JP2008133225A - Indole derivative and application thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indole derivative having high heat resistance, with the molecule being hardly crystallizable, and giving excellent properties including low-voltage drivability and long service life when used as a material for organic EL (electroluminescent) elements, and to provide the above compound capable of attaining the longer service life and low-voltage driving of organic EL elements when used in the form of a positive hole injection transport layer in particular among such materials. <P>SOLUTION: The indole derivative is represented by general formula [1]: Ar<SP>1</SP>Ar<SP>2</SP>N-X (wherein, Ar<SP>1</SP>, Ar<SP>2</SP>and X are each an aromatic hydrocarbon group, a heterocyclic group or the like). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel indole derivative, and more specifically, when used in an organic electroluminescence device (hereinafter abbreviated as an organic EL device), it has a low molecular crystallinity so that a stable film can be formed. Since it is high, it relates to an indole derivative that exhibits excellent performance (low voltage drive, long life, high stability).

  In recent years, organic EL elements are required to have a longer life and be driven with lower power consumption. There are various factors that may affect the lifetime of the element and power consumption improvement (see Non-Patent Document 1). For example, regarding the lifetime, the heat resistance and crystallinity of the material constituting the element have a great influence. It is considered a thing.

  Regarding the molecular structure and heat resistance, in general, the higher the molecular structure of the material, the higher the heat resistance. However, the higher the symmetry, the higher the crystallinity. It is difficult to obtain a highly stable film. When a thin film is formed by vacuum vapor deposition or spin coating, the stability of the film is low and it easily crystallizes, and the EL element has a problem that its lifetime is extremely short.

  In addition, if a material with low thermal stability is used, the material will be thermally decomposed during vapor deposition and film formation, so the material must be replaced frequently, which may cause yield during panel manufacturing. It was.

  Among materials for organic EL elements, materials having a triphenylamine skeleton in a partial structure are well known as materials having a hole injection property and a hole transport property. For example, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1-biphenyl-4,4′-diamine (TPD) or N, N ′-(1-naphthyl) -N , N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPD) is known, but these materials have low heat resistance and the lifetime of the EL element is not sufficient.

  On the other hand, indole derivatives have been used for a long time as pharmaceutical intermediates, and there are many examples of their synthesis (see Non-Patent Document 2).

  However, there are few examples of applying these indole derivatives to the field of optical / electronic materials such as organic semiconductors.

As such an example. For example, application of isoindole derivatives to hole transport materials for organic EL has been attempted (see Non-Patent Document 2). In addition, an indole derivative having a styryl group has been studied as a light emitting material for organic EL (see Patent Document 1).
Indole derivatives having an arylamino group have been studied as materials for organic EL devices and materials for electrophotographic photoreceptors (see Patent Documents 2 to 4). However, these indole derivatives are not described for their heat resistance, and the lifetime of the device has not been clarified.

  Further, when the benzene ring is condensed at the 2nd and 3rd positions of the indole derivative, a carbazole skeleton is formed. These compounds having a carbazole skeleton have been variously applied as materials for organic EL devices (Patent Document 5), but carbazole and indole have three-dimensional structures depending on the presence or absence of condensation of one benzene ring, which is the difference in structure. Since the electronic structures are greatly different, they have greatly different physical properties, and it is considered that new effects and characteristics are exhibited.

Shizutoki Tokito, Chiba Adachi, Hideyuki Murata, Organic EL Display, Ohmsha, 2004, 139 pages The Chemistry of Heterocyclic Compounds parts 1-4, John Wiley & Sons, Inc. Issue Thin Solid Films Vol. 353, 1999, p. 218 JP 2000-91075 A JP 2002-148835 A JP-A-10-310574 JP-A-10-251633 JP 2004-536134 A

  An object of the present invention is to provide an indole derivative having high heat resistance, molecules that are difficult to crystallize, and excellent characteristics such as low voltage drive, long life, and high stability when used as a material for an organic EL device. Is to provide. Furthermore, it is to provide an indole derivative having a high thermal stability in which a material is not decomposed even in a film forming process such as vapor deposition. Another object of the present invention is to provide the above-described compound that can achieve a long lifetime of the device and a low voltage drive among the materials constituting the EL device, particularly when used as a hole injecting and transporting layer.

As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention.
That is, the present invention relates to an indole derivative represented by the following general formula [1].

General formula [1]

(In the formula, Ar ¹ and Ar ² are each independently a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a carbon number which may have a substituent. It represents a monovalent heterocyclic group having 2 to 18 or a group represented by the following general formula [2].
X represents a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a monovalent heterocyclic group having 2 to 18 carbon atoms which may have a substituent, and a substituent. It represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, a group represented by the following general formula [2], or a group represented by the following general formula [3].
However, at least one of Ar ¹ , Ar ² , and X is a group represented by the general formula [2].
In addition, Ar ¹ , Ar ² , and X may be substituted with a halogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent heterocyclic group, cyano, A group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfinyl group, and an arylsulfinyl group. )

General formula [2]

Wherein R ¹ is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a monovalent heterocyclic ring having 2 to 18 carbon atoms which may have a substituent. Represents a group or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms which may have a substituent,
R ^{2 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a monovalent organic residue. The substituent which R ¹ may have is the same as Ar ¹ , Ar ² and the substituent which may have in X in the general formula [1].
Further, R ^{2 to} R ⁶ may be adjacent to each other to form a C 3-8 aliphatic ring which may have a substituent. )

General formula [3]

(In the formula, Y is an optionally substituted divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and an optionally substituted divalent heterocyclic group having 2 to 18 carbon atoms. A C1-C18 divalent aliphatic hydrocarbon group which may have a substituent, a silylene group which may have a substituent, -O-, -S-, -CO-, -SO- And a divalent linking group consisting of any one of —SO ₂ — or a combination thereof.

Ar ⁴ and Ar ⁵ are each independently a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a C 2 to 18 carbon atom which may have a substituent. It represents a monovalent heterocyclic group or a group represented by the general formula [2].
The substituent that Y, Ar ⁴ , and Ar ⁵ may have has the same meaning as the substituent that Ar ¹ , Ar ² , and X in General Formula [1] may have. )

The present invention also relates to the above indole derivative, wherein Ar ¹ and Ar ² are a group represented by the general formula [2].

The present invention also relates to the above indole derivative, wherein R ¹ is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

  The present invention also relates to an organic electroluminescent element material comprising the above indole derivative.

  Further, the present invention provides an organic electroluminescent device comprising a light emitting layer or a plurality of organic layers including a light emitting layer between a pair of electrodes, wherein at least one of the organic layers comprises the material for an organic electroluminescent device. It is related with the organic electroluminescent element which comprises.

  Further, the present invention further includes a hole injection layer and / or a hole transport layer between the anode and the light emitting layer, and the hole injection layer and / or the hole transport layer is the organic electroluminescence device. The organic electroluminescent device according to claim 5, comprising a material for use.

  An organic EL element using the indole derivative of the present invention as a material for an organic EL element has a very high stability of a thin film, emits light at a low driving voltage, and has a long life. And can be suitably used as a flat light emitter, and can be applied to light sources such as copiers and printers, light sources such as liquid crystal displays and instruments, display plates, and indicator lights.

  Hereinafter, the present invention will be described in detail. First, the indole derivative represented by the general formula [1] will be described.

Ar ¹ and Ar ² in the general formula [1] each independently have a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms and a substituent which may have a substituent. Or a monovalent heterocyclic group having 2 to 18 carbon atoms or a group represented by the general formula [2].

  Examples of the monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms include monovalent monocyclic, condensed ring, and ring assembly aromatic hydrocarbon groups having 6 to 18 carbon atoms.

  Here, as monovalent monocyclic aromatic hydrocarbon group having 6 to 18 carbon atoms, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,4-xylyl group, p-cumenyl And monovalent monocyclic aromatic hydrocarbon groups having 6 to 18 carbon atoms, such as a group and a mesityl group.

  Examples of the monovalent condensed ring aromatic hydrocarbon group include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 9-phenanthryl group, Examples thereof include monovalent condensed ring aromatic hydrocarbon groups having 10 to 18 carbon atoms such as 1-acenaphthyl group, 2-azurenyl group, 1-pyrenyl group and 2-triphenylyl group.

  Moreover, as monovalent ring assembly aromatic hydrocarbon group, C1-C18 monovalent ring assembly aromatic hydrocarbons, such as o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, terphenyl group, etc. Group.

  Examples of the heterocyclic group of a monovalent heterocyclic group having 2 to 18 carbon atoms include an aliphatic heterocyclic group and an aromatic heterocyclic group.

  Examples of the monovalent aliphatic heterocyclic group include monovalent aliphatic heterocyclic groups having 3 to 18 carbon atoms such as a 2-pyrazolino group, a piperidino group, a morpholino group, and a 2-morpholinyl group.

  Examples of the monovalent aromatic heterocyclic group include triazolyl group, 3-oxadiazolyl group, 2-furyl group, 3-furyl group, 2-thienyl group, 3-thienyl group, 1-pyrrolyl group and 2-pyrrolyl group. 3-pyrrolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-pyrazyl group, 2-oxazolyl group, 3-isoxazolyl group, 2-thiazolyl group, 3-isothiazolyl group, 2-imidazolyl group 3-pyrazolyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 2-quinoxalinyl group , 2-benzofuryl group, 2-benzothienyl group, N-indolyl group, N-acridinyl group, (2,2′-bithienyl) -4-yl group and 2 to 1 carbon atoms Monovalent aromatic heterocyclic group can be mentioned.

  Preferred monovalent aromatic heterocyclic groups include triazolyl, oxadiazolyl, furyl, thienyl, pyrrolyl, pyridyl, pyrazyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl And a quinolyl group, an isoquinolyl group, a quinoxalinyl group, a benzofuryl group, a benzothienyl group, and an indolyl group obtained by condensing one benzene ring with the monocyclic monovalent aromatic heterocyclic group.

When Ar ¹ and Ar ² are a monovalent aromatic hydrocarbon group and a monovalent heterocyclic group, these aromatic hydrocarbon group and heterocyclic group may have a substituent. Examples of the substituent that may be present include a halogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent aliphatic heterocyclic group, a monovalent aromatic heterocyclic group, cyano A group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfinyl group, and an arylsulfinyl group.

  As used herein, the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  In addition, the monovalent aliphatic hydrocarbon group refers to a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, and examples thereof include an alkyl group, an alkenyl group, an alkynyl group, and a cycloalkyl group. can give.

  Therefore, as the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, hexyl group, heptyl group, octyl group, C1-C18 alkyl groups, such as a decyl group, a dodecyl group, a pentadecyl group, and an octadecyl group, are mentioned.

  Examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group, 1-decenyl group, 1 -An alkenyl group having 2 to 18 carbon atoms such as an octadecenyl group.

  Examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group and 1-octadecynyl group. Examples thereof include alkynyl groups having 2 to 18 carbon atoms.

  Examples of the cycloalkyl group include cycloalkyl groups having 3 to 18 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclooctadecyl group.

  Furthermore, examples of the monovalent aromatic hydrocarbon group, monovalent aliphatic heterocyclic group, and monovalent aromatic heterocyclic group include those described above.

  Examples of the alkoxy group include C1-C8 alkoxyl groups such as methoxy group, ethoxy group, propoxy group, butoxy group, tert-butoxy group, octyloxy group, and tert-octyloxy group.

  Examples of the aryloxy group include aryloxy groups having 6 to 14 carbon atoms such as phenoxy group, 4-tert-butylphenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, and 9-anthryloxy group. .

  Examples of the alkylthio group include C1-C8 alkylthio groups such as a methylthio group, an ethylthio group, a tert-butylthio group, a hexylthio group, and an octylthio group.

  Examples of the arylthio group include arylthio groups having 6 to 14 carbon atoms such as a phenylthio group, a 2-methylphenylthio group, and a 4-tert-butylphenylthio group.

  Examples of the acyl group include acyl groups having 2 to 14 carbon atoms such as an acetyl group, a propionyl group, a pivaloyl group, a cyclohexylcarbonyl group, a benzoyl group, a toluoyl group, an anisoyl group, and a cinnamoyl group.

  Moreover, as an alkoxycarbonyl group, C2-C14 alkoxycarbonyl groups, such as a methoxycarbonyl group, an ethoxycarbonyl group, a benzyloxycarbonyl group, are mention | raise | lifted.

  Examples of the aryloxycarbonyl group include C2-C14 aryloxycarbonyl groups such as a phenoxycarbonyl group and a naphthyloxycarbonyl group.

  Moreover, as an alkylsulfonyl group, C2-C14 alkylsulfonyl groups, such as a mesyl group, an ethylsulfonyl group, a propylsulfonyl group, are mention | raise | lifted.

  Moreover, as an arylsulfonyl group, C2-C14 arylsulfonyl groups, such as a benzenesulfonyl group and p-toluenesulfonyl group, are mention | raise | lifted.

  Examples of the alkylsulfinyl group include alkylsulfinyl groups having 1 to 12 carbon atoms such as a methylsulfinyl group and an ethylsulfinyl group.

  Examples of the arylsulfinyl group include arylsulfinyl groups having 6 to 14 carbon atoms such as a phenylsulfinyl group, a (4-methyl-phenyl) -sulfinyl group, and a biphenylsulfinyl group.

  The monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, monovalent aliphatic heterocyclic group, and monovalent aromatic heterocyclic group described above are further substituted with other substituents. May be. Moreover, substituents may couple | bond together and it may form the ring.

  Next, X in the general formula [1] will be described. X represents a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a monovalent heterocyclic group having 2 to 18 carbon atoms which may have a substituent, and a substituent. It represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, a group represented by the general formula [2], or a group represented by the general formula [3].

A monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a monovalent heterocyclic group having 2 to 18 carbon atoms which may have a substituent, and a substituent; as also good monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, Ar ^1, and has the same meaning as those explained in Ar ^2, and Ar ^1, also the substituent which may have, Ar ² Is synonymous with the substituent that may be present, and the substituents may be combined to form a ring.

More preferable examples of Ar ¹ , Ar ² , and X described above include general formula [2], general formula [3], or a substituent such as a phenyl group or a naphthyl group which may have a substituent. An example is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may be included.

Next, the group of the general formula [2] formed by at least one of Ar ¹ , Ar ² , and X in the general formula [1] will be described.

In general formula [2], R ¹ is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or 1 having 2 to 18 carbon atoms which may have a substituent. A valent heterocyclic group or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms which may have a substituent.

These groups, Ar ^1, and has the same meaning as those explained in Ar ^2, Ar ¹ substituent which may have, and has the same meaning as the substituent that may be possessed by Ar ^2, substituted Groups may be bonded to form a ring.

As more preferable for R ^1, R ¹ is a substituent a phenyl group which may have a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent such as naphthyl group There are cases.

Next, R ^{2 to} R ⁶ in the general formula [2] will be described. R ^{2 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a monovalent organic residue.

  Examples of the halogen atom include those described above.

  The monovalent organic residue is not particularly limited, but may be a monovalent aliphatic hydrocarbon group that may have a substituent, a monovalent aromatic hydrocarbon group that may have a substituent, or a substituent. A monovalent aliphatic heterocyclic group which may have a monovalent aromatic heterocyclic group which may have a substituent, a cyano group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group An alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfinyl group, an arylsulfinyl group, and the like. Here, aryl in an aryloxy group or an arylthio group represents an aromatic hydrocarbon and an aromatic heterocyclic ring.

Specific examples of the group described above as the monovalent organic residue include those described above as the substituents that Ar ¹ and Ar ² in General Formula [1] may have.

  The monovalent organic residue described above may be further substituted with another substituent. These substituents may be bonded to each other to form a ring.

Further, R ^{2 to} R ⁶ may be adjacent to each other to form a C 3-8 aliphatic ring which may have a substituent. A preferable example of forming a ring is a case where R ² and R ³ form a ring, and a 5-membered ring and a 6-membered ring are particularly preferable.

Among R ^{2 to} R ⁶ listed above, particularly preferred are a hydrogen atom, a fluorine atom, a cyano group, a methyl group, an ethyl group, a phenyl group, a tolyl group, and a naphthyl group, and R ² and R ^It is also particularly preferred when ³ has the following structure forming an aliphatic ring. Among the structures below, the structure in which the aliphatic ring is a 6-membered ring forms a tetrahydrocarbazole skeleton, but the aliphatic ring is significantly different in steric and electronic structure compared to the aromatic ring. The carbazole compound has different properties.

  Next, the group of the general formula [3] that X can take will be described.

Y in the general formula [3] is a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a divalent divalent hydrocarbon having 2 to 18 carbon atoms which may have a substituent. A heterocyclic group, a C1-C18 divalent aliphatic hydrocarbon group which may have a substituent, a silylene group which may have a substituent, -O-, -S-, -CO-, It represents a divalent linking group composed of any one of —SO— and —SO ₂ — or a combination thereof.

Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms that may have a substituent and the divalent heterocyclic group having 2 to 18 carbon atoms that may have a substituent include Ar ¹ , and , Ar ² includes those having another bond in the above-described monovalent group.

Examples of the divalent aliphatic hydrocarbon group having carbon atoms of 1 to 18 which may have a substituent, Ar ^1, and, Ar ² is a 1 to 18 carbon atoms in which raised as a substituent which may have One having a single bond on a monovalent aliphatic hydrocarbon group is exemplified.

  Examples of the silylene group that may have a substituent include a dialkylsilylene group having 2 to 18 carbon atoms, a diarylsilylene group having 6 to 18 carbon atoms, and an alkylarylsilylene group having 2 to 18 carbon atoms. Examples thereof include a dimethylsilylene group, a diethylsilylene group, a diphenylsilylene group, and a ditolylsilylene group.

  As described above, Y may be a divalent linking group composed of a single group or a plurality of combinations as described above. Preferred examples of such Y are shown in Table 1 below, but Y is not limited thereto.

Table 1

The substituents R ^X , R ^Y , and R ^{Z in} Table 1 are each independently a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. Represents a monovalent heterocyclic group having 2 to 18 carbon atoms, and examples thereof include those described above for Ar ¹ and Ar ² .

  In addition, most of the divalent linking groups exemplified in Table 1 are those in which the substituent of the aromatic group or heterocyclic group is a hydrogen atom, but may have other substituents. Preferred examples of the substituent other than a hydrogen atom include a halogen atom, a methyl group, an ethyl group, a cyano group, a phenyl group, and a tolyl group.

Next, Ar ⁴ and Ar ⁵ in the general formula [3] each independently have a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms and a substituent which may have a substituent. Represents a monovalent heterocyclic group having 2 to 18 carbon atoms or a group represented by the general formula [2], and more specifically, Ar ¹ and Ar in the general formula [1] ² represents the same group.

The substituents that may be present in Y, Ar ⁴ , and Ar ⁵ in the general formula [3] described above are those in Ar ¹ , Ar ² , and X in the general formula [1]. The substituents may be combined to form a new ring.

  Now, as a more preferred form of the indole derivative of the present invention, the following structures can be mentioned.

(1) The indole derivative according to claim ¹ , wherein Ar ¹ and Ar ² are a group represented by the general formula [2].
(2) The indole derivative according to claim ¹ , wherein X is represented by the general formula [3], and Ar ¹ and Ar ⁴ are groups represented by the general formula [2].
(3) The structure of (2) and Y is the aromatic ring of (1a), (2a), (3a), (6a), (10a), (17a), (18a) in Table 1 Any of the divalent linking groups in the system, or the hydrogen atom on the aromatic ring of these linking groups has been replaced by a halogen atom, a methyl group, an ethyl group, a cyano group, a phenyl group, or a tolyl group The indole derivative according to claim 1, which is a divalent linking group.

Now, the indole derivative of the general formula [1] described above can have an indol-3-yl group represented by the general formula [2] in Ar ¹ , Ar ² , Ar ⁴ , or Ar ⁵ . The number of groups may be any of 1 to 4, and as the number of groups increases, the heat resistance of the compound improves, but the increase in molecular weight makes it difficult to form a thin film using a vapor deposition process. . For these reasons, it is particularly preferred that the number of groups be one or two when emphasizing vapor deposition rather than heat resistance.

  By the way, the effect of the indole group bonded at the 5-position will be mentioned. Usually, the amino group serves as an electron donor, but the nitrogen atom of the indole has little donor properties with respect to substituents bonded on the nitrogen atom. This is because the indole ring has planarity and is a bulky substituent, which is thought to be due to the difficulty of taking a planar structure with the substituent on the nitrogen atom. . On the other hand, since the indole ring has ring planarity, it can be an electron donor property to the benzene ring portion (see Chemical formula 5).

  Therefore, in the indole derivative having an indole group bonded at the 5-position of the present invention, both the amino group bonded to the indole ring and the nitrogen atom of the indole ring are electron donors to the benzene ring of the indole ring. It is considered that an electron donor effect equivalent to or higher than that of a phenylenediamine structure can be exhibited (see Chemical Formula 6).

  For these reasons, the indole derivative of the present invention tends to be a compound having a small ionization potential (a compound in which the ground state of the organic molecule is at a higher energy level). Alternatively, it can be a compound having a high hole transporting property, and can be suitably used as a material for a hole transporting layer or a hole injecting layer.

  Further, the advantage of the indole derivative of the present invention is that since the symmetry of the molecule is low, the crystallinity of the molecule is low and the amorphous property is high, so that the stability when forming a thin film is high. .

  The indole derivatives represented by the general formula [1] used in the present invention have been described above. When these indole derivatives are used as materials for organic EL devices, the molecular weight of the compound is preferably 1500 or less, and 1300 The following is more preferable, 1200 or less is more preferable, and 1100 or less is particularly preferable. This is because, when the molecular weight is large, there is a concern that the vapor deposition property in the case of producing an element by vapor deposition is deteriorated.

  Representative examples of the compounds of the present invention are shown in Table 2 below, but the present invention is not limited to these representative examples.

In the table, X, Y, Ar ¹ , Ar ² , Ar ⁴ , and Ar ⁵ correspond to those in general formula [1] or general formula [3] described above. That is, the indole derivatives of the present invention exemplified below in Table 2 are represented by the following general formula [4] or general formula [5]. Further, (1a) to (61a) in Table 2 correspond to the divalent linking groups in Table 1. In Table 2, Ph represents a phenyl group.

General formula [4]

(In the formula, Ar ¹ and Ar ² are each independently a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a carbon number which may have a substituent. The monovalent heterocyclic group of 2-18, or group represented by General formula [2] is represented.
X represents a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a monovalent heterocyclic group having 2 to 18 carbon atoms which may have a substituent, and a substituent. The monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have or a group represented by the general formula [2] is represented.
However, at least one of Ar ¹ , Ar ² , and X is a group represented by the general formula [2].
Further, Ar ^1, Ar ^2, and the substituent which may be perforated for X, Ar ¹ in the general formula [1], Ar ^2, and is synonymous with organic and may be a substituent at X. )

General formula [5]

(In the formula, Y is an optionally substituted divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and an optionally substituted divalent heterocyclic group having 2 to 18 carbon atoms. A C1-C18 divalent aliphatic hydrocarbon group which may have a substituent, a silylene group which may have a substituent, -O-, -S-, -CO-, -SO- And a divalent linking group consisting of any one of —SO ₂ — or a combination thereof.

Ar ¹ , Ar ² , Ar ⁴ , and Ar ⁵ may each independently have a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms and a substituent that may have a substituent. It represents a monovalent heterocyclic group having 2 to 18 carbon atoms or a group represented by the general formula [2].
The substituents that Y, Ar ¹ , Ar ² , Ar ⁴ , and Ar ⁵ may have are the substituents that Ar ¹ , Ar ² , and X in General Formula [1] may have It is synonymous. )

Table 2

  By the way, the indole derivative of the present invention can be used for various applications. As a material that develops functions such as sensitizing effect, heat generation effect, coloring effect, fading effect, phosphorescence effect, phase change effect, photoelectric conversion effect, photomagnetic effect, photocatalytic effect, light modulation effect, optical recording effect, radical generation effect, etc. Or conversely, it can also be used as a material having a light emitting function under these effects. More specifically, light emitting materials, photoelectric conversion materials, optical recording materials, image forming materials, photochromic materials, organic EL materials, photoconductive materials, dichroic materials, radical generating materials, acid generating materials, base generating materials, phosphorescent materials Materials, nonlinear optical materials, second harmonic generation materials, third harmonic generation materials, photosensitive materials, light absorption materials, near infrared absorption materials, photochemical hole burning materials, optical sensing materials, optical marking materials, photochemical treatment Examples thereof include sensitizing materials, optical phase change recording materials, photosintered recording materials, magneto-optical recording materials, and dyes for photodynamic therapy.

  Of these various uses, the organic EL material (organic EL material, organic EL element material) is particularly preferably used.

  In the case of use as an organic EL material, a high-purity material is particularly required. In such a case, the indole derivative of the present invention is obtained by sublimation purification, recrystallization, reprecipitation, zone melt, It is possible to carry out a method such as a ting method, a column purification method, an adsorption method, or a combination of these methods. Of these purification methods, the recrystallization method is preferred. For compounds having sublimation properties, it is preferable to employ a sublimation purification method. In the sublimation purification, it is preferable to employ a method in which the sublimation boat is maintained at a temperature lower than the temperature at which the target compound sublimates, and the sublimation impurities are removed beforehand. In addition, it is desirable to apply a temperature gradient to the portion where the sublimate is collected so that the sublimate is dispersed in the impurities and the target product. Sublimation purification as described above is purification that separates impurities, and can be applied to the present invention. In addition, sublimation purification is useful for predicting the difficulty of the material vapor deposition.

  Here, the organic EL element that can be prepared using the indole derivative of the present invention will be described in detail.

  The organic EL element is composed of an element in which a single layer or a multilayer organic layer is formed between an anode and a cathode. Here, the single layer type organic EL element is an element composed of only a light emitting layer between an anode and a cathode. Point to. On the other hand, the multilayer organic EL element facilitates injection of holes and electrons into the light emitting layer in addition to the light emitting layer, and facilitates recombination of holes and electrons in the light emitting layer. For the purpose of this, it refers to a layer in which a hole injection layer, a hole transport layer, a hole blocking layer, an electron injection layer, and the like are laminated. Therefore, typical element configurations of the multilayer organic EL element include (1) anode / hole injection layer / light emitting layer / cathode, and (2) anode / hole injection layer / hole transport layer / light emitting layer / cathode. (3) Anode / hole injection layer / light emitting layer / electron injection layer / cathode, (4) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode, (5) Anode / positive Hole injection layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (6) anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron injection layer / cathode, (7) An element structure in which a multilayer structure of anode / light emitting layer / hole blocking layer / electron injection layer / cathode, (8) anode / light emitting layer / electron injection layer / cathode, etc., is considered.

  Moreover, each organic layer mentioned above may be formed by the layer structure of two or more layers, respectively, and several layers may be laminated | stacked repeatedly. As such an example, an element configuration called “multi-photon emission” in which a part of the above-described multilayer organic EL element is multilayered has been proposed in recent years for the purpose of improving light extraction efficiency. For example, in an organic EL device composed of a glass substrate / anode / hole transport layer / electron transporting light emitting layer / electron injection layer / charge generating layer / light emitting unit / cathode, the charge generating layer and the light emitting unit A method of laminating a plurality of layers is an example.

  The indole derivative (material for organic EL device) of the present invention may be used for any of the above-mentioned layers, but can be suitably used particularly for a hole injection layer, a hole transport layer, and a light emitting layer. When used as a hole transport layer or a hole injection layer, the ionization potential is preferably 5.0 to 5.5 eV, and more preferably 5.2 to 5.4 eV. By being in this range, injection or transportation of holes is performed smoothly.

  The organic EL device material of the present invention can be used not only as a single compound but also as a combination of two or more compounds, that is, mixed, co-evaporated, laminated, etc. is there. Further, in the above-described hole injection layer, hole transport layer, and light emitting layer, they may be used together with other materials.

For the hole injection layer, a hole injection material that exhibits an excellent hole injection effect with respect to the light emitting layer and that can form a hole injection layer excellent in adhesion to the anode interface and thin film formability is used. In addition, when such materials are laminated in multiple layers and a material having a high hole injection effect and a material having a high hole transport effect are laminated, the materials used for each are called a hole injection material and a hole transport material. Sometimes. The organic EL device material of the present invention can be suitably used for both hole injection materials and hole transport materials. These hole injection materials and hole transport materials need to have a high hole mobility and a small ionization energy of usually 5.5 eV or less. Such a hole injection layer is preferably a material that transports holes to the light emitting layer with a lower electric field strength, and further has a hole mobility of at least when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. What is 10 ^<-6 > cm ^{< 2} > / V * second is preferable. Other hole injection materials and hole transport materials that can be used by mixing with the organic EL device material of the present invention are not particularly limited as long as they have the above-mentioned preferable properties. Any material can be selected and used from those commonly used as charge transport materials for holes in a conductive material and known materials used for hole injection layers of organic EL devices.

  Specific examples of such hole injection materials and hole transport materials include triazole derivatives (see US Pat. No. 3,112,197) and oxadiazole derivatives (US Pat. No. 3,189,447). Imidazole derivatives (see Japanese Patent Publication No. 37-16096), polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989, 3,542,544, JP-B-45-555, JP-A-51-10983, JP-A-51-93224, JP-A-55-17105, JP-A-56-4148, JP-A-55- No. 108667, No. 55-156953, No. 56-36656, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. No. 3,180, No. 29, No. 4,278,746, JP-A 55-88064, No. 55-88065, No. 49-105537, No. 55-51086, No. 56-80051. No. 56-88141, No. 57-45545, No. 54-112437, No. 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404, Japanese Patent Publication Nos. 51-10105, 46-3712, 47-25336, JP 54-53435, 54-110536, 54-1119925, etc.), arylamine Derivatives (US Pat. Nos. 3,567,450, 3,180,703, 3,240,597, 3 No. 658,520, No. 4,232,103, No. 4,175,961, No. 4,012,376, JP-B 49-35702, No. 39 -27577, JP-A-55-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,110,518, etc.), amino-substituted chalcone derivatives (US patents) No. 3,526,501), oxazole derivatives (disclosed in US Pat. No. 3,257,203, etc.), styryl anthracene derivatives (see JP 56-46234 A, etc.), Fluorenone derivatives (see JP-A-54-110837, etc.), hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143, 55-52063, 55-52064, 55-46760, 55-85495, 57-11350, 57-148749, JP-A-2-311591, etc. Stilbene derivatives (Japanese Patent Laid-Open Nos. 61-210363, 61-228451, 61-14642, 61-72255, 62-47646, 62-36674) 62-10652, 62-30255, 60-93455, 60-94462, 60-174749, 60-175052, etc.), silazane derivatives (US) Patent No. 4,950,950), polysilane (JP-A-2-204996), aniline copolymer (JP-A-2-282263), an electroconductive oligomer (particularly a thiophene oligomer) disclosed in JP-A-1-211399 and the like.

  As the hole injecting material and the hole transporting material, those described above can be used. Porphyrin compounds (Japanese Patent Laid-Open No. 63-295965), aromatic tertiary amine compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27033, 54-58445, 54-149634, 54-64299, 55-79450, 55-144250 No. 56-119132, No. 61-295558, No. 61-98353, No. 63-295695, etc.) can also be used. For example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl having two condensed aromatic rings in the molecule described in US Pat. No. 5,061,569, etc. And 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) -N-phenyl, in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type. Amino) triphenylamine, etc. In addition, examples of the hole injection material include phthalocyanine derivatives such as copper phthalocyanine and hydrogen phthalocyanine, and other aromatic dimethylidene compounds, p-type Si, p-type SiC, etc. These inorganic compounds can also be used as hole injection materials and hole transport materials.

  Specific examples of the aromatic tertiary amine derivative include, for example, N, N′-diphenyl-N, N ′-(3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N , N ′, N ′-(4-methylphenyl) -1,1′-phenyl-4,4′-diamine, N, N, N ′, N ′-(4-methylphenyl) -1,1′- Biphenyl-4,4′-diamine, N, N′-diphenyl-N, N′-dinaphthyl-1,1′-biphenyl-4,4′-diamine, N, N ′-(methylphenyl) -N, N '-(4-n-Butylphenyl) -phenanthrene-9,10-diamine, N, N-bis (4-di-4-tolylaminophenyl) -4-phenyl-cyclohexane, N, N'-bis (4 '-Diphenylamino-4-biphenylyl) -N, N'-diphenyl Nzine, N, N′-bis (4′-diphenylamino-4-phenyl) -N, N′-diphenylbenzidine, N, N′-bis (4′-diphenylamino-4-phenyl) -N, N ′ -Di (1-naphthyl) benzidine, N, N'-bis (4'-phenyl (1-naphthyl) amino-4-phenyl) -N, N'-diphenylbenzidine, N, N'-bis (4'- Phenyl (1-naphthyl) amino-4-phenyl) -N, N′-di (1-naphthyl) benzidine and the like can be mentioned, and these can be used for both hole injection materials and hole transport materials.

  In order to form the hole injection layer and the hole transport layer described above, the above-described compound is formed into a thin film 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 injection layer or hole transport layer is not particularly limited, but is usually 5 nm to 5 μm.

  On the other hand, for the electron injection layer, an electron injection material that exhibits an excellent electron injection effect with respect to the light emitting layer and that can form an electron injection layer excellent in adhesion to the cathode interface and thin film formability is used. Examples of such electron injection materials include metal complex compounds, nitrogen-containing five-membered ring derivatives, fluorenone derivatives, anthraquinodimethane derivatives, diphenoquinone derivatives, thiopyrandioxide derivatives, perylenetetracarboxylic acid derivatives, fluorenylidenemethane. Derivatives, anthrone derivatives, silole derivatives, triarylphosphine oxide derivatives, calcium acetylacetonate, sodium acetate and the like. In addition, inorganic / organic composite materials doped with metal such as cesium in bathophenanthroline (Proceedings of the Society of Polymer Science, Vol. 50, No. 4, 660, published in 2001), and the 50th Applied Physics Related Lecture Lecture Proceedings, No. Examples of electron injection materials include BCP, TPP, T5MPyTZ, etc. published on page 3, 1402, 2003. Electrons can be transported by forming a thin film necessary for device fabrication and injecting electrons from the cathode. If it is material, it will not specifically limit to these.

  Preferred examples of the electron injection material include metal complex compounds, nitrogen-containing five-membered ring derivatives, silole derivatives, and triarylphosphine oxide derivatives. As a preferable metal complex compound that can be used in the present invention, a metal complex of 8-hydroxyquinoline or a derivative thereof is suitable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include tris (8-hydroxyquinolinate) aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (4-methyl-8- Hydroxyquinolinato) aluminum, tris (5-methyl-8-hydroxyquinolinato) aluminum, tris (5-phenyl-8-hydroxyquinolinato) aluminum, bis (8-hydroxyquinolinato) (1-naphtholate) ) Aluminum, bis (8-hydroxyquinolinate) (2-naphtholate) aluminum, bis (8-hydroxyquinolinate) (phenolate) aluminum, bis (8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Aluminum, bis (4-methyl-8) Hydroxyquinolinato) (1-naphtholato) aluminum, bis (5-methyl-8-hydroxyquinolinato) (2-naphtholato) aluminum, bis (5-phenyl-8-hydroxyquinolinato) (phenolate) aluminum, Bis (5-cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholato) aluminum, bis (8-hydroxyquinolinato) chloroaluminum, bis (8-hydroxyquinolinato) (o-cresolate) Aluminum complex compounds such as aluminum, tris (8-hydroxyquinolinato) gallium, tris (2-methyl-8-hydroxyquinolinato) gallium, tris (4-methyl-8-hydroxyquinolinato) gallium, tris ( 5-Methyl-8-hydroxyquinolinate Gallium, tris (2-methyl-5-phenyl-8-hydroxyquinolinato) gallium, bis (2-methyl-8-hydroxyquinolinato) (1-naphtholato) gallium, bis (2-methyl-8-hydroxy) Quinolinate) (2-naphtholato) gallium, bis (2-methyl-8-hydroxyquinolinato) (phenolate) gallium, bis (2-methyl-8-hydroxyquinolinato) (4-cyano-1-naphtholate) ) Gallium, bis (2,4-dimethyl-8-hydroxyquinolinato) (1-naphtholate) gallium, bis (2,5-dimethyl-8-hydroxyquinolinato) (2-naphtholato) gallium, bis (2 -Methyl-5-phenyl-8-hydroxyquinolinate) (phenolate) gallium, bis (2-methyl-5- Cyano-8-hydroxyquinolinate) (4-cyano-1-naphtholate) gallium, bis (2-methyl-8-hydroxyquinolinate) chlorogallium, bis (2-methyl-8-hydroxyquinolinate) ( In addition to gallium complex compounds such as o-cresolate) gallium, 8-hydroxyquinolinate lithium, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, bis (10-hydroxybenzo [h And quinolinato) beryllium, bis (8-hydroxyquinolinato) zinc, and bis (10-hydroxybenzo [h] quinolinato) zinc.

  Among the electron injection materials that can be used in the present invention, preferable nitrogen-containing five-membered ring derivatives include oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, and triazole derivatives. , 5-bis (1-phenyl) -1,3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -1, 3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) 1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1 , 3,4-oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxadiazolyl) -4-tert-butylbenzene Zen], 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-thiadiazole, 2,5-bis (1-naphthyl) -1,3,4-thiadiazole 1,4-bis [2- (5-phenylthiadiazolyl)] benzene, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-triazole, 2 , 5-bis (1-naphthyl) -1,3,4-triazole, 1,4-bis [2- (5-phenyltriazolyl)] benzene and the like.

  Further, among the electron injection materials that can be used in the present invention, particularly preferable oxadiazole derivatives include oxadiazole derivatives described in WO2005-092888.

  Among the electron injection materials that can be used in the present invention, particularly preferred triazole derivatives include triazole derivatives described in the 2nd Annual Meeting of the Organic EL Discussion Group, Journal of Materials Chemistry, 16, 221 and 2006. It is done.

  Among the electron injection materials that can be used in the present invention, particularly preferred silole derivatives include Applied Physics Letter, vol. 80, 2, 14 2002, pages 189-191, WO 2004-052057, JP 2005-104986, and JP 09-194487.

  Of the electron injecting materials that can be used in the present invention, preferred triarylphosphine oxide derivatives include those disclosed in JP-A-2002-63989, JP-A-2004-95221, JP-A-2004-203828, and JP-A-2004. -204140 triarylphosphine oxide derivatives.

  Furthermore, a hole blocking material that can prevent holes from passing through the light emitting layer from reaching the electron injection layer and form a layer having excellent thin film formability is used for the hole blocking layer. Examples of such hole blocking materials include aluminum complex compounds such as bis (8-hydroxyquinolinate) (4-phenylphenolate) aluminum, and bis (2-methyl-8-hydroxyquinolinate) ( 4-phenylphenolate) gallium complex compounds such as gallium, and nitrogen-containing condensed aromatic compounds such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP).

The light emitting layer of the organic EL device of the present invention preferably has the following functions.
Injection function; function transport function that can inject holes from the anode or hole injection layer when an electric field is applied, and electrons from the cathode or electron injection layer; electric field of injected charges (electrons and holes) Light emitting function: A function that provides a field for recombination of electrons and holes and connects it to light emission. However, there is a difference between the ease of hole injection and the ease of electron injection. In addition, the transport ability represented by the mobility of holes and electrons may be large or small, but it is preferable to move one of the charges.

  The light-emitting material of the organic EL element is mainly an organic compound, and specifically, the following compounds are used depending on a desired color tone.

  For example, when violet emission is obtained from the ultraviolet region, p-quaterphenyl derivatives and p-quinkphenyl derivatives are preferably used. More specifically, [1,1 ′; 4 ′, 1 ″; 4 ″, 1 ′ ″] quaterphenyl, 4,4 ′ ″-dimethyl- [1,1 ′; 4 ′, 1 ″; 4 ″, 1 ′ ″] quarterphenyl, 4,4 ′ ″-dimethoxy- [1,1 ′; 4 ′, 1 ″; 4 ″, 1 ′ ″] quarterphenyl, 4 ″ ″ -Methyl- [1,1 ′; 4 ′, 1 ″; 4 ″, 1 ′ ″; 4 ′ ″, 1 ″ ″] quinkphenyl, 3,5,3 ″ ″, 5 ″ ″-tetra-tert-butyl- [1,1 ′; 4 ′, 1 ″; 4 ″, 1 ″ ′; 4 ′ ″, 1 ″ ″] quinkphenyl Etc.

  In order to obtain light emission in the visible range, particularly blue to green, for example, a fluorescent brightener such as benzothiazole, benzimidazole, and benzoxazole, a metal chelated oxinoid compound, and a styrylbenzene compound may be used. it can. Specific examples of these compounds include compounds disclosed in, for example, JP-A-59-194393. Still other useful compounds are listed in Chemistry of Synthetic Soybean (1971) pages 628-637 and 640.

  As the metal chelated oxinoid compound, for example, compounds disclosed in JP-A-63-295695 can be used. As typical examples, 8-hydroxyquinoline metal complexes such as tris (8-quinolinol) aluminum, dilithium epinetridione and the like can be mentioned as suitable compounds.

  Further, as the styrylbenzene compound, for example, those disclosed in European Patent No. 0319881 and European Patent No. 0373582 can be used. And the distyrylpyrazine derivative currently disclosed by Unexamined-Japanese-Patent No. 2-252793 can also be used as a material of a light emitting layer. In addition, polyphenyl compounds disclosed in EP 0387715 can also be used as a material for the light emitting layer.

  Further, in addition to the above-described fluorescent brightener, metal chelated oxinoid compound, styrylbenzene compound and the like, for example, 12-phthaloperinone (J. Appl. Phys., Vol. 27, L713 (1988)), 1,4- Diphenyl-1,3-butadiene, 1,1,4,4-tetraphenyl-1,3-butadiene (Appl. Phys. Lett., Vol. 56, L799 (1990)), naphthalimide derivatives No. 2-305886), perylene derivatives (Japanese Patent Laid-Open No. 2-189890), oxadiazole derivatives (Japanese Patent Laid-Open No. Hei 2-216791, or the 38th Applied Physics Related Conference) were disclosed by Hamada et al. Oxadiazole derivatives), aldazine derivatives (JP-A-2-220393), pyrazirine Conductor (JP-A-2-220394), cyclopentadiene derivative (JP-A-2-289675), pyrrolopyrrole derivative (JP-A-2-29691), styrylamine derivative (Appl. Phys. Lett., 56th) Vol. L799 (1990), coumarin compounds (Japanese Patent Laid-Open No. 2-191694), International Patent Publications WO 90/13148 and Appl. Phys. Lett., Vol 58, 18, P1982 (1991). High molecular compounds, 9,9 ′, 10,10′-tetraphenyl-2,2′-bianthracene, PPV (polyparaphenylene vinylene) derivatives, polyfluorene derivatives, copolymers thereof, and the like can be used.

  9,10-bis (N- (4- (2-phenylvinyl-1-yl) phenyl) -N-phenylamino) anthracene or the like can also be used as a material for the light emitting layer. Furthermore, phenylanthracene derivatives as disclosed in JP-A-8-12600 can also be used as the light emitting material.

In addition, the general formula (Rs-Q) _2- Al-O-L3 (wherein L3 is a hydrocarbon having 6 to 24 carbon atoms including a phenyl moiety) described in JP-A-5-258862, etc. O-L3 is a phenolate ligand, Q represents a substituted 8-quinolinolato ligand, Rs sterically represents that two or more substituted 8-quinolinolato ligands are bonded to an aluminum atom. And a bis (2-methyl-8-quinolinolato) (para-phenylphenolato) aluminum (III) compound, which represents an 8-quinolinolato ring substituent selected to interfere. ), Bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum (III), and the like.

  In addition, there is a method for obtaining high-efficiency blue and green mixed light emission using doping described in JP-A-6-9953. In this case, examples of the host include the above-described light-emitting materials, and examples of the dopant include strong fluorescent dyes from blue to green, for example, coumarins or fluorescent dyes similar to those used as the host. Specifically, a light-emitting material having a distyrylarylene skeleton as a host, particularly preferably 4,4′-bis (2,2-diphenylvinyl) biphenyl, and diphenylaminovinylarylene as a dopant, particularly preferably, for example, N, N-diphenyl Amino vinyl benzene can be mentioned.

Although there is no restriction | limiting in particular as a light emitting layer which obtains white light emission, The following can be used.
The energy level of each layer of the organic EL laminated structure is defined and light is emitted using tunnel injection (European Patent No. 0390551).
Similarly, a white light-emitting element is described as an example using tunnel injection (Japanese Patent Laid-Open No. 3-230584).
A light-emitting layer having a two-layer structure is described (JP-A-2-220390 and JP-A-2-216790).
A structure in which a light emitting layer is divided into a plurality of materials each having a different emission wavelength (Japanese Patent Laid-Open No. 4-51491).
A structure in which a blue phosphor (fluorescence peak 380 to 480 nm) and a green phosphor (480 to 580 nm) are stacked and a red phosphor is further contained (Japanese Patent Laid-Open No. 6-207170).
The blue light emitting layer contains a blue fluorescent dye, the green light emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (Japanese Patent Laid-Open No. 7-142169).
Among these, those having the above-described configuration are particularly preferable.

  In the organic EL device of the present invention, a phosphorescent material can be used. Examples of the phosphorescent material or doping material that can be used in the organic EL device of the present invention include, for example, an organometallic complex, where the metal atom is usually a transition metal, and preferably has a period of 5th or 6th period. In the group, elements from Group 6 to Group 11, more preferably Group 8 to Group 10 are targeted. Specific examples include iridium and platinum. Examples of the ligand include 2-phenylpyridine and 2- (2'-benzothienyl) pyridine, and the carbon atom on these ligands is directly bonded to the metal. Another example is a porphyrin or tetraazaporphyrin ring complex, and the central metal is platinum.

Furthermore, the material used for the anode of the organic EL device of the present invention is preferably a material having a work function (4 eV or more) metal, alloy, electrically conductive compound or a mixture thereof as an electrode substance. Specific examples of such an electrode substance include metals such as Au and conductive materials such as CuI, ITO, SnO ₂ and ZnO. In order to form this anode, a thin film can be formed from these electrode materials by a method such as vapor deposition or sputtering. The anode desirably has such a characteristic that when light emitted from the light emitting layer is extracted from the anode, 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. Further, although the film thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

  The material used for the cathode of the organic EL device of the present invention is a material having a small work function (4 eV or less) metal, alloy, electrically conductive compound and a mixture thereof as an electrode substance. 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 extracted from the cathode, the transmittance of the cathode for light emission is preferably greater than 10%. The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

  Regarding the method for producing the organic EL device of the present invention, an anode, a light emitting layer, a hole injection layer as necessary, and an electron injection layer as necessary are formed by the above materials and methods, and finally a cathode is formed. do it. Moreover, an organic EL element can also be produced from the cathode to the anode in the reverse order.

  This organic EL element is manufactured on a translucent substrate. This translucent substrate is a substrate that supports the organic EL element, and for the translucency, it is desirable that the transmittance of light in the visible region of 400 to 700 nm is 50% or more, preferably 90% or more, Further, it is preferable to use a smooth substrate.

  These substrates have mechanical and thermal strengths and are not particularly limited as long as they are transparent. For example, glass plates, synthetic resin plates and the like are preferably used. 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 of polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, polysulfone resin, and the like.

  As a method for forming each layer of the organic EL element of the present invention, a dry film forming method such as vacuum deposition, electron beam irradiation, sputtering, plasma, ion plating, or a wet film forming method such as spin coating, dipping, or flow coating is used. Either method can be applied. In addition, Special Tables 2002-534882 and S.A. T.A. Lee, et al. , Proceedings of SID'02, p. LITI (Laser Induced Thermal Imaging) method described in 784 (2002), printing (offset printing, flexographic printing, gravure printing, screen printing), inkjet, and the like can also be applied.

  The organic layer is particularly preferably a molecular deposited film. Here, the molecular deposited film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidifying from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom. Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, which is then thinned by a spin coat method or the like. An organic layer can be formed. The film thickness of each layer is not particularly limited, but if the film thickness is too thick, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. Conversely, if the film thickness is too thin, pinholes, etc. And it becomes difficult to obtain sufficient light emission luminance even when an electric field is applied. Accordingly, the thickness of each layer is suitably in the range of 1 nm to 1 μm, but more preferably in the range of 10 nm to 0.2 μm.

  Further, in order to improve the stability of the organic EL element with respect to temperature, humidity, atmosphere and the like, a protective layer may be provided on the surface of the element, or the entire element may be covered or sealed with a resin or the like. In particular, when the entire element is covered or sealed, a photocurable resin that is cured by light is preferably used.

  The current applied to the organic EL element of the present invention is usually a direct current, but a pulse current or an alternating current may be used. The current value and the voltage value are not particularly limited as long as the element is within a range not destroying the element. However, considering the power consumption and life of the element, it is desirable to efficiently emit light with as little electrical energy as possible.

  The organic EL device driving method of the present invention can be driven not only by the passive matrix method but also by the active matrix method. Further, the method for extracting light from the organic EL device of the present invention is applicable not only to the method of bottom emission for extracting light from the anode side but also to the method of top emission for extracting light from the cathode side. These methods and techniques are described in Shinji Kido, “All about organic EL”, published by Nihon Jitsugyo Shuppansha (published in 2003).

  The main methods of the full color method of the organic EL element of the present invention include a three-color coating method, a color conversion method, and a color filter method. In the three-color coating method, there are a vapor deposition method using a shadow mask, an ink jet method and a printing method. In addition, Special Tables 2002-534882 and S.A. T.A. Lee, et al. , Proceedings of SID'02, p. 784 (2002) can also be used. The laser thermal transfer method (also referred to as Laser Induced Thermal Imaging, LITI method) can also be used. In the color conversion method, a blue light emitting layer is used to convert green and red having a longer wavelength than blue through a color conversion (CCM) layer in which fluorescent dyes are dispersed. The color filter method uses a white light emitting organic EL element to extract light of three primary colors through a color filter for liquid crystal. In addition to these three primary colors, a part of white light is directly extracted and used for light emission. Thus, the luminous efficiency of the entire device can be increased.

  Furthermore, the organic EL element of the present invention may adopt a microcavity structure. This is because the organic EL element has a structure in which the light emitting layer is sandwiched between the anode and the cathode, and the emitted light causes multiple interference between the anode and the cathode, but the reflectance and transmission of the anode and the cathode. This is a technology that actively uses the multiple interference effect and controls the emission wavelength extracted from the device by appropriately selecting the optical characteristics such as the rate and the film thickness of the organic layer sandwiched between them. . Thereby, it is also possible to improve the emission chromaticity. For the mechanism of this multiple interference effect, see J.A. Yamada et al., AM-LCD Digest of Technical Papers, OD-2, p. 77-80 (2002).

  As described above, the organic EL element using the indole derivative of the present invention can emit light for a long time with a low driving voltage. Therefore, this organic EL device can be used as a flat panel display such as a wall-mounted television and various flat light emitters, as well as a light source such as a copying machine or a printer, a light source such as a liquid crystal display or an instrument, a display board, a marker lamp, etc. Can be applied.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the following Example.

Method for Synthesizing Compound of the Present Invention Each compound could be obtained by reactions 1 to 8 shown below.

Reaction 1

Reaction 2

Reaction 3

Reaction 4

Reaction 5

Reaction 6

Reaction 7

Reaction 8

  The 5-bromoindole derivatives and 5-nitroindole derivatives used in the above reactions could be synthesized using the methods described in the following documents.

Tetrahedron Letters, 1991, 6695-6696, Tetrahedron Letters, 1977, 1923-1926, Tetrahedron, 1992, 5991-6010, SYNTHESIS, 2005, 1706-1712, Tetrahedron Publication, pages 6425-6437, Macromolecules, 1996 publication, pages 2359-2364, Chem. Commun. , 2003, 1822-1823, J. Am. Mater. Chem., 2002, pages 58-64, Chem. Commun. 2004, pp. 2824-2825, ORGANIC LETTERS, 2004, 4129-4132, J. Am. Org. Chem. , 2004, 1126-1136 Chem. Commun. 2004, pp. 158-159, Tetrahedron Letters, 2001, 3865-3868, J. Am. Org. Chem. 1995, pages 6218-6220, J. Am. Org. Chem. 1975, pp. 3784-3786; Am. Chem. Soc. 1991, pp. 6343-6345. Chem. Soc. Perkin Trans. 1, 2001, 695-700, SYNTHESIS, 1987, 383-385, SYNTHESIS, 1981, 461-462, J. MoI. Org. Chem. 1987, pp. 1673-1680, J. MoI. Heterocyclic Chem. 1987, pp. 811-815, J. Am. Chem. Soc. Perkin Trans. 1, 1999, pp. 529-534, J. Am. Org. Chem. , 1981, 4511-4515, J. Am. Am. Chem. Soc. 2006, pp. 4972-4773; Am. Chem. Soc. , 1995, 4468-4475, J. Am. Org. Chem. 1994, 5215-5229, J. MoI. Org. Chem. , 2001, 7729-7737, J. Am. Am. Chem. Soc. , 2002, 11684-11688, J. Am. Org. Chem. , 1997, 2676-2777, J. Am. Org. Chem. 1998, pp. 7652-7621, Chem. Mater. 2003, 699-707, Tetrahedron, 2005, 11311-11316, Tetrahedron, 2005, 11374-11379, Tetrahedron Letters, 200, 9541-9544, Tetrahedron, 2003, 1917-1923

  Reactions (j), (k), and (n) in the above reaction formula are amine synthesis methods generally called the Ullmann method. The Ullman method is a coupling reaction of aryl iodide and arylamine, in which a copper powder and a base such as anhydrous potassium carbonate are reacted at a temperature of about 100 to 180 ° C. in a high boiling point solvent such as nitrobenzene. The method known in the industry described in 7-126226 etc. was referred.

  In the above reaction formula, the reactions (a), (b), (d), (e), (f), (g), (h), (i), (m), (o) are odors. In this reaction, a palladium compound and a phosphorus compound were used as a catalyst in the presence of a base instead of the copper powder and base used in the Ullman method. Regarding this method, JP-A-10-81667, JP-A-10-139742, JP-A-10-310561, John F. et al. By Hartwig, Angew. Chem. Int. Ed. 37, 2046-2067 (1998), Bryant H., et al. Yang, Stephen L Buchwald, J.A. Organomet. Chem. 576, 125-146 (1999), John P. et al. Wolfe, Stephen L Buchwald, J.A. Org. Chem. 65, 1144-1157 (2000), John P. Wolfe, Stephen L Buchwald, J.A. Org. Chem. 62, 1264-1267 (1997), Janis Louie, Michael S., et al. Driver, Blake C .; Hammann, John F. By Hartwig, J.H. Org. Chem. 62, pp. 1268 to 1273 (1997), JP-A 63-35548, JP-A 6-100503, JP-T 2001-515879, and re-published patent WO 2002/076922.

  In addition, the conversion reaction from the nitro group to the amino group in (c) and (l) in the above reaction formula is a well-known nitro group reduction reaction, and zinc or tin chloride under acidic conditions. Reduction by (II), reduction with hydrogen in the presence of a catalyst such as palladium black or Raney nickel, and reduction using a reducing agent such as lithium aluminum hydride can yield the corresponding amine compound from the nitro compound in good yield. It was. This reduction reaction is described in Calvin A. et al. Buehler, Donald E. et al. Pearson, SURVEY OF ORGANIC SYNTHESES, pp. 413-417, Wiley-Interscience (1970), The Chemical Society of Japan, New Experimental Chemistry Course 14, 1333-1335, Maruzen (1978) The method of was referred.

Example 1
Synthesis Method of Compound (2b) in Table 2 15.9 g (99.9 mmol) of 1,2,3-trimethyl-1H-indole was dissolved in 100 ml of toluene under a nitrogen atmosphere. Under stirring, a solution prepared by dissolving 17.8 g (100 mmol) of N-bromosuccinimide (NBS) in 50 ml of DMF was added dropwise over 1 hour. After completion of dropping, the mixture was stirred for 2 hours, and the reaction solution was washed with water. When the organic layer was distilled under reduced pressure, 20.2 g of 5-bromo-1,2,3-trimethyl-1H-indole was obtained. Next, 3.1 g (12.8 mmol) of 5-bromo-1,2,3-trimethyl-1H-indole obtained, 5.0 g (29.5 mmol) of diphenylamine, 0.17 g of palladium acetate, tri-tert-butylphosphine 0.30 g and 3.4 g of sodium tert-butoxide were placed in a 50 ml four-necked flask, 20 ml of dehydrated xylene was added, and the mixture was heated to reflux for 3 hours under a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain the target compound (2b) in 3.1 g (yield 75%). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 2
Synthesis method of compound (3b) in Table 2 Except that 1,2,3-trimethyl-1H-indole was changed to 2,3-dimethyl-1-phenyl-1H-indole in Example 1, it was the same as Example 1. As a result, the compound (3b) was obtained in a yield of 86%. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 3
Synthesis Method of Compound (24b) in Table 2 Under a nitrogen atmosphere, 27.1 g (99.9 mmol) of 2,3-dimethyl-1- (α-naphthyl) -1H-indole was dissolved in 150 ml of toluene. Under stirring, a solution prepared by dissolving 17.8 g (100 mmol) of N-bromosuccinimide (NBS) in 50 ml of DMF was added dropwise over 1 hour. After completion of dropping, the mixture was stirred for 2 hours, and the reaction solution was washed with water. The organic layer was distilled under reduced pressure to obtain 27.3 g of 5-bromo-2,3-dimethyl-1- (α-naphthyl) -1H-indole. Next, 9.0 g (25.6 mmol) of 5-bromo-2,3-dimethyl-1- (α-naphthyl) -1H-indole obtained, 1.1 g (11.8 mmol) of aniline, 0.13 g of palladium acetate, 0.24 g of tri-tert-butylphosphine and 2.5 g of sodium tert-butoxide were placed in a 50 ml four-necked flask, 30 ml of dehydrated xylene was added, and the mixture was heated to reflux for 3 hours under a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain the target compound (24b) in 6.2 g (yield 83%). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 4
Method for synthesizing compound (36b) in Table 2 In Example 3, except that 2,3-dimethyl-1- (α-naphthyl) -1H-indole was replaced with 2,3-difluoro-1-phenyl-1H-indole Was treated in the same manner as in Example 3 to obtain compound (36b) in a yield of 58%. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 5
Synthesis Method of Compound (45b) in Table 2 Under a nitrogen atmosphere, 26.6 g (100 mmol) of 2,3-dimethyl-5-nitro-1-phenyl-1H-indole was dissolved in 100 ml of toluene, and palladium carbon (5 %) Was added. Under stirring, 20 g of a hydrazine aqueous solution (80%) was slowly added dropwise. After completion of the dropwise addition, the mixture was stirred for 2 hours under reflux, and the reaction solution was filtered. The filtrate was concentrated and recrystallized from ethanol to obtain 18.5 g of 5-amino-2,3-dimethyl-1-phenyl-1H-indole. Next, 2.7 g (10.1 mmol) of 5-amino-2,3-dimethyl-1-phenyl-1H-indole obtained and the reaction intermediate 5-bromo-2,3-dimethyl obtained in Example 2 were obtained. -1-phenyl-1H-indole 7.0 g (23.3 mmol) 0.11 g of palladium acetate, 0.20 g of tri-tert-butylphosphine and 2.1 g of sodium tert-butoxide were placed in a 50 ml four-necked flask, 20 ml of dehydrated xylene was added and heated under reflux for 3 hours in a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain 3.7 g (yield 55%) of the desired compound (45b). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), 1H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 6
Synthesis Method of Compound (51b) in Table 2 In Example 5, 2,3-dimethyl-5-nitro-1-phenyl-1H-indole was converted to 1-biphenyl-2,3-dimethyl-5-nitro-1H-indole. Instead, 5-bromo-2,3-dimethyl-1-phenyl-1H-indole was replaced with 1-biphenyl-5-bromo-2,3-dimethyl-1H-indole. The compound (51b) was obtained with a yield of 45%. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 7
Synthesis Method of Compound (72b) in Table 2 6.0 g (20.0 mmol) of 5-bromo-2,3-dimethyl-1-phenyl-1H-indole, which is a synthesis intermediate of Example 2, and N, N ′ -2.4 g (9.1 mmol) of diphenyl-1,4-phenylenediamine, 0.22 g of palladium acetate, 0.4 g of tri-tert-butylphosphine and 2.1 g of sodium tert-butoxide in a 50 ml four-necked flask Then, 30 ml of dehydrated xylene was added, and the mixture was heated to reflux for 3 hours under a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain 5.7 g (yield 89%) of the desired compound (72b). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 8
Synthesis Method of Compound (81b) in Table 2 5-Bromo-1,2,3 synthesized in the same manner as in Example 1 instead of 5-bromo-2,3-dimethyl-1-phenyl-1H-indole The same operation as in Example 7 was carried out except that triphenyl-1H-indole was used and N, N′-diphenyl-benzidine was used instead of N, N′-diphenyl-1,4-phenylenediamine. Compound (81b) was obtained with a yield of 85%. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 9
Synthesis Method of Compound (267b) in Table 2 5-Bromo-1,2,3-triphenyl-1H-indole 38.2 g (90 mmol) and aniline 9.3 g (100 mmol), palladium acetate 0.75 g, tri- 1.36 g of tert-butylphosphine and 10.6 g of sodium tert-butoxide were placed in a 30 ml four-necked flask, 200 ml of dehydrated xylene was added, and the mixture was heated to reflux for 3 hours under a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain 31.4 g of phenyl- (1,2,3-triphenyl-1H-indol-5-yl) -amine. . Next, 4.4 g (10.1 mmol) of the obtained phenyl- (1,2,3-triphenyl-1H-indol-5-yl) -amine, 4.1 g (10.1 mmol) of diiodobiphenyl and copper powder 0.2 g and 2.8 g of potassium carbonate were heated and stirred at 50 ° C. for 5 hours in 50 ml of nitrobenzene. After filtration of the reaction solution, nitrobenzene was removed by steam distillation, and the resulting oil was purified by silica gel column chromatography to obtain (4′-iodo-biphenyl-4-yl) -phenyl- (1,2,3- 3.6 g of triphenyl-1H-indol-5-yl) -amine were obtained. Next, 3.6 g (5.0 mmol) of (4′-iodo-biphenyl-4-yl) -phenyl- (1,2,3-triphenyl-1H-indol-5-yl) -amine obtained, diphenylamine 0.85 g (5.0 mmol), 0.1 g of copper powder, and 1.4 g of potassium carbonate were heated and stirred at 150 ° C. for 6 hours in 30 ml of nitrobenzene. After filtering the reaction solution, nitrobenzene was removed by steam distillation, and the resulting oil was purified by silica gel column chromatography to obtain 3.0 g (yield 80%) of the desired compound (267b). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 10
Synthesis method of compound (277b) in Table 2 4- (5-bromo-2,3) synthesized in the same manner as in Example 1 instead of 5-bromo-1,2,3-triphenyl-1H-indole -Dimethyl-indol-1-yl) -benzonitrile was used in the same manner as in Example 9 to obtain compound (277b) in a yield of 71%. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 11
Synthesis Method of Compound (297b) in Table 2 4.7 g (20.3 mmol) of the intermediate 5-amino-2,3-dimethyl-1-phenyl-1H-indole obtained in Example 5 and 5-bromo- 100 ml of 2,3-dimethyl-1-phenyl-1H-indole 5.5 g (18.5 mmol), palladium acetate 0.22 g, tri-tert-butylphosphine 0.4 g, sodium tert-butoxide 2.4 g The flask was put into a one-necked flask, 50 ml of dehydrated toluene was added, and the mixture was reacted at 100 ° C. for 2 hours in a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain 7.0 g of bis- (2,3-dimethyl-1-phenyl-1H-indol-5-yl) -amine. It was. Next, 4.6 g (10 mmol) of the obtained bis- (2,3-dimethyl-1-phenyl-1H-indol-5-yl) -amine and the synthetic intermediate synthesized in Example 9 (4′- (2,3-Dimethyl-1-phenyl-1H-) synthesized in the same manner as iodo-biphenyl-4-yl) -phenyl- (1,2,3-triphenyl-1H-indol-5-yl) -amine 5.9 g (10 mmol) of indol-5-yl)-(4′-iodo-biphenyl-4-yl) -phenyl-amine, 0.2 g of copper powder and 1.4 g of potassium carbonate in 150 ml of nitrobenzene at 150 ° C. Stir with heating for hours. After filtering the reaction solution, nitrobenzene was removed by steam distillation, and the obtained oil was purified by silica gel column chromatography to obtain 5.7 g (yield 63%) of the desired compound (297b). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 12
Synthesis method of compound (311b) in Table 2 9-phenyl-6,7,8,9-tetrahydro-5H-carbazole-3 instead of 5-amino-2,3-dimethyl-1-phenyl-1H-indole Using -ylamine and using 6-bromo-9-phenyl-2,3,4,9-tetrahydro-1H-carbazole instead of 5-bromo-2,3-dimethyl-1-phenyl-1H-indole, The same operation as in Example 11 was performed to synthesize bis- (9-phenyl-6,7,8,9-tetrahydro-5H-carbazol-3-yl) -amine, which was used in Example 11 (2, Instead of 3-dimethyl-1-phenyl-1H-indol-5-yl)-(4′-iodo-biphenyl-4-yl) -phenyl-amine, (4′-methyl-biphenyl-4-yl)- Using phenyl- (9-phenyl-6,7,8,9-tetrahydro-5H-carbazol-3-yl) -amine, the same operation as in Example 11 was carried out, and the compound (311b) was obtained in a yield of 59%. I got it. The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

Example 13
Synthesis Method of Compound (331b) in Table 2 By the same synthesis method as the intermediate bis- (2,3-dimethyl-1-phenyl-1H-indol-5-yl) -amine obtained in Example 11 Bis- (1,2,3-trimethyl-1H-indol-5-yl) -amine was synthesized. The obtained bis- (1,2,3-trimethyl-1H-indol-5-yl) -amine 6.6 g (20 mmol) and dibromobiphenyl 2.8 g (9.0 mmol), palladium acetate 0.11 g, tri- 0.2 g of tert-butylphosphine and 2.1 g of sodium tert-butoxide were placed in a 100 ml four-necked flask, 60 ml of dehydrated xylene was added, and the mixture was heated to reflux for 4 hours under a nitrogen atmosphere. The reaction solution was poured into methanol, and the precipitated solid was purified by silica gel column chromatography to obtain 3.9 g (yield 53%) of the desired compound (331b). The compound was identified by mass spectrum (manufactured by Bruker Daltonics, Autoflex II), ¹ H-NMR, ¹³ C-NMR (manufactured by JEOL Ltd., GSX270).

  In the same manner as in Examples 1 to 13, the compounds of the present invention described in Table 2 could be synthesized. The structure of the obtained compound was confirmed by mass spectrum (manufactured by Bruker Daltonics, Autoflex II). The results are shown in Table 3. The compound numbers are the same as those in Table 2.

Table 3

Examples of Organic EL Devices In the following examples, all mixing ratios are weight ratios unless otherwise specified. Vapor deposition (vacuum deposition) was performed in a vacuum of 10 ⁻⁶ Torr and under conditions without temperature control such as substrate heating and cooling. In the evaluation of the light emission characteristics of the element, the characteristics of an organic EL element having an electrode area of 2 mm × 2 mm were measured.

  The compounds other than the compounds of the present invention used in the following examples are shown in Tables 4 and 5.

Table 4

Table 5

Example 347
On the washed glass plate with an ITO electrode, the compound (1b) in Table 2 was vacuum-deposited to obtain a hole injection layer having a thickness of 60 nm. Subsequently, (1d) in Table 5 was vacuum-deposited to obtain a 20 nm hole transport layer. Further, tris (8-hydroxyquinolinate) aluminum complex (Alq3) was vacuum-deposited to prepare a 60 nm-thickness electron-injection-type light-emitting layer. An electrode was formed by vapor-depositing (Al) at 200 nm to obtain an organic EL element. The half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. In addition, luminance was measured by continuously emitting light at a current density of 10 mA / cm ² for 100 hours in an environment of 100 ° C. The results are shown in Table 6.

Examples 348-395
An element similar to that of Example 111 was prepared, except that a hole injection layer was formed using the compounds shown in Table 6. The half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. In addition, luminance was measured by continuously emitting light at a current density of 10 mA / cm ² for 100 hours in an environment of 100 ° C. The results are shown in Table 6.

Comparative Examples 1-3
A device was prepared in the same manner as in Example 111 except that a hole injection layer was prepared using the compounds (1c) to (3c) in Table 4. The half life when this device was driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was measured. In addition, luminance was measured by continuously emitting light at a current density of 10 mA / cm ² for 100 hours in an environment of 100 ° C. The results are shown in Table 6.

表６から明らかなように、本発明の化合物を用いて作成した素子は、比較例の化合物よりも低電圧で駆動でき、また、長寿命で高い輝度が得られた。 Table 6

As is apparent from Table 6, the device prepared using the compound of the present invention was able to be driven at a lower voltage than that of the compound of the comparative example, and had a long lifetime and high luminance.

Example 396
Copper phthalocyanine was deposited on a glass plate with an ITO electrode to form a hole injection layer having a thickness of 25 nm. Next, the compound (7b) in Table 2 and the compound (4c) in Table 4 were co-evaporated at a composition ratio of 100: 8 to form a light emitting layer having a thickness of 45 nm. Further, the compound (5c) in Table 4 was deposited to form an electron injection layer having a thickness of 20 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium oxide (Li ₂ O) and 100 nm of aluminum (Al) to obtain an organic EL device. This device showed an external quantum efficiency of 8.0% at a DC voltage of 10V. Further, the half-life when driven at a constant current at an emission luminance of 200 (cd / m ² ) was 5000 hours or more.

Examples 397-407
Instead of compound (7b) in Table 2, compounds (9b), (272b), (275b), (276b), (277b), (279b), (282b), (283b), (287b) in Table 2 ), (290b), and (294b) were used, and an element was prepared in the same manner as in Example 396. These devices exhibited an external quantum efficiency of 7% or more at a DC voltage of 10 V, and had a half life of 5000 hours or more when driven at a constant current at an emission luminance of 200 (cd / m ² ).

Example 408
A compound (2d) in Table 5 was vapor-deposited on a glass plate with an ITO electrode to form a 60 nm-thick hole injection layer, and then the compound (50b) in Table 2 was vapor-deposited to form a positive 20 nm-thick film. A hole transport layer was formed. Next, Alq3 was deposited to form an electron injecting light emitting layer having a film thickness of 60 nm, and an electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride and 200 nm of aluminum to obtain an organic EL device. The light emission efficiency of this device at a DC voltage of 5 V was 2.0 (lm / W). In addition, the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 409-413
A device was prepared in the same manner as in Example 408 except that the compounds (3d), (4d), (5d), (6d), and (9d) in Table 5 were used. When these devices were driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ), all the half lives were 5000 hours or more.

Examples 414-424
Instead of the compound (50b) in Table 2, the compounds (63b), (66b), (69b), (91b), (95b), (102b), (110b), (123b), (127b) in Table 2 ), (141b), and (146b) were used, and an element was prepared in the same manner as in Example 408. When these devices were driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ), all the half lives were 5000 hours or more.

Example 425
NPD was vacuum-deposited on a glass plate with an ITO electrode to obtain a hole injection layer having a thickness of 40 nm. Next, the compound (16b) in Table 2 and the compound (6c) in Table 4 were co-evaporated at a ratio of 98: 3 to form a light-emitting layer having a film thickness of 40 nm, and then Alq3 was vacuum-deposited to form a film thickness. A 30 nm electron injection layer was prepared. An electrode was formed thereon by vacuum-depositing lithium fluoride at 0.7 nm and then aluminum at 200 nm to obtain an organic EL element. This device emitted light with an emission luminance of 480 (cd / m ² ) and a maximum emission luminance of 93500 (cd / m ² ) at a DC voltage of 5V. The half life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 4500 hours.

Examples 426-435
Instead of the compound (16b) in Table 2, the compounds (54b), (58b), (113b), (120b), (156b), (162b), (169b), (170b), (178b) in Table 2 ) And (333b) were used, and an element was prepared in the same manner as in Example 425. When these devices were driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ), all the half lives were 5000 hours or more.

Example 436
After vapor-depositing (6d) in Table 5 on a glass plate with an ITO electrode to form a 50 nm-thick hole injection layer, the compound (285b) in Table 2 was vapor-deposited to 20 nm to form a hole transport layer. Formed. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, the compound (10d) in Table 5 was deposited to form an electron injection layer having a thickness of 30 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic EL device. This device showed an emission luminance of 730 (cd / m ² ) at a DC voltage of 5.3 V. Further, the half-life when the element was driven at a constant current at an emission luminance of 500 (cd / m ² ) at room temperature was 5000 hours or more immediately after the element was created and after being stored in an oven at 100 ° C. for 1 hour. .

Examples 437-445
Instead of the compound (10d) in Table 5 used in Example 436, the compounds (11d), (12d), (13d), (14d), (15d), (16d) in Table 5 were used as the electron injection layer. -(19d) was used to produce a device under the same conditions as in Example 222. The characteristics of the element were measured for the element immediately after the element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 446-456
Instead of the compound (285b) in Table 2, the compound (104b), (181b), (182b), (188b), (192b), (208b), (213b), (236b), (236) in Table 2 An element was fabricated under the same conditions as in Example 436 except that 248b), (259b), and (300b) were used. The characteristics of the element were measured for the element immediately after the element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 457
On the glass plate with ITO electrode, the compound (7d) in Table 5 was deposited to form a hole injection layer having a film thickness of 55 nm, and then the compound (32b) in Table 2 was deposited to 20 nm to form a hole transport layer. Formed. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, the compound (20d) in Table 5 was deposited to form an electron injection layer having a thickness of 30 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic EL device. This device showed an emission luminance of 740 (cd / m ² ) at a DC voltage of 5V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Examples 458-470
Instead of the compound (20d) in Table 5 used in Example 457, the compound (21d), (22d), (23d), (24d), (25d), (26d) in Table 5 was used as the electron injection layer. Using (28d) and (29d) to (33d), an element was fabricated under the same conditions as in Example 457. The characteristics of the element were measured for the element immediately after the element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 471
On the glass plate with an ITO electrode, the compound (8d) in Table 5 was deposited to form a hole injection layer having a film thickness of 60 nm, and then the compound (251b) in Table 2 was deposited to 15 nm to form a hole transport layer. Formed. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. Further, the compound (34d) in Table 5 was deposited to form an electron injection layer having a thickness of 30 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium oxide and 100 nm of aluminum to obtain an organic EL device. This device showed a luminous efficiency of 2.6 (lm / W) at a DC voltage of 5.0 V. In addition, the half-life when the element was stored at room temperature at an emission luminance of 500 (cd / m ² ) immediately after element preparation and after storage for 1 hour in an oven at 100 ° C. was 5000 hours for all elements. That was all.

Example 472
On the glass plate with an ITO electrode, the compound (256b) in Table 2 was dissolved in 1,2-dichloroethane, and a 50 nm-thick hole injection layer was formed by spin coating. Next, Alq3 is deposited to form an electron injecting light emitting layer having a thickness of 30 nm, and an electrode having a thickness of 100 nm is formed thereon using an alloy in which magnesium and silver are mixed at a ratio of 10: 1. Got. The light emission efficiency of this device at a DC voltage of 8.4 V was 2.3 (lm / W). In addition, the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 473
On the glass plate with an ITO electrode, the compound (121b) in Table 2 was deposited to form a hole injection layer having a thickness of 75 nm. Next, the compound (7c) in Table 4 and Alq3 were co-evaporated at a composition ratio of 1:20 to form a light emitting layer having a thickness of 35 nm. Further, Alq3 was deposited to form an electron injection layer with a thickness of 30 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride (LiF) and 200 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a luminous efficiency of 0.65 (lm / W) at a DC voltage of 5.0 V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 474-484
Instead of the compound (121b) in Table 2 used in Example 473, the compounds (13b), (37b), (45b), (97b), (107b), (144b), (159b) in Table 2 were used. , (243b), (250b), (262b), and (303b), an element was fabricated under the same conditions as in Example 473. All of the elements have element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, a luminance of 400 (cd / m ² ) or more, and an emission luminance of 500 ( The half life when driven at a constant current at room temperature at cd / m ² ) was 5000 hours or more.

Example 485
On the glass plate with an ITO electrode, the compounds (15b) and (68b) in Table 2 were co-evaporated at a composition ratio of 1: 1 to form a hole injection layer having a thickness of 80 nm. Next, the compound (8c) in Table 4 was vapor-deposited to form a 20 nm-thick luminescent layer. Further, Alq3 was deposited to form an electron injection layer having a thickness of 20 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride (LiF) and 200 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a luminous efficiency of 2.3 (lm / W) at a DC voltage of 5.3 V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 486-490
Instead of the compound (15b) in Table 2 used in Example 485, the compounds (84b), (224b), (307b), (321b) and (327b) in Table 2 were used, and Example 485 and Devices were created under the same conditions. All of the elements have element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, a luminance of 400 (cd / m ² ) or more, and an emission luminance of 500 ( The half life when driven at a constant current at room temperature at cd / m ² ) was 5000 hours or more.

Example 491
On the glass plate with an ITO electrode, the compound (179b) in Table 2 was deposited to form a hole injection layer having a thickness of 60 nm. Next, the compound (9c) in Table 4 and the compound (10c) in Table 4 were co-evaporated at a composition ratio of 20: 1 to form a light emitting layer having a thickness of 30 nm. Further, Alq3 was deposited to form an electron injection layer having a thickness of 20 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride (LiF) and 200 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a light emission efficiency of 5.9 (lm / W) at a DC voltage of 6.2 V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 492-497
Instead of the compound (179b) in Table 2 used in Example 485, the compounds (116b), (150b), (173b), (217b), (309b) and (324b) in Table 2 were used. An element was created under the same conditions as in Example 491. All of the elements have element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, a luminance of 400 (cd / m ² ) or more, and an emission luminance of 500 ( The half life when driven at a constant current at room temperature at cd / m ² ) was 5000 hours or more.

Example 498
On the glass plate with an ITO electrode, the compound (36b) in Table 2 was deposited to form a hole injection layer having a thickness of 60 nm. Next, the compound (11c) in Table 4 and the compound (12c) in Table 4 were co-evaporated at a composition ratio of 20: 1 to form a light emitting layer having a thickness of 35 nm. Further, Alq3 was deposited to form an electron injection layer with a thickness of 30 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride (LiF) and 200 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a light emission efficiency of 2.9 (lm / W) at a DC voltage of 3.5V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 499
On the glass plate with an ITO electrode, the compound (215b) in Table 2 was deposited to form a hole injection layer having a thickness of 50 nm. Next, the compound (13c) in Table 4 and Alq3 were co-evaporated at a composition ratio of 1: 1 to form an electron-transporting light-emitting layer having a thickness of 50 nm. Furthermore, an electrode having a thickness of 200 nm was formed from an alloy in which magnesium and silver were mixed at a ratio of 1: 3 to obtain an organic electroluminescence device. The light emission efficiency of this device at a DC voltage of 8 V was 1.1 (lm / W). Further, the half-life when driven at a constant current at room temperature with an emission luminance of 350 (cd / m ² ) was 5000 hours or more.

Example 500
On the glass plate with an ITO electrode, the compound (212b) in Table 2 was deposited to form a hole injection layer having a thickness of 50 nm. Next, the compound (11c) in Table 4 and the compound (14c) in Table 4 were co-evaporated at a composition ratio of 100: 1 to form a light emitting layer having a thickness of 25 nm. Further, BCP was deposited to form an electron injection layer having a thickness of 25 nm. On top of this, 0.5 nm of lithium (Li) and 150 nm of silver were further deposited to obtain an organic electroluminescence device. This device showed a luminous efficiency of 0.89 (lm / W) at a DC voltage of 10V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 501
On the glass plate with an ITO electrode, the compound (218b) in Table 2 was deposited to form a hole injection layer having a thickness of 40 nm. Next, the compound (15c) in Table 4 was deposited by 10 nm to form a hole transport layer. The compound (16c) in Table 4 and the compound (17c) in Table 4 were co-evaporated at a composition ratio of 1: 9 to form a light emitting layer having a thickness of 25 nm. Further, BCP was deposited to form a 15 nm hole blocking layer. Further, Alq3 was deposited to form an electron injection layer having a thickness of 25 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium fluoride (LiF) and 100 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed an external quantum efficiency of 7.3% at a DC voltage of 10V. Further, the half-life when driven at a constant current at an emission luminance of 100 (cd / m ² ) was 5000 hours or more.

Example 502
On the glass plate with an ITO electrode, the compound (239b) in Table 2 was deposited by 60 nm to form a hole injection layer. Further, Alq3 was deposited to form a light emitting layer with a thickness of 20 nm. The compound (34d) in Table 5 was deposited to form an electron injection layer having a thickness of 30 nm. A cathode was formed thereon by vapor deposition of 1 nm of lithium oxide (Li ₂ O) and 100 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a luminous efficiency of 2.2 (lm / W) at a DC voltage of 4.0 V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 503-508
The experiment was performed under the same conditions as in Example 502 except that the compound (35d) and (37d) to (41d) in Table 5 were used as the electron injection layer instead of the compound (34d) in Table 5. The characteristics of the element were measured for the element immediately after the element preparation and after storage for 1 hour in an oven at 100 ° C. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 509-514
Instead of the compound (239b) in Table 2 used in Example 502, the compounds (19b), (165b), (198b), (203b), (311b) and (336b) in Table 2 were used. An element was prepared under the same conditions as in Example 502. All of the elements have element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, a luminance of 400 (cd / m ² ) or more, and an emission luminance of 500 ( The half life when driven at a constant current at room temperature at cd / m ² ) was 5000 hours or more.

Example 515
On the glass plate with an ITO electrode, the compound (231b) in Table 2 was deposited to form a hole injection layer having a thickness of 55 nm. Further, NPD was deposited to form a 20 nm thick hole transport layer. Next, compounds (18c) and (19c) in Table 4 were co-evaporated at a composition ratio of 50: 1 to form a light emitting layer having a thickness of 35 nm. Furthermore, the compound (20c) in Table 4 was deposited to form an electron injection layer having a thickness of 30 nm. An electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride (LiF) and 200 nm of aluminum (Al) to obtain an organic electroluminescence device. This device showed a luminous efficiency of 4.1 (lm / W) at a DC voltage of 3.5V. In addition, the half-life when driven at a constant current at an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 516-522
The same conditions as in Example 515 except that (40b), (100b), (118b), (139b), (186b), (234b) and (253b) were used instead of the compound (231b) in Table 2. An element was created. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Example 523
On the glass plate with an ITO electrode, the compound (255b) in Table 2 was vapor-deposited to form a 60 nm-thick hole injection layer, and then the compound (255b) in Table 2 was vapor-deposited to form a positive 20-nm thick film. A hole transport layer was formed. Next, Alq3 was deposited to form an electron injecting light emitting layer having a film thickness of 60 nm, and an electrode was formed thereon by vacuum deposition of 1 nm of lithium fluoride and 200 nm of aluminum to obtain an organic EL device. The light emission efficiency of this device at a DC voltage of 5 V was 2.0 (lm / W). In addition, the half-life when driven at a constant current at room temperature with an emission luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 524-530
Implementation was performed except that the compound (75b), (86b), (93b), (125b), (148b), (164b), (175b) in Table 2 was used instead of the compound (155b) in Table 2. A device was produced under the same conditions as in Example 523. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

Examples 531-540
Instead of the compound (255b) in Table 2, the compounds in Table 2, (238b), (245b), (258b), (296b), (305b), (319b), (338b), (340b), (340b), A device was fabricated under the same conditions as in Example 523 except that 343b) and (345b) were used. As a result, each element has element characteristics when driven at a current density of 10 (mA / cm ² ), a voltage of 4.0 (V) or less, and a luminance of 400 (cd / m ² ) or more. The half-life when driven at a constant current at room temperature with a luminance of 500 (cd / m ² ) was 5000 hours or more.

  As described above, a high-performance EL element can be produced by using the indole derivative shown in the present invention. It is clear that remarkably high performance is exhibited with respect to the comparative compound, and it is possible to achieve a low driving voltage and a long life of the organic EL element.

Claims (6)

An indole derivative represented by the following general formula [1].
General formula [1]

(In the formula, Ar ¹ and Ar ² are each independently a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a carbon number which may have a substituent. It represents a monovalent heterocyclic group having 2 to 18 or a group represented by the following general formula [2].
X represents a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a monovalent heterocyclic group having 2 to 18 carbon atoms which may have a substituent, and a substituent. It represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, a group represented by the following general formula [2], or a group represented by the following general formula [3].
However, at least one of Ar ¹ , Ar ² , and X is a group represented by the general formula [2].
In addition, Ar ¹ , Ar ² , and X may be substituted with a halogen atom, a monovalent aliphatic hydrocarbon group, a monovalent aromatic hydrocarbon group, a monovalent heterocyclic group, cyano, A group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylsulfinyl group, and an arylsulfinyl group. )
General formula [2]

Wherein R ¹ is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a monovalent heterocyclic ring having 2 to 18 carbon atoms which may have a substituent. Represents a group or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms which may have a substituent,
R ^{2 to} R ⁶ each independently represents a hydrogen atom, a halogen atom, or a monovalent organic residue. The substituent which R ¹ may have is the same as Ar ¹ , Ar ² and the substituent which may have in X in the general formula [1].
Further, R ^{2 to} R ⁶ may be adjacent to each other to form a C 3-8 aliphatic ring which may have a substituent. )

General formula [3]

(In the formula, Y is an optionally substituted divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and an optionally substituted divalent heterocyclic group having 2 to 18 carbon atoms. A C1-C18 divalent aliphatic hydrocarbon group which may have a substituent, a silylene group which may have a substituent, -O-, -S-, -CO-, -SO- And a divalent linking group consisting of any one of —SO ₂ — or a combination thereof.
Ar ⁴ and Ar ⁵ are each independently a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a C 2 to 18 carbon atom which may have a substituent. It represents a monovalent heterocyclic group or a group represented by the general formula [2].
The substituent that Y, Ar ⁴ , and Ar ⁵ may have has the same meaning as the substituent that Ar ¹ , Ar ² , and X in General Formula [1] may have. ) The indole derivative according to claim ¹ , wherein Ar ¹ and Ar ² are a group represented by the general formula [2]. The indole derivative according to claim 1 or 2, wherein R ¹ is a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. The material for organic electroluminescent elements which comprises the indole derivative in any one of Claims 1-3. In the organic electroluminescent element formed by forming a light emitting layer or a plurality of organic layers including a light emitting layer between a pair of electrodes, at least one of the organic layers contains the material for an organic electroluminescent element according to claim 4. An organic electroluminescence device. Furthermore, it has a positive hole injection layer and / or a positive hole transport layer between an anode and a light emitting layer, The said positive hole injection layer and / or a positive hole transport layer are materials for organic electroluminescent elements of Claim 4. An organic electroluminescence device according to claim 5 comprising: