group having 1 to 20 carbon atoms. At least one of R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ is a group other than a hydrogen atom or a deuterium atom.

  Furthermore, the electron transfer compound may be a polymer compound containing the nitrogen-containing heterocyclic group or the nitrogen-containing heterocyclic derivative.

The electron transport layer of the organic EL device of the present invention particularly preferably contains at least one nitrogen-containing heterocyclic derivative represented by the following formulas (E) to (G).

(In Formula (E) to Formula (G), Z ¹ , Z ^2, and Z ³ are each independently a nitrogen atom or a carbon atom.
R ¹ and R ² are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms, substituted or unsubstituted carbon. They are a C1-C20 alkyl group, a substituted or unsubstituted C1-C20 haloalkyl group, or a substituted or unsubstituted C1-C20 alkoxy group.

n is an integer of 0 to 5, and when n is an integer of 2 or more, the plurality of R ¹ may be the same as or different from each other. Further, two adjacent R ¹ may be bonded to each other to form a substituted or unsubstituted hydrocarbon ring.
Ar ¹ is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.
Ar ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted Alternatively, it is an unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.

However, ^one of Ar ¹ and Ar ² is a substituted or unsubstituted condensed aromatic hydrocarbon ring group having 10 to 50 ring carbon atoms or a substituted or unsubstituted condensed aromatic group having 9 to 50 ring atoms. It is a heterocyclic group.
Ar ³ is a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroarylene group having 5 to 50 ring atoms.
L ¹ , L ² and L ³ are each independently a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent ring having 9 to 50 ring atoms. A condensed aromatic heterocyclic group. )

Examples of the aryl group having 6 to 50 ring carbon atoms include phenyl, naphthyl, anthryl, phenanthryl, naphthacenyl, chrysenyl, pyrenyl, biphenyl, terphenyl, tolyl, fluoranthenyl, fluorenyl Groups and the like.
Examples of heteroaryl groups having 5 to 50 ring atoms include pyrrolyl, furyl, thienyl, silolyl, pyridyl, quinolyl, isoquinolyl, benzofuryl, imidazolyl, pyrimidyl, carbazolyl, selenophenyl Group, oxadiazolyl group, triazolyl group, pyrazinyl group, pyridazinyl group, triazinyl group, quinoxalinyl group, acridinyl group, imidazo [1,2-a] pyridinyl group, imidazo [1,2-a] pyrimidinyl group and the like.

Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the haloalkyl group having 1 to 20 carbon atoms include groups obtained by substituting one or more hydrogen atoms of the alkyl group with at least one halogen atom selected from fluorine, chlorine, iodine and bromine.
Examples of the alkoxy group having 1 to 20 carbon atoms include groups having the alkyl group as an alkyl moiety.
Examples of the arylene group having 6 to 50 ring carbon atoms include a group obtained by removing one hydrogen atom from the aryl group.
Examples of the divalent condensed aromatic heterocyclic group having 9 to 50 ring atoms include groups obtained by removing one hydrogen atom from the condensed aromatic heterocyclic group described as the heteroaryl group.

Although the film thickness of an electron carrying layer is not specifically limited, Preferably it is 1 nm-100 nm.
Moreover, it is preferable to use an insulator or a semiconductor as an inorganic compound in addition to the nitrogen-containing ring derivative as a component of the electron injection layer that can be provided adjacent to the electron transport layer. If the electron injection layer is made of an insulator or a semiconductor, current leakage can be effectively prevented and the electron injection property can be improved.

As such an insulator, it is preferable to use at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is preferable in that the electron injection property can be further improved. Specifically, preferable alkali metal chalcogenides include, for example, Li ₂ O, K ₂ O, Na ₂ S, Na ₂ Se, and Na ₂ O, and preferable alkaline earth metal chalcogenides include, for example, CaO, BaO. , SrO, BeO, BaS and CaSe. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

  Further, as a semiconductor, an oxide, nitride, or oxynitride containing at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and Zn. One kind alone or a combination of two or more kinds of products may be mentioned. In addition, the inorganic compound constituting the electron injection layer is preferably a microcrystalline or amorphous insulating thin film. If the electron injection layer is composed of these insulating thin films, a more uniform thin film is formed, and pixel defects such as dark spots can be reduced. Examples of such inorganic compounds include alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides.

  When such an insulator or semiconductor is used, the preferred thickness of the layer is about 0.1 nm to 15 nm. Further, the electron injection layer in the present invention is preferable even if it contains the above-mentioned electron donating dopant.

(Hole transport layer)
An organic layer formed between the light emitting layer and the anode, and has a function of transporting holes from the anode to the light emitting layer. When the hole transport layer is composed of a plurality of layers, an organic layer close to the anode may be defined as a hole injection layer. The hole injection layer has a function of efficiently injecting holes from the anode into the organic layer unit.

As another material for forming the hole transport layer, an aromatic amine compound, for example, an aromatic amine derivative represented by the following formula (H) is preferably used.

In the formula (H), Ar ^{1 to} Ar ⁴ represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 ring carbon atoms or a condensed aromatic hydrocarbon group, a substituted or unsubstituted ring forming atom number of 5 to 5 50 aromatic heterocyclic groups or condensed aromatic heterocyclic groups, or a group in which these aromatic hydrocarbon groups or condensed aromatic hydrocarbon groups and aromatic heterocyclic groups or condensed aromatic heterocyclic groups are bonded.
In the formula (H), L represents a substituted or unsubstituted aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted ring atom number of 5 to 50. Represents an aromatic heterocyclic group or a condensed aromatic heterocyclic group.

Specific examples of the compound of formula (H) are shown below.

  An aromatic amine represented by the following formula (J) is also preferably used for forming the hole transport layer.

In the formula (J), the definitions of Ar ^{1 to} Ar ³ are the same as the definitions of Ar ^{1 to} Ar ^{4 in} the formula (H). Specific examples of the compound of formula (J) are shown below, but are not limited thereto.

The hole transport layer of the organic EL device of the present invention may have a two-layer structure of a first hole transport layer (anode side) and a second hole transport layer (cathode side).
Although the film thickness of a positive hole transport layer is not specifically limited, It is preferable that it is 10-200 nm.

In the organic EL device of the present invention, a layer containing an acceptor material may be bonded to the anode side of the hole transport layer or the first hole transport layer. This is expected to reduce drive voltage and manufacturing costs.
As the acceptor material, a compound represented by the following formula (K) is preferable.

(In the above formula (K), R _{21 to} R ₂₆ may be the same as or different from each other, and each independently represents a cyano group, —CONH ₂ , a carboxyl group, or —COOR ₂₇ (R ₂₇ has 1 to 20 carbon atoms). Represents an alkyl group or a cycloalkyl group having 3 to 20 carbon atoms, provided that one or two or more pairs of R ₂₁ and R ₂₂ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ are combined. A group represented by -CO-O-CO- may be formed.)
Examples of R ₂₇ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, and a cyclohexyl group.
The thickness of the layer containing the acceptor material is not particularly limited, but is preferably 5 to 20 nm.

(N / p doping)
In the hole transport layer and the electron transport layer described above, as described in Japanese Patent No. 3695714, the carrier injection ability is improved by doping the donor material (n) and acceptor material (p). Can be adjusted.
A typical example of n doping is a method of doping a metal such as Li or Cs into an electron transport material, and a typical example of p doping is F ₄ TCNQ (2, 3, 5, 6) as a hole transport material. -Tetrafluor-7,7,8,8-tetracyanoquinodimethane) and the like may be used.

(Space layer)
For example, when the fluorescent layer and the phosphorescent layer are laminated, the space layer is a fluorescent layer for the purpose of adjusting the carrier balance so that excitons generated in the phosphorescent layer are not diffused into the fluorescent layer. It is a layer provided between the layer and the phosphorescent light emitting layer. In addition, the space layer can be provided between the plurality of phosphorescent light emitting layers.
Since the space layer is provided between the light emitting layers, a material having both electron transport properties and hole transport properties is preferable. In order to prevent diffusion of triplet energy in the adjacent phosphorescent light emitting layer, the triplet energy is preferably 2.6 eV or more. Examples of the material used for the space layer include the same materials as those used for the above-described hole transport layer.

(Barrier layer)
The organic EL device of the present invention preferably has a barrier layer such as an electron barrier layer, a hole barrier layer, or a triplet barrier layer in a portion adjacent to the light emitting layer. Here, the electron barrier layer is a layer that prevents electrons from leaking from the light emitting layer to the hole transport layer, and the hole barrier layer is a layer that prevents holes from leaking from the light emitting layer to the electron transport layer. is there.
The triplet barrier layer prevents the triplet excitons generated in the light emitting layer from diffusing into the surrounding layers, and confins the triplet excitons in the light emitting layer, thereby transporting electrons other than the light emitting dopant of the triplet excitons. It has a function of suppressing energy deactivation on the molecules of the layer.

In the case where a triplet barrier layer is provided, in the phosphorescent device, if the triplet energy of the phosphorescent dopant in the light emitting layer is E ^T _d and the triplet energy of the compound used as the triplet barrier layer is E ^T _TB , E ^T _d < If the energy magnitude relationship of E ^T _TB is satisfied, the triplet exciton of the phosphorescent dopant is confined (cannot move to other molecules) and the energy deactivation path other than light emission on the dopant is interrupted. It is assumed that light can be emitted with high efficiency. However, even if the relationship of E ^T _d <E ^T _TB is satisfied, if this energy difference ΔE ^T = E ^T _TB −E ^T _d is small, under the environment of room temperature, which is the actual element driving environment, , endothermically triplet excitons overcame this energy difference Delta] E ^T by thermal energy near is considered to be possible to move to another molecule. In particular, in the case of phosphorescence emission, the exciton lifetime is longer than that of fluorescence emission, so that the influence of the endothermic exciton transfer process is likely to appear. The energy difference ΔE ^T is preferably as large as possible relative to the thermal energy at room temperature, more preferably 0.1 eV or more, and particularly preferably 0.2 eV or more. On the other hand, in the fluorescent element, the organic EL element material of the present invention can be used as a triplet barrier layer having a TTF element structure described in International Publication WO2010 / 134350A1.

Further, the electron mobility of the material constituting the triplet barrier layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of the electric field strength of 0.04 to 0.5 MV / cm. As a method for measuring the electron mobility of an organic material, several methods such as the Time of Flight method are known. Here, the electron mobility is determined by impedance spectroscopy.
The electron injection layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of electric field strength of 0.04 to 0.5 MV / cm. This facilitates the injection of electrons from the cathode into the electron transport layer, and also promotes the injection of electrons into the adjacent barrier layer and the light emitting layer, thereby enabling driving at a lower voltage.

The organic EL device of the present invention can be used in a panel module used for various displays as a light emitting device.
The organic EL device of the present invention can be used for display devices such as televisions, portable terminals, personal computers, and electronic devices such as lighting.

[Synthesis of benzotriazole derivatives]
Synthesis Example 1 (Synthesis of Compound 1)
(1) Synthesis of boronic acid intermediate

(A) Synthesis of Intermediate (A) Under an argon atmosphere, benzotriazole (23.6 g, 198 mmol), 1-bromo-4-iodobenzene (50.9 g, 180 mmol), copper (I) iodide (3.43 g) DMF (400 mL) was added to cesium carbonate (117 g, 360 mmol), and the mixture was stirred at 140 ° C. for 15 hours. After the reaction, the reaction mixture was diluted with toluene and water, and the organic layer was washed 3 times with water, dried over magnesium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel column chromatography to obtain intermediate (A) (23.2 g, 84.6 mmol) (yield 47%).

(B) Synthesis of intermediate (B) Under argon atmosphere, intermediate (A) (13.2 g, 48.0 mmol), bis (pinacolato) diboron (18.3 g, 72.0 mmol), 1,1′-bis 1,4-Dioxane (150 mL) was added to (diphenylphosphino) ferrocene-palladium (II) dichloride (1.96 g, 2.40 mmol) and potassium acetate (9.42 g, 96.0 mmol), and the mixture was heated to reflux for 9 hours. Stirred under. After cooling to room temperature, the reaction solution was extracted with ethyl acetate, washed twice with water, dried over magnesium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel column chromatography to obtain intermediate (B) (8.44 g, 26.4 mmol) (yield 55%).

(2) Synthesis of compound (1)

  Under an argon atmosphere, intermediate (A) (5.48 g, 20.0 mmol), 10- (2-naphthyl) anthracene-9-boronic acid (10.4 g, 30.0 mmol), palladium (II) acetate (225 mg, 1.00 mmol), 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl (821 mg, 10.0 mmol), potassium phosphate (8.49 g, 60.0 mmol), tetrahydrofuran (100 mL) and mixed for 8 hours. The mixture was stirred under heating to reflux. After cooling to room temperature, the reaction mixture was filtered, passed through a short column, and then washed with ethyl acetate to obtain compound (1) (2.99 g, 6.00 mmol) (yield 30%). As a result of mass spectrometry, this compound was the target product, and the molecular weight was 497.60 and m / e = 497.

Synthesis Example 2 (Synthesis of Compound (2))

  In the synthesis of compound (1), (4- (1H-benzo [d] [1,2,3] triazol-1-yl) phenylboronic acid instead of 10- (2-naphthyl) anthracene-9-boronic acid 9,9- (5-bromo-1,3-phenylene) bis-9H-carbazole instead of 1- (4-bromophenyl) -1H-benzo [d] [1,2,3] triazole The compound (2) was synthesized in the same manner as described above, and as a result of mass spectrometry, the target compound was found to be m / e = 502 with respect to a molecular weight of 502.58.

Synthesis Example 3 (Synthesis of Compound (3))

  In the synthesis of compound (1), (4- (1H-benzo [d] [1,2,3] triazol-1-yl) phenylboronic acid instead of 10- (2-naphthyl) anthracene-9-boronic acid Was synthesized in the same manner except that 2- (4′-bromobiphenyl-4-yl) dibenzofuran was used instead of 1- (4-bromophenyl) -1H-benzo [d] [1,2,3] triazole. As a result of mass spectrometry, this compound was the target product, and the molecular weight was 513.60, and m / e = 513.

Synthesis Example 4 (Synthesis of Compound (4))

  In the synthesis of compound (1), 3- (9-phenylcarbazol-3-yl) -9H-carbazole was used instead of 10- (2-naphthyl) anthracene-9-boronic acid, and palladium (II) acetate was used instead. Tris (dibenzylideneacetone) dipalladium (0), tri-t-butylphosphine instead of 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl, and sodium t-butoxy instead of potassium phosphate The compound (4) was obtained in the same manner using toluene instead of tetrahydrofuran. As a result of mass spectrometry, the compound was a target product, and the molecular weight was 601.71, and m / e = 601.

Synthesis Example 5 (Synthesis of Compound (5))

  Under an argon atmosphere, 2,6-diiodo-9,10-dinaphthalen-2-yl-anthracene (3.00 g, 4.40 mmol), benzotriazole (2.62 g, 22.0 mmol), copper (I) iodide DMSO (30 mL) was added to (167 g, 0.879 mmol), trans-N, N′-dimethyl-1,2-cyclohexanediamine (250 g, 1.76 mmol) and potassium phosphate (6.53 g, 30.8 mmol). , And stirred at 150 ° C. for 10 hours. After the reaction, the reaction mixture was diluted with dichloromethane, and the organic layer was washed with 1% HCl, water and saturated brine, dried over magnesium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel column chromatography to obtain compound (5) (1.23 g, 1.85 mmol) (yield 42%). As a result of mass spectrometry, this compound was the target product. The molecular weight was 664.77, and m / e = 664.

[Production of organic EL element]
Example 1
A 25 mm × 75 mm × 1.1 mm thick glass substrate with ITO transparent electrode (anode) (manufactured by Geomatic) was ultrasonically cleaned in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes. The glass substrate with the transparent electrode line after the cleaning is attached to the substrate holder of the vacuum deposition apparatus, and first, the following compound HI-1 is deposited on the surface on which the transparent electrode line is formed so as to cover the transparent electrode. Then, a HI-1 film having a thickness of 10 nm was formed to form a hole injection layer.
Next, on this hole injection layer, the following compound A-1 was deposited as a first hole transport material to form an A-1 film having a thickness of 80 nm, thereby forming a first hole transport layer.
Next, the following compound A-2 was vapor-deposited on the first hole transport layer to form an A-2 film having a thickness of 10 nm, thereby forming a second hole transport layer.

Further, on the A-2 film, the following host H-1 and the following dopant D-1 were formed by co-evaporation at a film thickness ratio of 24: 1 with a film thickness of 25 nm to form a light emitting layer. A compound (1) synthesized in Synthesis Example 1 and lithium 8-hydroxyquinolate (Liq) with a film thickness of 35 nm were formed on the light emitting layer by co-evaporation at a film thickness ratio of 1: 1, did.
An organic EL element was formed by depositing metal Al on the electron transport layer to a thickness of 80 nm to form a metal cathode.

The organic EL element produced as described above was caused to emit light by a direct current of 10 mA / cm ² and the luminous efficiency was measured. As a result, the external light emission quantum efficiency was 5.50%. Thereby, it was found that the compound of this example can be applied to an organic EL device.

  Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Organic EL element 2 Substrate 3 Anode 4 Cathode 5 Light emitting layer 6 Hole injection / transport layer 7 Electron injection / transport layer 10 Light emitting unit

Claims (20)

A benzotriazole derivative represented by the following formula (1-1) .

(Wherein R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent,
L is a single bond or a linking group;
A is a group having a condensed ring structure of 3 or more rings,
n is an integer of 1 to 4, and m is an integer of 1 to 4.
The condensed ring structure of 3 or more rings of A includes an anthracene ring, benzoanthracene ring, phenanthrene ring, benzophenanthrene ring, benzofluorene ring, dibenzofluorene ring, picene ring, tetracene ring, pentacene ring, chrysene ring, benzochrysene ring, s -An indacene ring, an as-indacene ring, a fluoranthene ring, a benzofluoranthene ring, a triphenylene ring, a benzotriphenylene ring, a perylene ring, a coronene ring, or a dibenzoanthracene ring.
The linking group of L is substituted or unsubstituted aromatic hydrocarbon ring group, substituted or unsubstituted aromatic heterocyclic group, or substituted or unsubstituted aromatic hydrocarbon ring group, substituted or unsubstituted A group in which at least one unsubstituted aromatic heterocyclic group is linked.
When m is 2 or more, the plurality of A may be the same as or different from each other.
When n is 2 or more, the plurality of R _{1 to} R ₄ may be the same as or different from each other.
Adjacent R _{1 to} R ₄ may be bonded to each other to form a ring structure. ) A benzotriazole derivative represented by the following formula (1-2) .

(Wherein R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent,
L is a single bond or a linking group;
A is a group represented by the following formula (5) ,
n is an integer of 1 to 4, and m is an integer of 1 to 4.
The linking group of L is substituted or unsubstituted aromatic hydrocarbon ring group, substituted or unsubstituted aromatic heterocyclic group, or substituted or unsubstituted aromatic hydrocarbon ring group, substituted or unsubstituted A group in which at least one unsubstituted aromatic heterocyclic group is linked.
When m is 2 or more, the plurality of A may be the same as or different from each other.
When n is 2 or more, the plurality of R _{1 to} R ₄ may be the same as or different from each other.
Adjacent R _{1 to} R ₄ may be bonded to each other to form a ring structure. )

(In Formula (5), X ₁ represents NR ₂₁ , and R ₂₁ represents a single bond or a substituent.
A _{21 to} A ₂₈ each independently represent CR ₂₂ or a nitrogen atom N, and R ₂₂ represents a single bond, a hydrogen atom or a substituent. If R ₂₂ is plural, R ₂₂ may be the same or different, may form a bonded is adjacent R ₂₂ together a ring structure.
At least one of A _{21 to} A ₂₈ and X ₁ is bonded to the nitrogen atom of the benztriazole ring of the formula (1) through a single bond or a linking group. ) The benzotriazole derivative according to claim 1 or 2 , wherein n is 1. The benzotriazole derivative according to claim 1, wherein A is represented by the following formula (2).

(In the formula (2), R _{11 to} R ₂₀ each independently represents a single bond, a hydrogen atom, or a substituent, and at least one of the above formulas (1 −1 ) through a single bond or a linking group L. To the nitrogen atom of the benztriazole ring of The benzotriazole derivative according to claim 4, which is a compound represented by the following formula (3).

(In the formula, R _{1 to} R ₄ , R _{11 to} R ₂₀ and L each independently represent the same groups as those in the formula (1 -1 ) and the formula (2). The group is bonded to the nitrogen atom of the benztriazole ring through a single bond or a linking group L.) The benzotriazole derivative according to claim 5, which is a compound represented by the following formula (4).

(In the formula, R _{1 to} R ₄ , R _{11 to} R _20, and L each independently represent the same group as in the formula (1 -1 ) and the formula (2)). 7. The R _{20 according} to claim 4, wherein R ₂₀ is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms. Benzotriazole derivatives. The benzotriazole derivative according to claim 2 , which is a compound represented by the following formula (6).

_{(Wherein, R 1 ~R 4, A 21} ~A 28, X 1, and L are each independently, the formula (1 -2) and (5) represent the same group. Equation (6) The group in parentheses is bonded to the nitrogen atom of the benztriazole ring through a single bond or a linking group L.) The benzotriazole derivative according to claim 8, which is a compound represented by the following formula (7).

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , and L each independently represent the same group as in the formula (6).) The benzotriazole derivative according to claim 8 , which is a compound represented by the following formula (8).

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , X ₁ , and L each independently represent the same group as the formula (6). One of A _{21 to} A ₂₄ is It is bonded to the nitrogen atom of the L or benztriazole ring by a single bond.) The benzotriazole derivative according to claim 10 , which is a compound represented by the following formula (9).

(In the formula, R _{1 to} R ₄ , A _{21 to} A ₂₈ , X ₁ , and L each independently represent the same group as in the formula (8). A ₂₃ represents L or a benztriazole ring by a single bond. It is bonded to the nitrogen atom of A material for an organic electroluminescence device containing a benzotriazole derivative as claimed in any one of claims 1 to 11. Have one or more organic thin film layers including a light emitting layer between a cathode and an anode, at least one layer of the organic thin film layer, an organic electro-containing benzotriazole derivative according to any one of claims 1 to 11 Luminescence element. The organic electroluminescence device according to claim 13 , wherein the light emitting layer contains the benzotriazole derivative. The organic electroluminescence device according to claim 13 or 14 , further comprising an anode-side organic thin film layer between the anode and the light emitting layer, wherein the anode-side organic thin film layer contains the benzotriazole derivative. The organic electroluminescence device according to claim 13 , further comprising a cathode-side organic thin film layer between the cathode and the light-emitting layer, wherein the cathode-side organic thin film layer contains the benzotriazole derivative. . The organic electroluminescent element according to claim 13 , wherein the light emitting layer contains a fluorescent light emitting material. The organic electroluminescent element according to claim 13 , wherein the light emitting layer contains a phosphorescent material. The organic electroluminescent device according to claim 18 , wherein the phosphorescent material is an orthometalated complex of a metal atom selected from iridium (Ir), osmium (Os) and platinum (Pt). An electronic device provided with the organic electroluminescent element in any one of Claims 13-19 .

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