JP2000119229A - Tetraarylmethane compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound for use in organic electroluminescent elements, electrophotographic photoreceptors or the like, useful as a charge transporter exhibiting excellent charge transport performance and storage stability. SOLUTION: This new compound is a tetraarylmethane compound of formula I (Ar1 and Ar2 are each an aryl; R is a halogen, alkyl, aryl, alkoxy, aryloxy or the like; (m) is 0-4; and (n) is 1-4), e.g. a compound of formula II. The compound of formula I (wherein (n) is 1) is synthesized based on Ullmann-type reaction where a compound of formula III (X is Br or I) is reacted with a base in the presence of a metallic copper catalyst, whereas the compound of formula I (wherein (n)>=2) is synthesized based on Suzuki reaction where the compound of formula II is coupled with a compound of formula IV (R" is H or an alkyl) in the presence of a palladium catalyst. Thereby, use of this new compound as a material for EL elements affords high-performance devices and enables the performance to be improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an organic electroluminescence (E)
L) The present invention relates to a tetraarylmethane compound useful as a charge transporting agent for use in devices, electrophotographic photoreceptors, and the like.

[0002]

2. Description of the Related Art Vanslike and Tan et al., For example, U.S. Pat. Nos. 4,539,507 and 4,720,
No. 432, JP-A-5-234681, and an aromatic tertiary amine containing a phenyl group, a phenylene group or a biphenylene group is internally bonded to organic electroluminescence (EL).
It has been shown that use of the device in the charge (hole) injection / transport zone improves the stability of light output, thereby extending the operating life. Subsequently, many researchers attempted to improve the aromatic tertiary amine used in this charge (hole) injection / transport zone in order to measure the stability of further light output, and many patent applications were filed. It has been reported to the academic literature. For example, regarding biphenyl tertiary amines, Japanese Journal of AppliedPhysics, 27, L269 (1
988), JP-A-59-194393, Appl. Phys.
Lett., 66, 2679 (1995), JP-A-5-234681, JP-A-7-331238, JP-A-8-48656, and WO95 / 09147. . Phys. Lett., 65,
807 (1994) and JP-B-7-110940.
However, the compounds disclosed so far do not yet have sufficient performance (especially storage stability), and further improvement is desired.

In recent years, the practical use of electrophotographic photoconductors (organic photoconductors (OPC)) using organic substances has rapidly spread, and OPC has now completely occupied the center of electrophotographic photoconductors. I have. Recent OPCs use a charge generating agent (CG
M) and a charge transport agent (CTM) are mainly used. The lamination type OPC electrophotographic photoreceptor greatly improved the sensitivity to visible light, charge retention, surface strength, and the like. CTM includes hydrazone-based compounds (JP-B-55-42380, JP-A-57-101844, JP-A-54-150128, etc.), triarylamine-based compounds (JP-B-58-32372, etc.),
And stilbene compounds (JP-A-58-198043) are used, but their characteristics such as sensitivity are not always sufficient to cope with recent high-speed operation. Therefore,
Research on CTM is still active, and recently, a new hydrazone compound (JP-A-8-143550) has been developed.
) And carbazole stilbene compounds (Japanese Unexamined Patent Publication No.
-59615) and trisubstituted ethylene compounds (JP-A-63-225660, JP-A-9-59256).
Has been proposed , but it is still insufficient.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel compound used for an organic electroluminescence (EL) device, an electrophotographic photoreceptor and the like. Another object of the present invention is to provide a novel charge transporting agent which is used for an organic electroluminescence (EL) device and an electrophotographic photoreceptor and has excellent charge transporting ability and storage stability.

[0005]

According to the present invention, a novel tetraarylmethane compound represented by the following general formula (I) is provided, and the above object of the present invention is achieved.

[0006]

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(In the general formula (I), Ar ₁ and Ar ₂ are
The same or different, and represents an optionally substituted aryl group, which may be bonded directly or indirectly via a linking group. R may be the same or different when a plurality of R are present, and may be a halogen atom, an alkyl group which may be substituted, an aryl group which may be substituted, an alkoxy group which may be substituted, Represents an optionally substituted aryloxy group, an optionally substituted dialkylamino group, an optionally substituted N-alkyl-N-arylamino group, or an optionally substituted diarylamino group. m is an integer of 0 to 4, and n is an integer of 1 to 4. )

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION First, Ar ₁ , A of the general formula (I)
r ₂ , R, m and n will be described. Ar ₁ and Ar
₂ represents the same or different and represents a substituted or unsubstituted aryl group. Specifically, it represents a substituted or unsubstituted phenyl group, naphthyl group, phenanthrenyl group, pyrenyl group or the like. Ar ₁ and Ar ₂ may be bonded directly or indirectly via a linking group.

When Ar ₁ and Ar ₂ have a substituent,
Examples of the substituent include a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxy group, a nitro group, a carboxy group, a sulfo group, an amino group, an alkoxy group, an aryloxy group, an acylamino group, an alkylamino group, Dialkylamino group, N-alkyl-N-arylamino group, diarylamino group, anilino group, ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxycarbonylamino group, sulfonamide group, carbamoyl group, sulfamoyl group , A sulfonyl group, an alkoxycarbonyl group, a heterocyclic oxy group,
Azo group, acyloxy group, carbamoyloxy group, silyloxy group, aryloxycarbonylamino group, imide group, heterocyclic thio group, sulfinyl group, phosphonyl group, aryloxycarbonyl group, acyl group, silyl group, azolyl group, etc. .

Among them, preferred substituents are a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a dialkylamino group, an N-alkyl-N-arylamino group, and a diarylamino group. Is a chlorine atom, a linear or branched C1-6,
Or a cyclic alkyl group (eg, a methyl group, a t-butyl group, a cyclohexyl group), an aryl group having 6 to 18 carbon atoms (eg, a phenyl group, a naphthyl group, a biphenylyl group), and an alkoxy group having 1 to 6 carbon atoms (eg, Methoxy group, ethoxy group, cyclohexyloxy group), carbon number 6
To 18 aryloxy groups (eg, phenoxy group, naphthoxy group), dialkylamino groups having 2 to 8 carbon atoms (eg, dimethylamino group, diethylamino group), and 7 to 18 carbon atoms.
15 N-alkyl-N-arylamino groups (e.g. N
-Methyl-N-phenylamino group, N-methyl-N-naphthylamino group) or a diarylamino group having 12 to 28 carbon atoms (eg, diphenylamino group, N- (3-methylphenyl) -N-phenylamino group , A dinaphthylamino group).

When Ar ₁ and Ar ₂ are not directly or indirectly bonded, preferred Ar ₁ and Ar ₂ are a substituted or unsubstituted phenyl group or a naphthyl group, particularly preferably an unsubstituted or alkyl-substituted phenyl group. Or a naphthyl group.

Ar ₁ and Ar ₂ may be bonded directly or indirectly via a linking group. Specific examples of the linking group when linked indirectly are described below.

[0013]

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In the above linking group, R 'represents an alkyl group (preferably having 1 to 20 carbon atoms) or an aryl group (preferably having 6 to 20 carbon atoms). These linking groups may have a substituent, and the substituent has the same meaning as the above-mentioned substituent that Ar ₁ and Ar ₂ may have, and further preferable groups are also the same.

In the general formula (I), R is a halogen atom (each atom of fluorine, chlorine, bromine and iodine), an optionally substituted alkyl group having preferably 1 to 20 carbon atoms, The aryl group preferably has 6 to 36 carbon atoms, and preferably has 1 to 20 carbon atoms which may be substituted.
An alkoxy group, an optionally substituted aryloxy group having preferably 6 to 36 carbon atoms, an optionally substituted dialkylamino group having 2 to 20 carbon atoms,
The carbon atom which may be substituted preferably has 7 to 42 carbon atoms.
-Represents an alkyl-N-arylamino group or a diarylamino group having preferably 12 to 48 carbon atoms which may be substituted. In addition, the said carbon number is a carbon number which does not contain the carbon atom of a substituent.

Specific examples of the group other than the halogen atom are as follows. Alkyl group: methyl group, ethyl group, isopropyl group, n
-Butyl group, t-butyl group, n-dodecyl group, cyclohexyl group and the like. Aryl group: phenyl group, naphthyl group, anthracenyl group, phenanthrenyl group, pyrenyl group, naphthacenyl group, pentacenyl group, pentaphenyl group and the like. Alkoxyl group: methoxy, ethoxy, isopropoxy, n-hexyloxy, cyclohexyloxy, octyloxy, dodecyloxy and the like. Aryloxy group: phenoxy group, naphthoxy group, anthracenoxy group, pentacenoxy group and the like. Dialkylamino group: dimethylamino group, diethylamino group, dibutylamino group, dioctylamino group, N-ethyl-N-butylamino group and the like. N-alkyl-N-arylamino group: N-methyl-N
-Phenylamino group, N-ethyl-N-phenylamino group, N-isopropyl-N- (3-methylphenyl) amino group, N-methyl-N- (1-naphthyl) amino group,
N-butyl-N- (1-naphthacenyl) amino group and the like. Diarylamino group: diphenylamino group, N-phenyl-N- (1-naphthyl) amino group, N- (1-naphthyl) -N- (1-naphthyl) amino group, N-phenyl-
N- (1-anthracenyl) amino group, N- (1-anthracenyl) -N- (1-phenanthrenyl) amino group and the like.

When R has a substituent, the substituent includes a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxy group, a nitro group, a carboxy group, a sulfo group, an amino group, an alkoxy group, Aryloxy, acylamino, alkylamino, anilino, ureido, sulfamoylamino, alkylthio, arylthio, alkoxycarbonylamino, sulfonamide, carbamoyl, sulfamoyl, sulfonyl, alkoxycarbonyl A heterocyclic oxy group, an azo group, an acyloxy group, a carbamoyloxy group, a silyloxy group, an aryloxycarbonylamino group, an imide group, a heterocyclic thio group, a sulfinyl group,
Examples include a phosphonyl group, an aryloxycarbonyl group, an acyl group, a silyl group and an azolyl group. Above all,
Alkyl, aryl, alkoxy, aryloxy or anilino groups are preferred substituents.

Preferred R is an alkyl group, an aryl group,
An alkoxy group, a dialkylamino group, and a diarylamino group, and particularly preferable R is an alkyl group and a diarylamino group. When m is an integer of 2 or more, each R
May be the same or different. When n is an integer of 2 or more, Rs bonded to each benzene skeleton may be the same or different.

M is an integer of 0 to 4, preferably 0 or 1. n is an integer of 1 to 4, preferably 1 or 2.

Next, specific examples of the compound represented by formula (I) of the present invention are shown below, but the present invention is not limited to these.

[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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Next, a method for synthesizing the compound of the present invention will be described below. A typical synthetic method is shown in (Scheme 1).

[0028]

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In the formula, X represents bromine or iodine;
Represents a hydrogen atom or an alkyl group. Ar ₁ , Ar ₂ ,
R, m and n represent the same groups or numbers as defined above.

From (A) to (B) in (Scheme 1)
Is a synthesis method based on an Ullmann-type reaction using a metal copper catalyst and a base (US Pat. No. 4,764,6).
No. 25) and the synthesis method from (A) to (C) is based on the Suzuki reaction (Synth. Commun., 11,513 (1) in which a boron compound (D) and a halogen compound are coupled with a palladium catalyst.
981)).

[0031]

The present invention will be described below with reference to examples.
The present invention is not limited by these examples.

Example 1 (Synthesis of Exemplified Compound (1)) Tetrakis (4-iodophenyl) methane (J. Am. Che
m. Soc., 113, 4696 (1991)).
0 g (2.43 mmol), 3.6 g (19.4 mmol) of 3-methyldiphenylamine, potassium hydroxide 1.
4 g (24.3 mmol) and copper powder 0.62 g (9.
74 mmol) was mixed with 50 ml of decahydronaphthalene, and heated and stirred at an external temperature of 200 ° C. for about 24 hours under a nitrogen stream. After cooling to near room temperature, chloroform was added and celite filtration was performed to remove insolubles. Add water to the filtrate,
An extraction operation is performed, and the obtained reaction concentrate is purified by silica gel column chromatography, whereby crystalline tetrakis [(3-methyldiphenylamino) phenyl] methane mixed with a small amount of raw material 3-methyldiphenylamine (exemplified compound (1) )). Ethanol was added, and the mixture was stirred and filtered to obtain 1.4 g (yield: 55.1%) of almost pure Exemplified Compound (1) as pale yellow crystals, which was further recrystallized from a mixed solvent of tetrahydrofuran and ethanol. 0.9 g of pure exemplary compound (1) (3
5.4%). Melting point: 264-266C. mass (FAB-posi): 1045 (M +) 1H-NMR (CDCl3): d (ppm) 2.2
3 (12H, s), 6.80-7.25 (52H, m)

Example 2 (Synthesis of Exemplified Compound (6)) In the same manner as in Example 1, except that 5H-dibenz [b, f] azepine is used instead of 3-methyldiphenylamine, an exemplified compound is prepared. (6) was synthesized. Yield 15%.

Example 3 (Synthesis of Exemplified Compound (7)) In the method shown in Example 1, instead of 3-methyldiphenylamine, 9H-tribenz [b, d, f] azepine (J. Org. Chem., Exemplified compound (7) was synthesized in the same manner except that Compound (7) was used. Yield 12%.

Example 4 (Synthesis of Exemplified Compound (8)) 2.0 g of tetrakis (4-iodophenyl) methane
(2.43 mmol), 2.43 g of 4- (3-methyldiphenylamino) phenylboronic acid (8.02 mmol)
l), 0.1 g (0.087 mmol) of tetrakis (triphenylphosphine) palladium (0), and 6.0 ml (12.0 mmol) of a 2M aqueous sodium carbonate solution were added to a toluene / dimethylformamide solution (30 ml / 20).
ml) and refluxed under heating for about 10 hours under a nitrogen stream.
The reaction solution was extracted with chloroform, post-treated by a conventional method, dried over anhydrous magnesium sulfate and concentrated under reduced pressure, and the residue was purified by silica gel column chromatography, and recrystallized from a mixed solvent of tetrahydrofuran / ethanol,
Exemplified compound (8) was obtained in a yield of 45%.

[0036]

The novel tetraarylmethane compound having a triarylamine structure in the molecule of the present invention is excellent in storage stability and charge transport ability, and is used as a material for an organic electroluminescence (EL) device or an electrophotographic photosensitive material. This is effective in improving their performance. In particular, when the compound of the present invention is used as a material for an organic electroluminescence (EL) device, it gives a high-performance device and can greatly improve the performance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07D 223/26 C07D 223/26 4H006 223/28 223/28 265/38 265/38 G03G 5/06 312 G03G 5/06 312 H01L 33/00 H01L 33/00 A H05B 33/22 H05B 33/22 DF term (reference) 2H068 AA20 AA21 BA12 BA14 BA16 3K007 AB03 AB11 DA01 DB03 EB00 FA01 4C034 DM01 DU12 4C056 AA02 AB01 AC03 AD05 AE01 EC11 4C204 BB05 CB25 DB01 EB01 FB16 GB02 4H006 AA01 AB92 BJ50 BU46

Claims (1)

[Claims] 1. A tetraarylmethane compound represented by the following general formula (I). Embedded image (In the general formula (I), Ar ₁ and Ar ₂ are the same or different and represent an optionally substituted aryl group, which may be bonded directly or indirectly via a linking group. R may be the same or different when a plurality of R are present, and may be a halogen atom, an alkyl group which may be substituted, an aryl group which may be substituted, an alkoxy group which may be substituted, Represents an optionally substituted aryloxy group, an optionally substituted dialkylamino group, an optionally substituted N-alkyl-N-arylamino group, or an optionally substituted diarylamino group, where m is 0-4. And n is an integer of 1 to 4.)