WO2009084544A1

WO2009084544A1 - Nitrogen-containing heterocyclic derivative and organic electroluminescent device using the same

Info

Publication number: WO2009084544A1
Application number: PCT/JP2008/073464
Authority: WO
Inventors: Hiroshi Yamamoto; Takashi Arakane
Original assignee: Idemitsu Kosan Co., Ltd.
Priority date: 2007-12-27
Filing date: 2008-12-24
Publication date: 2009-07-09
Also published as: TW200936569A

Abstract

Disclosed is a novel nitrogen-containing heterocyclic derivative having a specific structure, which is useful as a constituent of an organic EL device. Also disclosed is an organic electroluminescent device having one or more organic thin film layers including a light-emitting layer between a cathode and an anode, wherein at least one of the organic thin film layers contains the nitrogen-containing heterocyclic derivative. The organic electroluminescent device has high emission luminance and high luminous efficiency even at a low voltage.

Description

Nitrogen-containing heterocyclic derivative and organic electroluminescence device using the same

The present invention relates to a novel nitrogen-containing heterocyclic derivative, a material for an organic electroluminescence element (organic EL element) using the same, and an organic EL element, and particularly, a nitrogen-containing heterocyclic derivative useful as a component of the organic EL element. Is used for at least one of the organic compound layers, which relates to an organic EL element having high luminous efficiency while being low in voltage.

An organic EL element using an organic substance is considered to be promising for use as an inexpensive large-area full-color display element of a solid light emitting type, and many developments have been made. In general, an organic EL element is composed of a light emitting layer and a pair of counter electrodes sandwiching the layer. In light emission, when an electric field is applied between both electrodes, electrons are injected from the cathode side and holes are injected from the anode side. Furthermore, this is a phenomenon in which electrons recombine with holes in the light emitting layer to generate an excited state, and energy is emitted as light when the excited state returns to the ground state.
Conventional organic EL elements have a higher driving voltage and lower light emission luminance and light emission efficiency than inorganic light-emitting diodes. Further, the characteristic deterioration has been remarkably not put into practical use. Although recent organic EL devices have been gradually improved, higher light emission luminance and higher light emission efficiency are required at a lower voltage.
As a solution to these problems, for example, Patent Document 1 discloses an element using a compound having a benzimidazole structure as a light-emitting material, and describes that the element emits light with a luminance of 200 cd / m ² at a voltage of 9 V. Has been. Patent Documents 2 and 3 describe compounds having a benzimidazole ring and an anthracene skeleton. However, those having higher emission luminance and emission efficiency than those of organic EL devices using these compounds are demanded.

Japanese Patent Laid-Open No. 10-092578 (US Pat. No. 5,645,948) JP 2002-38141 A International Publication WO 2004/080975 (US Publication 2006/147747)

The present invention has been made to solve the above-described problems, and provides a novel nitrogen-containing heterocyclic derivative useful as a component of an organic EL device, and this nitrogen-containing heterocyclic derivative is added to at least one layer of an organic compound layer. It is an object of the present invention to realize an organic EL element having high emission luminance and high emission efficiency while being at a low voltage.

As a result of intensive studies to achieve the above object, the present inventors have used a novel nitrogen-containing heterocyclic derivative having a specific structure in at least one organic compound layer of an organic EL device, The present inventors have found that it is possible to achieve a low voltage and high efficiency of an organic EL element, and have completed the present invention.

That is, the present invention provides a nitrogen-containing heterocyclic derivative (benzimidazole compound) represented by the following general formula (1).

[In the general formula (1), R ¹ to R ⁶ are each independently a hydrogen atom, 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 haloalkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms (provided that A substituted or unsubstituted carbazolyl group or azacarbazolyl group), a halogen atom, a cyano group, or a nitro group, wherein two adjacent groups of R ¹ to R ⁶ are bonded to each other to form a ring structure or it may form a linking group of unsubstituted, saturated or unsaturated, also at least one of R ¹ ~ R ⁶ is derived from the fused ring compound represented by the following general formula (2) It is a monovalent group.

(In the general formula (2), R ^1a to R ^10a are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted ring atom having 5 to 60 ring atoms. Heteroaryl group (excluding substituted or unsubstituted carbazolyl group and azacarbazolyl group), substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms , A halogen atom, a cyano group, or a nitro group, and adjacent groups of R ^1a to R ^10a may be bonded to each other to form a substituted or unsubstituted saturated or unsaturated linking group constituting a ring structure. .)

The present invention also provides an organic electroluminescent device comprising one or more organic thin film layers including a light emitting layer between a cathode and an anode, wherein at least one of the organic thin film layers contains the nitrogen-containing heterocyclic derivative. Is.

The nitrogen-containing heterocyclic derivative of the present invention and the organic EL device using the same have a high luminous efficiency, an excellent electron transport property and a high luminous efficiency while being at a low voltage.

It is a schematic sectional drawing which shows the preferable layer structure of the organic electroluminescent element of this invention.

The nitrogen-containing heterocyclic derivative of the present invention is represented by the following general formula (1).

In the general formula (1), R ¹ to R ⁶ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms. Substituted or unsubstituted haloalkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted aryl groups having 6 to 20 ring carbon atoms, substituted or unsubstituted heteroaryl groups having 5 to 20 ring atoms (provided that A substituted or unsubstituted carbazolyl group and azacarbazolyl group), a halogen atom, a cyano group, or a nitro group.

Examples of the substituted or unsubstituted alkyl group having 1 to 50 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, and n-pentyl group. N-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group, 1,3- Dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1, 2-diaminoethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, Anomethyl group, 1-cyanoethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2, 3-tricyanopropyl group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t- Examples thereof include a butyl group and a 1,2,3-trinitropropyl group.

Examples of the substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1- Examples include a norbornyl group and a 2-norbornyl group.

As the substituted or unsubstituted haloalkyl group having 1 to 50 carbon atoms, the hydrogen atom of the alkyl group having 1 to 50 carbon atoms is substituted with a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Groups such as trifluoromethyl group, 2,2,2-trifluoroethyl group, pentafluoroethyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2- Dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl Group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2,3- Libromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group 1,2,3-triiodopropyl group and the like.

Examples of the substituted or unsubstituted aryl group having 6 to 20 ring carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m -Terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group p-t-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methyl Biphenylyl group, 4 ″ -t-butyl-p-terphenyl-4-yl group, fluoranthenyl group, fluorenyl group and the like. Among these, phenyl group, naphthyl group, biphenyl group, anthracenyl group, A phenanthryl group, a pyrenyl group, a chrycenyl group, a fluoranthenyl group, and a fluorenyl group are preferred.

Substituted or unsubstituted heteroaryl groups having 5 to 20 ring atoms (excluding substituted or unsubstituted carbazolyl groups and azacarbazolyl groups) include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, Pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7- Indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2- Benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuran group Nyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7- Isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4 -Isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-phenanthridinyl group, 2-phenanthridinyl group Nantridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group N-tridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline- 2-yl group, 1,7-phenanthroline-3-yl group, 1,7-phenanthroline-4-yl group, 1,7-phenanthroline-5-yl group, 1,7-phenanthroline-6-yl group, 1 , 7-phenanthroline-8-yl group, 1,7-phenanthroline-9-yl group, 1,7-phenanthroline-10-yl group, 1,8-phenanthroline-2-yl group, 1,8-phenanthroline-3 -Yl group, 1,8-phenanthroline-4-yl group, 1,8-phenanthroline-5-yl group, 1,8-phenanthroline-6-yl group, 1,8-phenanthroline-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthroline-10-yl group, 1,9-phenanthroline-2-yl group, 1,9-phenanthroline- 3-yl group, 1,9-phenanthroline-4-yl group, 1,9-phenanthroline-5-yl group, 1,9-phenanthroline-6-yl group, 1,9-phenanthroline-7-yl group, 1 , 9-phenanthroline-8-yl group, 1,9-phenanthroline-10-yl group, 1,10-phenanthroline-2-yl group, 1,10-phenanthroline-3-yl group, 1,10-phenanthroline-4 -Yl group, 1,10-phenanthroline-5-yl group, 2,9-phenanthroline-1-yl group, 2,9-phenanthroline-3-yl group, 2,9- Enanthroline-4-yl group, 2,9-phenanthroline-5-yl group, 2,9-phenanthroline-6-yl group, 2,9-phenanthroline-7-yl group, 2,9-phenanthroline-8-yl group 2,9-phenanthroline-10-yl group, 2,8-phenanthroline-1-yl group, 2,8-phenanthroline-3-yl group, 2,8-phenanthroline-4-yl group, 2,8-phenanthroline -5-yl group, 2,8-phenanthroline-6-yl group, 2,8-phenanthroline-7-yl group, 2,8-phenanthroline-9-yl group, 2,8-phenanthroline-10-yl group, 2,7-phenanthroline-1-yl group, 2,7-phenanthroline-3-yl group, 2,7-phenanthroline-4-yl group, 2,7-phenanthroline 5-yl group, 2,7-phenanthroline-6-yl group, 2,7-phenanthroline-8-yl group, 2,7-phenanthroline-9-yl group, 2,7-phenanthroline-10-yl group, 1 -Phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 10-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3 -Phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group, 3 -Thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl Group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4- Yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4 -Methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group, 4-t-butyl-1-indolyl group, 2- Examples thereof include a t-butyl-3-indolyl group and a 4-t-butyl-3-indolyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Two adjacent groups of R ¹ to R ⁶ , in particular, two adjacent groups selected from R ³ to R ⁶ are bonded to each other to form a substituted or unsubstituted saturated or unsaturated group constituting a ring structure. A linking group may be formed.

At least one of R ¹ to R ⁶ , preferably at least one of R ¹ , R ² and R ⁴ is a group derived from a condensed ring compound represented by the following general formula (2).

In the general formula (2), R ^1a to R ^10a are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted hetero atom having 5 to 60 ring atoms. An aryl group (excluding a substituted or unsubstituted carbazolyl group and azacarbazolyl group), 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 halogen atom, a cyano group, or a nitro group;

R ^1a to R ^10a represent a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 60 ring atoms, a substituted or unsubstituted carbon number of 1 to 50 The alkyl group, the substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms and the halogen atom are each selected from the groups exemplified as the substituents represented by R ¹ to R ⁶ .

Two adjacent groups of R ^1a to R ^10a may be bonded to each other to form a substituted or unsubstituted saturated or unsaturated linking group constituting a ring structure. In particular, R ^9a and R ^10a may be bonded to each other to form a linking group constituting a ring structure, and may form a spiro structure together with the 5-membered ring in the fluorene structure to which R ^9a and R ^10a are bonded.

In the group (—FL) derived from the condensed ring compound represented by the general formula (2), the bond may be on any carbon forming the fluorene skeleton. In this case, -FL is directly bonded to any atom of the benzimidazole skeleton. Further, the bond may be on any atom contained in R ^1a to R ^10a (except in the case of a hydrogen atom, a halogen atom, a cyano group, and a nitro group). For example, when any of R ^1a to R ^10a is an aryl group, the bond may be on any carbon of the aryl group. In this case, the fluorene skeleton is bonded to any atom of the benzimidazole skeleton via the arylene group.

The nitrogen-containing heterocyclic derivative represented by the general formula (1) is preferably represented by any one of the following general formulas (3) to (5).

In the general formulas (3) to (5), R ¹ to R ⁶ are the same as described above, and FL is a group derived from the condensed ring compound represented by the general formula (2).

The group (—FL) derived from the condensed ring compound represented by the general formula (2) is particularly preferably represented by the following general formula (6).
-Ar ^1- (fluorene structure) -Ar ² (6)

In Formula (6), Ar ¹ is a single bond or an arylene group. Examples of the arylene group include a phenylene group (preferably a p-phenylene group). Ar ² represents a hydrogen atom or an aryl group. Examples of the aryl group include phenyl group, 1-naphthyl group, 2-naphthyl group, 1,2 or 4-pyrenyl group. -(Fluorene structure)-is selected from the following divalent groups.

In the above-mentioned “substituted or unsubstituted... Group” and the like, optional substituents include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and a ring forming carbon atom having 6 to 20 carbon atoms. An aryl group, a heteroaryl group having 3 to 20 ring carbon atoms (excluding carbazolyl group and azacarbazolyl group), an alkoxy group having 1 to 20 carbon atoms, a cycloalkoxy group having 3 to 20 carbon atoms, and 6 to 30 ring carbon atoms Aryloxy groups, aralkyl groups having 7 to 31 carbon atoms, halogen atoms, nitro groups, cyano groups, hydroxyl groups, and the like.

The compound represented by the general formula (1) (the following BI-FL) includes a corresponding halogen substituted benzimidazole (including the following BI-X, including a halogen-substituted aryl substituted) and a corresponding fluorene boronic acid or boron. A coupling reaction with an acid ester derivative (FL-B (OR) ₂ below), or a halogenated fluorene derivative corresponding to a boronic acid or boronic acid ester derivative of benzimidazole (BI-B (OR) ₂ below) ( The following FL-X, including halogen-substituted aryl substituents) and general Suzuki coupling reactions, Tetrahedron Lett., 38, 3447 (1997), Tetrahedron Lett., 38, 3841 (1997), Tetrahedron Lett , 38, 1197 (1997), etc., and the reaction conditions are easily selected and determined by those skilled in the art. It can be.

(In the above formula, X is a halogen atom, and R, n and L are substituents selected so as to satisfy the definitions of R ¹ to R ⁶ in formula (1) and R ^1a to R ^10a in formula (2). And an integer.)

The nitrogen-containing heterocyclic derivative of the present invention is preferably used as an organic EL device material, particularly as a light emitting material, an electron injection material or an electron transport material.

Specific examples of the nitrogen-containing heterocyclic derivative represented by the general formula (1) of the present invention are shown below, but are not limited to these exemplified compounds.

Next, the organic EL element of the present invention will be described.
The organic EL device of the present invention has one or more organic thin film layers including a light emitting layer between the cathode and the anode, and at least one of the organic thin film layers contains the nitrogen-containing heterocyclic derivative of the present invention.
In a preferred embodiment of the present invention, the organic thin film layer has an electron injection layer or an electron transport layer, and the electron injection layer or the electron transport layer contains the nitrogen-containing heterocyclic derivative of the present invention. Furthermore, the electron transport layer preferably contains a nitrogen-containing heterocyclic derivative, and more preferably, the electron injection layer or the electron transport layer further contains a reducing dopant.
In another preferred embodiment of the present invention, the light emitting layer contains the nitrogen-containing heterocyclic derivative of the present invention. The light emitting layer can further contain at least one of a phosphorescent dopant and a fluorescent dopant in addition to the nitrogen-containing heterocyclic derivative of the present invention. By including such a dopant, it can function as a phosphorescence emission layer and a fluorescence emission layer.

As a typical configuration of the organic EL element of the present invention,
(1) Anode / light emitting layer / cathode (2) Anode / hole injection layer / light emitting layer / cathode (3) Anode / light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / light emitting layer / electron Injection layer / cathode (5) Anode / organic semiconductor layer / light emitting layer / cathode (6) Anode / organic semiconductor layer / electron barrier layer / light emitting layer / cathode (7) Anode / organic semiconductor layer / light emitting layer / adhesion improving layer / Cathode (8) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode (9) Anode / insulating layer / light emitting layer / insulating layer / cathode (10) Anode / inorganic semiconductor layer / insulating layer / Light emitting layer / insulating layer / cathode (11) Anode / organic semiconductor layer / insulating layer / light emitting layer / insulating layer / cathode (12) Anode / insulating layer / hole injection layer / hole transport layer / light emitting layer / insulating layer / Cathode (13) Anode / insulating layer / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode But, but it is not limited to these. Of these, the configuration of (8) is preferably used.

The nitrogen-containing heterocyclic derivative of the present invention may be used in any organic thin film layer of an organic EL device, but can be preferably used in a light emission band or an electron transport band, and particularly preferably an electron injection layer, an electron transport layer, and Used for the light emitting layer.

Fig. 1 shows the configuration (8). The organic EL element 1 includes a cathode 10 and an anode 20, and a hole injection layer 31, a hole transport layer 32, a light emitting layer 33, and an electron injection layer 34 sandwiched therebetween. The hole injection layer 31, the hole transport layer 32, the light emitting layer 33, and the electron injection layer 34 correspond to a plurality of organic thin film layers. At least one of these organic thin film layers 31 to 34 contains the nitrogen-containing heterocyclic derivative of the present invention.

Hereinafter, each member of the organic EL element will be described.
The organic EL element is usually produced on a substrate, and the substrate supports the organic EL element. It is preferable to use a smooth substrate. When light is extracted through this substrate, it is desirable that the substrate is translucent and that the transmittance of light in the visible region with a wavelength of 400 to 700 nm is 50% or more.
As such a translucent board | substrate, a glass plate, a synthetic resin board, etc. are used suitably, for example. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the synthetic resin plate include plates made of polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, polysulfone resin, and the like.

It is effective for the anode to inject holes into the hole injection layer, the hole transport layer, or the light emitting layer and to have a work function of 4.5 eV or more. Specific examples of anode materials include indium tin oxide (ITO), a mixture of indium oxide and zinc oxide (IZO), a mixture of ITO and cerium oxide (ITCO), a mixture of IZO and cerium oxide (IZCO), and indium oxide and oxide. Examples thereof include a mixture of cerium (ICO), a mixture of zinc oxide and aluminum oxide (AZO), tin oxide (NESA), gold, silver, platinum, and copper. The anode can be formed from these electrode materials by vapor deposition or sputtering.
When light emitted from the light emitting layer is extracted from the anode, it is preferable that the transmittance of the anode for light emission is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Although the film thickness of the anode depends on the material, it is usually 10 nm to 1 μm, preferably 10 to 200 nm.

The light emitting layer has the following functions.
(I) Injection function: a function capable of injecting holes from the anode or hole injection layer when an electric field is applied, and a function capable of injecting electrons from the cathode or electron injection layer (ii) transport function: injected charge (electrons (Iii) Light emission function: Function to recombine electrons and holes and connect them to light emission

As a method for forming the light emitting layer, for example, a known method such as a vapor deposition method, a spin coating method, or an LB method can be applied. The light emitting layer is particularly preferably a molecular deposited film. The molecular deposited film is a film formed by depositing a material compound in a gas phase state or a film formed by solidifying a material compound in a solution state or a liquid phase state. Usually, this molecular deposited film is an LB. The thin film (molecular accumulation film) formed by the method can be classified by the difference in aggregated structure and higher order structure, and the functional difference resulting therefrom. The light emitting layer can also be formed by dissolving a binder such as a resin and a material compound in a solvent to form a solution, and then thinning the solution by a spin coating method or the like.

Examples of the light emitting material or the doping material that can be used for the light emitting layer include anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, Coumarin, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran, polymethine , Merocyanine, imidazole chelating oxinoid compounds, quinacridone, rubrene and their derivatives And a fluorescent dye and the like, but not limited thereto.

Specific examples of the host material that can be used for the light emitting layer include compounds represented by the following (i) to (ix).
Asymmetric anthracene represented by the following formula (i).

(In the formula, Ar ⁰⁰¹ is a substituted or unsubstituted condensed aromatic group having 10 to 50 ring carbon atoms. Ar ⁰⁰² is a substituted or unsubstituted aromatic group having 6 to 50 ring carbon atoms. X ⁰⁰¹ to X ⁰⁰³ are each independently a substituted or unsubstituted aromatic group having 6 to 50 ring carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 ring atoms, a substituted or unsubstituted group; An 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 forming carbon atom having 6 to 50 carbon atoms Aryloxy group, substituted or unsubstituted arylthio group having 6 to 50 carbon atoms, substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, carboxyl group, halogen atom, cyano group, nitro group, A, b, and c are each an integer of 0 to 4. n is an integer of 1 to 3. When n is 2 or more, [] is the same or different. May be.)

An asymmetric monoanthracene derivative represented by the following formula (ii).

(In the formula, Ar ⁰⁰³ and Ar ⁰⁰⁴ are each independently a substituted or unsubstituted aromatic ring group having 6 to 50 ring carbon atoms, and m and n are each an integer of 1 to 4, provided that , M = n = 1, and Ar ⁰⁰³ and Ar ⁰⁰⁴ are symmetric with respect to the benzene ring, Ar ⁰⁰³ and Ar ⁰⁰⁴ are not the same, and m or n is an integer of 2 to 4 Where m and n are different integers.
R ⁰⁰¹ to R ⁰¹⁰ each independently represents a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 ring atoms. Substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted Aralkyl group having 7 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, substituted or unsubstituted carbon number 2 to 50 alkoxycarbonyl groups, substituted or unsubstituted silyl groups, carboxyl groups, halogen atoms, cyano groups, nitro groups, and hydroxy groups. )

An asymmetric pyrene derivative represented by the following formula (iii).

( ^Wherein Ar ⁰⁰⁵ and Ar ⁰⁰⁶ are each a substituted or unsubstituted aromatic group having 6 to 50 ring carbon atoms.
L ⁰⁰¹ and L ⁰⁰² are a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthalenylene group, a substituted or unsubstituted fluorenylene group, or a substituted or unsubstituted dibenzosilolylene group, respectively.
m is an integer from 0 to 2, n is an integer from 1 to 4, s is an integer from 0 to 2, and t is an integer from 0 to 4.

An asymmetric anthracene derivative represented by the following formula (iv):

(In the formula, A ⁰⁰¹ and A ⁰⁰² are each independently a substituted or unsubstituted condensed aromatic ring group having 10 to 20 ring carbon atoms.
Ar ⁰⁰⁷ and Ar ⁰⁰⁸ are each independently a hydrogen atom or a substituted or unsubstituted aromatic ring group having 6 to 50 ring carbon atoms.
R ⁰¹¹ to R ⁰²⁰ each independently represents a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 ring atoms. Substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted Aralkyl group having 7 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, substituted or unsubstituted carbon number 2 to 50 alkoxycarbonyl groups, substituted or unsubstituted silyl groups, carboxyl groups, halogen atoms, cyano groups, nitro groups or hydroxy groups.
Ar ⁰⁰⁷ , Ar ⁰⁰⁸ , R ⁰¹⁹ and R ⁰²⁰ may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure.

An anthracene derivative represented by the following formula (v).

Wherein R ⁰²¹ to R ⁰³⁰ are each independently a hydrogen atom, 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, substituted or unsubstituted Unsubstituted aryl group having 6 to 50 ring carbon atoms, substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted An alkylamino group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted ring atom number 5 to show the 50 heterocyclic group, a and b are each an integer of 1 to 5; when they are 2 or more, R ⁰²¹ s or R ⁰²² each other, in each be the same or different It may have, also, may have R ⁰²¹ s or R ⁰²² may combine with each other to form a ring, R ⁰²³ and R ^024, R ⁰²⁵ and R ^026, R ⁰²⁷ and R ^028, R ⁰²⁹ and R ⁰³⁰ L ⁰⁰³ may be a single bond, —O—, —S—, —N (R) — (where R is a substituted or unsubstituted alkyl having 1 to 50 carbon atoms). A substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms), a substituted or unsubstituted alkylene group having 1 to 50 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms. Is shown.)

An anthracene derivative represented by the following formula (vi).

(Wherein R ⁰³¹ to R ⁰⁴⁰ each independently represents a hydrogen atom, 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, substituted or unsubstituted, Unsubstituted aryl group having 6 to 50 ring carbon atoms, substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted An alkylamino group having 1 to 50 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; c, d , E and f each represent an integer of 1 to 5, and when they are 2 or more, R ⁰³¹ , R ⁰³² , R ⁰³⁶ or R ⁰³⁷ may be the same or different from each other, Also R ⁰³¹ , R ⁰³² , R ^036, or R ⁰³⁷ may combine to form a ring, or R ⁰³³ and R ⁰³⁴ , or R ⁰³⁸ and R ⁰³⁹ combine to form a ring. L ⁰⁰⁴ may be a single bond, —O—, —S—, —N (R) — (where R is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted ring carbon number. A substituted or unsubstituted alkylene group having 1 to 50 carbon atoms or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms.)

Spirofluorene derivatives represented by the following formula (vii).

( ^Wherein A ⁰⁰⁵ to A ⁰⁰⁸ are each independently a substituted or unsubstituted biphenylyl group or a substituted or unsubstituted naphthyl group.)

A condensed ring-containing compound represented by the following formula (viii):

( ^Wherein A ⁰¹¹ to A ⁰¹³ are each independently a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms. A ⁰¹⁴ to A ⁰¹⁶ are each independently a hydrogen atom, An unsubstituted aryl group having 6 to 50 ring carbon atoms, each of R ⁰⁴¹ to R ⁰⁴³ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, carbon An alkoxyl group having 1 to 6 carbon atoms, an aryloxy group having 6 to 18 ring carbon atoms, an aralkyloxy group having 7 to 18 carbon atoms, an arylamino group having 6 to 16 ring carbon atoms, a nitro group, a cyano group, and a carbon number 2 to 6 ester groups or halogen atoms, and at least one of A ⁰¹¹ to A ⁰¹⁶ is a group having three or more condensed aromatic rings.

A fluorene compound represented by the following formula (ix).

Wherein R ⁰⁵¹ and R ⁰⁵² are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted ring-forming carbon; An aryl group having 6 to 50 atoms, a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, a substituted or unsubstituted amino group having 1 to 50 carbon atoms, a cyano group, or a halogen atom. R ⁰⁵¹ together, R ⁰⁵² together to bind to may be different even in the same, R ⁰⁵¹ and R ⁰⁵² bonding to the same fluorene group may .R ⁰⁵³ and be different even in the same R ⁰⁵⁴ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. Also A substituted or unsubstituted ring atoms 5-50 heterocyclic group, each other R ⁰⁵³ which bonded to different fluorene groups R ⁰⁵⁴ may be different even in the same, bind to the same fluorene group R ⁰⁵³ and R ⁰⁵⁴ may be the same or different, Ar ⁰¹¹ and Ar ⁰¹² may be a substituted or unsubstituted condensed polycyclic aromatic group having a total of three or more benzene rings or a benzene ring. A condensed polycyclic heterocyclic group in which the total number of heterocyclic rings is bonded to a fluorene group by 3 or more substituted or unsubstituted carbons, and Ar ⁰¹¹ and Ar ⁰¹² may be the same or different, and n is different. Represents an integer of 1 to 10.)

In the organic EL device of the present invention, the light emitting layer may contain a phosphorescent dopant and / or a fluorescent dopant in addition to the light emitting material of the present invention, if desired. Moreover, you may laminate | stack the light emitting layer containing these dopants on the light emitting layer containing the compound of this invention.

A phosphorescent dopant is a compound that can emit light from triplet excitons. Although it is not particularly limited as long as it emits light from triplet excitons, it is preferably a metal complex containing at least one metal selected from the group consisting of Ir, Ru, Pd, Pt, Os and Re, and is preferably a porphyrin metal complex or ortho Metalated metal complexes are preferred. The phosphorescent compounds may be used alone or in combination of two or more.

The porphyrin metal complex is preferably a porphyrin platinum complex.
There are various ligands that form ortho-metalated metal complexes. Preferred ligands include compounds having a phenylpyridine skeleton, bipyridyl skeleton or phenanthroline skeleton; 2-phenylpyridine derivatives; 7,8- Benzoquinoline derivatives; 2- (2-thienyl) pyridine derivatives; 2- (1-naphthyl) pyridine derivatives; 2-phenylquinoline derivatives and the like. These ligands may have a substituent as needed. In particular, a fluorinated compound or a compound having a trifluoromethyl group introduced is preferable as a blue dopant. Furthermore, you may have ligands other than the said ligands, such as an acetylacetonate and picric acid, as an auxiliary ligand.

Specific examples of such metal complexes include tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, tris (2- Phenylpyridine) osmium, tris (2-phenylpyridine) rhenium, octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, octaphenylpalladium porphyrin, etc. An appropriate complex is selected depending on the device performance and the host compound to be used.

There is no restriction | limiting in particular as content in the light emitting layer of a phosphorescent dopant, Although it can select suitably according to the objective, For example, it is 0.1-70 mass%, and 1-30 mass% is preferable. If the content of the phosphorescent compound is less than 0.1% by mass, the light emission is weak and the effect of the content may not be sufficiently exhibited. If the content exceeds 70% by mass, a phenomenon called concentration quenching becomes prominent. The device performance may be degraded.

Fluorescent dopants are required from amine compounds, aromatic compounds, chelate complexes such as tris (8-quinolinolato) aluminum complex, coumarin derivatives, tetraphenylbutadiene derivatives, bisstyrylarylene derivatives, oxadiazole derivatives, etc. It is preferable to select a compound according to the emission color, and a styrylamine compound, a styryldiamine compound, an arylamine compound, and an aryldiamine compound are more preferable. Moreover, the condensed polycyclic aromatic compound which is not an amine compound is also preferable. These fluorescent dopants may be used alone or in combination.

As the styrylamine compound and styryldiamine compound, those represented by the following formula (A) are preferable.

(In the formula, Ar ¹⁰¹ is a p-valent group derived from benzene, naphthalene, biphenyl, terphenyl, stilbene, or distyrylaryl, and Ar ¹⁰² and Ar ¹⁰³ are aromatic carbon atoms having 6 to 20 carbon atoms, respectively. A hydrogen group, Ar ¹⁰¹ , Ar ¹⁰² and Ar ¹⁰³ may be substituted, and any one of Ar ¹⁰¹ to Ar ¹⁰³ is substituted with a styryl group, more preferably at least Ar ¹⁰² or Ar ¹⁰³ One is substituted with a styryl group, and p is an integer of 1 to 4, preferably an integer of 1 to 2.)
Here, examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, and a terphenyl group.

As the arylamine compound and the aryldiamine compound, those represented by the following formula (B) are preferable.

(In the formula, Ar ¹¹¹ is a q-valent substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms; Ar ¹¹² , Ar ¹¹³ Each represents a substituted or unsubstituted aryl group having 6 to 40 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms, q is an integer of 1 to 4, preferably 1 It is an integer of ~ 2.)
Examples of the aryl group and heteroaryl group include a phenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, a pyrenyl group, a coronyl group, a biphenyl group, a terphenyl group, a pyrrolyl group, a furanyl group, a thiophenyl group, and a benzothiophenyl group. Oxadiazolyl group, diphenylanthranyl group, indolyl group, carbazolyl group, pyridyl group, benzoquinolyl group, fluoranthenyl group, acenaphthofluoranthenyl group, stilbene group, perylenyl group, chrysenyl group, picenyl group, triphenylenyl group, rubicenyl group, Examples include a benzoanthracenyl group, a phenylanthranyl group, and a bisanthracenyl group, and a naphthyl group, an anthranyl group, a chrycenyl group, and a pyrenyl group are preferable.

Preferred substituents for the aryl group and heteroaryl group include alkyl groups having 1 to 6 carbon atoms (ethyl group, methyl group, isopropyl group, n-propyl group, s-butyl group, t-butyl group, pentyl group, Hexyl group, etc.), C3-C6 cycloalkyl group (cyclopentyl group, cyclohexyl group, etc.), C1-C6 alkoxy group (ethoxy group, methoxy group, isopropoxy group, n-propoxy group, s- Butoxy group, t-butoxy group, pentoxy group, hexyloxy group, etc.), cycloalkoxy group having 3 to 6 carbon atoms (cyclopentoxy group, cyclohexyloxy group, etc.), aryl group having 6 to 40 ring carbon atoms, ring An amino group substituted with an aryl group having 6 to 40 carbon atoms, an ester group having an aryl group having 6 to 40 ring carbon atoms, an aryl group having 1 to 6 carbon atoms An ester group having Kill group, a cyano group, a nitro group and a halogen atom.

The light emitting layer may contain a hole transport material, an electron transport material, and a polymer binder as necessary. The thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 7 to 50 nm, and most preferably 10 to 50 nm. If the thickness is less than 5 nm, it is difficult to form a light emitting layer, and it may be difficult to adjust the chromaticity. If the thickness exceeds 50 nm, the driving voltage may increase.

The hole injection layer and the hole transport layer help to inject holes into the light emitting layer and transport to the light emitting region, and have a high hole mobility and a small ionization energy of usually 5.5 eV or less. As a material for such a hole injection layer and a hole transport layer, a material that transports holes to the light emitting layer with lower electric field strength is preferable, and the hole mobility is, for example, 10 ⁴ to 10 ⁶ V / cm. When an electric field is applied, it is preferably 10 ⁻⁴ cm ² / V · sec or more.
The material for the hole injection layer and the hole transport layer is not particularly limited, and is conventionally used as a charge transport material for holes in optical transmission materials, and the hole injection layer and holes for organic EL devices. An arbitrary thing can be selected and used from the well-known things used for the transport layer.

For the hole injection layer and the hole transport layer, for example, an aromatic amine derivative represented by the following formula can be used.

(Wherein Ar ²¹¹ to Ar ²¹³ and Ar ²²¹ to Ar ²²³ are each 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. Ar ²⁰³ to Ar ²⁰⁸ are each 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, a to c and p to r is an integer of 0 to 3. Ar ²⁰³ and Ar ²⁰⁴ , Ar ²⁰⁵ and Ar ²⁰⁶ , Ar ²⁰⁷ and Ar ²⁰⁸ may be connected to each other to form a saturated or unsaturated ring.

Specific examples of the substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1 -Phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4 -Pyrenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl Group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p- Ryl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4 Examples include a '-methylbiphenylyl group, 4 ″ -t-butyl-p-terphenyl-4-yl group.

Specific examples of the substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms include groups obtained by removing one hydrogen atom from the aryl group.

Specific examples of the substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-i Benzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5- Quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8- Isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group 7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group Group, 9-acridinyl group, 1,7-phenanthroline-2-yl group, 1,7-phenanthroline-3-yl group, 1,7-phenanthroline-4-yl group, 1,7-phenanthroline-5-yl group 1,7-phenanthroline-6-yl group, 1,7-phenanthroline-8-yl group, 1,7-phenanthroline-9-yl group, 1,7-phenanthroline-10-yl group, 1,8-phenanthroline -2-yl group, 1,8-phenanthroline-3-yl group, 1,8-phenanthroline-4-yl group, 1,8-phenanthroline-5-yl group, 1 , 8-phenanthroline-6-yl group, 1,8-phenanthroline-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthroline-10-yl group, 1,9-phenanthroline-2 -Yl group, 1,9-phenanthroline-3-yl group, 1,9-phenanthroline-4-yl group, 1,9-phenanthroline-5-yl group, 1,9-phenanthroline-6-yl group, 1, 9-phenanthroline-7-yl group, 1,9-phenanthroline-8-yl group, 1,9-phenanthroline-10-yl group, 1,10-phenanthroline-2-yl group, 1,10-phenanthroline-3- Yl group, 1,10-phenanthroline-4-yl group, 1,10-phenanthroline-5-yl group, 2,9-phenanthroline-1-yl group, 2,9-phenyl group Nantrolin-3-yl group, 2,9-phenanthroline-4-yl group, 2,9-phenanthroline-5-yl group, 2,9-phenanthroline-6-yl group, 2,9-phenanthroline-7-yl group 2,9-phenanthroline-8-yl group, 2,9-phenanthroline-10-yl group, 2,8-phenanthroline-1-yl group, 2,8-phenanthroline-3-yl group, 2,8-phenanthroline -4-yl group, 2,8-phenanthroline-5-yl group, 2,8-phenanthroline-6-yl group, 2,8-phenanthroline-7-yl group, 2,8-phenanthroline-9-yl group, 2,8-phenanthroline-10-yl group, 2,7-phenanthroline-1-yl group, 2,7-phenanthroline-3-yl group, 2,7-phenanthroline- -Yl group, 2,7-phenanthroline-5-yl group, 2,7-phenanthroline-6-yl group, 2,7-phenanthroline-8-yl group, 2,7-phenanthroline-9-yl group, 2, 7-phenanthroline-10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 10-phenothiazinyl group, 1 -Phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3 -Flazanyl group, 2-thienyl group, 3-thienyl group, 2-methylpyrrole-1 -Yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrole-2 -Yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3- (2-phenylpropyl) pyrrol-1-yl group 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl 1-indolyl group, 4-t -Butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group.

Specific examples of the substituted or unsubstituted heteroarylene group having 6 to 50 ring carbon atoms include groups obtained by removing one hydrogen atom from the heteroaryl group.

Furthermore, the hole injection layer and the hole transport layer may contain a compound represented by the following formula.

(Wherein Ar ²³¹ to Ar ²³⁴ are each 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. L is a linking group. A single bond, 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, where x is an integer of 0 to 5 is there.)
Ar ²³² and Ar ²³³ may ^combine with each other to form a saturated or unsaturated ring. Specific examples of the substituted or unsubstituted aryl group and arylene group having 6 to 50 ring carbon atoms and the substituted or unsubstituted heteroaryl group and heteroarylene group having 5 to 50 ring atoms are as described above. The same can be mentioned.

Furthermore, specific examples of the material for the hole injection layer and the hole transport layer include, for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives. And amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers (particularly thiophene oligomers).

The above materials can be used for the hole injection layer and the hole transport layer, but porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds, particularly aromatic tertiary amine compounds should be used. Is preferred.

Further, compounds having two condensed aromatic rings in the molecule, such as 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl (hereinafter abbreviated as NPD), triphenylamine unit 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) -N-phenylamino) triphenylamine (hereinafter abbreviated as MTDATA), etc., which are connected in a starburst type. preferable.

In addition, a nitrogen-containing heterocyclic derivative represented by the following formula can also be used.

In the formula, each of R ²⁰¹ to R ²⁰⁶ is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted carbon group having 7 to 50 carbon atoms. An aralkyl group, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms. R ²⁰¹ and R ^202, R ²⁰³ and R ^204, R ²⁰⁵ and R ^206, R ²⁰¹ and R ^206, R ²⁰² and R ^203, or R ²⁰⁴ and R ²⁰⁵ may form a condensed ring.

Furthermore, the compound of a following formula can also be used.

R ²¹¹ to R ²¹⁶ are substituents, preferably each an electron withdrawing group such as a cyano group, a nitro group, a sulfonyl group, a carbonyl group, a trifluoromethyl group, and a halogen.

In addition, inorganic compounds such as p-type Si and p-type SiC can also be used as materials for the hole injection layer and the hole transport layer.
The hole injection layer and the hole transport layer can be formed by thinning the above-described compound by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. The thickness of the hole injection layer and the hole transport layer is not particularly limited, but is usually 5 nm to 5 μm. The hole injection layer and the hole transport layer may be composed of one or more layers made of the above-mentioned materials, or a plurality of hole injection layers and hole transport layers made of different compounds are laminated. There may be.

The electron barrier layer is a layer that improves luminous efficiency by confining electrons injected from the cathode in the light emitting layer. In the organic EL device of the present invention, an aromatic tertiary amine compound or the like is used among the compounds used for the hole transport layer.

The organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 ⁻¹⁰ S / cm or more. As a material for such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer or an arylamine oligomer, a conductive dendrimer such as an arylamine dendrimer, or the like can be used.

The electron injection layer and the electron transport layer (electron transport zone) are layers that assist the injection of electrons into the light emitting layer and transport them to the light emitting region, and have a high electron mobility and an electron affinity of usually 2.5 eV or more. . As such an electron injection layer and an electron transport layer, a material that transports electrons to the light emitting layer with a lower electric field strength is preferable. Further, when an electron mobility is 10 ⁴ to 10 ⁶ V / cm, for example, At least 10 ⁻⁶ cm ² / V · sec is preferable.
When the nitrogen-containing heterocyclic derivative of the present invention is used in the electron transport zone, the nitrogen-containing heterocyclic derivative of the present invention alone may form an electron injection layer or an electron transport layer, or may be mixed with other materials.
The material for forming the electron injecting layer and the electron transporting layer by mixing with the nitrogen-containing heterocyclic derivative of the present invention is not particularly limited as long as it has the above-mentioned preferable properties. An arbitrary material can be selected and used from those commonly used as a transport material and known materials used for an electron injection layer and an electron transport layer of an organic EL element.
The adhesion improving layer is a layer made of a material that is particularly good in adhesion to the cathode among the electron injection layer. In the organic EL device of the present invention, the compound of the present invention is preferably used as an electron injection layer, an electron transport layer, and an adhesion improving layer.

A preferred form of the organic EL device of the present invention is a device containing a reducing dopant in an electron transporting region or an interface region between a cathode and an organic layer. In this invention, the organic EL element which contains a reducing dopant in this invention compound is preferable. Here, the reducing dopant is defined as a substance capable of reducing the electron transporting compound. Accordingly, various materials can be used as long as they have a certain reducibility, such as alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metals. At least selected from the group consisting of oxides, alkaline earth metal halides, rare earth metal oxides or rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, rare earth metal organic complexes One substance can be preferably used.
More specifically, preferable reducing dopants include Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV) and Cs (work function: 1 .95 eV), at least one alkali metal selected from the group consisting of Ca (work function: 2.9 eV), Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV). Particularly preferred are those having a work function of 2.9 eV or less, including at least one alkaline earth metal selected from the group consisting of: Among these, a more preferable reducing dopant is at least one alkali metal selected from the group consisting of K, Rb, and Cs, more preferably Rb or Cs, and most preferably Cs. . These alkali metals have particularly high reducing ability, and the addition of a relatively small amount to the electron injection region can improve the light emission luminance and extend the life of the organic EL element. Further, as a reducing dopant having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable. Particularly, a combination containing Cs, for example, Cs and Na, Cs and K, Cs and Rb, A combination of Cs, Na and K is preferred. By including Cs in combination, the reducing ability can be efficiently exhibited, and by adding to the electron injection region, the emission luminance and the life of the organic EL element can be improved.

In the present invention, an electron injection layer composed of an insulator or a semiconductor may be further provided between the cathode and the organic layer. At this time, 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 constituting the electron transport layer, an oxide containing at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and Zn. , Nitrides or oxynitrides, or a combination of two or more thereof. Moreover, it is preferable that the inorganic compound which comprises an electron carrying layer is a microcrystal or an amorphous insulating thin film. If the electron transport 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 the alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides described above.

As the cathode, in order to inject electrons into the electron injecting layer, the electron transporting layer, or the light emitting layer, a material having a small work function (4 eV or less) metal, an alloy, an electrically conductive compound, and a mixture thereof is used. . Specific examples of such electrode materials include sodium, sodium / potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide, aluminum / lithium alloy, indium, and rare earth metals.
The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
Here, when light emitted from the light emitting layer is taken out from the cathode, it is preferable that the transmittance with respect to the light emitted from the cathode is larger than 10%.
The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

Organic EL elements apply an electric field to an ultra-thin film, so pixel defects are likely to occur due to leaks or shorts. In order to prevent this, it is preferable to insert an insulating thin film layer between the pair of electrodes. Examples of the material used for the insulating layer include aluminum oxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, aluminum nitride, titanium oxide, silicon oxide, and oxide. Germanium, silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide, vanadium oxide, and the like may be used, and a mixture or laminate of these may be used.

By forming an anode, a light emitting layer, if necessary, a hole injection layer, a hole transport layer, and if necessary, an electron injection layer, an electron transport layer, and further forming a cathode by the materials and formation methods exemplified above An organic EL element can be produced. Moreover, an organic EL element can also be produced from the cathode to the anode in the reverse order.
Hereinafter, an example of manufacturing an organic EL element having a structure in which an anode / a hole injection layer / a light emitting layer / an electron injection layer / a cathode are sequentially provided on a translucent substrate will be described.
First, a thin film made of an anode material is formed on a suitable light-transmitting substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 to 200 nm, to produce an anode. Next, a hole injection layer is provided on the anode. As described above, the hole injection layer can be formed by a vacuum deposition method, a spin coating method, a casting method, an LB method, or the like, but a uniform film can be easily obtained and pinholes are hardly generated. From the point of view, it is preferable to form by vacuum deposition. When forming a hole injection layer by vacuum deposition, the deposition conditions vary depending on the compound used (the material of the hole injection layer), the crystal structure of the target hole injection layer, the recombination structure, etc. The source temperature is preferably selected from the range of 50 to 450 ° C., the degree of vacuum of 10 ⁻⁷ to 10 ⁻³ Torr, the deposition rate of 0.01 to 50 nm / second, the substrate temperature of −50 to 300 ° C., and the film thickness of 5 nm to 5 μm. .

Next, the formation of the light emitting layer in which the light emitting layer is provided on the hole injection layer is also performed by thinning the organic light emitting material using a desired organic light emitting material by a method such as vacuum deposition, sputtering, spin coating, or casting. However, it is preferably formed by a vacuum deposition method from the viewpoint that a homogeneous film is easily obtained and pinholes are hardly generated. When the light emitting layer is formed by the vacuum vapor deposition method, the vapor deposition condition varies depending on the compound used, but it can be generally selected from the same condition range as that of the hole injection layer.
Next, an electron injection layer is provided on the light emitting layer. As with the hole injection layer and the light emitting layer, it is preferable to form by a vacuum evaporation method because it is necessary to obtain a homogeneous film. Deposition conditions can be selected from the same condition range as the hole injection layer and the light emitting layer.
The nitrogen-containing heterocyclic derivative of the present invention varies depending on which layer in the light emission band or the hole transport band is contained, but when a vacuum vapor deposition method is used, it can be co-deposited with other materials. Moreover, when using a spin coat method, it can be made to contain by mixing with another material.
Finally, an organic EL element can be obtained by laminating a cathode.
The cathode is made of metal, and vapor deposition or sputtering can be used. However, vacuum deposition is preferred to protect the underlying organic layer from damage during film formation.
The organic EL element is preferably manufactured from the anode to the cathode consistently by a single vacuum.

The formation method of each layer of the organic EL element of the present invention is not particularly limited. Conventionally known methods such as vacuum deposition and spin coating can be used. The organic thin film layer containing the compound represented by the general formula (1) used in the organic EL device of the present invention is prepared by vacuum evaporation, molecular beam evaporation (MBE), a solution dipping method dissolved in a solvent, spin It can be formed by a known method such as a coating method, a casting method, a bar coating method, a roll coating method or the like.
The film thickness of each organic layer of the organic EL device of the present invention is not particularly limited. Generally, if the film thickness is too thin, defects such as pinholes are likely to occur. Conversely, if it is too thick, a high applied voltage is required and the efficiency is deteriorated. Therefore, the range of several nm to 1 μm is usually preferable.
When a direct current voltage is applied to the organic EL element, light emission can be observed by applying a voltage of 5 to 40 V with the anode set to + and the cathode set to a negative polarity. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an alternating voltage is applied, uniform light emission is observed only when the anode has a positive polarity and the cathode has a negative polarity. The waveform of the alternating current to be applied may be arbitrary.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Synthesis of intermediate A1

In a 300 mL three-necked flask under an argon stream, 20 g (50 mmol) of 2-bromo-7-iodo-9,9-dimethyl-9H-fluorene, 6.6 g (54 mmol) of phenylboronic acid, tetrakistriphenylphosphine palladium (0) 1. 2 g (1.0 mmol), 200 mL of toluene, 100 mL of 1,2-dimethoxyethane, and 80 mL of 2M aqueous sodium carbonate solution were added, and the mixture was heated to reflux for 8 hours. After completion of the reaction, water was added, and the precipitated solid was washed with water and further washed with methanol. The obtained solid was purified by recrystallization from toluene-hexane to obtain 12.0 g of a white powder. Yield 69%

Synthesis of intermediate A2

Intermediate A2 was obtained by performing the same operation as in the synthesis of intermediate A1, except that 1-naphthaleneboronic acid was used instead of phenylboronic acid. Yield 55%.

Synthesis Example 1 (Synthesis of Compound 1)

In a 100 mL three-necked flask under an argon stream, 3.0 g (8.6 mmol) of 1- (4-bromophenyl) -2-phenyl-1H-benzimidazole, 2.2 g (8.7 mmol) of bis (pinacolato) dipolone, [ 1,1′-bis (diphenylphosphino) ferrocene] dichloropalladium (II) 0.21 g (0.29 mmol), potassium acetate 2.5 g (25 mmol) and DMF 50 ml were added, and the mixture was heated at 80 ° C. for 3 hours. After confirming disappearance of the raw material bromide, the mixture was cooled to room temperature, and 3.0 g (8.6 mmol) of intermediate A1 and 0.21 g of [1,1′-bis (diphenylphosphino) ferrocene] dichloropalladium (II) ( 0.29 mmol), 21 mL of 2M aqueous sodium carbonate solution was added, and the mixture was heated and stirred at 80 ° C. for 3 hours. After completion of the reaction, water was added, and the precipitated crystals were collected by filtration, washed with water and methanol, and then dried under reduced pressure to obtain a reaction crude product. Purification by column chromatography (silica gel, dichloromethane: hexane) gave 2.8 g (yield 61%) of white crystals. This was identified as Compound 1 by measurement of FD-MS (Field Desorption Mass Spectrum).

Synthesis Example 2 (Synthesis of Compound 2)

The same operation as in Synthesis Example 1 except that 1- (4-bromophenyl) -2-methyl-1H-benzimidazole was used instead of 1- (4-bromophenyl) -2-phenyl-1H-benzimidazole. To obtain compound 2. Yield 50%.

Synthesis Example 3 (Synthesis of Compound 3)

The same operation as in Synthesis Example 1 except that 5-bromo-1-methyl-2-phenyl-1H-benzimidazole was used instead of 1- (4-bromophenyl) -2-phenyl-1H-benzimidazole. This gave compound 3. Yield 45%.

Synthesis Example 4 (Synthesis of Compound 4)

The same operation as in Synthesis Example 1 except that 2- (4-bromophenyl) -1-methyl-1H-benzimidazole was used instead of 1- (4-bromophenyl) -2-phenyl-1H-benzimidazole. To obtain Compound 4. Yield 40%.

Synthesis Example 5 (Synthesis of Compound 5)

The same operation as in Synthesis Example 1 except that 2- (4-bromophenyl) -1-phenyl-1H-benzimidazole was used instead of 1-phenyl-2- (4-bromophenyl) -1H-benzimidazole. To give compound 5. Yield 55%.

Synthesis Example 6 (Synthesis of Compound 6)

Compound 6 was obtained in the same manner as in Synthesis Example 1 except that Intermediate A2 was used instead of Intermediate A1. Yield 60%.

Synthesis Example 7 (Synthesis of Compound 7)

In Synthesis Example 1, instead of 1- (4-bromophenyl) -2-phenyl-1H-benzimidazole, 1- (4-bromophenyl) -2-methyl-1H-benzimidazole was used instead of intermediate A1. Compound 7 was obtained by carrying out the same operation except that Intermediate A2 was used. Yield 65%.

Synthesis Example 8 (Synthesis of Compound 8)

Compound 8 was obtained in the same manner as in Synthesis Example 1, except that 2-bromo-9,9'-spirobifluorene was used instead of intermediate A1. Yield 70%.

Synthesis Example 9 (Synthesis of Compound 9)

Compound 9 was obtained in the same manner as in Synthesis Example 1, except that 2-bromo-9,9'-dimethyl-9H-fluorene was used instead of intermediate A1. Yield 60%.

Example 1 (Preparation of an organic EL device using the compound of the present invention for an electron injection layer)
A glass substrate (manufactured by Geomat Co.) with an ITO transparent electrode (anode) having a thickness of 25 mm × 75 mm × 1.1 mm was subjected to ultrasonic cleaning in isopropyl alcohol for 5 minutes, and then UV ozone cleaning was performed for 30 minutes. A glass substrate with a transparent electrode line after washing is mounted on a substrate holder of a vacuum deposition apparatus, and N, N ′ having a film thickness of 60 nm is first covered so that the transparent electrode is covered on the surface on which the transparent electrode line is formed. -Bis (N, N'-diphenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl film (hereinafter abbreviated as "TPD232 film") was formed. . This TPD232 film functions as a hole injection layer. Following the formation of the TPD232 film, a 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl film (hereinafter abbreviated as “NPD film”) having a thickness of 20 nm is formed on the TPD232 film. Was deposited. This NPD film functions as a hole transport layer.
Further, the following styryl derivative (DPVDPAN) and the following styrylamine derivative (S1) were formed on this NPD film at a film thickness ratio of 40: 2 to form a blue light emitting layer.

On this film, the compound (1) was deposited as an electron transport layer with a film thickness of 20 nm by vapor deposition. Thereafter, LiF was formed to a thickness of 1 nm. On the LiF film, metal Al was deposited to a thickness of 150 nm to form a metal cathode to form an organic EL light emitting device.

Example 2
An organic EL device was produced in the same manner as in Example 1 except that the compound (3) was used instead of the compound (1).

Example 3
An organic EL device was produced in the same manner as in Example 1 except that the compound (4) was used instead of the compound (1).

Example 4
In Example 1, an organic EL device was produced in the same manner except that the compound (7) was used instead of the compound (1).

Example 5
An organic EL device was produced in the same manner as in Example 1 except that the compound (8) was used instead of the compound (1).

Example 6
In Example 1, an organic EL device was produced in the same manner except that the compound (9) was used instead of the compound (1).

Comparative Example 1
An organic EL device was produced in the same manner as in Example 1 except that the following compound A described in International Publication No. WO 2004/080975 A1 was used instead of the compound (1).

Comparative Example 2
In Example 1, an organic EL device was produced in the same manner except that the following compound B described in JP-A-2002-38141 was used instead of the compound (1).

Comparative Example 3
An organic EL device was produced in the same manner as in Example 1 except that Alq (aluminum complex of 8-hydroxyquinoline) was used instead of the compound (1).

Evaluation of Organic EL Device The organic EL devices obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were measured for luminance, luminous efficiency, and chromaticity under the conditions of applying the DC voltage described in Table 1 below. Measured and observed the emission color. The results are shown in Table 1.

From the results shown in Table 1, it can be seen that by using the nitrogen-containing heterocyclic derivative of the present invention for the electron injection layer, a device having extremely high light emission luminance and light emission efficiency can be produced.

Claims

A nitrogen-containing heterocyclic derivative represented by the following general formula (1).

[In the general formula (1), R 1 to R 6 are each independently a hydrogen atom, 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 haloalkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms (provided that A substituted or unsubstituted carbazolyl group and azacarbazolyl group), a halogen atom, a cyano group, or a nitro group, and two adjacent groups of R 1 to R 6 are bonded to each other to form a ring structure It may form a linking group of a substituted or unsubstituted, saturated or unsaturated be, also, the fused ring compound at least one of R 1 ~ R 6 is represented by the following general formula (2) A guide to the group.

(In the general formula (2), R 1a to R 10a are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted ring atom having 5 to 60 ring atoms. Heteroaryl group (excluding substituted or unsubstituted carbazolyl group and azacarbazolyl group), substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms , A halogen atom, a cyano group, and a nitro group, and two adjacent groups of R 1a to R 10a are bonded to each other to form a substituted or unsubstituted saturated or unsaturated linking group constituting a ring structure. It may be.)]
The nitrogen-containing heterocyclic derivative according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by any one of the following general formulas (3) to (5).

(In the general formulas (3) to (5), R 1 to R 6 are the same as described above, and FL is a group derived from the condensed ring compound represented by the general formula (2).)
The nitrogen-containing heterocyclic derivative according to claim 1 or 2, which is a material for an organic electroluminescence device.
The nitrogen-containing heterocyclic derivative according to claim 1, which is an electron injection material or an electron transport material for an organic electroluminescence device.
The nitrogen-containing heterocyclic derivative according to claim 1 or 2, which is a light-emitting material for an organic electroluminescence device.
The organic electroluminescent element which has one or more organic thin film layers containing a light emitting layer between a cathode and an anode, and at least one layer of the said organic thin film layer contains the nitrogen-containing heterocyclic derivative of Claim 1 or 2.
7. The organic electroluminescence device according to claim 6, wherein the organic thin film layer has an electron injection layer or an electron transport layer, and the electron injection layer or the electron transport layer contains the nitrogen-containing heterocyclic derivative.
7. The organic electroluminescence device according to claim 6, wherein the light emitting layer contains the nitrogen-containing heterocyclic derivative.
The organic electroluminescence device according to claim 7, wherein the electron injection layer or the electron transport layer further contains a reducing dopant.
The reducing dopant is an alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkaline earth metal oxide, alkaline earth metal halide, rare earth metal oxide. The organic electroluminescence according to claim 9, wherein the organic electroluminescence is one or more selected from the group consisting of a rare earth metal halide, an alkali metal organic complex, an alkaline earth metal organic complex, and a rare earth metal organic complex. element.