JPH0362175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a carbazole polymer having conductivity or semiconductivity. More specifically, the present invention relates to a method for obtaining conductive or semiconductive and chemically stable carbazole polymers through a simple process.

<Prior Art> Conventionally, for example, J. Burgon et al., I.
B.M., Journal of Research Development, Volume 27 (No. 4) [J.Bargon
et.al., IBM J.Res.Develop.vol 27 (No. 4)], 330
(1983) and others describe a method in which carbazole is electrolytically oxidized and polymerized in the presence of an electrolyte such as tetra-n-butylammonium perchlorate to deposit a polycarbazole polymer on an electrode plate. The electrical conductivity is reported to be 10 ^-4 to ^{10 -3} S/cm.

Since such electrolytic oxidative polymerization is carried out on an electrode plate, the form of the reaction is subject to significant restrictions. From this point of view, it would be desirable if a chemical oxidative polymerization method could be used to obtain a carbazole polymer. However, P. Maitland et.al., Journal of the Chemical Society, 1388 (1927) [P. Maitland et.al., J.
Chem.Soc., 1388 (1927)] et al., for example, when chemical oxidation is carried out using dichromate ions in the presence of sulfate ions, a dimer of 3,3'-dicarbasyl can be obtained. , it is said that a 9,9' duplex can be obtained depending on the conditions, but it is stated that a carbazole polymer is not produced.

Also, S.T. Wellinghoff et al.
“Abstract Conférence Intervals La Fizique et la Himie”
De Polimère Consultaires Les Arcs France” 1982, 26B [STWellinghoff et
al., “Abstr.Conf Interval sur La Physique et
La Chimiedes Polymers Conducteurs Les
Arcs.Fr.”1982, 26B] is N-methyl-3,6
- Poly(N-methyl-3,6-carbazolediyl) by Grignard reaction of dibromocarbazole
is obtained by chemical polymerization. This method has difficulties from an industrial standpoint because it uses a special reaction called the Grignard process. Furthermore, in order to increase the conductivity of the obtained material, it is necessary to dope it with an electron-accepting compound such as arsenic pentafluoride or iodine.

<Object of the invention> The present invention has been made in view of the above circumstances, and its main purpose is to provide a highly stable and
The present invention provides a method for obtaining conductive polycarbazole through a simple process without resorting to doping.

<Structure of the Invention> That is, the present invention involves chemically oxidatively polymerizing at least one carbazole with or without a monovalent hydrocarbon substituent on the nitrogen atom in the presence of a trivalent iron compound. This is a characteristic method for producing carbazole polymers.

Hereinafter, a specific configuration of the present invention will be explained in detail.

The carbazole polymer of the present invention can be easily obtained by mixing and stirring carbazole with a suitable solution containing a trivalent iron compound as a chemical oxidizing agent. Moreover, according to this method, anions coexisting in the reaction system are simultaneously incorporated into the resulting polymer as a dopant, so that high conductivity can be achieved without the need for additional doping with an electron-accepting compound.

In addition to carbazole, carbazoles used in the present invention include those having a monovalent carbon hydrogen substituent on the nitrogen atom.

Examples include carbazole, N-methylcarbazole, N-ethylcarbazole, N-butylcarbazole, N-phenylcarbazole, and the like.

As the chemical oxidizing agent, trivalent iron compounds such as ferric chloride, ferric perchlorate, ferric nitrate, ferric sulfate, ferric citrate, and ferric phosphate are used. It will be done.

Those having crystal water are also preferably used. Ferric chloride and ferric perchloride, which have excellent solubility in organic solvents, and those containing water of crystallization thereof are more preferably used.

When these oxidizing agents are used, the anions contained in the oxidizing agent are incorporated into the produced polymer as dopants, but in order to make this doping effect even more effective, hydrochloric acid, sulfuric acid, nitric acid,
Inorganic acids such as perchloric acid, acetic acid, methanesulfonic acid,
Organic acids such as p-toluenesulfonic acid and oxalic acid can also be present.

Here, the amount of the chemical oxidizing agent used for the carbazole is suitably 0.1 to 10 equivalents, preferably 1 to 5 equivalents, per equivalent of the carbazole. When the amount is less than 0.1 equivalent, not only the yield of the obtained polymer is extremely poor, but also the electrical conductivity is extremely low. Moreover, even if 10 equivalents or more are used, the effect is small and it is also uneconomical. From the standpoint of polymer yield and electrical conductivity of the obtained product, 1 to 5 equivalents are used.

The reaction is generally carried out using a solvent. Solvents used include alcohol, ketone solvents such as acetone and methyl ethyl ketone, nitrile solvents such as acetonitrile and benzonitrile, nitro compounds such as tetrahydrofuran, nitromethane and nitrobenzene, aromatic hydrocarbons such as benzene, toluene and xylene, ethyl acetate, Examples include ester solvents such as butyl acetate, amide solvents such as N,N'-dimethylacetamide, pyrrolidone solvents such as N-methylpyrrolidone, and dimethyl sulfoxide.

The reaction temperature is -50°C to 100°C. A temperature of -30°C to 50°C is preferably used. The reaction time is
The time period ranges from 30 minutes to one week, and is selected appropriately depending on the reaction temperature.

<Effects and Applications of the Invention> According to the present invention, a carbazole polymer having conductivity can be obtained through a simple process.

The obtained carbazole polymer can be widely used as an electronic material, an organic semiconductor material, and a photoconductive material.

Next, the present invention will be further clarified by the following examples. Hereinafter, all parts are by weight.

The four-terminal method was used to measure the conductivity.

Example 1 16.7 parts of carbazole was dissolved in 1000 parts of acetonitrile, and 46.2 parts of ferric perchlorate hexahydrate dissolved in 100 parts of acetonitrile was added thereto at room temperature. The solid produced by stirring at room temperature for 8 hours was collected by filtration, washed with acetonitrile, water, and acetonitrile in this order, and dried. Poly(3,6 carbazole diyl) containing perchlorate ions was obtained. I got 9.5 copies. The conductivity of this material was 3.2×10 ^-3 S/cm, and strong absorption of ClO ₄ ^- was confirmed at 1087 cm ^-1 from the infrared absorption spectrum (see Figure 1).

Example 2 16.7 parts of carbazole was dissolved in 2000 parts of acetonitrile, and to this was added a solution of 32.4 parts of anhydrous ferric chloride in 1000 parts of acetonitrile at room temperature. The solid produced after reacting at room temperature for 24 hours was filtered. This was washed with acetonitrile, water, and acetonitrile, and dried to obtain poly(3,6 carbazolediyl) containing 3 parts of chlorine ions. The conductivity of this material was 4.4×10 ^-1 S/cm.

Example 3 0.7 parts of carbazole was dissolved in 200 parts of nitromethane, and 2.0 parts of Fe was dissolved in 100 parts of nitromethane.
(ClO ₄ ) ₃ ·6H ₂ O was dissolved and added at room temperature. The reaction solution immediately turned dark blue. After stirring overnight at room temperature, the produced black-green poly(3,6-carbazolediyl) containing perchlorate ions was filtered and washed with nitromethane, water, and nitromethane. The yield after drying was 1.1 parts. this thing
After molding into a disk using an IR tablet molding machine, the electrical conductivity was measured to be 3.9×10 ⁻⁴ S/cm.

Example 4 9.75 parts of N-ethylcarbazole was dissolved in 700 parts of acetonitrile, and 23.1 parts of Fe(ClO ₄ ) ₃ ·6H ₂ O
added. After stirring for two days and nights at room temperature, the resulting dark green polymer was filtered off and washed with acetonitrile and water. Upon drying, poly(N-ethyl-3.6-carbazolediyl) containing 6.0 parts of perchlorate ion was obtained. This material was molded into a disk using an IR tablet molding machine, and its electrical conductivity was measured to be 3.2×10 ^-3 S/cm.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum of the carbazole polymer obtained in Example 1.

Claims (1)

[Claims] 1. Production of a carbazole polymer, which comprises chemically oxidizing and polymerizing at least one carbazole with or without a monovalent hydrocarbon substituent on the nitrogen atom in the presence of a trivalent iron compound. Method.