WO2014065300A1

WO2014065300A1 - Compound having acridan ring structure, and organic electroluminescence element

Info

Publication number: WO2014065300A1
Application number: PCT/JP2013/078632
Authority: WO
Inventors: 紀昌横山; 大三神田; 秀一林
Original assignee: 保土谷化学工業株式会社
Priority date: 2012-10-23
Filing date: 2013-10-22
Publication date: 2014-05-01
Also published as: JPWO2014065300A1; JP5525665B1; TW201431861A

Abstract

The present invention provides a compound having acridan ring structure represented by general formula (1), and an organic electroluminescence element having a pair of electrodes and at least one organic layer held therebetween, wherein said compound is used as a constituent material of the organic layer. This compound, as a material for use in this high-efficiency, high-durability organic electroluminescence element, has excellent hole injection and transport performance, has an electron blocking capability, high stability in a thin film state, and excellent heat resistance properties.

Description

COMPOUND HAVING ACRYDAN RING STRUCTURE AND ORGANIC ELECTROLUMINESCENT DEVICE

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 an acridan ring structure and an organic compound using the compound. The present invention relates to an electroluminescence element.

Since an organic electroluminescence element (hereinafter sometimes referred to as an organic EL element) is a self-luminous element, it is brighter and more visible than a liquid crystal element, and a clear display is possible. Therefore, active research has been conducted on organic EL elements.

In 1987, Eastman Kodak's C.I. W. Tang et al. Have developed an organic EL element using an organic material by developing a stacked structure element in which various roles are assigned to each material. They laminate a phosphor capable of transporting electrons, namely tris (8-hydroxyquinoline) aluminum (hereinafter abbreviated as Alq ₃ ) and an aromatic amine compound capable of transporting holes. By injecting both charges into the phosphor layer and emitting light, high luminance of 1000 cd / m ² or more was obtained at a voltage of 10 V or less (see Patent Document 1 and Patent Document 2).

Until now, many improvements have been made for practical use of organic EL elements. For example, an electroluminescent device is known in which various roles are further subdivided and an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode are sequentially provided on a substrate. High efficiency and durability are achieved by such an element.

Also, 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.

Furthermore, an element using light emission by thermally activated delayed fluorescence (TADF) has been developed, and an external quantum efficiency of 5.3% is realized by the element using the thermally activated delayed fluorescence material.

The light emitting layer can also be prepared by doping a charge transporting compound generally called a host material with a phosphor or a phosphorescent material. The selection of an organic material for forming each layer in an organic EL element greatly affects various characteristics such as efficiency and durability of the element.

In the organic EL element, the light injected from both electrodes is recombined 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. For example, the probability of recombination of holes and electrons is improved by increasing the hole injection property and blocking the electron injected from the cathode, and further excitons generated in the light emitting layer. By confining, 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.

Also, the heat resistance and amorphous nature of the material are 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 EL devices so far include N, N′-diphenyl-N, N′-di (α-naphthyl) benzidine (hereinafter abbreviated as NPD) and various aromatic amines. Derivatives are known (see 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 deteriorated due to crystallization under high temperature conditions. Further, among the aromatic amine derivatives described in Patent Document 1 and Patent Document 2, there are compounds having an excellent mobility such as a hole mobility of 10 ⁻³ cm ² / Vs or more. Is insufficient, a part of electrons pass through the light emitting layer, and there is a problem that improvement in luminous efficiency cannot be expected. Therefore, in order to further increase the efficiency, there has been a demand for a material having higher electron blocking properties, a more stable thin film, and higher heat resistance.

As compounds having improved properties such as heat resistance, hole injection properties, and electron blocking properties, arylamine compounds (compounds A to C) having a substituted acridan structure represented by the following formula have been proposed. (See Patent Documents 3 to 5).

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. Therefore, there has been a demand for a compound capable of further reducing the driving voltage and further increasing the light emission efficiency while enhancing the amorphous property.

JP-A-8-048656 Japanese Patent No. 3194657 WO2006 / 033563 publication WO2007 / 110228 publication WO 2010/147319

The object of the present invention is as a highly efficient and durable organic EL device material with excellent hole injection / transport performance, electron blocking ability, high stability in a thin film state, and heat resistance. It is to provide an organic compound having excellent characteristics.
Another object of the present invention is to provide an organic EL device having high luminous efficiency and high durability using this compound.

As physical properties that the organic compound to be provided by the present invention should have,
(Α) good hole injection characteristics;
(Β) high hole mobility;
(Γ) Excellent electron blocking ability,
(Δ) that the thin film state is stable,
(Ε) Excellent heat resistance,
Can be mentioned. Moreover, as a physical characteristic that the organic EL element to be provided by the present invention should have,
(Α) high luminous efficiency and power efficiency,
(Β) Low emission start voltage,
(Γ) The practical drive voltage is low,
Can be mentioned.

In order to achieve the above object, the present inventors have confirmed that an aromatic tertiary amine structure has a high hole injection / transport capability, a predetermined acridan ring structure (benzothienoacridan ring structure or benzofloor). Focusing on the effects of the given acridan ring structure on the heat resistance and thin film stability, the compound having an acridan ring structure is designed and chemistry. Synthesized. Furthermore, various organic EL devices were prototyped using the compound, and the characteristics of the devices were earnestly evaluated. As a result, the present invention has been completed.

According to the present invention, a compound having an acridan ring structure represented by the following general formula (1) is provided.

Where
X represents an oxygen atom or a sulfur atom,
R ¹ to R ⁹ are hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano group, nitro group, alkyl group having 1 to 6 carbon atoms, carbon atom number 5 to
10 cycloalkyl groups, alkenyl groups having 2 to 6 carbon atoms, alkyloxy groups having 1 to 6 carbon atoms, cycloalkyloxy groups having 5 to 10 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups A condensed polycyclic aromatic group or an aryloxy group, which may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom to form a ring;
R ¹⁰ and R ¹¹ are each an alkyl group having 1 to 6 carbon atoms,
10 cycloalkyl groups, alkenyl groups having 2 to 6 carbon atoms, alkyloxy groups having 1 to 6 carbon atoms, cycloalkyloxy groups having 5 to 10 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups A condensed polycyclic aromatic group or an aryloxy group, which may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom to form a ring;
Ar ¹ , Ar ² and Ar ³ represent an aromatic hydrocarbon group, an aromatic heterocyclic group or a condensed polycyclic aromatic group, and Ar ² and Ar ³ represent a single bond, a methyl group, an oxygen atom or sulfur. They may be joined together through atoms to form a ring,
A is an aromatic hydrocarbon, aromatic heterocyclic ring or condensed polycyclic aromatic 2
Represents a valent group or a single bond,
When A is an aromatic hydrocarbon, aromatic heterocycle or condensed polycyclic aromatic divalent group, A and Ar ² are bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom. To form a ring.

In the compound of the present invention, the following embodiments are preferable.
(I) For the benzene ring to which A is bonded, R ¹ , R ² , R ³ and A are
Bonded at the position represented by the following general formula (1-1).

In the formula, X, R ¹ to R ¹¹ , Ar ¹ to Ar ^3, and A represent the above general formula (1
).
(II) A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group.
(III) A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group represented by the following general formula (2).

Where
r ¹² represents an integer of 0 to 4,
R ¹² represents a deuterium atom, a fluorine atom, a chlorine atom, a cyano group,
Nitro group, alkyl group having 1 to 6 carbon atoms, 5 to carbon atoms
10 cycloalkyl groups, alkenyl groups having 2 to 6 carbon atoms, alkyloxy groups having 1 to 6 carbon atoms, and 5 to 1 carbon atoms
0 cycloalkyloxy group, aromatic hydrocarbon group, aromatic heterocyclic group, condensed polycyclic aromatic group or aryloxy group, or linking group, and when there are a plurality of R ¹² , R ¹² may form a ring with each other.
(IV) A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group represented by the following general formula (2 ′).

In the formula, r ¹² and R ¹² have the same meanings as described in the formula (2).
(V) As represented by the following general formula (1-2), r ¹² = 1 and R ¹²
Is a linking group, and the bonding position of R ¹² is determined.

Where
X, R ¹ to R ¹¹ , Ar ¹ , Ar ³ and A are defined by the general formula (1)
Moreover, it has the same meaning as described in (1-1),
Ar ⁴ represents Ar ² described in the general formula (1) or (1-1).
Represents a divalent group of groups belonging to
Ar ³ and Ar ⁴ may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom to form a ring.
(VI) A is a single bond.

According to the present invention, in the organic EL device having a pair of electrodes and at least one organic layer sandwiched between the pair of electrodes, the compound having the acridan ring structure is a constituent material of the organic layer. The organic electroluminescent element characterized by being used as is provided.

In the organic electroluminescence device of the present invention,
(VII) the organic layer is a hole transport layer;
(VIII) the organic layer is an electron blocking layer;
(IX) the organic layer is a hole injection layer;
(X) the organic layer is a light emitting layer;
Is preferred.

The compound having an acridan ring structure of the present invention is a novel compound, and a predetermined acridan ring structure (benzothienoacridan ring structure or benzoflourcridan ring structure) has an electron blocking property, and this predetermined Acridan ring structure has heat resistance and thin film stability. Therefore, the compound having an acridan ring structure of the present invention is
(A) has excellent electron blocking ability,
(B) It has excellent amorphous properties, and (C) the thin film state is stable.

Particularly regarding (C) the thin film state, the compound of the present invention has a high glass transition point (Tg) as an index of heat resistance, and specifically has a Tg of 100 ° C. or higher, particularly 140 ° C. or higher. Therefore, a thin film formed using the compound of the present invention is hardly crystallized even under high temperature conditions.

The compound of the present invention can be used, for example, as a constituent material of a hole injection layer and / or a hole transport layer of an organic EL device. The compound of the present invention has higher (a) hole injection properties than conventional materials,
(B) High hole mobility,
(C) The electron blocking property is high, and (d) since the stability to electrons is high, in the hole injection layer and / or hole transport layer obtained by using the compound of the present invention as a constituent material, Can confine excitons generated in, and the probability of recombination of holes and electrons is improved, high luminous efficiency can be obtained, driving voltage is lowered, and durability of the organic EL element is improved. The effect of doing is given.

Moreover, the compound of this invention can be used also as a constituent material of the electron blocking layer of an organic EL element. The compounds of the present invention
(E) has excellent electron blocking ability,
(F) Excellent hole transportability compared to conventional materials, and (g) Since the stability of the thin film state is high, the electron blocking layer obtained by using the compound of the present invention as a constituent material has high luminous efficiency. However, the driving voltage is lowered, the current resistance is improved, and the maximum light emission luminance of the organic EL element is improved.

Furthermore, the compound of this invention can be used also as a constituent material of the light emitting layer of an organic EL element. The compounds of the present invention
(H) Excellent hole transportability compared to conventional materials, and (i) Wide band gap, so the compound of the present invention is used as a host material for a light emitting layer, and a phosphor or phosphorescent material called a dopant is used. By obtaining a light emitting layer by supporting a light emitting body, an organic EL element with reduced driving voltage and improved light emission efficiency can be realized.

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 are realized.

As described above, 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, and has an excellent electron blocking ability and is excellent. It has the ability to block electrons, has good amorphous properties, is stable in a thin film state, 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 H-NMR chart of the compound of Example 1 (Compound 2). ¹ H-NMR chart of the compound of Example 2 (Compound 20). ¹ H-NMR chart of the compound of Example 3 (Compound 27). ¹ H-NMR chart of the compound of Example 4 (Compound 4). ¹ H-NMR chart of the compound of Example 5 (Compound 25). ¹ H-NMR chart of the compound of Example 6 (Compound 41). ¹ H-NMR chart of the compound of Example 7 (Compound 42). ¹ H-NMR chart of the compound of Example 8 (Compound 23). The figure which showed the EL element structure of Examples 11-18 and the comparative example 1. FIG.

The compound of the present invention is represented by the following general formula (1), and has a predetermined acridan ring structure and an aromatic tertiary amine structure.

Among the compounds of the present invention represented by the general formula (1), in the benzene ring to which A is bonded, R ¹ , R ² , R ³ and A are represented by the following general formula (1-1). A compound bonded at a certain position is preferred.

<X>
X represents an oxygen atom or a sulfur atom. When X is a sulfur atom, the compound of the present invention has a benzothienoacridan ring structure. When X is an oxygen atom, the compound of the present invention has a benzoflouridane ring structure.

<R ¹ to R ⁹ >
R ¹ to R ⁹ may be the same or different from each other, and are a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano group, nitro group, alkyl group having 1 to 6 carbon atoms, 10 cycloalkyl groups, alkenyl groups having 2 to 6 carbon atoms, alkyloxy groups having 1 to 6 carbon atoms, cycloalkyloxy groups having 5 to 10 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups Represents a condensed polycyclic aromatic group or an aryloxy group. These groups may be bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom to form a ring.

Examples of the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ include the following examples. .
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, cyclohexyl Group, 1-adamantyl group, 2-adamantyl group, vinyl group, allyl group, isopropenyl group, 2-butenyl group and the like.
As understood from the above examples, the alkyl group having 1 to 6 carbon atoms and the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ may be linear or branched.

The alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ may have a substituent. The following examples can be given as examples of the substituent.
Deuterium atom;
A cyano group;
A nitro group;
Halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine 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 group, such as an allyl group;
An aryloxy group such as a phenyloxy group, a tolyloxy group;
Arylalkyloxy groups such as benzyloxy group, phenethyloxy group;
Aromatic hydrocarbon group or condensed polycyclic aromatic group 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;
Aromatic heterocyclic groups such as pyridyl, thienyl, furyl, pyrrolyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl,
Benzothiazolyl group, quinoxalyl group, benzimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, carbolinyl group;
These substituents may further have a substituent. Examples of the substituent further include the same examples as the above-described substituent. Further, the substituents may be bonded to each other via a single bond or a methylene group, oxygen atom or sulfur atom which may have a substituent, to form a ring.

Examples of the alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹ to R ⁹ include the following examples.
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.
As understood from the above examples, the alkyloxy group having 1 to 6 carbon atoms represented by R ¹ to R ⁹ may be linear or branched.

The alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹ to R ⁹ may have a substituent. The substituent may have an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ^9. The same example as a substituent can be given. Moreover, these substituents may further have a substituent. Further, as the substituents, the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ has The same examples can be given as good substituents. The substituents exemplified above may be bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom to form a ring.

Examples of the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ include the following.
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 group, thienyl 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, dibenzothienyl group, carbolinyl Group etc.
The aromatic heterocyclic group represented by R ¹ to R ⁹ is preferably a sulfur-containing aromatic heterocyclic group such as a thienyl group, a benzothienyl group, a benzothiazolyl group, or a dibenzothienyl group.

The aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have a substituent. The following examples can be given as examples of the substituent.
Deuterium atom;
A trifluoromethyl group;
A cyano group;
A nitro group;
Halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine atoms;
Linear or branched alkyl group having 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 alkyloxy group having 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;
An aralkyl group, such as a benzyl group, a naphthylmethyl group, a phenethyl group;
An aryloxy group such as a phenyloxy group, a tolyloxy group;
Arylalkyloxy groups such as benzyloxy group, phenethyloxy group;
An aromatic hydrocarbon group or a condensed polycyclic aromatic group such as a phenyl group,
Biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group,
Perylenyl group, fluoranthenyl group, triphenylenyl group;
Aromatic heterocyclic groups such as pyridyl, thienyl, furyl, pyrrolyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl,
Benzothiazolyl group, quinoxalyl group, benzimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, carbolinyl group;
Aryl vinyl groups such as styryl groups, naphthyl vinyl groups;
An acyl group, such as an acetyl group, a benzoyl group;
A dialkylamino group, such as a dimethylamino group, a diethylamino group;
A disubstituted amino group substituted by an aromatic hydrocarbon group or a condensed polycyclic aromatic group, such as a diphenylamino group, a dinaphthylamino group;
Diaralkylamino group, such as dibenzylamino group, diphenethylamino group;
A disubstituted amino group substituted by an aromatic heterocyclic group, such as a dipyridylamino group, a dithienylamino group;
Dialkenylamino groups, such as diallylamino groups;
A disubstituted amino group substituted by a substituent selected from an alkyl group, an aromatic hydrocarbon group, a condensed polycyclic aromatic group, an aralkyl group, an aromatic heterocyclic group or an alkenyl group;
These substituents may further have a substituent. Examples of the substituent further include the same examples as the above-described substituents of the aromatic hydrocarbon group represented by R ¹ to R ⁹ . Further, the substituents may be bonded to each other via a single bond or a methylene group, oxygen atom or sulfur atom which may have a substituent, to form a ring.

Examples of the aryloxy group represented by R ¹ to R ⁹ include the following examples.
Phenyloxy group, biphenylyloxy group, terphenylyloxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group, fluorenyloxy group, indenyloxy group, pyrenyloxy group, perylenyloxy group and the like.

The aryloxy group represented by R ¹ to R ⁹ may have a substituent. Examples of the substituent include the same examples as the substituent which the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. These substituents may further have a substituent. Examples of the substituent further include the same examples as the substituent that the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. . The substituents may be bonded to each other through a single bond or a methylene group, oxygen atom or sulfur atom which may have a substituent to form a ring.

^{^<R 10,} ^R ^11>
R ¹⁰ and R ¹¹ may be the same or different from each other, and are an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or the number of carbon atoms An alkyloxy group having 1 to 6 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms, an aromatic hydrocarbon group, an aromatic heterocyclic group, a condensed polycyclic aromatic group, or an aryloxy group. These groups may be bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom to form a ring.

The alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms or the alkenyl group having 2 to 6 carbon atoms represented by R ¹⁰ and R ¹¹ is represented by R ¹ to R ^9. Examples thereof are the same as the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, and the alkenyl group having 2 to 6 carbon atoms.
As understood from the exemplified groups, the alkyl group having 1 to 6 carbon atoms or the alkenyl group having 2 to 6 carbon atoms represented by R ¹⁰ and R ¹¹ may be linear or branched.

The alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹⁰ and R ¹¹ may have a substituent. The substituent may have an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ^9. The same example as a substituent can be given. These substituents may further have a substituent. Further, as the substituents, the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ has The same examples can be given as good substituents. The substituents may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom which may have a substituent to form a ring.

Examples of the alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹⁰ and R ¹¹ include those having 1 to 6 carbon atoms represented by R ¹ to R ⁹ . The same examples as the alkyloxy group or the cycloalkyloxy group having 5 to 10 carbon atoms can be given.
As will be understood from the exemplified groups, the alkyloxy group having 1 to 6 carbon atoms may be linear or branched.

The alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹⁰ and R ¹¹ may have a substituent. The substituent may have an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ^9. The same example as a substituent can be given. Moreover, these substituents may further have a substituent. Further, as the substituents, the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ has The same examples can be given as good substituents. The substituents exemplified above may be bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom to form a ring.

Examples of the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹⁰ and R ¹¹ include aromatic hydrocarbon groups and aromatic heterocyclic groups represented by R ¹ to R ⁹ Or the same example as a condensed polycyclic aromatic group can be mentioned.
The aromatic heterocyclic group represented by R ¹⁰ and R ¹¹ is preferably a sulfur-containing aromatic heterocyclic group such as a thienyl group, a benzothienyl group, a benzothiazolyl group, or a dibenzothienyl group.

The aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹⁰ and R ¹¹ may have a substituent. Examples of the substituent include the same examples as the substituent which the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. These substituents may further have a substituent. Examples of the substituent further include the same examples as the substituent that the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. . The substituents may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom which may have a substituent to form a ring.

Examples of the aryloxy group represented by R ¹⁰ and R ¹¹ include the same examples as the aryloxy groups represented by R ¹ to R ⁹ .

The aryloxy group represented by R ¹⁰ and R ¹¹ may have a substituent. Examples of the substituent include the same examples as the substituent which the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. These substituents may further have a substituent. Examples of the substituent further include the same examples as the substituent that the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ may have. . The substituents may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom which may have a substituent to form a ring.

<Ar ¹ , Ar ² , Ar ³ >
Ar ¹ , Ar ² , and Ar ³ may be the same as or different from each other, and each represents an aromatic hydrocarbon group, an aromatic heterocyclic group, or a condensed polycyclic aromatic group. The groups Ar ¹ , Ar ² , and Ar ³ may be bonded to each other through a single bond or a methylene group, oxygen atom, or sulfur atom that may have a substituent, for example, Ar ² and Ar ³ may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom which may have a substituent to form a ring.

The aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by Ar ¹ , Ar ² , Ar ^{3 includes} an aromatic hydrocarbon group represented by R ¹ to R ⁹ , aromatic The same examples as the heterocyclic group or the condensed polycyclic aromatic group can be given.
As the aromatic heterocyclic group represented by Ar ¹ , Ar ² , Ar ³ , a sulfur-containing aromatic heterocyclic group such as thienyl group, benzothienyl group, benzothiazolyl group, dibenzothienyl group; or furyl group, benzofuranyl group And oxygen-containing aromatic heterocycles such as benzoxazolyl group and dibenzofuranyl group are preferable.

The aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by Ar ¹ , Ar ² or Ar ³ may have a substituent. The following examples can be given as examples of the substituent.
Deuterium atom;
A cyano group;
A nitro group;
Halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine atoms;
Linear or branched alkyl group having 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 alkyloxy group having 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;
An aryloxy group such as a phenyloxy group, a tolyloxy group;
Arylalkyloxy groups such as benzyloxy group, phenethyloxy group;
An aromatic hydrocarbon group or a condensed polycyclic aromatic group such as a phenyl group,
Biphenylyl group, terphenylyl group, naphthyl group, anthracenyl group, phenanthryl group, fluorenyl group, indenyl group, pyrenyl group,
Perylenyl group, fluoranthenyl group, triphenylenyl group, etc .;
Aromatic heterocyclic groups such as pyridyl, thienyl, furyl, pyrrolyl, quinolyl, isoquinolyl, benzofuranyl, benzothienyl, indolyl, carbazolyl, benzoxazolyl,
Benzothiazolyl group, quinoxalyl group, benzimidazolyl group, pyrazolyl group, dibenzofuranyl group, dibenzothienyl group, carbolinyl group, etc .;
Aryl vinyl groups such as styryl groups, naphthyl vinyl groups, etc .;
An acyl group, such as an acetyl group, a benzoyl group;
Moreover, these substituents may further have a substituent. Further, examples of the substituent further include the same examples as the substituents possessed by the aromatic hydrocarbon groups represented by Ar ¹ , Ar ² , and Ar ³ .
The substituents or substituents and Ar ¹ , Ar ² , Ar ³ are bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom to form a ring. May be.

Ar ¹ is preferably an aromatic hydrocarbon group, a sulfur-containing aromatic heterocyclic group or a condensed polycyclic aromatic group, and in particular, a phenyl group, a biphenylyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a thienyl group, a benzothienyl group. Group and dibenzothienyl group are preferable, and phenyl group, biphenylyl group, fluorenyl group, benzothienyl group and dibenzothienyl group are most preferable.
Ar ² and Ar ³ are preferably an aromatic hydrocarbon group, an oxygen-containing aromatic heterocyclic group, a sulfur-containing aromatic heterocyclic group or a condensed polycyclic aromatic group, and in particular, a phenyl group, a biphenylyl group, a terphenylyl group, Naphtyl group, anthryl group, phenanthryl group, fluorenyl group, triphenylenyl group, furyl group, thienyl group, benzofuranyl group, benzothienyl group, dibenzofuranyl group, dibenzothienyl group are preferable, phenyl group, biphenylyl group, naphthyl group, phenanthryl group Fluorenyl group, triphenylenyl group, furyl group, thienyl group, benzofuranyl group, benzothienyl group, dibenzofuranyl group, dibenzothienyl group are most preferable.

<A>
A represents an aromatic hydrocarbon, an aromatic heterocyclic ring or a condensed polycyclic aromatic divalent group, or a single bond. Examples of such aromatic hydrocarbons, aromatic heterocycles and condensed polycyclic aromatics include the following.
Benzene, biphenyl, terphenyl, tetrakisphenyl, styrene, naphthalene, anthracene, acenaphthalene, fluorene, phenanthrene, indane, pyrene, pyridine, pyrimidine, triazine, furan, pyrrole, thiophene, quinoline, isoquinoline, benzofuran, benzo Thiophene, indoline, carbazole, carboline, benzoxazole, benzothiazole, quinoxaline, benzimidazole, pyrazole, dibenzofuran, dibenzothiophene,
Naphthyridine, phenanthroline, acridinine, etc.
The divalent group represented by A can be formed by removing two hydrogen atoms from the aromatic hydrocarbon, aromatic heterocyclic ring or condensed polycyclic aromatic.
As the aromatic heterocycle, sulfur-containing aromatic heterocycles such as thiophene, benzothiophene, benzothiazole, and dibenzothiophene; or oxygen-containing aromatic heterocycles such as furan, benzofuran, benzoxazole, and dibenzofuran; are preferable.

The aromatic hydrocarbon, aromatic heterocyclic ring or condensed polycyclic aromatic may have a substituent. Examples of the substituent include the same examples as the substituent that the aromatic hydrocarbon, aromatic heterocyclic ring or condensed polycyclic aromatic represented by Ar ¹ , Ar ² , Ar ³ may have.
These substituents may further have a substituent. Further, examples of the substituent further include the same examples as the substituent that the aromatic hydrocarbon group, the aromatic heterocyclic group, or the condensed polycyclic aromatic group represented by Ar ¹ , Ar ² , and Ar ³ may have. be able to. Further, the substituents may be bonded to each other via a single bond or a methylene group, oxygen atom or sulfur atom which may have a substituent to form a ring.

A is preferably an aromatic hydrocarbon divalent group, a condensed polycyclic aromatic divalent group or a single bond, and particularly preferably a divalent group or a single bond derived from benzene.

When A is a single bond, the compound having an acridan ring structure of the present invention specifically includes the following general formula (1-3);

Preferably, the bonding positions of R ¹ to R ³ and Ar ³ Ar ² N— are determined as represented by the following general formula (1-4).

Specifically, the divalent group derived from benzene is represented by the following formula (2);

Preferably, the following formula (2 ′);

It is represented by

r ¹² represents the number of the group R ¹² described in detail later, and is an integer of 0 to 4. The r ¹² is 0, it means that the expression (2) and the benzene ring in the formula (2 ') is ^(hydrogen is present at the position of ^{R 12)} ^{where R} is not substituted with ^12.

R ¹² represents a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms. An alkyloxy group having 1 to 6 carbon atoms, a cycloalkyloxy group having 5 to 10 carbon atoms, an aromatic hydrocarbon group, an aromatic heterocyclic group, a condensed polycyclic aromatic group, an aryloxy group, or a linking group. To express. When a plurality of R ¹² are present (when r ¹² is 2 or more), the plurality of R ¹² are bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom. To form a ring.

Examples of the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹² include carbon atoms represented by R ¹ to R ^9. Examples thereof are the same as those shown as the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms. As the substituent that these groups may have, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or a carbon number of 2 represented by the above R ¹ to R ⁹ may be used. Mention may be made of the same examples as indicated for the alkenyl groups of ˜6. Preferred embodiments are also shown for the alkyl group having 1 to 6 carbon atoms, the cycloalkyl group having 5 to 10 carbon atoms, or the alkenyl group having 2 to 6 carbon atoms represented by R ¹ to R ⁹ described above. Is the same.

Examples of the alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹² include an alkyloxy group having 1 to 6 carbon atoms represented by R ¹ to R ⁹ Alternatively, the same examples as the cycloalkyloxy group having 5 to 10 carbon atoms can be given. As the substituents that these groups may have, the above-mentioned alkyloxy groups having 1 to 6 carbon atoms or cycloalkyloxy groups having 5 to 10 carbon atoms represented by R ¹ to R ⁹ are shown. The same examples can be given. Preferred embodiments are also the same as those shown for the alkyloxy group having 1 to 6 carbon atoms or the cycloalkyloxy group having 5 to 10 carbon atoms represented by R ¹ to R ⁹ above.

Examples of the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹² include an aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic represented by R ¹ to R ^9. The same example as what was shown as a ring aromatic group can be given. Examples of the substituent that these groups may have are the same as those shown for the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ above. Can be mentioned. Preferred embodiments are also the same as those shown for the aromatic hydrocarbon group, aromatic heterocyclic group or condensed polycyclic aromatic group represented by R ¹ to R ⁹ above.

Examples of the aryloxy group represented by R ¹² include the same examples as those shown as the aryloxy represented by R ¹ to R ⁹ . Examples of the substituent that these groups may have include the same examples as those shown for the aryloxy represented by the above R ¹ to R ⁹ . The preferred embodiments are also the same as those shown for the aryloxy represented by R ¹ to R ⁹ above.

When R ¹² is a linking group, the benzene ring to which R ¹² is bonded and Ar ² are bonded to each other via a single bond or an optionally substituted methylene group, oxygen atom or sulfur atom. A ring is formed, and preferably, as represented by the following general formula (1-2), a benzene ring to which R ¹² is bonded and Ar ⁴ are bonded to each other through a single bond to form a ring. is doing.

Ar ⁴ represents a divalent group of Ar ² . That is, examples of Ar ⁴ include divalent groups derived from the same groups as those shown for Ar ² . Examples of the substituent that the group constituting Ar ⁴ may have include the same groups as those described above for Ar ² . Further, even if the preferred aromatic heterocyclic group include the same as those indicated for the above Ar ^2. Ar ⁴ may be bonded to Ar ^{3 through a} single bond, an optionally substituted methylene group, an oxygen atom or a sulfur atom to form a ring.

<Manufacturing method>
The compound having an acridan ring structure of the present invention is a novel compound and can be synthesized, for example, as follows.
Of the compounds of the present invention, a method for synthesizing a compound having a benzothienoacridan ring structure (where X is a sulfur atom) will be described.
First, methyl 2- (dibenzothiophen-2-yl) aminobenzoate is synthesized by reaction of methyl 2-aminobenzoate with 2-bromodibenzothiophene.
Next, the obtained methyl 2- (dibenzothiophen-2-yl) aminobenzoate and methylmagnesium chloride are reacted to give 2- {2- (dibenzothiophen-2-yl) amino) phenyl} propane- By synthesizing 2-ol followed by cyclization reaction, 13,13-dimethyl-8,13-dihydrobenzothieno [3,2-a] acridine is synthesized.
By performing a condensation reaction of this 13,13-dimethyl-8,13-dihydrobenzothieno [3,2-a] acridine and an aryl halide, for example, the Buchwald-Hartwig reaction, the 8-position was substituted with an aryl group. A benzothienoacridan derivative can be synthesized.
Subsequently, bromination with N-bromosuccinimide or the like can be performed to synthesize a benzothienoacridan derivative in which the 11-position is brominated. At this time, when the bromination reagent and conditions are changed, bromo-substituted products having different substitution positions can be obtained.
Further, the bromo-substituted product and various boronic acids or boronic acid esters {J. Org. Chem. , 60, 7508 (1995)}, for example, Suzuki coupling {Synth. Commun. , 11, 513 (1981)}, the compound having the benzothienoacridan ring structure of the present invention can be synthesized.

On the other hand, among the compounds of the present invention, the compound having a benzofloricridan ring structure (where X is an oxygen atom) is the above-described method for synthesizing a compound having a benzothienoacridan ring structure of the present invention. In the reaction between methyl aminobenzoate and 2-bromodibenzothiophene, 2-bromodibenzofuran can be used instead of 2-bromodibenzothiophene, and then the same synthesis reaction can be performed.

The compound having an acridan ring structure of the present invention can also be synthesized by the following method. That is, the benzothienoacridan ring structure of the present invention has a cross coupling such as Buchwald-Hartwig reaction between a bromo-substituted benzothienoacridan derivative substituted with an aryl group at the 8-position and various diarylamines. It can synthesize | combine by performing reaction.
Similarly, the compound having a benzoflouridan ring structure of the present invention is a compound such as the Buchwald-Hartwig reaction between the bromo-substituted benzoflouridan derivative substituted with an aryl group at the 8-position and various diarylamines. It can be synthesized by performing a cross-coupling reaction.

The resulting compound can be purified by column chromatography; adsorption purification using silica gel, activated carbon, activated clay, etc .; recrystallization or crystallization using a solvent; The resulting compound is identified by NMR analysis.

As a physical property value of the obtained compound, a glass transition point (Tg) and a work function are measured. The glass transition point (Tg) is an index of the stability of the thin film state. The work function is an index of hole transportability.
A glass transition point (Tg) is calculated | required with a highly sensitive differential scanning calorimeter (The Bruker AXS make, DSC3100SA), for example using powder.

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

Specific examples of preferable compounds among the compounds having an acridan ring structure of the present invention represented by the general formula (1) described above are shown below. Compound 1 is a missing number.

<Organic EL device>
The organic EL element provided with the organic layer formed using the compound having an acridan ring structure of the present invention described above has a layer structure shown in FIG. 9, for example.

That is, a transparent anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, an electron injection layer on a glass substrate 1 (a transparent substrate such as a transparent resin substrate may be used). 7 and a cathode 8 are provided.
Of course, the organic EL element to which the compound having an acridan ring structure of the present invention is applied is not limited to the above layer structure. For example, an electron blocking layer is provided between the hole transport layer 4 and the light emitting layer 5. (Not shown) can also be provided. In addition, some organic layers in these multilayer structures may be omitted. That is, the hole injection layer 3 between the transparent anode 2 and the hole transport layer 4 and the electron injection layer 7 between the electron transport layer 6 and the cathode 8 are omitted, and the anode 2 and the positive electrode are formed on the substrate 1. A simple configuration including the hole transport layer 4, the light emitting layer 5, the electron transport layer 6, and the cathode 8 may be employed.

The compound having an acridan ring structure of the present invention comprises an organic layer (for example, a hole injection layer 3, a hole transport layer 4, an electron blocking layer (not shown), or the like provided between the transparent anode 2 and the cathode 8. It is preferably used as a material for forming the light emitting layer 5).

In the above organic EL element, the transparent anode 2 may be formed of a known electrode material. For example, an electrode material having a large work function such as ITO or gold is formed on the substrate 1 (transparent substrate such as a glass substrate). It is formed by vapor deposition.

Moreover, the hole injection layer 3 provided on the transparent anode 2 can be formed using the compound having an acridan ring structure of the present invention described above, or may be formed using a conventionally known material, for example, the following materials. it can.
Porphyrin compounds represented by copper phthalocyanine;
Starburst type triphenylamine derivatives;
An arylamine having a structure in which a plurality of triphenylamine skeletons are linked by a single bond or a divalent group not containing a hetero atom (for example, a tetramer of triphenylamine);
An acceptor heterocyclic compound such as hexacyanoazatriphenylene;
Coating type polymer material, for example, poly (3,4-ethylenedioxythiophene) (hereinafter abbreviated as PEDOT), poly (styrene sulfonate) (hereinafter abbreviated as PSS);
Formation of a layer (thin film) using the above materials can be performed by a known method such as a spin coating method or an ink jet method in addition to a vapor deposition method. Similarly, various layers described below can be formed by vapor deposition, spin coating, ink jetting, or the like.

The hole transport layer 4 provided on the hole injection layer 3 can also be formed using the compound having an acridan ring structure of the present invention, and a conventionally known hole transport material is used. It can also be formed. Typical examples of such conventionally known hole transport materials are as follows.
Benzidine derivatives such as 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′-tetrabiphenylylbenzidine;
Amine derivatives such as
1,1-bis [4- (di-4-tolylamino) phenyl] cyclohexane (hereinafter abbreviated as TAPC);
Various triphenylamine trimers and tetramers;
The above-mentioned coating type polymer material that is also used for a hole injection layer;

The compounds used as such a hole transport material may be formed alone, but may be formed by mixing two or more kinds, and one or more of the above compounds may be used. A multilayer film in which a plurality of layers are formed and these layers are laminated can be used as the hole transport layer 4.

Moreover, it can also be set as the layer which served as the positive hole injection layer 3 and the positive hole transport layer 4, and such a positive hole injection / transport layer should be formed by coating using polymeric materials, such as PEDOT. Can do.

Further, in the hole transport layer 4 (the same applies to the hole injection layer 3), it is possible to use a material that is usually used for the layer and further P-doped with trisbromophenylamine hexachloroantimony. Alternatively, the hole transport layer 4 (the same applies to the hole injection layer 3) can be formed using a polymer compound having a TPD basic skeleton.

Further, an electron blocking layer (not shown) (which can be provided between the light emitting layer 5 and the hole transport layer 4) is formed using the compound having an acridan ring structure of the present invention having an electron blocking action. However, it can also be formed using a known electron blocking compound such as a carbazole derivative or a compound having a triphenylsilyl group and a triarylamine structure. Specific examples of the compound having a carbazole derivative and a triarylamine structure are as follows.
(Carbazole derivative)
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);
2,2-bis (4-carbazol-9-ylphenyl) adamantane (hereinafter abbreviated as Ad-Cz);
(Compound having a triphenylsilyl group and a triarylamine structure)
9- [4- (carbazol-9-yl) phenyl] -9- [4- (triphenylsilyl) phenyl] -9H-fluorene;

The electron blocking layer can be formed using one or more of the compounds having the acridan ring structure of the present invention and the above-mentioned known materials. A plurality of layers can be formed using one or more of these materials, and a multilayer film in which such layers are stacked can be used as an electron blocking layer.

The light emitting layer 5 of the organic EL element of the present invention can be formed using, for example, the following light emitting materials.
Metal complexes of quinolinol derivatives including Alq ₃ ;
Various metal complexes such as zinc, beryllium and aluminum;
Anthracene derivatives;
Bisstyrylbenzene derivatives;
Pyrene derivatives;
An oxazole derivative;
Polyparaphenylene vinylene derivatives;

Moreover, the light emitting layer 5 can also be comprised with a host material and a dopant material.
As the host material, in addition to the light emitting material described above, the compound having an acridan ring structure of the present invention can be used. In addition to the light emitting material, a thiazole derivative, a benzimidazole derivative, a polydialkylfluorene derivative, or the like can be used. You can also.
As the dopant material, quinacridone, coumarin, rubrene, perylene and their derivatives; benzopyran derivatives; rhodamine derivatives; aminostyryl derivatives;

The light-emitting layer 5 can also have a single-layer structure using one or more of various light-emitting materials, or a multilayer structure in which a plurality of layers are stacked.

Furthermore, the light emitting layer 5 can also be formed using a phosphorescent light emitting material as the light emitting material.
As the phosphorescent material, a phosphorescent material of a metal complex such as iridium or platinum can be used. For example, 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 can be used. The body is used by doping a hole-injecting / transporting host material or an electron-transporting host material.

Examples of the hole injecting / transporting host material include compounds having an acridan ring structure of the present invention, carbazoles such as 4,4′-di (N-carbazolyl) biphenyl (hereinafter abbreviated as CBP), TCTA, and mCP. Derivatives and the like can be used.
As an electron transporting host material, p-bis (triphenylsilyl) benzene (hereinafter abbreviated as UGH2), 2,2 ′, 2 ″-(1,3,5-phenylene) -tris (1- Phenyl-1H-benzimidazole) (hereinafter abbreviated as TPBI) and the like can be used. By using these, a high-performance organic EL element can be produced.

Note that the doping of the phosphorescent light-emitting material into the host material is preferably performed by co-evaporation in the range of 1 to 30 weight percent with respect to the entire light-emitting layer in order to avoid concentration quenching.

Further, it is also possible to use a material that emits delayed fluorescence, such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, 4CzIPN, etc. as a light emitting material {Appl. Phys. Let. , 98,083302 (2011)}.

A hole blocking layer (not shown in FIG. 9) that can be provided between the light emitting layer 5 and the electron transport layer 6 can be formed using a compound having a known hole blocking action. Examples of known compounds having such a hole blocking action include the following.
Phenanthroline derivatives such as bathocuproine (hereinafter abbreviated as BCP);
Metal complexes of quinolinol derivatives such as aluminum (III) bis (
2-methyl-8-quinolinato) -4-phenylphenolate (hereinafter abbreviated as BAlq);
Various rare earth complexes;
Triazole derivatives Triazine derivatives Oxadiazole derivatives;
These materials can also be used for forming the electron transport layer 6 described below, and the hole blocking layer and the electron transport layer 6 can be used in combination.

Such a hole blocking layer can also have a single layer or multilayer structure, and each layer is formed using one or more of the compounds having the hole blocking action described above.

The electron transport layer 6 is an electron transport compound known per se, for example,
Metal complexes of quinolinol derivatives such as Alq ₃ and BAlq;
Various metal complexes such as zinc, beryllium and aluminum;
Triazole derivatives;
Triazine derivatives;
Oxadiazole derivatives;
Thiadiazole derivatives;
Carbodiimide derivatives;
Quinoxaline derivatives;
Phenanthroline derivatives;
Silole derivatives;
Etc. are formed.
The electron transport layer 6 can also have a single layer or multilayer structure, and each layer is formed using one or more of the electron transport compounds described above.

Further, the electron injection layer 7 is also known per se, for example, alkali metal salts such as lithium fluoride and cesium fluoride; alkaline earth metal salts such as magnesium fluoride; metal oxides such as aluminum oxide; Can be formed.

For the cathode 8 of the organic EL element, 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.

An organic EL device in which at least one of organic layers (for example, a hole injection layer 3, a hole transport layer 4, an electron blocking layer or a light emitting layer 5) is formed using the compound having an acridan ring structure of the present invention, The luminous efficiency and power efficiency are high, the practical driving voltage is low, the light emission starting voltage is low, and it has extremely excellent durability.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

<Example 1 (Synthesis of Compound 2)>
Synthesis of 13,13-dimethyl-8-phenyl-11- (9-phenyl-9H-carbazol-3-yl) -8,13-dihydrobenzothieno [3,2-a] acridine;

The following compounds were added to a reaction vessel purged with nitrogen, and nitrogen gas was bubbled for 1 hour.
Methyl 2-aminobenzoate 10.0g
8.6 g of 2-bromodibenzothiophene
tert-Butoxy sodium 5.48g
100 ml of xylene
Then
Tris (dibenzylideneacetone) dipalladium (0)
0.7g
Tri-tert-butylphosphine in toluene (50%, w /
v) 0.9g
The mixture was heated and stirred at 115 ° C. for 3 hours. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation.
The collected organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product.
The obtained crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane), and 5.1 g of yellow powder of methyl 2-{(dibenzothiophen-2-yl) amino} benzoate. (Yield 40%) was obtained.

2-{(Dibenzothiophen-2-yl) amino} methyl benzoate 5.0 g
THF 50ml
Was added to a reaction vessel purged with nitrogen, and 18 ml of a THF solution (3 mol / L) of methylmagnesium chloride was added dropwise. After stirring at room temperature for 1 hour, 50 ml of 20% aqueous ammonium chloride solution was added, and extraction with toluene was performed to collect the organic layer. The organic layer was dehydrated with anhydrous magnesium sulfate and concentrated under reduced pressure to give 5.0 g of a pale yellow oil of 2- [2-{(dibenzothiophen-2-yl) amino} phenyl] propan-2-ol ( Yield 100%).

2- [2-{(Dibenzothiophen-2-yl) amino} phenyl] propan-2-ol 5.0 g
Phosphoric acid 10ml
Was added to a reaction vessel purged with nitrogen and stirred at room temperature for 1 hour. After adding 50 ml of toluene and 50 ml of water and stirring, the precipitate was collected by filtration, and 2.3 g of a pale yellow powder of 13,13-dimethyl-8,13-dihydrobenzothieno [3,2-a] acridine (contracted). 49%).

13,13-dimethyl-8,13-dihydrobenzothieno [3,2
-A] Acridine 20.0 g
13.6 g of iodobenzene
tert-butoxy sodium 9.1 g
200 ml of xylene
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour.
Tris (dibenzylideneacetone) dipalladium (0)
1.2g
1.5 g of 50% (w / v) toluene solution of tri-tert-butylphosphine
The mixture was heated and stirred at 115 ° C. for 1 hour. After cooling to room temperature and adding 200 ml of water, the organic layer was collected by extraction with toluene. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatograph (carrier: silica gel, eluent: toluene / n-hexane) to obtain 13,13-dimethyl-8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridine. 17.9 g (yield 72%) of white powder was obtained.

13,13-Dimethyl-8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridine 17.9 g
N, N-dimethylformamide 540 ml
8.1 g N-bromosuccinimide
Was added to a reaction vessel purged with nitrogen and stirred at 15 ° C. for 4 hours while cooling. After pouring into water, the precipitate was collected by filtration. Methanol was added to the precipitate, and the mixture was stirred and then filtered to give 21.0 g (yield) of white powder of 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridine. 98%) was obtained.

11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzothieno [3,2-a] acridine 11.0g
7.0 g of 9-phenyl-9H-carbazol-3-ylboronic acid
2M aqueous potassium carbonate solution 35ml
Toluene 88ml
Ethanol 22ml
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour. Tetrakis (triphenylphosphine) palladium 0.8g was added and heated, and it stirred at 72 degreeC for 3 hours. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and 13,13-dimethyl-8-phenyl-11- (9-phenyl-9H-carbazol-3-yl)- 10.8 g (yield 73%) of a white powder of 8,13-dihydrobenzothieno [3,2-a] acridine (Compound 2) was 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 32 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.69 (1H)
8.43 (1H)
8.26 (1H)
7.96 (1H)
7.95 (1H)
7.65-7.80 (7H)
7.45-7.65 (10H)
7.25-7.35 (2H)
6.54 (1H)
6.23 (1H)
2.43 (6H)

<Example 2 (Synthesis of Compound 20)>
N- (9,9-dimethyl-9H-fluoren-2-yl) -N- (13,13-dimethyl-8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridin-11-yl ) -Phenylamine synthesis;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridine was synthesized.
next,
11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzothieno [3,2-a] acridine 10.0 g
N- (9,9-dimethyl-9H-fluoren-2-yl) -phenylamine 6.4 g
tert-Butoxy sodium 3.1 g
100 ml of xylene
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour.
Tris (dibenzylideneacetone) dipalladium (0)
0.4g
Tri-tert-butylphosphine in toluene (50%, w /
v) 0.5g
The mixture was heated and stirred at 115 ° C. for 1 hour. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and N- (9,9-dimethyl-9H-fluoren-2-yl) -N- (13,13-dimethyl). 12.8 g (yield 89%) of a white powder of -8-phenyl-8,13-dihydrobenzothieno [3,2-a] acridin-11-yl) -phenylamine (Compound 20) was obtained.

^The following 38 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.51 (1H)
7.91 (1H)
7.60-7.75 (4H)
7.56 (1H)
7.40-7.50 (6H)
7.20-7.48 (6H)
7.10-7.20 (2H)
7.06 (1H)
6.96 (1H)
6.71 (1H)
6.51 (1H)
6.09 (1H)
2.20 (6H)
1.43 (6H)

<Example 3 (Synthesis of Compound 27)>
8- (9,9-dimethyl-9H-fluoren-2-yl) -13,13-dimethyl-11- (9-phenyl-9H-carbazol-3-yl) -8,13-dihydrobenzothieno [3 2-a] synthesis of acridine;

In the same manner as in Example 1, 11-bromo-8- (9,9-dimethyl-9H-fluoren-2-yl) -13,13-dimethyl-8,13-dihydrobenzothieno [3,2-a] Acridine was synthesized.
next,
11-Bromo-8- (9,9-dimethyl-9H-fluorene-2-
Yl) -13,13-dimethyl-8,13-dihydrobenzothieno [
3,2-a] acridine 3.0 g
1.2 g of 9-phenyl-9H-carbazol-3-ylboronic acid
2M aqueous potassium carbonate solution 8ml
Toluene 24ml
Ethanol 6ml
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour. Tetrakis (triphenylphosphine) palladium (0.2 g) was added and heated, and stirred at 72 ° C. for 18 hours. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane), and 8- (9,9-dimethyl-9H-fluoren-2-yl) -13,13-dimethyl-11- As a result, 2.8 g (yield 72%) of white powder of (9-phenyl-9H-carbazol-3-yl) -8,13-dihydrobenzothieno [3,2-a] acridine (Compound 27) was obtained.

^The following 40 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.70 (1H)
8.44 (1H)
8.26 (1H)
8.13 (1H)
7.90-8.00 (3H)
7.63-7.75 (5H)
7.38-7.63 (12H)
7.25-7.38 (2H)
6.66 (1H)
6.50 (1H)
2.45 (6H)
1.60 (6H)

<Example 4 (Synthesis of Compound 4)>
Synthesis of 13,13-dimethyl-8-phenyl-11- (9-phenyl-9H-carbazol-3-yl) -8,13-dihydrobenzofuro [3,2-a] acridine;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridine was synthesized.
next,
11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzofuro [3,2-a] acridine 10.0 g
6.6 g of 9-phenyl-9H-carbazol-3-ylboronic acid
2M aqueous potassium carbonate solution 33ml
Toluene 80ml
Ethanol 20ml
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour. Tetrakis (triphenylphosphine) palladium 0.8g was added and heated, and it stirred at 72 degreeC for 3 hours. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and 13,13-dimethyl-8-phenyl-11- (9-phenyl-9H-carbazol-3-yl)- There was obtained 11.3 g (yield 84%) of white powder of 8,13-dihydrobenzofuro [3,2-a] acridine (compound 4).

^The following 32 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.42 (1H)
8.38 (1H)
8.26 (1H)
7.93 (1H)
7.20-7.80 (20H)
6.48 (1H)
6.23 (1H)
2.32 (6H)

<Example 5 (Synthesis of Compound 25)>
N- (9,9-dimethyl-9H-fluoren-2-yl) -N- (13,13-dimethyl-8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridin-11-yl ) -Phenylamine synthesis;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridine was synthesized.
11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzofuro [3,2-a] acridine 10.0 g
N- (9,9-dimethyl-9H-fluoren-2-yl) -phenylamine 6.6 g
tert-Butoxy sodium 3.2g
100 ml of xylene
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour.
Tris (dibenzylideneacetone) dipalladium (0)
0.4g
Tri-tert-butylphosphine in toluene (50%, w /
v) 0.5g
The mixture was heated and stirred at 115 ° C. for 1 hour. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and N- (9,9-dimethyl-9H-fluoren-2-yl) -N- (13,13-dimethyl). 9.5 g (yield 66%) of white powder of -8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridin-11-yl) -phenylamine (Compound 25) was obtained.

^The following 38 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.21 (1H)
6.90-7.75 (22H)
6.71 (1H)
6.43 (1H)
6.09 (1H)
2.10 (6H)
1.43 (6H)

<Example 6 (Synthesis of Compound 41)>
Synthesis of 13,13-dimethyl-8-phenyl-11- (9H-carbazol-9-yl) -8,13-dihydrobenzofuro [3,2-a] acridine;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridine was synthesized.
11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzofuro [3,2-a] acridine 8.0g
9H-carbazole 3.1 g
tert-Butoxy sodium 2.5g
80 ml of xylene
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour.
Tris (dibenzylideneacetone) dipalladium (0)
0.3g
Tri-tert-butylphosphine in toluene (50%, w /
v) 0.4g
The mixture was heated and stirred at 115 ° C. for 1 hour. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and 13,13-dimethyl-8-phenyl-11- (9H-carbazol-9-yl) -8,13- 6.5 g (68% yield) of white powder of dihydrobenzofuro [3,2-a] acridine (Compound 41) was obtained.

^The following 28 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.29 (1H)
8.18 (2H)
7.10-7.80 (17H)
6.52 (1H)
6.38 (1H)
2.28 (6H)

<Example 7 (Synthesis of Compound 42)>
13,13-Dimethyl-8-phenyl-11- (3,3-dimethyl-1-phenyl-1,3-dihydroindeno [2,1-b] carbazol-10-yl) -8,13-dihydrobenzo Synthesis of furo [3,2-a] acridine;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8-phenyl-8,13-dihydrobenzofuro [3,2-a] acridine was synthesized.
11-bromo-13,13-dimethyl-8-phenyl-8,13-
Dihydrobenzofuro [3,2-a] acridine 7.0 g
3,3-dimethyl-1-phenyl-1,3-dihydroindeno [2
, 1-b] carbazol-10-ylboronic acid 7.5 g
2M aqueous potassium carbonate solution 23ml
Toluene 60ml
Ethanol 15ml
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour. Tetrakis (triphenylphosphine) palladium (0.5 g) was added and heated, followed by stirring at 72 ° C. for 5 hours. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and 13,13-dimethyl-8-phenyl-11- (3,3-dimethyl-1-phenyl-1,3 -Dihydroindeno [2,1-b] carbazol-10-yl) -8,13-dihydrobenzofuro [3,2-a] acridine (compound 42) white powder 8.7 g (yield 77%) Got.

^The following 40 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.64 (1H)
8.51 (1H)
8.38 (1H)
7.98 (1H)
7.92 (1H)
7.20-7.80 (21H)
6.49 (1H)
6.24 (1H)
2.35 (6H)
1.50 (6H)

<Example 8 (Synthesis of Compound 23)>
13,13-Dimethyl-8- (9,9-dimethyl-9H-fluoren-2-yl) -11- (9H-carbazol-9-yl) -8,13-dihydrobenzofuro [3,2-a] Synthesis of acridine;

In the same manner as in Example 1, 11-bromo-13,13-dimethyl-8- (9,9-dimethyl-9H-fluoren-2-yl) -8,13-dihydrobenzofuro [3,2-a] Acridine was synthesized.
11-bromo-13,13-dimethyl-8- (9,9-dimethyl-
9H-Fluoren-2-yl) -8,13-dihydrobenzofuro [3
, 2-a] Acridine 10.0 g
9H-carbazole 3.1g
tert-Butoxy sodium 2.5g
80 ml of xylene
Was added to the reaction vessel purged with nitrogen, and nitrogen gas was passed through for 1 hour.
Tris (dibenzylideneacetone) dipalladium (0)
0.3g
Tri-tert-butylphosphine in toluene (50%, w /
v) 0.4g
The mixture was heated and stirred at 115 ° C. for 1 hour. After cooling to room temperature and adding water and toluene, the organic layer was collected by a liquid separation operation. The organic layer was dehydrated with anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-hexane) and 13,13-dimethyl-8- (9,9-dimethyl-9H-fluoren-2-yl) -11- 11.5 g (yield 54%) of white powder of (9H-carbazol-9-yl) -8,13-dihydrobenzofuro [3,2-a] acridine (Compound 23) was obtained.

^The following 36 hydrogen signals were detected by ¹ H-NMR (THF-d ₈ ).
δ (ppm) = 8.61 (1H)
8.12-8.20 (3H)
7.88-8.00 (2H)
7.77 (1H)
7.66 (1H)
7.35-7.60 (11H)
7.24 (2H)
7.16 (1H)
6.68 (1H)
6.50 (1H)
2.37 (6H)
1.60 (6H)

<Example 9 (measurement of glass transition point)>
For the compounds having an acridan ring structure obtained in Examples 1 to 8, the glass transition point was determined by a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA). The results are as follows.
Glass transition point
Inventive Example 1 Compound 154 ° C.
Inventive Example 2 Compound 146 ° C.
Inventive Example 3 Compound 173 ° C.
Inventive Example 4 Compound 149 ° C.
Compound of Invention Example 5 141 ° C.
Inventive Example 6 Compound 145 ° C.
Compound of Example 7 of the present invention 201 ° C.
Inventive Example 8 Compound 177 ° C.
This shows that the compound of the present invention has a glass transition point of 100 ° C. or higher and exhibits a stable thin film state.

<Example 10 (Evaluation of work function)>
Using the compounds obtained in Examples 1 to 8, a deposited film with 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, manufactured by Sumitomo Heavy Industries, Ltd.). It was measured.
Work Function Compound of Invention Example 1 5.38 eV
Compound of Example 2 of the present invention 5.29 eV
Compound of Example 3 of the present invention 5.37 eV
Inventive Example 4 compound 5.52 eV
Compound of Example 5 of the present invention 5.29 eV
Inventive Example 6 Compound 5.61 eV
Inventive Example 7 Compound 5.42 eV
Inventive Example 8 Compound 5.54 eV
From the above results, the compound of the present invention shows a suitable energy level as well as a work function of 5.54 eV of general hole transport materials such as NPD and TPD, and has a good hole transport capability. You can see that

(Characteristic evaluation of organic EL elements)
<Example 11>
An organic EL device having the structure shown in FIG. 9 was prepared, which was provided with the hole transport layer 4 formed using the compound having the acridan ring structure obtained in Example 1 (Compound 2). This organic EL element has a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, and an electron injection layer 7 on a glass substrate 1 on which an ITO electrode is previously formed as a transparent anode 2. The cathode (aluminum electrode) 8 was 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 1 with ITO electrode was attached in a vacuum vapor deposition machine, and the inside of the vapor deposition machine was pressure-reduced to 0.001 Pa or less. Subsequently, a hole injection layer 3 having a thickness of 20 nm was formed so as to cover the transparent anode 2 using a compound 57 having the following structural formula.

On the hole injection layer 3, the compound of Example 1 (Compound 2) was deposited to form a hole transport layer 4 having a thickness of 40 nm.
On this hole transport layer 4, a compound 58 of the following structural formula and a compound 59 of the following structural formula are used, and binary deposition is performed at a deposition rate such that the deposition rate ratio is 58: 95:95. The light emitting layer 5 having a thickness of 30 nm was formed.

Using Alq _3, on the light-emitting layer 5, thereby forming an electron-transporting layer 6 having a thickness of 30 nm.
On the electron transport layer 6, an electron injection layer 7 having a thickness of 0.5 nm was formed using lithium fluoride.
Finally, aluminum was deposited to a thickness of 150 nm to form the cathode 8.

Table 1 shows the measurement results of the light emission characteristics of the organic EL device produced as described above when a DC voltage was applied in the atmosphere at room temperature.

<Example 12>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 2 (Compound 20) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 13>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 3 (Compound 27) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 14>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 4 (Compound 4) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 15>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 5 (Compound 25) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 16>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 6 (Compound 41) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 17>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 7 (Compound 42) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Example 18>
An organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound of Example 8 (Compound 23) instead of the compound of Example 1 (Compound 2). About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

<Comparative Example 1>
For comparison, an organic EL device was produced under the same conditions as in Example 11 except that the hole transport layer 4 was formed using the compound 60 having the following structural formula instead of the compound of Example 1 (Compound 2). did. About the produced organic EL element, the light emission characteristic was measured like Example 11, and the result was shown in Table 1.

As shown in Table 1, the driving voltage when a current density of 10 mA / cm ² was passed was 5.17 V in the organic EL element of Comparative Example 1, whereas Examples 1 to 8 of the present invention were used. In the organic EL device using this compound, the voltage was 4.70 to 5.05 V, that is, all of the voltages were lowered. Regarding the power efficiency, the power efficiency of the organic EL element of Comparative Example 1 is 5.49 lm / W, whereas the organic EL element using the compounds of Examples 1 to 8 of the present invention is 5. It was 91 to 6.78 lm / W, and all were greatly improved.

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 power efficiency compared to the organic EL device using the compound 60, which is a known material, 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, an excellent electron blocking capability, an excellent amorphous property, 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

A compound having an acridan ring structure represented by the following general formula (1).

Where
X represents an oxygen atom or a sulfur atom,
R 1 to R 9 are a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano group, nitro group, alkyl group having 1 to 6 carbon atoms, cycloalkyl group having 5 to 10 carbon atoms, carbon atom Alkenyl group having 2 to 6 carbon atoms, alkyloxy group having 1 to 6 carbon atoms, and 5 to 1 carbon atoms
0 cycloalkyloxy group, aromatic hydrocarbon group, aromatic heterocyclic group, condensed polycyclic aromatic group or aryloxy group, which are bonded to each other through a single bond or a methylene group, oxygen atom or sulfur atom To form a ring,
R 10 and R 11 are an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkyloxy group having 1 to 6 carbon atoms, carbon 5-10 atoms
A cycloalkyloxy group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a condensed polycyclic aromatic group or an aryloxy group, which are bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom. They may combine to form a ring,
Ar 1 , Ar 2 and Ar 3 represent an aromatic hydrocarbon group, an aromatic heterocyclic group or a condensed polycyclic aromatic group, and Ar 2 and Ar 3 represent a single bond, a methylene group, an oxygen atom or a sulfur atom. May be bonded to each other via a ring to form a ring,
A represents an aromatic hydrocarbon, an aromatic heterocycle or a condensed polycyclic aromatic divalent group, or a single bond;
A is an aromatic hydrocarbon, aromatic heterocycle or condensed polycyclic aromatic 2
In the case of a valent group, A and Ar 2 may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom to form a ring.
The acridan ring according to claim 1, wherein R 1 , R 2 , R 3 and A are bonded to the benzene ring to which A is bonded at the position represented by the following general formula (1-1). A compound having a structure.

Where
X, R 1 to R 11 , Ar 1 , Ar 2 , Ar 3 and A have the same meanings as described in the general formula (1).
The compound having an acridan ring structure according to claim 1 or 2, wherein A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group.
The compound having an acridan ring structure according to claim 3, wherein A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group represented by the following general formula (2).

Where
r 12 represents an integer of 0 to 4,
R 12 represents a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an alkenyl having 2 to 6 carbon atoms. Groups, alkyloxy groups having 1 to 6 carbon atoms, cycloalkyloxy groups having 5 to 10 carbon atoms, aromatic hydrocarbon groups, aromatic heterocyclic groups, condensed polycyclic aromatic groups or aryloxy groups, or linking groups Because
When a plurality of R 12 are present, the plurality of R 12 may be bonded to each other to form a ring.
The compound having an acridan ring structure according to claim 4, wherein A is an aromatic hydrocarbon or a condensed polycyclic aromatic divalent group represented by the following general formula (2 ').

Where
r 12 and R 12 have the same meaning as described in the formula (2).
The compound having an acridan ring structure according to claim 5 represented by the following general formula (1-2):

Where
X, R 1 to R 11 , Ar 1 , Ar 3 and A are each represented by the general formula (1
) Or (1-1) as described above,
Ar 4 represents a divalent group of the group belonging to Ar 2 described in the general formula (1) or (1-1),
Ar 3 and Ar 4 may be bonded to each other through a single bond or a methylene group, an oxygen atom or a sulfur atom to form a ring.
The compound having an acridan ring structure according to claim 1 or 2, wherein A is a single bond.
In the organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched between the pair of electrodes, the compound having an acridan ring structure according to claim 1 is used as a constituent material of the organic layer. An organic electroluminescence device characterized by comprising:
The organic electroluminescence device according to claim 8, wherein the organic layer is a hole transport layer.
The organic electroluminescence device according to claim 8, wherein the organic layer is an electron blocking layer.
The organic electroluminescence device according to claim 8, wherein the organic layer is a hole injection layer.
The organic electroluminescence device according to claim 8, wherein the organic layer is a light emitting layer.