JP3210481B2 - 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can maintain an amorphous state at normal temperature, and thus can be thinned by itself, and is useful as a photoelectric conversion element, a thermochromic element, an optical memory element and the like. And 1,3,5, which are novel compounds useful as organic compounds for forming a hole transport layer in an electroluminescent device.
-Tris [4- (N-carbazolyl) phenyl] benzene derivatives.

[0002]

2. Description of the Related Art Conventionally, low-molecular-weight organic compounds having a so-called opto-electronic function, which generate electrical conductivity and charge generation upon irradiation with light, have no thin-film forming ability by themselves. Is formed by dispersing it in a binder resin (accordingly, in a diluted state), applying it on a substrate,
It is necessary to make it thinner.

[0003]

DISCLOSURE OF THE INVENTION The present invention is different from such conventional low molecular weight organic compounds having an optical / electronic function,
A novel optical / electronic function that can maintain the amorphous state, that is, the glassy state at room temperature, and therefore can be formed into a thin film over a large area by a vacuum deposition method without using a binder resin. It is an object of the present invention to provide a low molecular weight organic compound having

[0004]

According to the present invention, a compound represented by the general formula (I):

[0005]

Embedded image

In the formula, Ra (a represents an integer of 1 to 4), Rb (b represents an integer of 1 to 4), Rc (c represents 1)
Shows an integer of ~ 4. ), Rd (d represents an integer of 1 to 4), Re (e represents an integer of 1 to 4) and Rf (f represents an integer of 1 to 4) are each independently hydrogen, It represents an alkyl group, an aryl group or an aralkyl group. The present invention provides a 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene derivative represented by the following formula:

In the present invention, the above Ra (a represents an integer of 1 to 4), Rb (b represents an integer of 1 to 4), Rc
(C represents an integer of 1 to 4), Rd (d represents an integer of 1 to 4), Re (e represents an integer of 1 to 4) and Rf.
(F represents an integer of 1 to 4) independently represents hydrogen, an alkyl group, an aryl group or an aralkyl group;
In the case of an alkyl group, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group is preferably used, and in the case of an aryl group, a phenyl group is preferably used. Is shown. In particular,
In the present invention, Ra, Rb, Rc, Rd, Re and Rf are preferably all hydrogen.

Therefore, according to the present invention, as a preferred embodiment, 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene is provided. The 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene derivative according to the present invention is generally obtained by the Ullmann reaction of 1,3,5-tris (4-iodophenyl) benzene with a carbazole derivative. Obtainable. That is, 1,3,5-tris (4-
The iodophenyl) benzene and the carbazole derivative may be heated and reacted in a solvent in the presence of a base and copper powder.

As the base, an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide is preferably used. As the solvent, a hydrocarbon such as decalin is preferably used, but it is not limited thereto. is not. After completion of the reaction, the obtained reaction mixture is cooled to room temperature, extracted with a hot solvent (preferably hot aromatic hydrocarbon), and purified by silica gel chromatography and a recrystallization method to obtain the desired product. 1,3,5-tris [4- (N-
A carbazolyl) phenyl] benzene derivative can be obtained.

The fact that the compound according to the present invention is in an amorphous and non-anisotropic amorphous state means, for example, that it has a glass transition temperature and does not show a clear peak in powder X-ray diffraction. It is proved by

[0011]

According to the present invention, the novel compounds 1,3,
Provided are 5-tris [4- (N-carbazolyl) phenyl] benzene derivatives, particularly 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene. This compound can be formed into an amorphous film which is stable at room temperature by an appropriate means such as a vacuum evaporation method, and can be formed into a large-area thin film by itself. Moreover, the compounds according to the invention have a rigid structure and a glass transition point of 170
Since the temperature is higher than ° C., the amorphous film has excellent heat resistance, is extremely stable at room temperature, and does not crystallize.

Thus, the compound according to the present invention can be formed into a thin film by itself at normal temperature, and is useful as a photoelectric conversion element, a thermochromic element, an optical memory element, and the like. It is also useful as an organic compound or the like for forming a hole transport layer.

[0013]

【Example】

(Synthesis of 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene) 1,3,5-tris (4-iodophenyl) benzene 2.0 g, carbazole 2.9 g, potassium hydroxide 2. 9 g and 1.5 g of copper powder were put into a four-necked flask together with 5 ml of decalin and reacted at 180 ° C. for 15 hours under a nitrogen atmosphere.

After completion of the reaction, the obtained reaction mixture was cooled to room temperature and extracted with hot toluene. The extract was purified by silica gel chromatography and recrystallization, and
220 mg of 3,5-tris [4- (N-carbazolyl) phenyl] benzene were obtained (9.4% yield).

[0015] Mass spectrometry M / Z = 801 Infrared absorption spectrum is shown in FIG. Differential Scanning Calorimetry (DSC) FIG. 2 shows a DSC thermogram of 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene according to the present invention, which was melted and then cooled to a solid. When the temperature of the sample in the glassy state is increased, the compound becomes 172 ° C.
Shows a glass transition, crystallizes at 215 ° C., then undergoes a crystal transition at 313 ° C., and then melts at 346 ° C.

This compound has a glass transition point of about 172 ° C.
And so high that the amorphous film is very stable at room temperature and does not crystallize at room temperature.

[Brief description of the drawings]

FIG. 1 shows an infrared absorption spectrum of 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene.

FIG. 2 shows a DSC thermogram of 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene.

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07D 209/86 C09K 3/00 C09K 9/00 C09K 11/00 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound of the general formula (I) (Where Ra represents an integer of 1 to 4), Rb (b represents 1
Shows an integer of ~ 4. ), Rc (c represents an integer of 1 to 4), Rd (d represents an integer of 1 to 4), Re (e represents 1)
Shows an integer of ~ 4. ) And Rf (f represents an integer of 1 to 4) each independently represent hydrogen, an alkyl group, an aryl group or an aralkyl group. 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene derivative represented by the formula: 2. A 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene.