JP2014227405A - Compound having cyclopentaindole ring structure, and organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an organic compound as an efficient and durable organic electroluminescent element material, which has excellent hole injection/transport performance and electron stopping capability and is stable in a thin film state; and an efficient and durable organic electroluminescent element using the compound.SOLUTION: An organic electroluminescent element includes a compound represented by the general formula (1) having a cyclopentaindole ring structure, and has a pair of electrodes and at least one organic layer interposed therebetween, where the compound is used as a constituent material of the at least one organic layer.

Description

The present invention relates to a compound suitable for an organic electroluminescence element, which is a self-luminous element suitable for various display devices, and the element, and more specifically, a compound having a cyclopentaindole ring structure and the compound. The present invention relates to an organic electroluminescence element.

  Since organic electroluminescent elements are self-luminous elements, they have been actively researched because they are brighter and more visible than liquid crystal elements and can display clearly.

In 1987, Eastman Kodak's C.I. W. Tang et al. Have made organic electroluminescence elements using organic materials practical by developing a laminated structure element that shares various roles with each material. They are composed of a phosphor that can transport electrons, tris (8-hydroxyquinoline) aluminum (hereinafter abbreviated as Alq ₃ ) and an aromatic amine compound that can transport holes, Was injected into the phosphor layer to emit light, whereby high luminance of 1000 cd / m ² or more was obtained at a voltage of 10 V or less (see, for example, Patent Document 1 and Patent Document 2).

  To date, many improvements have been made for the practical application of organic electroluminescence devices, and various roles have been further subdivided, and sequentially on the substrate, anode, hole injection layer, hole transport layer, light emitting layer, electron High efficiency and durability are achieved by an electroluminescent device provided with a transport layer, an electron injection layer, and a cathode (see, for example, Non-Patent Document 1).

Further, the use of triplet excitons has been attempted for the purpose of further improving the luminous efficiency, and the use of phosphorescent emitters has been studied (for example, see Non-Patent Document 2).
An element utilizing light emission by thermally activated delayed fluorescence (TADF) has also been developed. In 2011, Adachi et al. Of Kyushu University realized an external quantum efficiency of 5.3% with a device using a thermally activated delayed fluorescent material. (For example, see Non-Patent Document 3)

The light-emitting layer can also be produced by doping a charge transporting compound generally called a host material with a phosphor or a phosphorescent material. As described in the above seminar proceedings collection, the selection of an organic material in an organic electroluminescence element greatly affects various characteristics such as efficiency and durability of the element.

In an organic electroluminescence device, the light injected from both electrodes recombines in the light emitting layer to obtain light emission. However, it is important how efficiently both holes and electrons are transferred to the light emitting layer. Improve the probability of recombination of holes and electrons by increasing the hole injection property and blocking the electron injected from the cathode, and further confine excitons generated in the light emitting layer Thus, high luminous efficiency can be obtained. Therefore, the role of the hole transport material is important, and there is a demand for a hole transport material that has high hole injectability, high hole mobility, high electron blocking properties, and high durability against electrons. ing.

In addition, the heat resistance and amorphousness of the material are also important for the lifetime of the element. In a material having low heat resistance, thermal decomposition occurs even at a low temperature due to heat generated when the element is driven, and the material is deteriorated. In the case of a material having low amorphous property, the thin film is crystallized even in a short time, and the element is deteriorated. For this reason, the material used is required to have high heat resistance and good amorphous properties.

Examples of hole transport materials that have been used in organic electroluminescence devices so far include N, N′-diphenyl-N, N′-di (α-naphthyl) benzidine (hereinafter abbreviated as NPD) and various aromatics. Amine derivatives have been known (see, for example, Patent Document 1 and Patent Document 2). NPD has a good hole transport capability, but its glass transition point (Tg), which is an index of heat resistance, is as low as 96 ° C., and device characteristics are degraded due to crystallization under high temperature conditions (for example, Non-patent document 4). Further, among the aromatic amine derivatives described in Patent Document 1 and Patent Document 2, compounds having excellent mobility such as hole mobility of 10 ⁻³ cm ² / Vs or more are known. Because of insufficient electron blocking properties, some of the electrons pass through the light emitting layer and cannot be expected to improve luminous efficiency. For higher efficiency, the electron blocking properties are higher and the thin film is more stable. Therefore, a material having high heat resistance has been demanded.

As compounds having improved properties such as heat resistance, hole injection properties, and electron blocking properties, arylamine compounds having a substituted indole structure represented by the following formula (for example, Compound A and Compound B) have been proposed. (For example, see Patent Documents 3 and 4).

However, devices using these compounds in the hole injection layer or the hole transport layer have been improved in amorphous properties and light emission efficiency, but are still not sufficient, and the drive voltage is sufficiently low. That wasn't true. Therefore, further reduction in driving voltage and higher light emission efficiency have been demanded.

JP-A-8-48656 Japanese Patent No. 3194657 WO2011 / 102573 Publication WO2011 / 111996 publication

Proceedings of the 9th meeting of the Japan Society of Applied Physics 55-61 pages (2001) Proceedings of the 9th Workshop of the Japan Society of Applied Physics 23-31 pages (2001) Appl. Phys. Let. 98,083302 (2011) Proceedings of the 3rd Regular Meeting of the Organic EL Discussion Group, 13-14 pages (2006) J. et al. Org. Chem. , 60, 7508 (1995) Chem. Rev. , 95, 2457 (1995)

An object of the present invention is to provide an organic compound having excellent hole injection / transport performance, electron blocking ability, and high stability in a thin film state as a material for a highly efficient and durable organic electroluminescence device. The present invention also provides a highly efficient and highly durable organic electroluminescence device using this compound.

The physical characteristics that the organic compound to be provided by the present invention should have include (1) good hole injection characteristics, (2) high hole mobility, and (3) electron blocking ability. And (4) that the thin film state is stable. The physical characteristics of the organic electroluminescent device to be provided by the present invention include (1) high luminous efficiency and power efficiency, (2) low emission start voltage, and (3) practical use. The drive voltage is low.

  Therefore, in order to achieve the above object, the inventors of the present invention have a high hole injection / transport capability of the aromatic tertiary amine structure, a hole transport capability of the cyclopentaindole ring structure, In anticipation of the effects of this partial structure on heat resistance and thin film stability, a compound having a cyclopentaindole ring structure was designed and chemically synthesized, and various organic electroluminescence devices were prototyped using the compound. As a result of diligent evaluation of device characteristics, the present invention has been completed.

1) That is, the present invention is a compound having a cyclopentaindole ring structure represented by the following general formula (1).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and A represents a single bond, a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a substituted or unsubstituted condensed polycyclic ring. B represents an aromatic divalent group, B represents a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic ring or a substituted or unsubstituted condensed polycyclic aromatic divalent group, R ₁ -R ₉ may be the same or different from each other, and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a straight chain having 1 to 6 carbon atoms which may have a substituent. Or branched alkyl groups, A cycloalkyl group having 5 to 10 carbon atoms which may have a group, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, and a substituent. A linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, a substituted or unsubstituted aromatic group Represents a hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted aryloxy group, wherein Ar ₂ and Ar ₃ or Ar ₃ and B may be bonded to each other through a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.

2) Moreover, this invention is a compound which has the cyclopenta indole ring structure of said 1) represented by the following general formula (1a).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and A represents a single bond, a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a substituted or unsubstituted condensed polycyclic ring. B represents an aromatic divalent group, B represents a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic ring or a substituted or unsubstituted condensed polycyclic aromatic divalent group, R ₁ -R ₉ may be the same or different from each other, and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a straight chain having 1 to 6 carbon atoms which may have a substituent. Or branched alkyl groups, A cycloalkyl group having 5 to 10 carbon atoms which may have a group, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, and a substituent. A linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, a substituted or unsubstituted aromatic group Represents a hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted aryloxy group, wherein Ar ₂ and Ar ₃ or Ar ₃ and B may be bonded to each other through a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.

3) Further, the present invention provides the cyclopentaindole ring structure according to 1) above, wherein in the general formula (1), B is represented by a divalent group formed by removing two hydrogen atoms from substituted or unsubstituted benzene. It is a compound which has this.

4) Moreover, this invention is a compound which has a cyclopenta indole ring structure of said 3) represented by the following general formula (1a-1).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and R _{1 to} R ₉ may be the same or different from each other, and may have a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a substituent. A linear or branched alkyl group having 1 to 6 carbon atoms, an optionally substituted cycloalkyl group having 5 to 10 carbon atoms, and an optionally substituted carbon atom A linear or branched alkenyl group having 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group having 1 to 6 carbon atoms, or a substituent group. Cycloa having 5 to 10 carbon atoms It represents a killioxy group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. Ar ₂ and Ar ₃ may be bonded to each other via a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.

5) Further, the present invention provides an organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the compound having a cyclopentaindole ring structure described in 1) above is at least one organic layer. It is an organic electroluminescent element characterized by being used as a constituent material.

6) Moreover, this invention is an organic electroluminescent element of the said 5) description whose said organic layer is a positive hole transport layer.

7) Moreover, this invention is an organic electroluminescent element of the said 5) description whose said organic layer is an electron blocking layer.

8) Moreover, this invention is an organic electroluminescent element of the said 5) description whose said organic layer is a positive hole injection layer.

9) Moreover, this invention is an organic electroluminescent element of the said 5) description whose said organic layer is a light emitting layer.

“Substituted or unsubstituted aromatic hydrocarbon group”, “substituted or unsubstituted aromatic heterocyclic group” or “substituted or unsubstituted” represented by Ar ₁ , Ar _2, Ar ₃ in the general formula (1) Specific examples of the “aromatic hydrocarbon group”, “aromatic heterocyclic group” or “condensed polycyclic aromatic group” in the condensed polycyclic aromatic group of are as follows: phenyl group, biphenylyl group, terphenylyl group, naphthyl Group, anthryl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group, pyridyl group, furanyl group, pyrrolyl group, thienyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzo Thienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalyl group, benzoy Dazoriru group, a pyrazolyl group, and a dibenzofuranyl group, dibenzothienyl group, and carbolinyl group and the like. These groups may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.
Here, as the “aromatic heterocyclic group” in the “substituted or unsubstituted aromatic heterocyclic group” represented by Ar ₁ , Ar _2, Ar ₃ in the general formula (1), a thienyl group, benzothienyl Preferred are sulfur-containing aromatic heterocyclic groups such as a group, benzothiazolyl group and dibenzothienyl group, or oxygen-containing aromatic heterocyclic rings such as a furanyl group, a pyrrolyl group, a benzofuranyl group, a benzoxazolyl group and a dibenzofuranyl group.

The “substituent” in the “substituted aromatic hydrocarbon group”, “substituted aromatic heterocyclic group” or “substituted condensed polycyclic aromatic group” represented by Ar ₁ , Ar _2, Ar ₃ in the general formula (1) As the “substituent” in the “substituted aromatic hydrocarbon group”, “substituted aromatic heterocyclic group” or “substituted condensed polycyclic aromatic group”, specifically, a deuterium atom, a cyano group, Nitro group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group Linear or branched alkyl groups having 1 to 6 carbon atoms such as isopentyl group, neopentyl group and n-hexyl group; 1 to 6 carbon atoms such as methyloxy group, ethyloxy group and propyloxy group Linear or branched alkyloxy groups; alkenyl groups such as allyl groups; aryloxy groups such as phenyloxy groups and tolyloxy groups; arylalkyloxy groups such as benzyloxy groups and phenethyloxy groups; phenyl groups, biphenylyl groups, Aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group; pyridyl group, furanyl Group, thienyl group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalyl group, benzimidazolyl group, pyrazol Aromatic heterocyclic groups such as ryl, dibenzofuranyl, dibenzothienyl and carbolinyl groups; aryl vinyl groups such as styryl and naphthyl vinyl groups; and groups such as acyl groups such as acetyl and benzoyl groups These substituents may be further substituted with other substituents. In addition, these substituents or these substituents and Ar ₁ , Ar _2, Ar ₃ are bonded to each other via a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring. May be.

Represented by A and B in the general formula (1), “a divalent group of a substituted or unsubstituted aromatic hydrocarbon”, “a divalent group of a substituted or unsubstituted aromatic heterocyclic ring” or “substituted or "Substituted or unsubstituted aromatic hydrocarbon", "Substituted or unsubstituted aromatic heterocycle" or "Substituted or unsubstituted condensed polycyclic aromatic" in "Unsubstituted fused polycyclic aromatic divalent group" Specific examples of the “aromatic hydrocarbon”, “aromatic heterocycle” or “fused polycyclic aromatic” of benzene, biphenyl, terphenyl, tetrakisphenyl, styrene, naphthalene, anthracene, acenaphthalene, fluorene, Phenanthrene, indane, pyrene, pyridine, pyrimidine, triazine, furan, pyran, thiophene, quinoline, isoquinoline, benzofuran, benzothiophene, India Emissions, carbazole, can carboline, benzoxazole, benzothiazole, quinoxaline, benzimidazole, pyrazole, dibenzofuran, dibenzothiophene, naphthyridine, phenanthroline, and the like Akurijinin.
In addition, “a divalent group of a substituted or unsubstituted aromatic hydrocarbon”, “a divalent group of a substituted or unsubstituted aromatic heterocycle” represented by A or B in the general formula (1), or “substituted” Alternatively, the “unsubstituted fused polycyclic aromatic divalent group” is a divalent group formed by removing two hydrogen atoms from the above “aromatic hydrocarbon”, “aromatic heterocycle” or “fused polycyclic aromatic”. Represents.
Here, the “aromatic heterocycle” in the “divalent group of a substituted or unsubstituted aromatic heterocycle” is a sulfur-containing aromatic heterocycle such as thiophene, benzothiophene, benzothiazole, dibenzothiophene, furan, Oxygen-containing aromatic heterocycles such as pyran, benzofuran, benzoxazole and dibenzofuran are preferred.
A in the general formula (1) is preferably a single bond, “a divalent group of a substituted or unsubstituted aromatic hydrocarbon” or “a substituted or unsubstituted condensed polycyclic aromatic divalent group”. A bond or a divalent group derived from benzene is preferred.
B in the general formula (1) is preferably “a divalent group of a substituted or unsubstituted aromatic hydrocarbon” or “a divalent group of a substituted or unsubstituted condensed polycyclic aromatic”, and is selected from benzene or naphthalene. Derived divalent groups are preferred.

Represented by A and B in the general formula (1), “a divalent group of a substituted or unsubstituted aromatic hydrocarbon”, “a divalent group of a substituted or unsubstituted aromatic heterocyclic ring” or “substituted or As the “substituent” of “substituted aromatic hydrocarbon”, “substituted aromatic heterocycle” or “substituted condensed polycyclic aromatic” in “unsubstituted fused polycyclic aromatic divalent group”, the above general formula Regarding “substituent” in “substituted aromatic hydrocarbon group”, “substituted aromatic heterocyclic group” or “substituted condensed polycyclic aromatic group” represented by Ar ₁ , Ar _{2 and} Ar ₃ in (1) The same thing as what was shown can be mention | raise | lifted and the aspect which can be taken can also mention the same thing.

“A linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent” represented by R _{1 to} R ₉ in the general formula (1), “having a substituent In the “cycloalkyl group having 5 to 10 carbon atoms” or “straight or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent”. Examples of “straight or branched alkyl group of 6”, “cycloalkyl group of 5 to 10 carbon atoms” or “straight chain or branched alkenyl group of 2 to 6 carbon atoms” specifically include , Methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, cyclopentyl group, cyclo Hexyl group, 1-adamantyl, 2-adamantyl, vinyl group, allyl group, isopropenyl group include a 2-butenyl group, and the like. These groups may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

“A linear or branched alkyl group having 1 to 6 carbon atoms having a substituent” represented by R _{1 to} R ₉ in the general formula (1), “5 to 10 carbon atoms having a substituent” The “substituent” in the “cycloalkyl group of” or “the straight-chain or branched alkenyl group having 2 to 6 carbon atoms having a substituent” is Ar ₁ or Ar _{2 in the} above general formula (1). _, "substituted aromatic hydrocarbon group" represented by Ar _3, be given the same as those shown for the "substituent" in the "substituted aromatic heterocyclic group" or "substituted condensed polycyclic aromatic group" Examples of possible modes are the same.

“A linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent” represented by R _{1 to} R ₉ in the general formula (1) or “having a substituent. Or a “C1-C6 linear or branched alkyloxy group” or “C5-C10 cycloalkyloxy group”. Specifically, methyloxy group, ethyloxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, tert-butyloxy group, n-pentyloxy group, n-hexyloxy group, cyclopentyloxy group Cyclohexyloxy group, cycloheptyloxy group, cyclooctyloxy group, 1-adamantyloxy group, 2-adamantyloxy group Etc. can be mentioned. These groups may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

“A linear or branched alkyloxy group having 1 to 6 carbon atoms having a substituent” represented by R _{1 to} R ₉ in the general formula (1) or “a carbon atom having 5 to 5 carbon atoms having a substituent” As the “substituent” in the “cycloalkyloxy group of 10”, the “substituted aromatic hydrocarbon group” represented by Ar ₁ , Ar _2, Ar ₃ in the above general formula (1), “substituted aromatic hetero complex” The same thing as what was shown regarding the "substituent" in a "ring group" or a "substituted condensed polycyclic aromatic group" can be mention | raise | lifted, and the aspect which can be taken can also mention the same thing.

“Substituted or unsubstituted aromatic hydrocarbon group”, “substituted or unsubstituted aromatic heterocyclic group” represented by R _{1 to} R ₉ in the general formula (1), or “substituted or unsubstituted condensed poly group” As the “aromatic hydrocarbon group”, “aromatic heterocyclic group” or “fused polycyclic aromatic group” in the “ring aromatic group”, Ar ₁ , Ar _{2 and} Ar _{3 in the} above general formula (1) "Aromatic hydrocarbon group" in "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" represented by ”,“ Aromatic heterocyclic group ”or“ condensed polycyclic aromatic group ”can be exemplified, and the possible and preferred embodiments can also be exemplified.
These groups may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.
These groups may have a substituent, and as the substituent, a “substituted aromatic hydrocarbon group” represented by Ar ₁ , Ar _2, Ar ₃ in the above general formula (1), “ The same thing as what was shown regarding the "substituent" in a "substituted aromatic heterocyclic group" or a "substituted condensed polycyclic aromatic group" can be mention | raise | lifted, and the aspect which can be taken can also mention the same thing.

Specific examples of the “aryloxy group” in the “substituted or unsubstituted aryloxy group” represented by R _{1 to} R ₉ in the general formula (1) include a phenyloxy group, a biphenylyloxy group, a terfeny group. Examples thereof include a tolyloxy group, a naphthyloxy group, an anthryloxy group, a phenanthryloxy group, a fluorenyloxy group, an indenyloxy group, a pyrenyloxy group, and a perylenyloxy group. These groups may be bonded to each other through a single bond, a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom to form a ring.

The “substituent” in the “substituted aryloxy group” represented by R _{1 to} R ₉ in the general formula (1) is represented by Ar ₁ , Ar _{2 or} Ar ₃ in the general formula (1). A possible embodiment can include the same as those shown for the “substituent” in the “substituted aromatic hydrocarbon group”, “substituted aromatic heterocyclic group” or “substituted condensed polycyclic aromatic group”. The same can be mentioned.

In the general formula (1), Ar ₂ and Ar ₃ may be bonded to each other via a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.
Ar ₃ and B may be bonded to each other via a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.

The compound represented by the general formula (1) of the present invention and having a cyclopentaindole ring structure is a novel compound, has a hole injection ability superior to that of a conventional hole transport material, and has a thin film state. It is stable.

The compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention is a hole injection layer and / or a hole transport layer of an organic electroluminescence device (hereinafter abbreviated as an organic EL device). It can be used as a constituent material. By using a material with higher hole injection properties, higher mobility, higher electron blocking properties, and higher electron stability than conventional materials, it is possible to confine excitons generated in the light emitting layer. In addition, the probability of recombination of holes and electrons can be improved, high luminous efficiency can be obtained, the driving voltage is lowered, and the durability of the organic EL element is improved.

The compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention can also be used as a constituent material of an electron blocking layer of an organic EL device. By using a material with excellent electron blocking ability and hole transportability compared to conventional materials and high stability in the thin film state, the driving voltage is lowered and current resistance is maintained while having high luminous efficiency. Is improved and the maximum light emission luminance of the organic EL element is improved.

The compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention can also be used as a constituent material of a light emitting layer of an organic EL device. The material of the present invention, which has excellent hole transportability compared to conventional materials and has a wide band gap, is used as a host material for the light-emitting layer, and supports a fluorescent or phosphorescent emitter called a dopant to emit light. By using it as a layer, it has the effect | action that a drive voltage falls and can implement | achieve the organic EL element by which luminous efficiency was improved.

  The organic EL device of the present invention is a compound having a cyclopentaindole ring structure, which has a higher hole transport capability than conventional hole transport materials, an excellent electron blocking capability, and a stable thin film state As a result, it became possible to achieve high efficiency and high durability.

The compound having a cyclopentaindole ring structure of the present invention is useful as a constituent material of a hole injection layer, a hole transport layer, an electron blocking layer or a light emitting layer of an organic EL device, and has an excellent electron blocking ability. The thin film is stable and has excellent heat resistance. The organic EL device of the present invention has high luminous efficiency and high power efficiency, which can reduce the practical driving voltage of the device. The emission start voltage can be lowered and the durability can be improved.

1 is a ¹ H-NMR chart of the compound of Example 1 of the present invention (Compound 7). ^{1 is} a ¹ H-NMR chart of a compound of Example 2 of the present invention (Compound 9). It is the figure which showed the EL element structure of Examples 5-6 and Comparative Examples 1-2.

The compound having a cyclopentaindole ring structure of the present invention is a novel compound, and these compounds can be synthesized as follows, for example. For example, a 7-bromocyclopentaindole derivative can be synthesized by reacting 4-bromophenylhydrazine hydrochloride having a corresponding substituent with cyclopentanone. Subsequently, a 7-bromocyclopentaindole derivative in which the 4-position is substituted with an aryl group can be synthesized by performing a coupling reaction such as an Ullmann reaction between the 7-bromocyclopentaindole derivative and aryl iodide. it can. Subsequently, a cross-coupling reaction such as Suzuki coupling between the 7-bromocyclopentaindole derivative and various boronic acids or boronic esters (for example, see Non-Patent Document 5) is performed (for example, see Non-Patent Document 6). By performing, the compound having the cyclopentaindole ring structure of the present invention can be synthesized.
Similarly, by performing the same reaction using a raw material in which different positions of bromophenylhydrazine hydrochloride are substituted with bromo, substituents other than the 7-position can be introduced as substitution positions. Compounds having a cyclopentaindole ring structure of the present invention having different positions can be synthesized.

Specific examples of preferable compounds among the compounds having a cyclopentaindole ring structure represented by the general formula (1) are shown below, but the present invention is not limited to these compounds.

These compounds were purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization using a solvent, crystallization method, and the like. The compound was identified by NMR analysis. As a physical property value, a glass transition point (Tg) and a work function were measured. The glass transition point (Tg) is an index of stability in a thin film state, and the work function is an index of hole transportability.

The glass transition point (Tg) was determined with a high sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100S) using powder.

The work function was measured using an ionization potential measuring device (manufactured by Sumitomo Heavy Industries, Ltd., PYS-202 type) after forming a 100 nm thin film on the ITO substrate.

The structure of the organic EL device of the present invention includes an anode, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, and a cathode sequentially on the substrate, and between the anode and the hole transport layer. And those having an electron injection layer between the electron transport layer and the cathode, and those having a hole blocking layer between the light emitting layer and the electron transport layer. In these multilayer structures, several organic layers can be omitted. For example, a structure having an anode, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode sequentially on a substrate can be used. .

As the anode of the organic EL element of the present invention, an electrode material having a large work function such as ITO or gold is used. As the hole injection layer of the organic EL device of the present invention, in addition to the compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention, a porphyrin compound typified by copper phthalocyanine, a starburst tri Materials such as phenylamine derivatives and various triphenylamine tetramers, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials can be used. These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

As the hole transport layer of the organic EL device of the present invention, in addition to the compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention, N, N′-diphenyl-N, N′-di ( m-tolyl) benzidine (hereinafter abbreviated as TPD), N, N′-diphenyl-N, N′-di (α-naphthyl) benzidine (hereinafter abbreviated as NPD), N, N, N ′, N Benzidine derivatives such as' -tetrabiphenylylbenzidine, 1,1-bis [4- (di-4-tolylamino) phenyl] cyclohexane (hereinafter abbreviated as TAPC), various triphenylamine trimers and tetramers Etc. can be used. These may be formed alone, but may be used as a single layer formed by mixing with other materials, layers formed alone, mixed layers formed, or A stacked structure of layers formed by mixing with a layer formed alone may be used. Further, as a hole injection / transport layer, a coating type such as poly (3,4-ethylenedioxythiophene) (hereinafter abbreviated as PEDOT) / poly (styrene sulfonate) (hereinafter abbreviated as PSS) is used. These polymer materials can be used. These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

In addition, in the hole injection layer or the hole transport layer, a material that is usually used for the layer is further P-doped with trisbromophenylamine hexachloroantimony or the like, or a TPD structure having a partial structure. Molecular compounds and the like can be used.

As an electron blocking layer of the organic EL device of the present invention, in addition to the compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention, 4,4 ′, 4 ″ -tri (N-carbazolyl) Triphenylamine (hereinafter abbreviated as TCTA), 9,9-bis [4- (carbazol-9-yl) phenyl] fluorene, 1,3-bis (carbazol-9-yl) benzene (hereinafter abbreviated as mCP) ), Carbazole derivatives such as 2,2-bis (4-carbazol-9-ylphenyl) adamantane (hereinafter abbreviated as Ad-Cz), 9- [4- (carbazol-9-yl) phenyl] -9 -[4- (Triphenylsilyl) phenyl] -9H-Fluorene has an electron blocking action such as a compound having a triphenylsilyl group typified by a triarylamine structure. Compounds can be used. These may be formed alone, but may be used as a single layer formed by mixing with other materials, layers formed alone, mixed layers formed, or A stacked structure of layers formed by mixing with a layer formed alone may be used. These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

As the light emitting layer of the organic EL device of the present invention, various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, polyparaphenylene vinylene derivatives, etc., in addition to metal complexes of quinolinol derivatives including Alq ₃ Can be used. The light emitting layer may be composed of a host material and a dopant material. In addition to the compound having a cyclopentaindole ring structure represented by the general formula (1) of the present invention as the host material, , Thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, and the like can be used. As the dopant material, quinacridone, coumarin, rubrene, perylene, and derivatives thereof, benzopyran derivatives, rhodamine derivatives, aminostyryl derivatives, and the like can be used. These may be formed alone, but may be used as a single layer formed by mixing with other materials, layers formed alone, mixed layers formed, or A stacked structure of layers formed by mixing with a layer formed alone may be used.

In addition, a phosphorescent material can be used as the light emitting material. As the phosphorescent material, a phosphorescent material of a metal complex such as iridium or platinum can be used. Green phosphorescent emitters such as Ir (ppy) ₃ , blue phosphorescent emitters such as FIrpic and FIr6, red phosphorescent emitters such as Btp ₂ Ir (acac), and the like are used as host materials. In addition to carbazole derivatives such as 4,4′-di (N-carbazolyl) biphenyl (hereinafter abbreviated as CBP), TCTA, mCP, etc. as a hole injection / transport host material, A compound having a represented cyclopentaindole ring structure can be used. As an electron transporting host material, p-bis (triphenylsilyl) benzene (hereinafter abbreviated as UGH2) and 2,2 ′, 2 ″-(1,3,5-phenylene) -tris (1-phenyl) -1H-benzimidazole) (hereinafter abbreviated as TPBI) and the like, and a high-performance organic EL device can be produced.

In order to avoid concentration quenching, the host material of the phosphorescent light emitting material is preferably doped by co-evaporation in the range of 1 to 30 weight percent with respect to the entire light emitting layer.

These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

As a hole blocking layer of the organic EL device of the present invention, a phenanthroline derivative such as bathocuproine (hereinafter abbreviated as BCP) or aluminum (III) bis (2-methyl-8-quinolinato) -4-phenylphenolate In addition to metal complexes of quinolinol derivatives such as BAlq), various rare earth complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, and the like can be used. These materials may also serve as the material for the electron transport layer. These may be formed alone, but may be used as a single layer formed by mixing with other materials, layers formed alone, mixed layers formed, or A stacked structure of layers formed by mixing with a layer formed alone may be used. These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

As an electron transport layer of the organic EL device of the present invention, various metal complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline, in addition to metal complexes of quinolinol derivatives including Alq ₃ and BAlq. Derivatives, phenanthroline derivatives, silole derivatives and the like can be used. These may be formed alone, but may be used as a single layer formed by mixing with other materials, layers formed alone, mixed layers formed, or A stacked structure of layers formed by mixing with a layer formed alone may be used. These materials can be formed into a thin film by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method.

As the electron injection layer of the organic EL device of the present invention, an alkali metal salt such as lithium fluoride and cesium fluoride, an alkaline earth metal salt such as magnesium fluoride, and a metal oxide such as aluminum oxide can be used. In the preferred selection of the electron transport layer and the cathode, this can be omitted.

As the cathode of the organic EL device of the present invention, an electrode material having a low work function such as aluminum or an alloy having a lower work function such as a magnesium silver alloy, a magnesium indium alloy, or an aluminum magnesium alloy is used as the electrode material.

Hereinafter, embodiments of the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

<Synthesis of bis (biphenyl-4-yl)-{4- (4-phenyl-1,2,3,4-tetrahydrocyclopenta [b] indolo-7-yl) phenyl} amine (Compound 7)>
In a reaction vessel purged with nitrogen, 3.0 g of 7-bromo-4-phenyl-1,2,3,4-tetrahydrocyclopenta [b] indole, bis (biphenyl-4-yl)-{4- (4,4 , 5,5-tetramethyl- [1,3,2] dioxaboran-2-yl) phenyl} amine 5.5 g, tetrakis (triphenylphosphine) palladium 0.6 g, 2M aqueous potassium carbonate solution 15 ml, toluene 60 ml, ethanol 15 ml The mixture was heated and refluxed for 4.5 hours with stirring. After cooling to room temperature, 30 ml of toluene and 30 ml of water were added and stirred, and then an organic layer was collected by performing a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and concentrated to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and bis (biphenyl-4-yl)-{4- (4-phenyl-1,2,3,4-tetrahydro The white powder 3.4g (yield 56%) of cyclopenta [b] indolo-7-yl) phenyl} amine (compound 7) was obtained.

The structure of the obtained white powder was identified using NMR. ^{The 1} H-NMR measurement results are shown in FIG.

^The following 36 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 7.69 (1H), 7.62 (6H), 7.57 (4H), 7.53 (2H), 7.52 (2H), 7.46 (1H), 7.41 -7.32 (6H), 7.26 (2H), 7.22 (6H), 2.94 (2H), 2.92 (2H), 2.56 (2H).

<(Biphenyl-4-yl)-(9,9-dimethyl-9H-fluoren-2-yl)-{4- (4-phenyl-1,2,3,4-tetrahydrocyclopenta [b] indolo-7 Synthesis of -yl) phenyl} amine (Compound 9)>
Into a reaction vessel purged with nitrogen, 3.0 g of 7-bromo-4-phenyl-1,2,3,4-tetrahydrocyclopenta [b] indole, (biphenyl-4-yl)-(9,9-dimethyl-9H) -Fluoren-2-yl)-{4- (4,4,5,5-tetramethyl- [1,3,2] dioxaboran-2-yl) phenyl} amine 6.0 g, tetrakis (triphenylphosphine) palladium 0.6 g, 2 M aqueous potassium carbonate solution (15 ml), toluene (60 ml) and ethanol (15 ml) were added, heated, and refluxed for 10 hours with stirring. After cooling to room temperature, adding 30 ml of water and stirring, an organic layer was collected by performing a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and concentrated to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: eluent: toluene / n-hexane) and (biphenyl-4-yl)-(9,9-dimethyl-9H-fluoren-2-yl) -3.8 g (yield 59%) of white powder of {4- (4-phenyl-1,2,3,4-tetrahydrocyclopenta [b] indolo-7-yl) phenyl} amine (Compound 9) Obtained.

The structure of the obtained white powder was identified using NMR. ^The results of ¹ H-NMR measurement are shown in FIG.

^The following 40 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 7.69 (1H), 7.67 (1H), 7.65 (1H), 7.62 (4H), 7.56 (2H), 7.53-7.50 (4H) 7.45 (1H), 7.42-7.35 (5H), 7.33 (1H), 7.26 (2H), 7.23-7.17 (5H), 7.09 (1H) 2.93 (4H), 2.58-2.53 (2H), 1.43 (6H).

About the compound of this invention, the glass transition point was calculated | required with the high sensitivity differential scanning calorimeter (The product made by Bruker AXS, DSC3100S).
Glass transition point
Inventive Example 1 Compound 109 ° C.
Inventive Example 2 Compound 121 ° C.

The compound of the present invention has a glass transition point of 100 ° C. or higher, which indicates that the thin film state is stable in the compound of the present invention.

Using the compound of the present invention, a deposited film having a film thickness of 100 nm was prepared on an ITO substrate, and the work function was measured with an ionization potential measuring device (PYS-202 type, manufactured by Sumitomo Heavy Industries, Ltd.).
Work Function Compound of Invention Example 1 5.59 eV
Inventive Example 2 Compound 5.50 eV
NPD 5.54eV

As described above, the compound of the present invention exhibits a suitable energy level as compared with the work function of 5.5 eV which is possessed by general hole transport materials such as NPD and TPD, and has a good hole transport capability. You can see that

The organic EL element has a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer on a glass substrate 1 on which an ITO electrode is previously formed as a transparent anode 2 as shown in FIG. 6, an electron injection layer 7 and a cathode (aluminum electrode) 8 were deposited in this order.

Specifically, the glass substrate 1 on which ITO having a thickness of 150 nm was formed was washed with an organic solvent, and then the surface was washed by oxygen plasma treatment. Then, this glass substrate with an ITO electrode was mounted in a vacuum vapor deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, a compound 53 having the following structural formula was formed to a thickness of 20 nm as the hole injection layer 3 so as to cover the transparent electrode 2. On this hole injection layer 3, the compound (compound 7) of Example 1 of the present invention was formed as a hole transport layer 4 so as to have a film thickness of 40 nm. On the hole transport layer 4, a compound 54 having the following structural formula and a compound 55 having the following structural formula are deposited as the light emitting layer 5 in a binary manner at a deposition rate where the deposition rate ratio is compound 54: compound 55 = 5: 95. To form a film thickness of 30 nm. On this emitting layer 5 was formed to have the Alq ₃ film thickness 30nm as an electron transport layer 6. On the electron transport layer 6, lithium fluoride was formed as the electron injection layer 7 so as to have a film thickness of 0.5 nm. Finally, aluminum was deposited to a thickness of 150 nm to form the cathode 8. About the produced organic EL element, the characteristic measurement was performed at normal temperature in air | atmosphere.

Table 1 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the organic EL device produced using the compound of Example 1 (Compound 7) of the present invention.

In Example 5, the compound (Compound 9) of Example 2 of the present invention was formed so as to have a film thickness of 40 nm instead of the compound (Compound 7) of Example 1 of the present invention as the material for the hole transport layer 4. An organic EL element was produced under the same conditions. About the produced organic EL element, the characteristic measurement was performed at normal temperature in air | atmosphere. Table 1 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the produced organic EL element.

[Comparative Example 1]
For comparison, in Example 5, except that α-NPD was formed so as to have a film thickness of 40 nm instead of the compound of Example 1 of the present invention (Compound 7) as the material of the hole transport layer 4, the same as in Example 5 An organic EL element was produced under the conditions. About the produced organic EL element, the characteristic measurement was performed at normal temperature in air | atmosphere. Table 1 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the produced organic EL element.

[Comparative Example 2]
For comparison, in Example 5, except that the compound of the following structural formula was formed to a film thickness of 40 nm instead of the compound of Example 1 of the present invention (Compound 7) as the material of the hole transport layer 4. An organic EL element was produced under the same conditions. About the produced organic EL element, the characteristic measurement was performed at normal temperature in air | atmosphere. Table 1 summarizes the measurement results of the light emission characteristics when a DC voltage was applied to the produced organic EL element.

As shown in Table 1, the driving voltage when a current density of 10 mA / cm ² was passed was 5.36 V of the organic EL element of Comparative Example 1 using α-NPD, and Comparative Example 2 using Compound 56 In the organic EL device of Example 5 using the compound of Example 1 of the present invention (Compound 7) versus 5.09 V of the organic EL device of 4.88 V, the compound of Example 2 of the present invention (Compound 9) In the organic EL element of Example 6 using), the voltage was lowered to 4.65V. Further, in terms of power efficiency, the organic EL element of Comparative Example 1 using α-NPD was 4.64 lm / W, and the organic EL element of Comparative Example 2 using Compound 56 was 5.02 lm / W. In the organic EL device of Example 5 using the compound of Example 1 (Compound 7), 5.40 lm / W, in the organic EL device of Example 6 using the compound of Compound 2 (Compound 9) of the present invention, Both improved to 5.65 lm / W.

As is apparent from the above results, the organic EL device using the compound having a cyclopentaindole ring structure of the present invention improves the power efficiency even when compared with the organic EL device using α-NPD or compound 56. It was also found that a decrease in practical driving voltage can be achieved.

The results of measuring the light emission starting voltage are shown below.
Organic EL device Compound Luminescence start voltage [V]
Example 5 Compound 7 2.7
Example 6 Compound 9 2.7
Comparative Example 1 α-NPD 2.9
Comparative Example 2 Compound 56 2.8
As a result, the organic EL element of Example 5 was compared to the organic EL element of Comparative Example 1 using α-NPD of the structural formula, and the organic EL element of Comparative Example 2 using Compound 56 of the structural formula. It can be seen that in the organic EL element No. 6, the emission start voltage is lowered.

As described above, the organic EL device of the present invention is superior in power efficiency as compared with a device using α-NPD and compound 56 used as a general hole transport material, and further has a practical driving voltage. It has been found that a reduction can be achieved.

The compound having a cyclopentaindole ring structure of the present invention is excellent as a compound for an organic EL device because it has a high hole transport capability, an excellent electron blocking capability, and a stable thin film state. By producing an organic EL device using the compound, high luminous efficiency and power efficiency can be obtained, practical driving voltage can be lowered, and durability can be improved. For example, it has become possible to develop home appliances and lighting.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Transparent anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Electron transport layer 7 Electron injection layer 8 Cathode

Claims (9)

A compound represented by the following general formula (1) having a cyclopentaindole ring structure.

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and A represents a single bond, a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a substituted or unsubstituted condensed polycyclic ring. B represents an aromatic divalent group, B represents a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic ring or a substituted or unsubstituted condensed polycyclic aromatic divalent group, R ₁ -R ₉ may be the same or different from each other, and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a straight chain having 1 to 6 carbon atoms which may have a substituent. Or branched alkyl groups, A cycloalkyl group having 5 to 10 carbon atoms which may have a group, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, and a substituent. A linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, a substituted or unsubstituted aromatic group Represents a hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted aryloxy group, wherein Ar ₂ and Ar ₃ or Ar ₃ and B may be bonded to each other through a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring. The compound which has a cyclopenta indole ring structure of Claim 1 represented by the following general formula (1a).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and A represents a single bond, a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a substituted or unsubstituted condensed polycyclic ring. B represents an aromatic divalent group, B represents a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted aromatic heterocyclic ring or a substituted or unsubstituted condensed polycyclic aromatic divalent group, R ₁ -R ₉ may be the same or different from each other, and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a straight chain having 1 to 6 carbon atoms which may have a substituent. Or branched alkyl groups, A cycloalkyl group having 5 to 10 carbon atoms which may have a group, a linear or branched alkenyl group having 2 to 6 carbon atoms which may have a substituent, and a substituent. A linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, a substituted or unsubstituted aromatic group Represents a hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted aryloxy group, wherein Ar ₂ and Ar ₃ or Ar ₃ and B may be bonded to each other through a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring. The compound having a cyclopentaindole ring structure according to claim 1, wherein, in the general formula (1), B is represented by a divalent group formed by removing two hydrogen atoms from substituted or unsubstituted benzene. The compound which has a cyclopenta indole ring structure of Claim 3 represented by the following general formula (1a-1).

(In the formula, Ar ₁ , Ar ₂ and Ar ₃ may be the same or different from each other, and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed group. Represents a polycyclic aromatic group, and R _{1 to} R ₉ may be the same or different from each other, and may have a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, or a substituent. A linear or branched alkyl group having 1 to 6 carbon atoms, an optionally substituted cycloalkyl group having 5 to 10 carbon atoms, and an optionally substituted carbon atom A linear or branched alkenyl group having 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group having 1 to 6 carbon atoms, or a substituent group. Cycloa having 5 to 10 carbon atoms It represents a killioxy group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. Ar ₂ and Ar ₃ may be bonded to each other via a single bond or a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.   In an organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched therebetween, the compound having a cyclopentaindole ring structure according to claim 1 is used as a constituent material of at least one organic layer. An organic electroluminescence device characterized by comprising: 6. The organic electroluminescence device according to claim 5, wherein the organic layer is a hole transport layer. 6. The organic electroluminescence device according to claim 5, wherein the organic layer is an electron blocking layer. 6. The organic electroluminescence device according to claim 5, wherein the organic layer is a hole injection layer. The organic electroluminescence device according to claim 5, wherein the organic layer is a light emitting layer.

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