JP6251675B2 - COMPOUND HAVING ACRYDAN RING STRUCTURE AND ORGANIC ELECTROLUMINESCENT DEVICE - Google Patents

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 to the element. Specifically, the present invention relates to a compound having an acridan ring structure, and organic electroluminescence using the compound. The present invention relates to a luminescence 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% using a device using a thermally activated delayed fluorescent material (see, for example, 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 acridan structure represented by the following formula (for example, compounds A to C) have been proposed (for example, And Patent Documents 3 to 5).

(Compound A)

(Compound B)

(Compound C)

  However, devices using these compounds in the hole injection layer or hole transport layer have been improved in heat resistance and light emission efficiency, but are still not sufficient. The efficiency was not sufficient, and there was a problem with amorphousness. For this reason, there has been a demand for further lower drive voltage and higher light emission efficiency while enhancing amorphousness.

JP-A-8-48656 Japanese Patent No. 3194657 WO2006 / 033563 publication WO2007 / 110228 publication WO 2010/147319

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) Angew.Chem.Int.Ed., 42,5400 (2003)

  The object of the present invention is as a highly efficient and durable organic electroluminescent device material, excellent in hole injection / transport performance, electron blocking ability, high stability in a thin film state, and heat resistance It is another object of the present invention to provide an organic compound having excellent characteristics and to provide an organic electroluminescence device having high efficiency and high durability by 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. (4) The thin film state is stable, and (5) The heat resistance is excellent. 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 present inventors have that the aromatic tertiary amine structure has a high hole injection / transport capability and that the acridan ring structure has an electron blocking property. In addition, in anticipation of the effects on heat resistance and thin film stability of this partial structure, a compound having an acridan 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 an acridan ring structure represented by the following general formula (1).

(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. It represents polycyclic aromatic group, Ar ₂ and Ar ₃ is a single bond or a substituted or unsubstituted methylene group, an oxygen atom or bonded to each other to form a ring via the sulfur atom .R ₁ to R ₇ 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 trifluoromethyl group, a nitro group, or an optionally substituted carbon atom having 1 to 6 carbon atoms. A linear or branched alkyl group, an optionally substituted cycloalkyl group having 5 to 10 carbon atoms, an optionally substituted linear group having 2 to 6 carbon atoms Or a branched alkeni A linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, or a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent 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, a single bond, A ring may be bonded to each other via a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom, and R ₈ and R ₉ may be the same as or different from each other, and may be a trifluoromethyl group or a substituent. A linear or branched alkyl group having 1 to 6 carbon atoms which may have a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, or a substituent. May 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. An optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, 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 group; Or an unsubstituted aryloxy group which may be 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.

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

(1-1)

(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. It represents polycyclic aromatic group, Ar ₂ and Ar ₃ is a single bond or a substituted or unsubstituted methylene group, an oxygen atom or bonded to each other to form a ring via the sulfur atom .R ₁ to R ₇ 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 trifluoromethyl group, a nitro group, or an optionally substituted carbon atom having 1 to 6 carbon atoms. A linear or branched alkyl group, an optionally substituted cycloalkyl group having 5 to 10 carbon atoms, an optionally substituted linear group having 2 to 6 carbon atoms Or a branched alkeni A linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, or a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent 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, a single bond, A ring may be bonded to each other via a substituted or unsubstituted methylene group, an oxygen atom or a sulfur atom, and R ₈ and R ₉ may be the same as or different from each other, and may be a trifluoromethyl group or a substituent. A linear or branched alkyl group having 1 to 6 carbon atoms which may have a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, or a substituent. May 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. An optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, 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 group; Or an unsubstituted aryloxy group which may be 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.

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

(1-2)

(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. It represents polycyclic aromatic group, Ar ₂ and Ar ₃ is a single bond or a substituted or unsubstituted methylene group, an oxygen atom or bonded to each other to form a ring via the sulfur atom .R ₁ to R ₇ 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 trifluoromethyl group, a nitro group, or an optionally substituted carbon atom having 1 to 6 carbon atoms. A linear or branched alkyl group, an optionally substituted cycloalkyl group having 5 to 10 carbon atoms, an optionally substituted linear group having 2 to 6 carbon atoms Or a branched alkeni A linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, or a cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent 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, a single bond, It may be bonded to each other via a substituted or unsubstituted methylene group, oxygen atom or sulfur atom to form a ring.)

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

5) Moreover, this invention is an organic electroluminescent element of the said 4) description whose said organic layer is a positive hole transport layer.

6) Moreover, this invention is an organic electroluminescent element of the said 4) description whose said organic layer is an electron blocking layer.

7) Moreover, this invention is an organic electroluminescent element of the said 4) description whose said organic layer is a positive hole injection layer.

8) Moreover, this invention is an organic electroluminescent element of the said 4) description whose said organic layer is a light emitting layer.

"Substituted or unsubstituted aromatic hydrocarbon group" represented by Ar ₁ , Ar _2, Ar ₃ in General Formula (1-1), General Formula (1-1), and General Formula (1-2), Or an "aromatic hydrocarbon group", "aromatic heterocyclic group" or "condensed polycyclic aromatic group" in "unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" Specifically, 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, furyl group, Pyrrolyl, thienyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl, benzothia Lil group, quinoxalyl group, a benzimidazolyl 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, “substituted or unsubstituted aromatic heterocyclic group” represented by Ar ₁ , Ar _2, Ar ₃ in general formula (1), general formula (1-1), and general formula (1-2) As the “aromatic heterocyclic group”, a sulfur-containing aromatic heterocyclic group such as thienyl group, benzothienyl group, benzothiazolyl group, dibenzothienyl group, furyl group, benzofuranyl group, benzoxazolyl group, dibenzofuranyl group An oxygen-containing aromatic heterocyclic group such as a group , or an N-substituted carbazolyl group having a substituent selected from the above-mentioned “aromatic hydrocarbon group” or “fused polycyclic aromatic group” is preferable.

“Substituted aromatic hydrocarbon group” represented by Ar ₁ , Ar _2, Ar ₃ in the general formula (1), general formula (1-1), and general formula (1-2), “substituted aromatic heterocycle” Specific examples of the “substituent” in the “group” or “substituted condensed polycyclic aromatic group” include deuterium atom, cyano group, nitro group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; 1 to 6 carbon atoms such as 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 A linear or branched alkyl group of 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl group such as an allyl group; Aryloxy groups such as benzyloxy group and tolyloxy group; arylalkyloxy groups such as benzyloxy group and phenethyloxy group; phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl Group, perylenyl group, fluoranthenyl group, triphenylenyl group and other aromatic hydrocarbon groups or condensed polycyclic aromatic groups; pyridyl group, thienyl group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group Group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalyl group, benzoimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, carbolinyl group and other aromatic heterocyclic groups An aryl vinyl group such as a styryl group or a naphthyl vinyl group; a group such as an acyl group such as an acetyl group or a benzoyl group. These substituents may be substituted by the above-described substituents. Good. 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.

Formula (1), the general formula (1-1) in the _R 1 to R _9, the general formula (1-2) _R 1 is represented by to R ₇ "may have a substituent group carbon in A linear or branched alkyl group having 1 to 6 atoms ", a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent" or a carbon which may have a substituent. “Linear or branched alkyl group having 1 to 6 carbon atoms” in “linear or branched alkenyl group having 2 to 6 atoms”, “cycloalkyl group having 5 to 10 carbon atoms” or “ Specific examples of the “linear or branched alkenyl group having 2 to 6 carbon atoms” include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. , N-pentyl group, isopentyl group, neo A pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-adamantyl group, vinyl group, allyl group, isopropenyl group, 2-butenyl group and the like 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.

Formula (1), the general formula (1-1) _R 1 to R ₉ in, C 1 -C having "substituent represented by _R 1 to R ₇ in the general formula (1-2) 6 Linear or branched alkyl group "," substituted cycloalkyl group having 5 to 10 carbon atoms "or" substituted linear or branched alkenyl group having 2 to 6 carbon atoms ". As the “substituent” in the above, specifically, deuterium atom, cyano group, nitro group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; methyloxy group, ethyloxy group, propyloxy group, etc. A linear or branched alkyloxy group having 1 to 6 carbon atoms; an alkenyl group such as an allyl group; an aryloxy group such as a phenyloxy group or a tolyloxy group; a benzyloxy group or a phenethyloxy group Arylalkyloxy groups such as thio group; aromatics such as phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group Hydrocarbon group or condensed polycyclic aromatic group; pyridyl group, thienyl group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group , A quinoxalyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbolinyl group, and the like, and these substituents are further exemplified by the substituents exemplified above. Is replacing Good. These substituents may be 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.

Formula (1), the general formula (1-1) in the _R 1 to R _9, the general formula (1-2) _R 1 is represented by to R ₇ "may have a substituent group carbon in “Straight or branched alkyloxy group having 1 to 6 atoms” or “optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms” “directly having 1 to 6 carbon atoms” Specific examples of the “chain or branched alkyloxy group” or “cycloalkyloxy group having 5 to 10 carbon atoms” include 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, 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.

Formula (1), the general formula (1-1) _R 1 to R ₉ in, C 1 -C having "substituent represented by _R 1 to R ₇ in the general formula (1-2) 6 Specific examples of the “substituent” in the “straight-chain or branched alkyloxy group” or the “cycloalkyloxy group having 5 to 10 carbon atoms having a substituent” include a deuterium atom, a cyano group, and a nitro group. Group: halogen atom such as fluorine atom, chlorine atom, bromine atom and iodine atom; linear or branched alkyloxy group having 1 to 6 carbon atoms such as methyloxy group, ethyloxy group and propyloxy group; allyl group An alkenyl group such as a phenyloxy group, a tolyloxy group; an arylalkyloxy group such as a benzyloxy group or a phenethyloxy group; a phenyl group, a biphenylyl group, 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, thienyl Group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalyl group, benzoimidazolyl group, pyrazolyl group, dibenzofuranyl group, A group such as an aromatic heterocyclic group such as a dibenzothienyl group and a carbolinyl group can be exemplified, and these substituents may be further substituted with the substituents exemplified above. These substituents may be 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.

Formula (1), the general formula (1-1) _R 1 to R _9, the general formula (1-2) represented by _R 1 to R ₇ in the "substituted or unsubstituted aromatic hydrocarbon group in , “Substituted or unsubstituted aromatic heterocyclic group” or “substituted or unsubstituted condensed polycyclic aromatic group”, “aromatic hydrocarbon group”, “aromatic heterocyclic group” or “fused polycyclic aromatic” As the `` group group '', specifically, 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 , Furyl, pyrrolyl, thienyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl, benzoti An azolyl group, a quinoxalyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbolinyl group, and the like can be given. 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, the general formula (1), the general formula (1-1) _R 1 to R _9, "substituted or unsubstituted aromatic represented by the general formula (1-2) _R 1 to R ₇ in the in As the “aromatic heterocyclic group” in the “heterocyclic group”, a sulfur-containing aromatic heterocyclic group such as thienyl group, benzothienyl group, benzothiazolyl group, dibenzothienyl group, furyl group, benzofuranyl group, benzoxazolyl group And an oxygen-containing aromatic heterocyclic group such as a dibenzofuranyl group, or an N-substituted carbazolyl group having a substituent selected from the above-mentioned “aromatic hydrocarbon group” or “condensed polycyclic aromatic group”.

“Substituted aromatic hydrocarbon group” represented by R _{1 to} R ₉ in General Formula (1), R _{1 to} R ₇ in General Formula (1-2), and “Substitution” Specific examples of the “substituent” in the “aromatic heterocyclic group” or “substituted condensed polycyclic aromatic group” include deuterium atom, cyano group, nitro group; fluorine atom, chlorine atom, bromine atom, iodine atom, etc. A carbon atom such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, or an n-hexyl group. A linear or branched alkyl group having 1 to 6 carbon atoms; a linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl such as an allyl group Base Aryloxy groups such as phenyloxy group and tolyloxy group; arylalkyloxy groups such as benzyloxy group and phenethyloxy group; phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group Aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as pyrenyl group, perylenyl group, fluoranthenyl group, triphenylenyl group; pyridyl group, thienyl group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, Aromatic complex such as benzothienyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzothiazolyl group, quinoxalyl group, benzoimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, carbolinyl group Groups; aryl vinyl groups such as a styryl group and naphthyl vinyl group; groups such as acyl groups such as an acetyl group and a benzoyl group. These substituents are further substituted by the above-exemplified substituents. Also good. These substituents may be 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.

Formula (1), in the general formula (1-1) _R 1 to R ₉ in, represented by _R 1 to R ₇ in the general formula (1-2) "substituted or unsubstituted aryloxy group" Specific examples of the “aryloxy group” include phenyloxy group, biphenylyloxy group, terphenylyloxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group, fluorenyloxy group, indenyl Examples thereof include an oxy 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.

Formula (1), the general formula (1-1) _R 1 to R ₉ in the "substituent" in represented by _R 1 to R ₇ in the general formula (1-2) "substituted aryloxy group" Specifically, deuterium atom, 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 A linear or branched alkyl group having 1 to 6 carbon atoms such as a group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group; methyloxy group, ethyloxy group A linear or branched alkyloxy group having 1 to 6 carbon atoms such as propyloxy group; alkenyl group such as allyl group; aryloxy such as phenyloxy group and tolyloxy group Group: arylalkyloxy group such as benzyloxy group and phenethyloxy group; phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group, perylenyl group, fluoranthenyl group Aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as triphenylenyl group; pyridyl group, thienyl group, furyl group, pyrrolyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, carbazolyl group, benzoyl group Aromatic heterocyclic groups such as oxazolyl group, benzothiazolyl group, quinoxalyl group, benzimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group and carbolinyl group; aryl vinyl such as styryl group and naphthyl vinyl group ; An acetyl group, can be mentioned groups such as acyl groups such as benzoyl group, these substituents may further the exemplified substituents may be substituted. These substituents may be 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.

As R ₈ and R _{9 in the} general formula (1) and the general formula (1-1), a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent is preferable. , A methyl group, an ethyl group, and a propyl group are particularly preferable.
Ar ₁ , Ar ₂ , and Ar _{3 in the} general formula (1), the general formula (1-1), and the general formula (1-2) are “substituted or unsubstituted aromatic hydrocarbon groups”, “substituted or "Unsubstituted fused polycyclic aromatic group", "substituted or unsubstituted sulfur-containing aromatic heterocyclic group", "substituted or unsubstituted oxygen-containing aromatic heterocyclic group", or "N-arylcarbazolyl group" Are preferable, and a phenyl group, a biphenylyl group, an N-phenylcarbazolyl group, a dibenzofuranyl group, a dimethylfluorenyl group, and a dibenzothienyl group are particularly preferable.

  The compound having an acridan ring structure represented by general formula (1), general formula (1-1), or general formula (1-2) of the present invention is a novel compound, and is superior to conventional hole transport materials. It has the ability to block electrons, has excellent amorphous properties, and is stable in a thin film state.

  The compound having an acridan ring structure represented by the general formula (1), general formula (1-1), or general formula (1-2) of the present invention is referred to as an organic electroluminescence device (hereinafter abbreviated as an organic EL device). ) As a constituent material of the hole injection layer and / or hole transport layer. 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 an acridan ring structure represented by general formula (1), general formula (1-1), or general formula (1-2) of the present invention is also used as a constituent material of an electron blocking layer of an organic EL device. can do. 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 an acridan ring structure represented by general formula (1), general formula (1-1), or general formula (1-2) of the present invention is also used as a constituent material of a light emitting layer of an organic EL element. be able to. 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 has a higher mobility of holes than conventional hole transport materials, an excellent electron blocking ability, an excellent amorphous property, and a stable thin film state. Since a compound having a structure is used, high efficiency and high durability can be realized.

  The compound having an acridan 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, has an excellent electron blocking ability, and Amorphous property is good, thin film state is stable, and heat resistance is excellent. 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.

1 is a ¹ H-NMR chart of the compound of Example 1 of the present invention (Compound 17). ^{1 is} a ¹ H-NMR chart of a compound of Example 2 of the present invention (Compound 77). FIG. 3 is a ¹ H-NMR chart of the compound of Example 3 of the present invention (Compound 22). FIG. 3 is a ¹ H-NMR chart of the compound of Example 4 of the present invention (Compound 18). FIG. 6 is a diagram showing EL element configurations of Example 7 and Comparative Example 1.

The compound having an acridan ring structure of the present invention is a novel compound, and these compounds can be synthesized as follows, for example. First, 2-bromo-10-arylacridane was synthesized by bromination of the corresponding acridan substituted at the 10-position with an aryl group with bromine or N-bromosuccinimide (see, for example, Patent Document 3). The compound having an acridan ring structure of the present invention can be synthesized by performing a cross-coupling reaction such as Buchwald-Hartwig reaction between this bromo compound and various diarylamines.
Here, in the bromination of an acridan substituted with an aryl group at the 10-position, bromo-substituted products with different substitution positions can be obtained by changing the bromination reagent and conditions, and a similar cross-coupling reaction is performed. By carrying out the process, it is possible to synthesize compounds having an acridan ring structure of the present invention in which the substitution position of the diarylamino group is different.

  The compound having an acridan ring structure of the present invention can be synthesized as follows. First, an acridan ring of the present invention is obtained by performing a cross-coupling reaction such as Ullmann coupling between an acridan substituted with an arylamino group at the corresponding 2-position and various aryl halides (see, for example, Non-Patent Document 5). A compound having a structure can be synthesized.

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

(Compound 2)

(Compound 3)

(Compound 4)

(Compound 5)

(Compound 6)

(Compound 7)

(Compound 8)

(Compound 9)

(Compound 10)

(Compound 11)

(Compound 12)

(Compound 13)

(Compound 14)

(Compound 15)

(Compound 16)

(Compound 17)

(Compound 18)

(Compound 19)

(Compound 20)

(Compound 21)

(Compound 22)

(Compound 23)

(Compound 24)

(Compound 25)

(Compound 26)

(Compound 27)

(Compound 28)

(Compound 29)

(Compound 30)

(Compound 31)

(Compound 32)

(Compound 33)

(Compound 34)

(Compound 35)

(Compound 36)

(Compound 37)

(Compound 38)

(Compound 39)

(Compound 40)

(Compound 41)

(Compound 42)

(Compound 43)

(Compound 44)

(Compound 45)

(Compound 46)

(Compound 47)

(Compound 48)

(Compound 49)

(Compound 50)

(Compound 51)

(Compound 52)

(Compound 53)

(Compound 54)

(Compound 55)

(Compound 56)

(Compound 57)

(Compound 58)

(Compound 59)

(Compound 60)

(Compound 61)

(Compound 62)

(Compound 63)

(Compound 64)

(Compound 65)

(Compound 66)

(Compound 67)

(Compound 68)

(Compound 69)

(Compound 70)

(Compound 71)

(Compound 72)

(Compound 73)

(Compound 74)

(Compound 75)

(Compound 76)

(Compound 77)

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

  The glass transition point (Tg) and the melting point were determined with a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA) using powder.

  The work function was measured using an ionization potential measuring device (Sumitomo Heavy Industries, Ltd., PYS-202) 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. 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 an acridan ring structure represented by the general formula (1), general formula (1-1), and general formula (1-2) of the present invention, Materials such as porphyrin compounds represented by copper phthalocyanine, starburst triphenylamine derivatives, 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 an acridan ring structure represented by the general formula (1), general formula (1-1), and general formula (1-2) of the present invention, N, N′-diphenyl-N, N′-di (m-tolyl) benzidine (hereinafter abbreviated as TPD) and N, N′-diphenyl-N, N′-di (α-naphthyl) benzidine (hereinafter, Benzidine derivatives such as NPD, N, N, N ′, N′-tetrabiphenylylbenzidine, 1,1-bis [4- (di-4-tolylamino) phenyl] cyclohexane (hereinafter abbreviated as TAPC). ), Various triphenylamine trimers and tetramers 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 the electron blocking layer of the organic EL device of the present invention, in addition to the compound having an acridan ring structure represented by the general formula (1), general formula (1-1), and general formula (1-2) 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 Carbazole derivatives such as (carbazol-9-yl) benzene (hereinafter abbreviated as mCP), 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 represented by a triphenylsilyl group and a compound having a triarylamine structure Compounds having any electron blocking effect 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. Moreover, you may comprise a light emitting layer with host material and dopant material, and it represents with General formula (1), General formula (1-1), and General formula (1-2) of this invention as host material. In addition to the compound having an acridan ring structure, a thiazole derivative, a benzimidazole derivative, a polydialkylfluorene derivative, or the like can be used in addition to the light-emitting material. 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 emitter, a phosphorescent emitter 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, the general formula (1) of the present invention, A compound having an acridan ring structure represented by general formula (1-1) or general formula (1-2) 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.

  In addition, a material that emits delayed fluorescence such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, and 4CzIPN can be used as the light-emitting material (see, for example, Non-Patent Document 3).

  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.

[Example 1]
Synthesis of {{9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan-2-yl}-(biphenyl-4-yl) -phenylamine (Compound 17) >
Into a reaction vessel purged with nitrogen, 18 g of 2-bromo-9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan, 9 g of (biphenyl-4-yl) -phenylamine, tert -4.4 g of butoxy sodium, 0.24 g of palladium acetate, 1.44 ml of a 50% (W / V) toluene solution of tri-tert-butylphosphine and 130 ml of toluene were added and stirred at 90 ° C. overnight. After the reaction solution was concentrated under reduced pressure, the crude product was purified by column chromatography (carrier: silica gel, eluent: hexane / ethyl acetate). Subsequently, {9,9-dimethyl-10- (9,9-dimethyl) is repeated by repeating dispersion washing using methanol, dispersion washing using hexane, dispersion washing using acetone, and dispersion washing using toluene. A pale yellowish white powder (12 g, yield 52%) of -9H-fluoren-2-yl) acridan-2-yl}-(biphenyl-4-yl) -phenylamine was obtained.

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

^The following 40 hydrogen signals were detected by ¹ H-NMR (DMSO-d ₆ ). δ (ppm) = 8.13 (1H), 7.94 (1H), 7.69-7.50 (7H), 7.49-7.21 (10H), 7.09-6.82 (6H) ), 6.72 (1H), 6.23 (2H), 1.59 (6H), 1.49 (6H).

[Example 2]
Synthesis of <(biphenyl-4-yl)-{9,9-dimethyl-10- (biphenyl-4-yl) acridan-2-yl}-(9,9-dimethyl-9H-fluoren-2-yl) amine Synthesis of (Compound 77)>
Into a nitrogen-substituted reaction vessel, 8 g of 2-bromo-9,9-dimethyl-10- (biphenyl-4-yl) acridan, (9,9-dimethyl-9H-fluoren-2-yl)-(biphenyl-4-yl) was added. Yl) 7.8 g of amine, 2.6 g of tert-butoxy sodium, 0.12 g of palladium acetate, 0.36 ml of 50% (W / V) toluene solution of tri-tert-butylphosphine and 80 ml of toluene were added at 90 ° C. Stir overnight. After the reaction solution was concentrated under reduced pressure, the crude product was purified by column chromatography (carrier: silica gel, eluent: hexane / ethyl acetate). Subsequently, after repeating dispersion washing using methanol, dispersion washing using hexane, and dispersion washing using acetone, crystallization using toluene and crystallization using hexane were further repeated (biphenyl). -4-yl)-{9,9-dimethyl-10- (biphenyl-4-yl) acridan-2-yl}-(9,9-dimethyl-9H-fluoren-2-yl) amine pale yellowish white powder 5.1 g (39% yield) was obtained.

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

^The following 44 hydrogen signals were detected by ¹ H-NMR (DMSO-d ₆ ). δ (ppm) = 8.00 (2H), 7.80 (2H), 7.73 (2H), 7.65-7.38 (12H), 7.32-7.20 (6H), 7. 10-6.97 (4H), 6.97-6.70 (2H), 6.28 (2H), 1.58 (6H), 1.38 (6H).

[Example 3]
<(Biphenyl-4-yl)-{9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan-2-yl}-(9,9-dimethyl-9H-fluorene Synthesis of 2-yl) amine (Compound 22)>
Into a nitrogen-substituted reaction vessel, 11 g of 2-bromo-9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan, (9,9-dimethyl-9H-fluorene-2-yl) was added. Yl)-(biphenyl-4-yl) amine 9.9 g, tert-butoxy sodium 2.85 g, palladium acetate 0.15 g, tri-tert-butylphosphine in 50% (W / V) toluene solution 0.92 g, toluene 100 ml was added and stirred at 90 ° C. overnight. After the reaction solution was concentrated under reduced pressure, the crude product was purified by column chromatography (carrier: silica gel, eluent: hexane / ethyl acetate). Subsequently, after repeating dispersion washing using methanol, dispersion washing using hexane, and dispersion washing using acetone, crystallization using THF and crystallization using hexane were further repeated (biphenyl). -4-yl)-{9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan-2-yl}-(9,9-dimethyl-9H-fluoren-2- Yl) 7 g (41% yield) of pale yellowish white powder of amine was obtained.

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

^The following 48 hydrogen signals were detected by ¹ H-NMR (DMSO-d ₆ ). δ (ppm) = 8.14 (1H), 7.92 (1H), 7.77-7.18 (20H), 7.05-6.80 (5H), 6.75 (1H), 6. 30-6.18 (2H), 1.58 (6H), 1.49 (6H), 1.35 (6H).

[Example 4]
<(9,9-dimethyl-9H-fluoren-2-yl)-{9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan-2-yl} -phenylamine Synthesis of (Compound 18)>
Into a nitrogen-substituted reaction vessel, 12 g of 2-bromo-9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan, (9,9-dimethyl-9H-fluorene-2-yl) was added. Yl) -phenylamine 8.55 g, tert-butoxy sodium 2.84 g, palladium acetate 0.15 g, tri-tert-butylphosphine in 50% (W / V) toluene solution 0.92 g and toluene 10 ml were added, and 90 ° C. Stir overnight. After the reaction solution was concentrated under reduced pressure, the crude product was purified by column chromatography (carrier: silica gel, eluent: hexane / ethyl acetate). Subsequently, after repeating dispersion washing using methanol, dispersion washing using hexane, and dispersion washing using acetone, crystallization using toluene and crystallization using methanol are further repeated (9). , 9-dimethyl-9H-fluoren-2-yl)-{9,9-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) acridan-2-yl} -phenylamine pale yellow 11 g (yield 64%) of white powder was obtained.

The structure of the obtained pale yellowish white powder was identified using NMR. ^The result of ¹ H-NMR measurement is shown in FIG.

^The following 44 hydrogen signals were detected by ¹ H-NMR (DMSO-d ₆ ). δ (ppm) = 8.12 (1H), 7.92 (1H), 7.70-7.09 (16H), 7.05-6.80 (5H), 6.75 (1H), 6. 30-6.18 (2H), 1.56 (6H), 1.49 (6H), 1.35 (6H).

[Example 5]
About the compound of this invention, melting | fusing point and glass transition point were calculated | required with the highly sensitive differential scanning calorimeter (The product made from Bruker AXS, DSC3100SA).
Melting point Glass transition point Compound of Example 1 of the present invention 227 ° C 111 ° C
Compound of Example 2 of the present invention Not observed at 128 ° C
Compound of Example 3 of the present invention Not observed 142 ° C.
Compound of the present invention Example 4 not observed 125 ° 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.

[Example 6]
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 (Sumitomo Heavy Industries, Ltd., PYS-202).
Work Function Compound of Invention Example 1 5.40 eV
Inventive Example 2 compound 5.33 eV
Compound of Example 3 of the present invention 5.30 eV
Inventive Example 4 Compound 5.34 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

[Example 7]
As shown in FIG. 5, the organic EL element has a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, and an electron transport layer on a glass substrate 1 on which an ITO electrode is previously formed as a transparent anode 2. 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 78 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 anode 2. On this hole injection layer 3, the compound (Compound 17) 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 79 having the following structural formula and a compound 80 having the following structural formula are formed as the light emitting layer 5 by binary deposition at a deposition rate such that the deposition rate ratio is compound 79: compound 80 = 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 17) of the present invention.

(Compound 78)

(Compound 79)

(Compound 80)

[Comparative Example 1]
For comparison, in Example 4, except that the compound 81 of the following structural formula was formed to a film thickness of 40 nm instead of the compound (Compound 17) of Example 1 of the present invention 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.

(Compound 81)

As shown in Table 1, the driving voltage when a current having a current density of 10 mA / cm ² was passed was 5.17 V of the organic EL device using Compound 81, and the compound of Example 1 of the present invention (Compound 17). In the organic EL device using), the voltage was lowered to 4.88V. Also, in terms of power efficiency, the organic EL device using the compound of Example 1 of the present invention (Compound 17) is 6.37 lm / W, which is significantly larger than the 5.49 lm / W of the organic EL device using Compound 81. Improved. Moreover, the organic EL element using the compound of the present invention was improved with respect to the organic EL element using Compound 81 in both luminance and luminous efficiency.

  As is clear from the above results, the organic EL device using the compound having an acridan ring structure of the present invention is improved in luminous efficiency and power efficiency as compared with the organic EL device using the compound 81, and It was found that a decrease in practical driving voltage can be achieved.

  The compound having an acridan ring structure of the present invention is excellent as a compound for an organic EL device because it has a high hole transport capability, is excellent in amorphous properties, and is stable in a 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 (8)

A compound having an acridan ring structure represented by the following general formula (1).
(1)
(In the formula, Ar ₁ represents a 9,9-dimethylfluorenyl group, and Ar ₂ and Ar ₃ may be the same or different from each other, and may be an unsubstituted phenyl group, an unsubstituted biphenyl group, or 9,9- Represents a dimethylfluorenyl group, R _{1 to} R ₇ may be the same or different from each other, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a nitro group, or a substituent; A linear or branched alkyl group having 1 to 6 carbon atoms which may have, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, and a substituent. A linear or branched alkenyl group having 2 to 6 carbon atoms, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, and a substituent. Number of carbon atoms To 10 cycloalkyloxy groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups, or substituted or unsubstituted aryloxy groups R ₈ and R ₉ may be the same or different from each other, and may be a trifluoromethyl group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, and a substituent. 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. An optionally substituted linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, substituted or unsubstituted An 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.) The compound which has an acridan ring structure of Claim 1 represented by the following general formula (1-1).
(1-1)
(In the formula, Ar ₁ represents a 9,9-dimethylfluorenyl group, and Ar ₂ and Ar ₃ may be the same or different from each other, and may be an unsubstituted phenyl group, an unsubstituted biphenyl group, or 9,9- Represents a dimethylfluorenyl group, R _{1 to} R ₇ may be the same or different from each other, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a nitro group, or a substituent; A linear or branched alkyl group having 1 to 6 carbon atoms which may have, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, and a substituent. A linear or branched alkenyl group having 2 to 6 carbon atoms, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, and a substituent. Number of carbon atoms To 10 cycloalkyloxy groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups, or substituted or unsubstituted aryloxy groups R ₈ and R ₉ may be the same or different from each other, and may be a trifluoromethyl group, a linear or branched alkyl group having 1 to 6 carbon atoms which may have a substituent, and a substituent. 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. An optionally substituted linear or branched alkyloxy group having 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group having 5 to 10 carbon atoms, substituted or unsubstituted An 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.) The compound which has an acridan ring structure of Claim 1 represented by the following general formula (1-2).
(1-2)
(In the formula, Ar ₁ represents a 9,9-dimethylfluorenyl group, and Ar ₂ and Ar ₃ may be the same or different from each other, and may be an unsubstituted phenyl group, an unsubstituted biphenyl group, or 9,9- Represents a dimethylfluorenyl group, R _{1 to} R ₇ may be the same or different from each other, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a nitro group, or a substituent; A linear or branched alkyl group having 1 to 6 carbon atoms which may have, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, and a substituent. A linear or branched alkenyl group having 2 to 6 carbon atoms, a linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent, and a substituent. Number of carbon atoms To 10 cycloalkyloxy groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted condensed polycyclic aromatic groups, or substituted or unsubstituted aryloxy groups Represents.)   In an organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched therebetween, the compound having an acridan ring structure according to claim 1 is used as a constituent material of at least one organic layer. An organic electroluminescence device characterized by that.   The organic electroluminescence device according to claim 4, wherein the organic layer is a hole transport layer.   The organic electroluminescence device according to claim 4, wherein the organic layer is an electron blocking layer.   The organic electroluminescence device according to claim 4, wherein the organic layer is a hole injection layer.   The organic electroluminescent element according to claim 4, wherein the organic layer is a light emitting layer.