TW201412731A - Nitrogen-containing heteroaromatic ring compound and organic electroluminescence element using same - Google Patents

Abstract

A nitrogen-containing heteroaromatic ring compound represented by formula (1).

Description

Nitrogen-containing heteroaromatic ring compound, organic electroluminescent device using same

The present invention relates to a nitrogen-containing heteroaromatic ring compound, and an organic electroluminescent device using the same.

Organic electroluminescent (EL) elements have a fluorescent type and a phosphorescent type, and the optimum element design is being studied in accordance with the respective light-emitting mechanisms. In the case of a phosphorescent organic EL device, it is known that the light-emitting property is simply converted to a fluorescent device technology, and a high-performance device cannot be obtained.

Since phosphorescence is luminescence using triplet excitons, the energy gap of the compound used for the light-emitting layer must be large. The reason is that the value of the energy gap of a compound (hereinafter also referred to as singlet energy) is usually larger than the triplet energy of the compound (in the present invention, the energy difference between the lowest excited triplet state and the ground state). value.

As a material of such a phosphorescent organic EL device, a compound having a structure in which a plurality of heterocyclic rings are bonded has been studied (see Patent Documents 1 to 6).

Patent Document 1: International Publication No. WO 2008-156105

Patent Document 2: International Publication No. WO2007-77810

Patent Document 3: International Publication No. WO 2008-140114

Patent Document 4: International Publication No. WO 2008-146838

Patent Document 5: Special Opening 2007-180147

Patent Document 6: International Publication No. WO2011-19156

In the case of a phosphorescent organic EL device which emits blue light, it is necessary to use a compound having a large triplet energy in the light-emitting layer or its peripheral layer as compared with the phosphorescent organic EL device which emits green to red light. Specifically, in order to obtain blue phosphorescence, the triplet energy used for the host material of the light-emitting layer is preferably 3.0 eV or more. In order to obtain such a material, it is necessary to carry out a molecular design different from that of a material for a fluorescent element or a material for a phosphorescent element which emits green to red light with a new thinking.

The present inventors have found a material containing a nitrogen-containing heteroaromatic ring excellent in carrier injectability and having a structure in which at least four heterocyclic rings are bonded, and two or more of the heterocyclic rings are nitrogen-containing heteroaromatics. The ring, whereby high triplet energy can be retained, while the deterioration of the material can be suppressed by introducing an appropriate substituent.

According to the invention, the following nitrogen-containing heteroaromatic ring compound or the like is provided.

1. A nitrogen-containing heteroaromatic ring compound represented by the following formula (1), [In the formula (1), X represents an oxygen atom or a sulfur atom, and Y ₁₁ to Y ₁₈ , Y ₂₁ to Y ₂₈ and Y ₃₁ to Y ₃₈ each represent a CR ₁ or a nitrogen atom, and R ₁ represents a single bond, a hydrogen atom, Substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms a substituted or unsubstituted cycloalkyloxy group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, substituted or unsubstituted An aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, a fluorine atom, a substituted or unsubstituted a fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, or a cyano group, when a plurality of CR ₁ are present, R ₁ may be the same or different from each other, and A ₂ and A _{3 are} each a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formulas (a) to (e). R ₂ to R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having a ring carbon number of 3 to 20, substituted or not Substituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyloxy group having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic ring having 6 to 18 carbon atoms a hydrocarbon ring, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amine a fluorine atom, a fluorine atom, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, or a cyano group, and HAr means substituted or not A nitrogen-containing aromatic ring having a ring-ring number of 5 to 18 or a fused ring, a dibenzofuran ring having a substituent, or a substituted or unsubstituted dibenzothiophene ring.

By using the nitrogen-containing heteroaromatic ring compound of the present invention in the light-emitting layer, a low-voltage phosphorescent organic EL device can be obtained. Further, by using the compound of the present invention as a material of the electron transport layer, a phosphorescent organic EL device having high efficiency and long life can be obtained.

1‧‧‧Organic EL components

10‧‧‧Substrate

20‧‧‧Anode

30‧‧‧ hole transmission area

40‧‧‧phosphorescence layer

50‧‧‧Electronic transmission area

60‧‧‧ cathode

Fig. 1 is a schematic view showing a layer configuration of an embodiment of an organic EL device of the present invention.

The nitrogen-containing heteroaromatic ring compound of the present invention is a compound represented by the following formula (1).

The nitrogen-containing heteroaromatic ring compound represented by the formula (1) has a structure in which at least four heterocyclic rings are bonded, and two or more of the heterocyclic rings are nitrogen-containing heteroaromatic rings. The nitrogen-containing heteroaromatic ring represented by the formula (1) and the condensed heterocyclic ring at the center all have a high triplet energy, and can be formed into a structure suitable for phosphorescence by being bonded by an appropriate bond.

In the formula (1), X represents an oxygen atom or a sulfur atom. X is preferably an oxygen atom. Y ₁₁ ~Y ₁₈ , Y ₂₁ ~Y ₂₈ and Y ₃₁ ~Y ₃₈ each represent CR ₁ or a nitrogen atom.

R ₁ represents a single bond, a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, substituted or unsubstituted Alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyloxy group having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, A fluorine atom, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, or a cyano group.

Further, one of Y ₁₁ to Y ₁₄ has R ₁ which is a single bond, and is bonded to a nitrogen atom of a nitrogen-containing heteroaromatic ring. Similarly, one of Y ₁₅ to Y ₁₈ and one of Y ₃₁ to Y ₃₄ have a single bond bonded to each other.

In the case where a plurality of CR ₁ are present, R ₁ may be the same or different from each other.

A ₂ and A _{3 are} each a single bond, an oxygen atom, a sulfur atom, or a group represented by any one of the following formulas (a) to (e).

R ₂ to R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having a ring carbon number of 3 to 20, substituted or not Substituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyloxy group having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic ring having 6 to 18 carbon atoms a hydrocarbon ring, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amine a fluorine atom, a fluorine atom, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, or a cyano group.

A ₂ and A _{3 are} preferably each a single bond.

HAr represents a substituted or unsubstituted single ring or a ring of 5 to 18 ring atoms. A ring-containing nitrogen-containing aromatic ring, a substituted dibenzofuran ring, or a substituted or unsubstituted dibenzothiophene ring. Specifically, a nitrogen-containing heteroaromatic ring represented by the following formula (A-1) and a heteroaromatic ring represented by the following formula (A-2) are preferred.

In the formula (A-1), Y _1a to Y _1e each represent a CR _1a or a nitrogen atom. At least one of Y _1a to Y _1e is a nitrogen atom.

R _1a represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or a substituted or unsubstituted carbon number 1 to 20 alkoxy groups, substituted or unsubstituted cycloalkyloxy groups having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic hydrocarbon rings having 6 to 18 ring carbon atoms, substituted Or unsubstituted aryloxy group having 6 to 18 carbon atoms, substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, substituted or unsubstituted amino group, fluorine atom, Substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted diaryl group having 12 to 30 carbon atoms A phosphinyl group, a substituted or unsubstituted bisarylphosphino group having 12 to 30 carbon atoms, a substituted or unsubstituted diarylphosphinoaryl group having 18 to 30 carbon atoms, or a cyano group. When there are a plurality of CR _1a , R _1a may be the same or different from each other.

Examples of the nitrogen-containing heteroaromatic ring represented by the above formula (A-1) include the following structures. Made.

The nitrogen-containing heteroaromatic ring represented by the above formula (A-1) is preferably (a), (b), (c), (e), (g) or (j), more preferably (a) Or (b).

In the formula (A-2), Y _2a to Y _2i each represent a CR _2a or a nitrogen atom.

X ₂ represents an oxygen atom, a sulfur atom or -NR _2b .

R _2a represents a single bond, a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, substituted or unsubstituted Alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyloxy group having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, Fluorine atom, substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted carbon number 12 to 30 Diarylphosphino group, substituted or unsubstituted bisarylphosphino group having 12 to 30 carbon atoms, substituted or unsubstituted diarylphosphinoaryl having 18 to 30 carbon atoms, or cyanide Base, when there are a plurality of CR _2a , R _2a may be the same or different from each other.

When X ₂ represents an oxygen atom and at the same time R _2a all represents a single bond or a hydrogen atom, at least one of Y _2a to Y _2i represents a nitrogen atom.

R _2b represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or a substituted or unsubstituted ring carbon number 6 ~18 aromatic hydrocarbon ring, or substituted or unsubstituted heteroaromatic ring having 5~18 ring atoms.

In the formula (A-2), Y _{2g is} preferably CR _2a , and in this case, R _{2a is} preferably a substituted or unsubstituted aromatic hydrocarbon ring having a ring carbon number of 6 to 18, substituted or not. Substituted into an aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, or a cyano group.

Further, in the formula (A-2), at least one of Y _2a to Y _2i is preferably a nitrogen atom.

Among the nitrogen-containing heteroaromatic ring compounds represented by the formula (1), the following formula is preferred. (2) A nitrogen-containing heteroaromatic ring compound.

In the formula (2), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₁ to Y ₃₈ and HAr are the same as those in the formula (1). ]

The compound of the formula (2) corresponds to a single bond wherein R ₁ of Y ₁₂ of the formula (1) is a single bond, and a nitrogen atom of the nitrogen-containing heteroaromatic ring is bonded to a hetero ring having an X atom by the single bond. Due to such a configuration, high triplet energy can be retained, and it becomes suitable as a host material for a phosphorescent element.

The compound of the formula (2) is preferably represented by any one of the following formulas (3) to (6).

[wherein, X, Y ₁₁ , Y ₁₃ ~ Y ₁₈ , Y ₂₁ ~ Y ₂₈ , Y ₃₁ ~ Y ₃₈ , and HAr are the same as those of the formula (1). ]

Among the above compounds, the compound represented by the formula (3) has a high triplet energy and is easy to synthesize.

Hereinafter, examples of the respective bases of the above formulas (1) to (6) will be described.

In the present specification, the aromatic hydrocarbon ring comprises a monocyclic aromatic hydrocarbon ring group and a condensed aromatic hydrocarbon ring group obtained by condensing a plurality of hydrocarbon rings, and the heteroaromatic ring contains a monocyclic heteroaromatic ring group, plural a heterocondensed aromatic ring group obtained by condensing a heteroaromatic ring and a heterocondensed aromatic ring group formed by condensing an aromatic hydrocarbon ring with a heteroaromatic ring.

In the present invention, "the unsubstituted or unsubstituted ‧ ‧" "Generation" means that the bond has a hydrogen atom. Further, the hydrogen atom includes isotopes having different numbers of neutrons, that is, protium, deuterium, and tritium.

Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group and isobutyl group. Propyl, n-butyl, secondary butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, n-decyl, n-decyl, positive Twelve base, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadeca, n-heptyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl The group is a 1-pentylhexyl group, a 1-butylpentyl group, a 1-heptyloctyl group or a 3-methylpentyl group. Among them, those having a carbon number of 1 to 6 are preferred.

Specific examples of the cycloalkyl group having a ring carbon number of 3 to 20 include a cyclopropyl group and a cyclobutyl group. A group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a norbornyl group, an adamantyl group or the like, wherein a ring carbon number of 5 or 6 is preferred.

Further, "ring-forming carbon" means a carbon atom constituting a saturated ring, an unsaturated ring, or an aromatic ring.

Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group. A butoxy group, a pentyloxy group, a hexyloxy group or the like may be a linear group, a cyclic group or a branched one having a carbon number of 3 or more. Among them, those having a carbon number of 1 to 6 are preferred.

Examples of the cycloalkyloxy group having 3 to 20 ring carbon atoms include a cyclopentyloxy group and a cyclohexyloxy group. The base or the like is preferably a ring carbon number of 5 or 6.

Specific examples of the aromatic hydrocarbon ring (aromatic group) having 6 to 18 ring carbon atoms can be enumerated Phenyl, tolyl, xylyl, 2,4,6-trimethylphenyl, o-biphenyl, m-biphenyl, p-biphenyl, ortho Biphenylene, m-triphenyl, p-triphenyl, naphthyl, phenanthryl, extended triphenyl, and the like. Among them, a phenyl group, a m-biphenyl group, and a cross-linked triphenyl group are preferred.

Examples of the aryloxy group having 6 to 18 ring carbon atoms include a phenoxy group and a biphenyloxy group. And the like, preferably a phenoxy group.

Specific examples of the heteroaromatic ring (heteroaryl group) having 5 to 18 ring atoms may include pyrrolyl group and pyridyl group. Base, pyridyl, pyrimidinyl, anthracene Base, three Base, fluorenyl, isodecyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, quinolinyl, isoquinolinyl, quin Quinoxalinyl, oxazolyl, azacarbazolyl, phenazinyl, acridinyl, morpholinyl, thienyl, pyrrolidinyl, di Dioxanyl, piperidinyl, Olinyl group, piperazine Base, carbazolyl, phenylthio, Azolyl, Oxadiazolyl, benzo An oxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, imidazolyl, benzimidazolyl, piperidyl, benzo[c]dibenzofuranyl, etc. Among them, those having a ring-forming atom number of 6 to 14 are preferred.

Further, "ring-forming atom" means an atom constituting a saturated ring, an unsaturated ring or an aromatic ring.

The substituted amino group is represented by -N(R ^a )(R ^b ), and examples of (R ^a ) and (R ^b ) include the above alkyl group, aryl group or heteroaryl group. Specifically, it has a dimethylamino group, a diphenylamino group, a diphenylanilide group, a phenyl dibenzofuranylamino group, a dibenzofuranylbenzidine group, and a bis(N-phenyl)carbazolylamino group. Wait.

The fluoroalkyl group having 1 to 20 carbon atoms may be an alkyl group having 1 to 20 carbon atoms as described above. The group having one or more fluorine atoms is preferably a trifluoromethyl group, a pentafluoroethyl group, a 2,2,2-trifluoroethyl group or the like.

The fluoroalkoxy group having 1 to 20 carbon atoms is a group having one or more fluorine atoms substituted by the alkoxy group having 1 to 20 carbon atoms, and specifically, a trifluoromethoxy group or a pentafluoro group is preferable. Ethoxy, 2,2,2-trifluoroethoxy, and the like.

As a diarylphosphino group having 12 to 30 carbon atoms, a phosphino group may be substituted with the above aromatic The group of the hydrocarbon ring (aromatic group) is specifically a diphenylphosphino group or the like.

The diarylphosphine oxide group having 12 to 30 carbon atoms may be a group in which a phosphine oxide group is substituted with the above aromatic hydrocarbon ring (aromatic group), and specifically, diphenylphosphine oxide is preferred. Base.

The diarylphosphinoaryl group having a carbon number of 18 to 30 may be a group in which a phosphino group of a phosphinoaryl group is substituted with the above aromatic hydrocarbon ring (aryl group), and specifically, a diphenylphosphino group is preferred. Phenyl and the like.

"Substituted or unsubstituted ‧‧‧" of each group of the compound represented by formula (1) Examples of the substituent include an alkyl group, an aromatic group, a heteroaryl group, an alkoxy group, a fluoroalkyl group or a fluoroalkoxy group, and other examples thereof include a halogen atom (a fluorine, chlorine, bromine or iodine is preferred, and preferably A fluorine atom.), a mercapto group, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, an aryloxy group, an aralkyl group, a diarylphosphino group, a diarylphosphine oxide group, a diarylphosphinoaryl group, or the like.

The substituent (R _1a , R _2a , R _2b ) of HAr is preferably an aryl group such as a phenyl group, a biphenyl group or a terphenyl group; an oxazolyl group, a dibenzofuranyl group or a dibenzo group; a heteroaryl group such as a thienyl group or an azacarbazolyl group; a diarylphosphino group (diphenylphosphino group, etc.); a diarylphosphino group (diphenylphosphino group, etc.); a diarylphosphino group (diphenylphosphinophenyl, etc.).

These substituents may further have a substituent such as a cyano group, an aryl group or a heteroaryl group.

a substituent of a dibenzofuran ring having a substituent represented by HAr and a substituent (R _2a ) of a dibenzothiophene ring, preferably a cyano group; a heteroaromatic group such as a carbazolyl group or an azacarbazolyl group; a diarylphosphino group (diphenylphosphino group or the like); a diarylphosphino group (diphenylphosphino group or the like); a diarylphosphinoaryl group (diphenylphosphinophenyl group, etc.). These substituents may further have a substituent such as a cyano group, an aryl group or a heteroaryl group.

Specific examples of the compound represented by the above formula (1) are shown below.

The synthesis of the compound represented by the formula (1) can be referred to the international publication The conditions described in the WO2009-008100 pamphlet and the pamphlet of International Publication No. 2011-132684, or the use of the copper catalyst described in Tetrahedron 1435~1456 (1984) or J.Am.Chem.Soc. 7727-7729 (2001) The palladium catalyst described in the above is carried out by the production conditions for reacting a carbazole derivative with a halogenated aromatic compound.

The material for an organic EL device of the present invention (hereinafter, sometimes referred to as the material of the present invention) And characterized by containing the above-mentioned compound of the present invention.

The material for an organic EL device of the present invention can be suitably used as a material constituting an organic thin film layer of an organic EL device.

Next, an organic EL device of the present invention will be described.

The organic EL device of the present invention has an organic thin film layer including one or more layers of the light-emitting layer between the anode and the cathode. Further, at least one of the organic film layers contains the material for an organic EL device of the present invention.

In the organic EL device of the present invention, it is preferable that the light-emitting layer contains the material for an organic EL device of the present invention, and it is more preferable that the light-emitting layer contains the material for an organic EL device of the present invention as a host material.

Preferably, the luminescent layer comprises a phosphorescent material, and the phosphorescent material is preferably an ortho-metallization complex of a metal atom selected from the group consisting of iridium (Ir), osmium (Os) and platinum (Pt).

Further, in the organic EL device of the present invention, the electron transporting region between the cathode and the light-emitting layer has an organic thin film layer, and the organic thin film layer preferably contains the material for an organic EL device of the present invention. The organic thin film layer in the electron transporting region has an electron injecting layer or an electron transporting layer, a hole blocking layer, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the layer constitution of an embodiment of an organic EL device of the present invention. Sketch map.

The organic EL element 1 has a configuration in which an anode 20, a hole transporting region 30, a phosphorescent layer 40, an electron transporting region 50, and a cathode 60 are sequentially laminated on a substrate 10. The hole transfer region 30 means a hole transport layer or a hole injection layer, an electron blocking layer, and the like. Likewise, the electron transporting region 50 means an electron transporting layer or an electron injecting layer, a hole blocking layer, and the like. Although these may not be formed, it is preferable to form one or more layers. In this element, the organic thin film layer is disposed on each organic layer of the hole transmission region 30, The phosphor layer 40 and the organic layers disposed in the electron transporting region 50. Among these organic thin film layers, at least one layer contains the material for an organic EL device of the present invention. Thereby, the driving voltage of the organic EL element can be lowered.

Further, in the present invention, the content of the material in the organic thin film layer containing the material for an organic EL device is preferably from 1 to 100% by weight.

In the organic EL device of the present invention, preferably, the phosphorescent layer 40 contains the present invention. The material for the organic EL device is more preferably used as a host material of the light-emitting layer. Since the triplet energy of the material of the present invention is large enough, even if a blue phosphorescent dopant material is used, the triplet energy of the phosphorescent dopant material can be efficiently enclosed in the light-emitting layer. Further, it is not limited to the blue light-emitting layer, and may be used for a light-emitting layer of longer wavelength light (green to red), but is preferably used for the blue light-emitting layer.

The phosphorescent layer contains a phosphorescent material (phosphorescent dopant). Phosphorescence doping The compound may be a metal complex compound, preferably a compound having a metal atom and a ligand selected from the group consisting of Ir, Pt, Os, Au, Cu, Re and Ru. It is preferred that the ligand has an ortho metal bond.

The phosphorescent dopant is preferably a compound containing a metal atom selected from the group consisting of Ir, Os, and Pt from the viewpoint that the phosphorescence quantum yield is high and the external quantum efficiency of the light-emitting element can be further improved. Further, a metal complex such as a ruthenium complex or a platinum complex is more preferable. Among them, a ruthenium complex and a platinum complex are preferable, and an ortho-metalated ruthenium complex is preferred. The dopant may be used alone or in a mixture of two or more.

The concentration of the phosphorescent dopant in the phosphorescent layer is not particularly limited, but is Preferably, it is 0.1 to 40% by weight (wt%), more preferably 0.1 to 30% by weight (% by weight).

Moreover, it is also preferred to use the present invention in an organic thin film layer adjacent to the phosphorescent layer 40. Material. For example, when a layer (cathode side adjacent layer) containing the material of the present invention is formed between the phosphorescent layer 40 and the electron transporting region 50, the layer has a function as a hole barrier layer or a function as an exciton blocking layer. .

Further, the barrier layer (blocking layer) refers to a layer having a function of a moving barrier of a carrier or a diffusion barrier of an exciton. The organic layer for preventing the movement of the electron self-luminous layer to the hole transport region is sometimes defined as an electron barrier layer, and the organic layer for preventing the hole from moving from the light-emitting layer to the electron transport region is defined as a hole barrier layer. Further, an organic layer for preventing diffusion of triplet excitons generated in the light-emitting layer to a peripheral layer having a triplet energy lower than that of the light-emitting layer is sometimes defined as an exciton blocking layer (triplet barrier layer). ).

Further, the material of the present invention may be used for an organic thin film layer adjacent to the phosphorescent layer 40, and may be further used for other organic thin film layers bonded to the adjacent organic thin film layer.

In addition to the above embodiments, the organic EL device of the present invention can be known. Various compositions. Further, the light emission of the light-emitting layer can be emitted from the anode side, the cathode side, or both sides.

The organic EL device of the present invention preferably has an interface region between the cathode and the organic thin film layer At least one of an electron donating dopant and an organometallic complex is added to the domain. According to this configuration, it is possible to improve the luminance of the organic EL element and to extend the life thereof.

The electron donating dopant may be at least one selected from the group consisting of an alkali metal, an alkali metal compound, an alkaline earth metal, an alkaline earth metal compound, a rare earth metal, and a rare earth metal compound.

The organic metal complex compound may be at least one selected from the group consisting of an alkali metal-containing organometallic complex, an alkaline earth metal-containing organometallic complex, and a rare earth metal-containing organometallic complex.

Examples of the alkali metal include lithium (Li) (work function: 2.93 eV) and sodium (Na). (work function: 2.36eV), potassium (K) (work function: 2.28eV), 铷 (Rb) (work function: 2.16eV), 铯 (Cs) (work function: 1.95eV), etc., especially good work function Below 2.9eV. Among these, K, Rb, and Cs are preferred, and Rb or Cs is more preferred, and Cs is most preferred.

Examples of the alkaline earth metal include calcium (Ca) (work function: 2.9 eV), krypton (Sr) (work function: 2.0 eV or more and 2.5 eV or less), and barium (Ba) (work function: 2.52 eV), and the like. The work function is below 2.9eV.

Examples of the rare earth metal include cerium (Sc), cerium (Y), cerium (Ce), cerium (Tb), and ytterbium (Yb), and particularly preferably a work function of 2.9 eV or less.

A preferred metal of the above metals has a particularly high reducing ability, and is added to the electron injecting region in a relatively small amount, whereby the luminance of the organic EL element can be improved and the lifetime can be extended.

Examples of the alkali metal compound include alkali metal oxides such as lithium oxide (Li ₂ O), cesium oxide (Cs ₂ O), and potassium oxide (K ₂ O); lithium fluoride (LiF) and sodium fluoride (NaF). An alkali metal halide such as cesium fluoride (CsF) or potassium fluoride (KF) is preferably lithium fluoride (LiF), lithium oxide (Li ₂ O) or sodium fluoride (NaF).

Examples of the alkaline earth metal compound include barium oxide (BaO), strontium oxide (SrO), calcium oxide (CaO), and barium strontium sulphate (Ba _x Sr _1-x O) (0<x<1), Barium strontate (Ba _x Ca _1-x O) (0 < x < 1), etc., preferably BaO, SrO, CaO.

Examples of the rare earth metal compound include yttrium fluoride (YbF ₃ ), yttrium fluoride (ScF ₃ ), cerium oxide (ScO ₃ ), yttrium oxide (Y ₂ O ₃ ), cerium oxide (Ce ₂ O ₃ ), and fluorination. gadolinium (GdF _3), terbium fluoride (TbF ₃₎ and the like, preferably _{YbF 3, ScF 3, TbF 3} .

As described above, the organic metal complex is not particularly limited as long as it contains at least one of an alkali metal ion, an alkaline earth metal ion, and a rare earth metal ion as a metal ion. Further, the ligand is preferably quinolol, benzoquinolol, acridinol, phenanthridinol, hydroxyphenyl Oxazole, hydroxyphenylthiazole, hydroxydiaryl Diazole, hydroxydiarylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, hydroxyfluoroborane, bipyridyl, morpholine, anthraquinone, porphyrin Porphyrin), cyclopentadiene, β-diketone, methylimine, and the like, but are not limited thereto.

The addition form of the electron donating dopant and the organometallic complex is preferably formed into a layered or island shape in the interface region. The formation method is preferably a method of simultaneously vapor-depositing at least one of an electron-donating dopant and an organic metal complex by a resistance heating vapor deposition method while simultaneously vapor-depositing a light-emitting material or an electron forming an interface region. The organic material of the material is injected, and at least one of the electron donating dopant and the organometallic complex reducing dopant is dispersed in the organic matter. The dispersion concentration is usually in the molar ratio of the organic substance: electron donating dopant and/or organometallic complex = 100:1 to 1:100, preferably 5:1 to 1:5.

When at least one of the electron donating dopant and the organic metal complex is formed into a layer, the light emitting material or the electron injecting material as the interface organic layer is formed into a layer shape, and then the resistor is used. At least one of the electron donating dopant and the organic metal complex is vapor-deposited by the heating vapor deposition method, and the layer thickness is preferably 0.1 nm or more and 15 nm or less.

When at least one of the electron donating dopant and the organometallic complex is formed into an island shape, the luminescent material or the electron injecting material as the interface organic layer is formed into an island shape by At least one of the electron donating dopant and the organic metal complex is vapor-deposited by the resistance heating vapor deposition method, and the layer thickness is preferably 0.05 nm or more and 1 nm or less.

Further, the main component (light-emitting material or electron beam) in the organic EL device of the present invention The ratio of the material to the at least one of the electron donating dopant and the organometallic complex, if based on the molar ratio, is the main component: the electron donating dopant and/or the organic metal complex =5:1~1:5 is better, if it is 2:1~1:2, it is better.

In the organic EL device of the present invention, the organic EL having the above-described present invention is used. The configuration other than the layer of the material for the element is not particularly limited, and a known material or the like can be used. Hereinafter, the layer of the element of the first embodiment will be briefly described. However, the material of the organic EL element to which the present invention is applied is not limited to the following.

[substrate]

A glass plate, a polymer plate, or the like can be used as the substrate.

Examples of the glass plate include soda lime glass, bismuth-containing glass, lead glass, aluminum bismuth glass, borosilicate glass, bismuth boron bismuth glass, and quartz. Further, examples of the polymer sheet include polycarbonate, acrylic acid, polyethylene terephthalate, polyethersulfone, polyfluorene, and the like.

[anode]

The anode is made of, for example, a conductive material, and is preferably a conductive material having a work function of more than 4 eV.

Examples of the conductive material include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, and the like; and oxide metals such as tin oxide and indium oxide used in the ITO substrate and the NESA substrate. ; and an organic conductive resin such as polythiophene or polypyrrole.

The anode may be formed of a layer of two or more layers as needed.

[cathode]

The cathode is made of, for example, a conductive material, preferably a conductive material having a work function of less than 4 eV. material.

Examples of the conductive material include magnesium, calcium, tin, lead, titanium, lanthanum, lithium, lanthanum, manganese, aluminum, lithium fluoride, and the like, but are not limited thereto.

Further, examples of the alloy include magnesium/silver, magnesium/indium, and lithium/aluminum as representative examples, but the invention is not limited thereto. The ratio of the alloy can be controlled by the evaporation source temperature, the ambient atmosphere, the degree of vacuum, etc., and is selected at an appropriate ratio.

The cathode may be formed of a layer of two or more layers as needed, and the cathode may be formed by forming a thin film by vapor deposition or sputtering of the above-mentioned conductive material.

When the light from the light-emitting layer is emitted from the cathode, it is preferable to make the cathode pair The transmittance of luminescence is greater than 10%.

Further, the sheet resistance as the cathode is preferably several hundred Ω/□ or less, and the film thickness is usually from 10 nm to 1 μm, preferably from 50 to 200 nm.

[Light Emitting Layer]

When a phosphorescent layer is formed of a material other than the material of the organic EL device layer of the present invention, a known material can be used as the material of the phosphorescent layer. Specifically, Japanese Patent Application No. 2005-517938 and the like can be referred to.

The organic EL device of the present invention may have a fluorescent layer as shown in FIG. A well-known material can be used for the fluorescent layer.

The luminescent layer can also be formed as a dual host (also known as a host-co-host (co -host)). Specifically, the carrier balance in the light-emitting layer can be adjusted by combining the electron transporting host and the hole transporting host in the light-emitting layer.

Further, it may be formed as a double dopant. By placing more than two types of quantum products in the light-emitting layer A high rate of dopant material causes each dopant to illuminate. For example, a yellow light-emitting layer may be realized by co-evaporating a host, a red dopant, and a green dopant.

The luminescent layer may be a single layer or a laminated structure. If the light-emitting layer is laminated, electrons and holes can be accumulated at the light-emitting layer interface to concentrate the re-bonding region at the light-emitting layer interface. In this way, to improve quantum efficiency.

[hole injection layer and hole transmission layer]

The hole injection and transport layer helps the hole to be injected into the light-emitting layer and transmitted to the layer of the light-emitting region, which is a layer with large mobility and small free energy.

The material of the hole injection and transport layer is preferably a material capable of transporting holes to the light-emitting layer at a lower electric field strength, and the mobility of the holes is, for example, when an electric field of 10 ⁴ to 10 ⁶ V/cm is applied. It is preferably at least 10 ^-4 cm ² /V ‧ seconds.

The material of the hole injection and transport layer can be a crosslinked type material.

[Electronic injection layer and electron transport layer]

The electron injection and transport layer facilitates electron injection into the light-emitting layer and transport to the layer of the light-emitting region, which is a layer having a large electron mobility.

It is known that light emitted from an organic EL element is reflected by an electrode (for example, a cathode), so that light emitted directly from the anode and light emitted through reflection by the electrode interfere with each other. In order to effectively utilize the interference effect, the film thickness of the electron injecting and transporting layers is appropriately selected in the range of several nm to several μm, and particularly when the film thickness is thick, in order to avoid voltage rise, it is preferable to apply 10 ⁴ to 10 ^{At an} electric field of ⁶ V/cm, the electron mobility is at least 10 ^-5 cm ² /Vs or more.

As the electron transporting material used for the electron injecting and transporting layer, an aromatic heterocyclic compound containing one or more hetero atoms in the molecule is preferably used, and particularly preferably a nitrogen-containing ring derivative. Further, the nitrogen-containing ring derivative is preferably an aromatic ring having a nitrogen-containing 6-membered ring or a 5-membered ring skeleton, or a condensed aromatic ring compound having a nitrogen-containing 6-membered ring or a 5-membered ring skeleton, and for example, a skeleton is contained. Pyridine ring, pyrimidine ring, three a compound such as a ring, a benzimidazole ring, a phenanthroline ring, or a quinazoline ring.

Others, by doping (n) of the donor material, doping of the acceptor material (p) to form an organic layer having semiconductor properties. A representative example of N doping is a technique in which a metal such as Li or Cs is doped to an electron transporting material, and a representative example of P doping is a compound in which an acceptor material such as F4TCNQ is doped to a hole transporting material (for example, , refer to Japanese License No. 3695714).

The formation of each layer of the organic EL device of the present invention can be applied by vacuum evaporation, sputtering, or the like. A known method such as a dry film formation method such as plasma or ion plating, or a wet film formation method such as spin coating, dipping or flow coating.

The film thickness of each layer is not particularly limited, but it must be set to an appropriate film thickness. If the film thickness is too thick, in order to obtain a constant light output, a high applied voltage is required, and the efficiency is deteriorated. If the film thickness is too thin, pinholes or the like are generated, and even if an electric field is applied, sufficient light-emitting luminance cannot be obtained. The film thickness is usually in the range of 5 nm to 10 μm, more preferably in the range of 10 nm to 0.2 μm.

Example

[Nitrogen-containing heteroaromatic ring compound]

Synthesis Example 1 [Synthesis of Compound A]

(1) Synthesis of intermediate B

Intermediate B was synthesized by the following procedure.

In the argon environment, it is recorded in the pamphlet of International Publication No. 2009-008100. The intermediate A 41g (100 mmol) synthesized by the method was added to 500 ml of dehydrated THF, and stirred at -70 °C. Next, 62.5 ml of a 1.6 M n-butyllithium n-hexane solution was added dropwise. After stirring at -70 ° C for 1 hour, 56 g (300 mmol) of triisopropyl borate was added, and the mixture was stirred at -70 ° C for 1 hour, and then stirred at room temperature for 5 hours. After concentrating the reaction mixture, 1500 ml of dichloromethane and 3000 ml of 1N hydrochloric acid were added, and the mixture was stirred for 1 hour under ice-water bath. The organic phase was separated, dried over anhydrous magnesium sulfate and then filtered. The obtained solid was washed with a mixed solvent of hexane-toluene to obtain 23 g (yield: 61%) of Intermediate B as a white solid.

(2) Synthesis of intermediate C

Intermediate C was synthesized by the following procedure.

Under an argon atmosphere, 20 g (53 mmol) of intermediate B, bromocarbazole (53 mmol), 80 ml of 2M sodium carbonate aqueous solution, and 240 ml of 1,2-dimethoxyethane (D ME) were added, followed by the addition of hydrazine. (Triphenylphosphine) palladium 1.8 g (1.6 mmol) was stirred under reflux for 8 hours. The organic phase was separated and the aqueous phase was extracted twice with dichloromethane (300 mL). Organic phase After being added together, the residue was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/dichloromethane = 3/2) to give a pale yellow solid. Intermediate C 14.5 g (yield 55%).

(3) Synthesis of intermediate D

The intermediate D was synthesized by the following procedure.

Under argon, 16.7 g (100 mmol) of carbazole, 23.7 g (100 mmol) of 3,5-dibromopyridine, 19.0 g (100 mmol) of copper iodide, and 11.4 g of trans-1,2-cyclohexanediamine ( 100mmol), tripotassium phosphate 42.4g (200mmol) added to dehydrated 1,4-two 200 ml of alkane was stirred under reflux for 96 hours. The reaction solution was concentrated under reduced pressure, and then 500 ml of toluene was added to the residue obtained by concentration, and the mixture was heated to 120 ° C, and the insoluble material was filtered. The filtrate was concentrated under reduced pressure, and the obtained residue was purified by silica gel column chromatography (hexane / toluene = 4 / 1) to afford Intermediates D 6.8 g (yield 21%) .

(4) Synthesis of Compound A

Compound A was synthesized by the following procedure.

Under the argon atmosphere, intermediate C 3.0g (6mmol), intermediate D 1.94g (6mmol), ginseng (dibenzylideneacetone) dipalladium 0.22g (0.24mmol), tri-tertiary butyl tetrafluoroboric acid were added sequentially. Tri-tert-butylphosphonium tetrafluoroborate (0.28 g (0.96 mmol)), 0.81 g (8.4 mmol) of sodium butoxide, and 40 ml of anhydrous xylene were stirred under reflux for 8 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/ethyl acetate = 1/4) to give Compound A 2.5 %).

The NMR measurement results of this solid are shown below.

¹ H-NMR (400 MHz, CDCl ₃ ) δ 7.28-7.55 (15H, m), 7.59-7.66 (2H, m), 7.73-7.88 (4H, m), 8.15-8.24 (8H, m), 8.42 (1H) , d, J = 2.0 Hz), 9.04 (2H, d, J = 2.0 Hz and 4.8 Hz)

Further, as a result of FD-MS analysis, m/e = 740 for a molecular weight of 740.

Synthesis Example 2 [Synthesis of Compound B]

(1) Synthesis of intermediate E

The intermediate E was synthesized by the following procedure.

Under a nitrogen atmosphere, 100.1 g (575 mmol) of 2-bromo-3-hydroxypyridine, 88.5 g (632.5 mmol) of 2-fluorophenylboronic acid, and 88.5 g (2300 mmol) of potassium carbonate were placed in a three-neck flask. 1150 ml of N,N-dimethylacetamide and 13.3 g (11.5 mmol) of hydrazine (triphenylphosphine)palladium were heated and stirred at 90 ° C for 12 hours, and then stirred at 160 ° C for 8 hours with heating.

After completion of the reaction, the mixture was cooled to room temperature, and then 1000 ml of toluene and 1000 ml of water were added to the sample solution, and the mixture was transferred to a separatory funnel, and shaken thoroughly, the toluene phase was recovered, and extraction was carried out several times with toluene from the aqueous phase. The toluene solution was further washed with water several times, dried over anhydrous magnesium sulfate, and concentrated through a short column of a hydrazine gel. The obtained sample was recrystallized from 200 ml of hexane to obtain 54.4 g (yield: 56%) of Intermediate E as a pale yellow solid.

(2) Synthesis of intermediate F

The intermediate F was synthesized by the following procedure.

In an atmosphere, an intermediate E 52.6 g (310 mmol), nifedi 155 ml, and bromine 19.1 ml (372 mmol) were placed in a three-necked flask, and the mixture was stirred and heated at 140 ° C for 12 hours. After completion of the reaction, after cooling to room temperature, the reaction solution was cooled in an ice water bath, and the residual bromine was deactivated by adding an aqueous sodium thiosulfate solution, and an aqueous sodium hydroxide solution was further added to prepare an aqueous phase to pH 10. The solution was transferred to a separatory funnel and extracted several times with toluene. It was dried over anhydrous magnesium sulfate, filtered, and concentrated. This was purified by silica gel column chromatography (dichloromethane / ethyl acetate = 4 / 1), and the obtained solid was washed with hexane and filtered, and dried in vacuo (40 ° C, 6 hours). Thus, an intermediate F 32.1 g (yield 42%) of a pale yellow solid was obtained.

(3) Synthesis of Compound B

Compound B was synthesized by the following procedure.

Under the argon atmosphere, intermediate C 3.5g (7mmol), intermediate F 1.74g (7mmol), ginseng (dibenzylideneacetone) dipalladium 0.26g (0.28mmol), tri-tertiary butyl tetrafluoroboric acid were added sequentially. 0.33 g (1.12 mmol), sodium butoxide sodium 0.94 g (9.8 mmol), and dehydrated xylene 50 ml were stirred under reflux for 24 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/ethyl acetate = 1/1) %).

As a result of FD-MS analysis, for molecular weight 665, m/e = 665.

Synthesis Example 3 [Synthesis of Compound C]

(1) Synthesis of intermediate G

The intermediate G was synthesized by the following procedure.

3-Amino-2-chloropyridine 50 g (390 mmol), iodobenzene (936 mmol), palladium acetate 0.88 g (3.9 mmol), tri-tert-butylphosphine (tri-tert-) under argon atmosphere 4 ml of a 2 M toluene solution of butylphosphine and 150 g (1560 mmol) of sodium butoxide sodium were added to 1560 ml of dehydrated toluene, and the mixture was stirred under reflux for 24 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/dichloromethane = 1/2) to yield 78.8 g (yield: 72%).

(2) Synthesis of intermediate H

The intermediate H was synthesized by the following procedure.

Under the argon atmosphere, the intermediate G 11.2g (40mmol) and palladium acetate 0.45g were sequentially added. (2mmol), Tri-cyclohexylphosphonium tetrafluoroborate 1.47g (4mmol) was added to 40ml of N,N-dimethylacetamide and 40ml of toluene, and the Dean-Stark separator was installed to discharge water. Outside the system, it was stirred under heating and reflux for 6 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/dichloromethane = 1/10) to give 4.4 g (yield) 45%).

(3) Synthesis of Intermediate I

Intermediate I was synthesized by the following procedure.

In the atmosphere, add 8.9 g (36.4 mmol) of intermediate H, 100 ml of acetic acid, 18.7 ml (36.4 mmol) of bromine was stirred and heated at 100 ° C for 12 hours. After completion of the reaction, after cooling to room temperature, dichloromethane was added to the reaction solution, and the residual bromine was deactivated by adding an aqueous sodium thiosulfate solution while cooling in an ice water bath, and an aqueous sodium hydroxide solution was further added to prepare an aqueous phase to pH 10. The solution was transferred to a separatory funnel and extracted several times with dichloromethane. It was dried over anhydrous magnesium sulfate, filtered, and concentrated. The mixture was purified by a short-purchase column chromatography, and the filtrate was concentrated under reduced pressure. The concentrated solid was washed with a mixture solvent of hexane-ethyl acetate and filtered, and dried in vacuo (40 ° C, 5 hours), whereby an intermediate of the white solid I 9.6 g (yield 81%) was obtained.

(4) Synthesis of Compound C

Compound C was synthesized by the following procedure.

Under the argon atmosphere, intermediate C 3.5g (7mmol) and intermediate I 2.27g were added sequentially. (7 mmol), ginseng (dibenzylideneacetone) dipalladium 0.26 g (0.28 mmol), tris-tertiary butyl tetrafluoroborate 0.33 g (1.12 mmol), and tertiary sodium butoxide sodium 0.94 g (9.8 mmol), 50 ml of dehydrated xylene was stirred under reflux for 16 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane/ethyl acetate = 2/1) to afford compound C 3.5 g (yield 86%) .

As a result of FD-MS analysis, m/e = 740 for a molecular weight of 740.

Synthesis Example 4 [Synthesis of Compound D]

Compound D was synthesized by the following procedure.

Under the argon atmosphere, intermediate C 3.5g (7mmol) and intermediate A 2.9g were added sequentially. (7 mmol), ginseng (dibenzylideneacetone) dipalladium 0.26 g (0.28 mmol), tris-tertiary butyl tetrafluoroborate 0.33 g (1.12 mmol), and tertiary sodium butoxide sodium 0.94 g (9.8 mmol), 50 ml of dehydrated xylene was stirred under reflux for 8 hours. The reaction solution was concentrated under reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane / toluene = 1 / 1) to give the compound D as a white solid (yield: 36%) .

The results of FD-MS analysis showed a molecular weight of 829, m/e = 829.

[Organic EL Element]

Example 1

A 25 mm × 75 mm × 1.1 mm glass substrate (manufactured by Geomatec Co., Ltd.) with an ITO transparent electrode was subjected to ultrasonic cleaning for 5 minutes in isopropyl alcohol, and UV cleaning was performed for 30 minutes by UV (Ultraviolet). .

The glass substrate with the transparent electrode washed in the above manner is attached to the substrate holder of the vacuum vapor deposition apparatus. First, the surface of the glass substrate on which the transparent electrode line is formed is vapor-deposited so as to cover the transparent electrode. The following compound I having a thickness of 20 nm was used to obtain a hole injection layer. Connect On the film, the following compound II having a thickness of 60 nm was vapor-deposited to obtain a hole transport layer.

On the hole transport layer, a compound A as a phosphorescent host material having a thickness of 50 nm and the following compound D-1 as a phosphorescent material were co-deposited to obtain a phosphorescent layer. The concentration of the compound A in the phosphorescent layer was 80% by mass, and the concentration of the compound D-1 was 20% by mass.

Next, the following compound H-1 having a thickness of 10 nm was deposited on the phosphor layer to obtain an electron transport layer 1. Further, after the electron transport layer 2 was obtained by vapor-depositing the following compound III having a thickness of 10 nm, a LiF having a thickness of 1 nm and a metal Al having a thickness of 80 nm were sequentially deposited to form a cathode, thereby obtaining an organic EL device. In addition, for LiF, it is formed at a speed of 1 Å/min.

The organic EL element obtained in the above manner was driven to emit light by a direct current, and the current density was measured to obtain a voltage at a current density of 1 mA/cm ² . The results are shown in Table 1.

Example 2

An organic EL device was fabricated and evaluated in the same manner as in Example 1 except that the compound A was used instead of the compound H-1 as the material of the electron transport layer 1. The results are shown in Table 1.

Example 3

An organic EL device was fabricated and evaluated in the same manner as in Example 1 except that the compound B was used as the phosphorescent host material, and the compound B was used instead of the compound H-1 as the material of the electron transport layer 1. The results are shown in Table 1.

Example 4

An organic EL device was fabricated and evaluated in the same manner as in Example 1 except that the compound C was used as the phosphorescent host material, and the compound C was used instead of the compound H-1 as the material of the electron transport layer 1. The results are shown in Table 1.

Example 5

An organic EL device was fabricated and evaluated in the same manner as in Example 1 except that the compound D was used instead of the compound A as the phosphorescent host material, and the compound D was used instead of the compound H-1 as the material of the electron transport layer 1. The results are shown in Table 1.

Comparative example 1

An organic EL device was produced and evaluated in the same manner as in Example 1 except that the compound H-1 was used instead of the compound A as the phosphorescent host material. The results are shown in Table 1.

Comparative example 2

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-2 was used as the phosphorescent host material, and the compound H-2 was used instead of the compound H-1 as the material of the electron transport layer 1. And evaluate it. The results are shown in Table 1.

Comparative example 3

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-4 was used as the phosphorescent host material, and the compound H-4 was used instead of the compound H-1 as the material of the electron transport layer 1. And evaluate it. The results are shown in Table 1.

[Table 1]

From the results of Examples 1 to 5, it is understood that when the compound of the present invention is used in hair growth In the case of the optical layer, a blue light-emitting element which is lower in voltage than the comparative compound can be obtained.

Example 6

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-1 was used instead of the compound A as the phosphorescent host material, and the compound A was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Example 7

In addition to using compound H-1 instead of compound A as a phosphorescent host material, and using An organic EL device was produced and evaluated in the same manner as in Example 1 except that the compound B was used as the material of the electron transport layer 1. The results are shown in Table 2.

Example 8

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-1 was used instead of the compound A as the phosphorescent host material, and the compound C was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Example 9

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-1 was used instead of the compound A as the phosphorescent host material, and the compound D was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Comparative example 4

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-1 was used as the phosphorescent host material, and the compound H-2 was used instead of the compound H-1 as the material of the electron transport layer 1. And evaluate it. The results are shown in Table 2.

Comparative Example 5

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-1 was used as the phosphorescent host material, and the compound H-4 was used instead of the compound H-1 as the material of the electron transport layer 1. And evaluate it. The results are shown in Table 2.

Example 10

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-3 was used instead of the compound A as the phosphorescent host material, and the compound A was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Example 11

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-3 was used instead of the compound A as the phosphorescent host material, and the compound B was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Example 12

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-3 was used instead of the compound A as the phosphorescent host material, and the compound C was used instead of the compound H-1 as the material of the electron transport layer 1. Evaluation. The results are shown in Table 2.

Comparative Example 6

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-3 was used as the phosphorescent host material, and the compound H-2 was used instead of the compound H-1 as the material of the electron transport layer 1. And evaluate it. The results are shown in Table 2.

Comparative Example 7

An organic EL device was fabricated in the same manner as in Example 1 except that the compound H-3 was used as the host material, and the compound H-4 was used instead of the compound H-1 as the material of the electron transport layer 1. To be evaluated. The results are shown in Table 2.

The organic EL device obtained in the above manner was driven to emit light by a direct current, and the luminance and current density were measured to determine the luminous efficiency (external quantum efficiency) at a current density of 1 mA/cm ² . Further, the luminance of the initial luminance of 3,000 cd/m ² was 70% of the lifetime (the time when the luminance was reduced to 70%). The results are shown in Table 2.

[Table 2]

From the results of Examples 6 to 12, it is understood that when the compound of the present invention is used as In the case of an electron transport layer material, an element which is more efficient and has a longer life than the comparative compound can be obtained.

[Industrial availability]

The nitrogen-containing heteroaromatic ring compound of the present invention is suitable as a material for an organic EL device, for example, a host material of an luminescent layer or an electron transport layer material. Moreover, it can also be used for a blue phosphorescent element.

The material for an organic EL device of the present invention can be applied to an organic semiconductor, an organic solar cell or the like in addition to the organic EL device.

The organic EL device of the present invention can be applied to a light source or a display panel such as a flat illuminator such as a flat panel display of a wall-mounted television, a photocopying machine, a printer, a backlight of a liquid crystal display, or a meter. Marking lights, lighting devices, etc.

The embodiments and/or the embodiments of the present invention have been described in detail above, but those skilled in the art can readily exemplify the embodiments and/or embodiments of the present invention without departing from the novel teachings and effects of the present invention. Make a variety of changes. Accordingly, such variations are intended to be included within the scope of the present invention.

The contents of the Japanese application specification as a priority basis in this case are all incorporated herein.

Claims (17)

A nitrogen-containing heteroaromatic ring compound represented by the following formula (1), [In the formula (1), X represents an oxygen atom or a sulfur atom, and Y ₁₁ to Y ₁₈ , Y ₂₁ to Y ₂₈ and Y ₃₁ to Y ₃₈ each represent a CR ₁ or a nitrogen atom, and R ₁ represents a single bond, a hydrogen atom, Substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms a substituted or unsubstituted cycloalkyloxy group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, substituted or unsubstituted An aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, a fluorine atom, a substituted or unsubstituted a fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, or a cyano group, when a plurality of CR ₁ are present, R ₁ may be the same or different from each other, and each of A ₂ and A ₃ is a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formulas (a) to (e). R ₂ to R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having a ring carbon number of 3 to 20, substituted or not Substituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyloxy group having 3 to 20 ring carbon atoms, substituted or unsubstituted aromatic ring having 6 to 18 carbon atoms a hydrocarbon ring, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amine a fluorine atom, a fluorine atom, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, or a cyano group, and HAr means substituted or not A nitrogen-containing aromatic ring having a ring-ring number of 5 to 18 or a fused ring, a dibenzofuran ring having a substituent, or a substituted or unsubstituted dibenzothiophene ring. The nitrogen-containing heteroaromatic ring compound of claim 1, wherein the A ₂ and A ₃ are each a single bond. The nitrogen-containing heteroaromatic ring compound of the first aspect of the patent application, which is a nitrogen-containing heteroaromatic ring compound represented by the following formula (2), [In the formula (2), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₁ to Y ₃₈ and HAr are the same as the formula (1)]. The nitrogen-containing heteroaromatic ring compound of the first aspect of the patent application, which is a nitrogen-containing heteroaromatic ring compound represented by the following formula (3), [In the formula (3), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₁ , Y ₃₃ to Y ₃₈ , and HAr are the same as the formula (1)]. The nitrogen-containing heteroaromatic ring compound of the first aspect of the patent application, which is a nitrogen-containing heteroaromatic ring compound represented by the following formula (4), [In the formula (4), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₂ to Y ₃₈ , and HAr are the same as the formula (1)]. The nitrogen-containing heteroaromatic ring compound of the first aspect of the patent application, which is a nitrogen-containing heteroaromatic ring compound represented by the following formula (5), [In the formula (5), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₁ to Y ₃₂ , Y ₃₄ to Y ₃₈ , and HAr are the same as the formula (1)]. The nitrogen-containing heteroaromatic ring compound of the first aspect of the patent application, which is a nitrogen-containing heteroaromatic ring compound represented by the following formula (6), [In the formula (6), X, Y ₁₁ , Y ₁₃ to Y ₁₈ , Y ₂₁ to Y ₂₈ , Y ₃₁ to Y ₃₃ , Y ₃₅ to Y ₃₈ , and HAr are the same as the formula (1)]. The nitrogen-containing heteroaromatic ring compound according to any one of claims 1 to 7, wherein the HAr is represented by the following formula (A-1). In the formula (A-1), Y _1a to Y _1e each represent CR _1a or a nitrogen atom, and at least one of Y _1a to Y _1e represents a nitrogen atom, and R _1a represents a hydrogen atom, substituted or unsubstituted. An alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or not A substituted cycloalkyloxy group having 3 to 20 ring carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, a substituted or unsubstituted ring carbon number of 6 to 18 An aryloxy group, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, a fluorine atom, a substituted or unsubstituted carbon number of 1 to 20 Fluoroalkyl, substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted diarylphosphino group having 12 to 30 carbon atoms, substituted or unsubstituted carbon a 12 to 30 oxidized diarylphosphino group, a substituted or unsubstituted diarylphosphinoaryl group having 18 to 30 carbon atoms, or a cyano group, when a plurality of CR _1a are present, R _1a are mutually May be the same or different]. The nitrogen-containing heteroaromatic ring compound according to any one of claims 1 to 7, wherein the HAr is represented by the following formula (A-2). [In the formula (A-2), Y _2a to Y _2i each represent CR _2a or a nitrogen atom, X ₂ represents an oxygen atom, a sulfur atom or -NR _2b , and R _2a represents a single bond, a hydrogen atom, a substituted or an unsubstituted a substituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or Unsubstituted cycloalkyloxy group having 3 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, substituted or unsubstituted ring carbon number 6~ An aryloxy group of 18, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, a substituted or unsubstituted amino group, a fluorine atom, a substituted or unsubstituted carbon number 1~ a fluoroalkyl group of 20, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted diarylphosphino group having 12 to 30 carbon atoms, substituted or unsubstituted a diarylphosphino group having 12 to 30 carbon atoms, a substituted or unsubstituted diarylphosphinoaryl group having 18 to 30 carbon atoms, or a cyano group, in the case where a plurality of CR _2a are present, R _2a They may be the same or different, when X ₂ represents an oxygen atom, and When R _2a represents a case when all of hydrogen atoms or a single bond, Y _2a ~ Y _2i indicated at least one nitrogen atom, R _2b represents a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or Unsubstituted ring alkyl having 3 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 carbon atoms, or substituted or unsubstituted ring atoms 5~ 18 heteroaromatic rings]. The nitrogen-containing heteroaromatic ring compound according to claim 9, wherein in the formula (A-2), at least one of Y _2a to Y _2i is a nitrogen atom. A material for an organic electroluminescence device, which comprises the nitrogen-containing heteroaromatic ring compound according to any one of claims 1 to 10. An organic electroluminescence device having an organic thin film layer including one or more layers of a light-emitting layer between a cathode and an anode, wherein at least one of the organic thin film layers contains the material for an organic electroluminescence device according to claim 11 of the patent application. The organic electroluminescent device of claim 12, wherein the luminescent layer contains the material for the organic electroluminescent device. The organic electroluminescent device of claim 12, wherein the luminescent layer comprises a phosphorescent material, and the phosphorescent material is a neighboring metal atom selected from the group consisting of iridium (Ir), osmium (Os) and platinum (Pt). A metallization complex. The organic electroluminescent device of claim 12, wherein an organic thin film layer is provided between the cathode and the light-emitting layer, and the organic thin film layer contains the material for the organic electroluminescent device. The organic electroluminescent device of claim 15, wherein the organic thin film layer is adjacent to the luminescent layer. The organic electroluminescent device according to any one of claims 12 to 16, wherein at least an electron donating dopant and an organic metal complex are added to an interface region between the cathode and the organic thin film layer. One.