JPH06211836A - Azothiophene and its production and polyazothiophene and its production - Google Patents

Abstract

PURPOSE:To obtain a new azothiophene useful as a raw material for a new electrically conductive polymer suitable for producing a lightweight cell exhibiting excellent characteristics. CONSTITUTION:An azothiophene of formula I, a polyazothiophene of formula II ((n) is 5-10,000) and a polyazothiophene doped with an anion of formula III ((m) is 0.01-2; (a) is 1-3; X<-a> is anion). The azothiophene of formula I is obtained by oxidizing 2-aminothiophene, its salt or its metal complex in an organic solvent in the presence of manganese dioxide. The compound of formula II is prepared by oxidizing the azothiophene of formula I in the organic solvent in the presence of an oxidizing agent to give the polyazothiophene doped with the anion of formula III and further reducing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to azothiophene and a method for producing the same, polyazothiophene and a method for producing the same, and a secondary battery using the polyazothiophene.

[0002]

2. Description of the Related Art In recent years, miniaturization of electronic devices has progressed, and along with this, there has been a demand for development of batteries that are lightweight and exhibit excellent characteristics. Conductive polymers have attracted attention as electrode active materials for such batteries, and many conductive polymers such as polyaniline, polypyrrole, and polythiophene have been developed so far. These polymers are generally synthesized from monomers by electrolytic oxidative polymerization or chemical oxidative polymerization. To date, the starting materials for conductive polymer materials have been polyaniline,
Since most of them are pyrrole, thiophene and their derivatives, in polymers other than polyaniline containing a nitrogen atom, the conjugated structure of the polymer main chain is composed of carbon-carbon double bonds. It has been considered to improve stability and conductivity by introducing an azo group as a new structural component into the main chain conjugated system composed of such a carbon-carbon double bond. Although azophenylene has been synthesized, it has not yet exhibited the performance superior to that of the carbon-carbon double bond material.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel conductive polymer having an azo group in its main chain and excellent in stability and conductivity.

Another object of the present invention is to provide a battery which uses such a novel conductive polymer and is lightweight and exhibits excellent characteristics.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor succeeded in synthesizing a polyazothiophene having a novel structure, which was a conductive polymer. Then, it was found to be useful as a battery active material.

That is, the present invention provides the following inventions: General formula (1)

[0007]

[Chemical 11]

Azothiophene represented by:

2. General formula (2)

[0010]

[Chemical 12]

A polyazothiophene represented by the formula (n represents an integer of 5 to 10000).

3. General formula (3)

[0013]

[Chemical 13]

(Wherein n represents an integer of 5 to 10000; m is 0.01 to 2; a is 1, 2 or 3; X- ^a represents an anion) Ion-doped polyazothiophene.

4. 2-aminothiophene, a salt thereof or a metal complex thereof is oxidized in the presence of manganese dioxide in an organic solvent, and the general formula (1) is provided.

[0016]

[Chemical 14]

A method for producing azothiophene represented by:

5. General formula (1)

[0019]

[Chemical 15]

The azothiophene represented by the formula (3) is characterized in that it is oxidized in the presence of an oxidizing agent in an organic solvent.

[0021]

[Chemical 16]

(Wherein n is an integer of 5 to 10000; m is 0.01 to 2; a is 1, 2 or 3; X- ^a is an anion) Method for producing ion-doped polyazothiophene.

6. General formula (3)

[0024]

[Chemical 17]

(Wherein n is an integer of 5 to 10000; m is 0.01 to 2; a is 1, 2 or 3; X- ^a is an anion) General formula (2) characterized by reducing ion-doped polyazothiophene

[0026]

[Chemical 18]

A method for producing a polyazothiophene represented by the formula (n represents an integer of 5 to 10000).

7. General formula (2)

[0029]

[Chemical 19]

(Wherein n represents an integer of 5 to 10000) or the general formula (3)

[0031]

[Chemical 20]

(Wherein n is an integer of 5 to 10000; m is 0.01 to 2; a is 1, 2 or 3; X- ^a is an anion) A secondary battery comprising ion-doped polyazothiophene as an electrode active material.

In the polyazothiophene of the present invention represented by the general formula (2), the value of n is usually an integer of 5 to 10000, and more preferably an integer of 10 to 1000.

In the polyazothiophene doped with the anion represented by the general formula (3), the value of n is usually about 5 to 10000, and more preferably about 10 to 1000. Further, in an anion-doped polyazothiophene represented by the general formula (3),
The value of m is usually in the range of 0.001 to 2, 0.01 to
More preferably, it is in the range of 1. The value of a is an integer of 1 to 3, more preferably 1.

In the polyazothiophene of the present invention represented by the general formula (3) doped with anion, the anion represented by X is perchlorate ion, tetrafluoroborate ion, fluoroarsenate ion, Sulfate ion,
Examples thereof include inorganic acid ions such as iron chloride ion; halogen ions such as fluorine ion, chlorine ion, bromine ion, and iodine ion; organic acid ions such as p-toluenesulfonate ion and trifluoromethanesulfonate ion.

The anion-doped polyazothiophene represented by the general formula (3) can be prepared, for example, by the general formula (1)
It is obtained by chemically polymerizing azothiophene represented by the formula (3) using an oxidizing agent.

Azothiophene, which is a raw material (monomer) for the above-mentioned chemical polymerization, is prepared by subjecting 2-aminothiophene, its hydrochloride or its metal complex to chemical polymerization in the presence of an oxidizing agent as follows. And is used as it is in the solution state for the production of polyazothiophene.

More specifically, for example, an aqueous alkaline solution is added to the 2-aminothiophene tin complex, and the produced 2-aminothiophene is extracted with an organic solvent. As the alkaline aqueous solution, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate or the like is used. As the organic solvent, those which are hydrophobic and dissolve 2-aminothiophene are preferable, and specific examples thereof include chloroform, dichloromethane, benzene, hexane, propylene carbide, ether and the like, and among these, chloroform is more preferable. preferable. Then, the extracted 2-aminothiophene is oxidized in the presence of manganese dioxide to obtain the desired azothiophene. The amount of manganese dioxide used is 2 for 1 mol of 2-aminothiophene.
The amount is about 10 to 10 mol, more preferably about 3 to 6 mol. The temperature during the oxidation reaction is about -20 to 40 ° C,
More preferably, it is about 1 to 30 ° C.

Then, the azothiophene obtained as described above is subjected to a polymerization reaction in an organic solvent in the presence of an oxidizing agent.

As the polymerization solvent, the same solvent as used for dissolving 2-aminothiophene is used. More specific examples include chloroform, dichloromethane, benzene, hexane, propylene carbide, ether and the like, and among these, chloroform is more preferable. You may use these in mixture of 2 or more types. Upon polymerization, the azothiophene concentration is about 0.01 to 1 mol / liter, more preferably 0.1 to 0.5 mol / liter.
Use a solution of about 1 liter.

In this chemical polymerization, a commonly used oxidizing agent is used. Specific examples of the oxidizing agent include ferric chloride, ferric perchlorate, silver chloride, silver perchlorate, cupric chloride, transition metal salts such as copper perchlorate, hydrogen peroxide, and benzoquinone. , And quinones such as naphthoquinone. Among these oxidizing agents, ferric chloride, ferric perchlorate and other ferric compounds, and silver compounds such as silver chloride and silver perchlorate are more preferable. The amount of the oxidizing agent used is about 1 to 5 mol, and more preferably about 2 to 4 mol, based on 1 mol of azothiophene.

The polymerization reaction is not particularly limited, but is usually carried out at a temperature of about -30 to 80 ° C. for about 1 to 5 hours, more preferably at about 30 to 60 ° C. for about 2 to 4 hours. .

By the above reaction, polyazothiophene represented by the general formula (3) is obtained as a black powder, which is purified by washing with a solvent if necessary.

The anion-doped polyazothiophene represented by the general formula (3) can be prepared, for example, by the general formula (1)
It can also be obtained by electropolymerizing azothiophene represented by the formula (3) in a solution containing an anion source as a supporting electrolyte. The electrolysis may be carried out by a constant potential method, a constant current method, a potential scanning method, or a two-pole method or a three-pole method. When using the triode method, it is preferable to use an SCE or Ag / AgCl electrode as the reference electrode. As the electrodes, conductive glass, platinum, carbon electrodes and the like can be used.

As the anion, as described above, inorganic acid ions such as perchlorate ion, tetrafluoroborate ion, fluoroarsenate ion, sulfate ion and iron chloride ion;
Examples thereof include halogen ions such as fluorine ion, chlorine ion, bromine ion, and iodine ion; organic acid ions such as p-toluenesulfonate ion and trifluoromethanesulfonate ion.

Examples of the supporting electrolyte as the above-mentioned anion source include perchloric acid and its salts, tetrafluoroboric acid and its salts, fluoroarsenic acid and its salts, sulfuric acid and its salts, iron chloride; fluorine compounds, chlorine compounds. , Bromine compounds, iodine compounds; p-toluenesulfonic acid and its salts, trifluoromethanesulfonic acid and its salts, and the like.

The solvent used for this electrolytic polymerization is preferably one which dissolves the supporting electrolyte as an anion source well,
Specifically, alcohols such as methanol, ethanol and isopropanol; ethers such as tetrahydrofuran, dioxane and dimethylethylene glycol; carbonates such as propylene carbonate, ethylene carbonate and diethyl carbonate; nitro compounds such as nitrobenzene and nitromethane; other acetonitrile; Examples thereof include dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide and the like. Among these solvents, acetonitrile, propylene carbonate and tetrahydrofuran are more preferable. The concentration of the supporting electrolyte in the solvent is usually about 0.01 to 1 mol / liter, more preferably about 0.05 to 0.5 mol / liter.

The electropolymerization conditions for producing an anion-doped polyazothiophene are not particularly limited. For example, in the case of the constant current method, the current density is usually 0.01 to 10 mA / cm 2. ^{It is} about ² , more preferably about 0.1 to 1 mA / cm ² .

The polyazothiophene represented by the general formula (2) can be obtained by electrolytically reducing the anion-doped polyazothiophene represented by the general formula (3). This reduction reaction is, for example, 0.1 to 1 mA / c.
It is carried out by reducing the working electrode to −0.5 to 0 V with respect to Ag / AgCl under a constant current of about m ² .

Alternatively, the polyazothiophene represented by the general formula (2) is prepared by immersing the polyazothiophene doped with the anion represented by the general formula (3) in, for example, methanol and heating the anion. Can also be obtained by the chemical method of removing

As a battery using the polyazothiophene of the present invention as a positive electrode active material, various secondary batteries can be mentioned. Other constituent materials such as the negative electrode active material and the electrolytic solution in such a battery may be the same as the known constituent materials in the battery. As such a negative electrode active material in a polymer secondary battery, polyacetylene, polyparaphenylene,
Conductive polymers such as polypyridine and carbon materials can be used. As a negative electrode active material in a lithium secondary battery, L
Examples thereof include i or Li and Al, Mg, Pb, Si, Ga or In. As the electrolytic solution, a solution in which a known electrolyte is dissolved in an organic solvent is used. Examples of the electrolyte include salts with metal cations, cations such as organic cations, and anions. Examples of cations include quaternary ammonium ions. Also,
As anions, BF ₄ ⁻ , ClO ₄ ⁻ , PF ₆ ⁻ , A
s ₆ ⁻ , CF ₃ SO ₃ ⁻ , I ⁻ , Br ⁻ , Cl ⁻ , F ⁻ . Specific examples of such an electrolyte include lithium tetrafluoroborate, lithium perchlorate, lithium hexafluorophosphate, tetraethylammonium tetrafluoroborate, tetra-n-butylammonium perchlorate,
Examples include lithium trifluoromethanesulfonate, lithium iodide, lithium bromide and the like. The organic solvent for dissolving the electrolyte is preferably an aprotic one with high conductivity, nitriles, carbonates, ethers,
Nitro compounds, amides, sulfur-containing compounds, chlorinated carbon compounds, ketones, esters and the like can be used. You may use these organic solvents in mixture of 2 or more types. More preferable specific examples of the organic solvent include acetonitrile, propylene carbonate, tetrahydrofuran, dioxane, nitromethane, N, N-dimethylformamide, dimethyl sulfoxide, 1,2-
Examples include dichloroethane and γ-butyrolactone.

Inorganic and organic solid electrolytes can also be used as the electrolyte. Examples of the inorganic solid electrolyte include metal halides such as AgCl, AgBr, AgI and LiI, RbAg ₄ I ₅ and RbAg ₄ I ₄ N. Examples of the organic solid electrolyte include a polymer electrolyte such as polyethylene oxide, polypropylene oxide, polyvinylidene fluoride, polyacrylamide, and the like, in which the above-mentioned electrolytic salt is dissolved in a polymer matrix, or a cross-linked body of these composites. .

[0053]

Industrial Applicability The polyazothiophene of the present invention is electrochemically active and highly stable. Therefore, by using the polyazothiophene, a secondary battery which is lightweight and exhibits excellent characteristics can be obtained.

[0054]

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Synthesis of 2-Aminothiophene While introducing argon gas into a three-necked flask equipped with an inert gas introduction tube, a stirrer and a cooling tube, 2.0 g (3 g) of a tin complex of 2-aminothiophene (3 0.8 mmol) and 15 cc of water were added, and the mixture was stirred until it became homogeneous. Chloroform (75 cc) was added to this solution, and a solution of sodium hydroxide (4.0 g) in water (10 cc) was added dropwise at room temperature. Then, the chloroform layer was separated to obtain a chloroform solution containing 2-aminothiophene.

Synthesis of azothiophene 3.28 g (38 mmol) of manganese dioxide was added to the chloroform solution of 2-aminothiophene obtained above, and the mixture was reacted at room temperature for 3 hours, and chloroform containing azothiophene represented by the general formula (1) was used. A solution was obtained.

The analytical data of the obtained azothiophene are shown below.

¹ H-NMR ((CD ₃ ) ₂ CO): 7.
13ppm (dd), 7.78ppm (dd ), 7.68ppm (dd) UV (CH 3 OH): 358.7nm, the chloroform solution of azo thiophene obtained in the above 291.8nm polyazo thiophene 1
The solution was concentrated to 0 cc, and 1.24 g of ferric chloride was added dropwise to a suspension of 5 cc of chloroform. 60 ℃
After reacting for 2 hours at room temperature to obtain a black powder, it is further washed with methanol and dried under reduced pressure at 70 ° C. to obtain the compound represented by the general formula (3).
0.23 g of polyazothiophene represented by

The polyazothiophene obtained was doped with iodine ions, pelletized and the conductivity was measured and found to be 10 ^-6 S / cm. After the pellets were left in the air for 6 months, the conductivity was measured again and no change was observed.

FT-IR data of the polyazothiophene of the general formula (3) obtained above is shown below.

FT-IR (KBr) ν (cm ^-1 ): 16
06, 1569, 1540, 1436, 1262, 11
94, 846, 802, 708, 488 Table 1 shows the elemental analysis values of the products together with theoretical values. The theoretical value is 1 for FeCl ₄ ⁻ which is an anion.
It is a value when it is assumed to contain 8.9% by weight.

[0062]

[Table 1]

From the elemental analysis values shown in Table 1, the result that carbon / nitrogen (molar ratio) = 4 (theoretical value 4) was obtained, and this product was obtained by using azothiophene as a target substance as a repeating unit. It was confirmed that the polymer was the polymer of the general formula (3).

The following analytical instruments were used.

NMR: JNM-GX270 type (270M
Hz, manufactured by JOEL) UV-VIS: U-3140 type (manufactured by Hitachi, Ltd.) IR: Nicolet 20SXC conductivity meter: Mitsubishi Yuka Loresta AP Elemental analysis: PERKIN ELMER 2400 Example 2 2-amino during polymerization reaction Polyazothiophene 0.32 of the general formula (3) was prepared in the same manner as in Example 1 except that 4 mol of ferric chloride as an oxidizing agent was used with respect to 1 mol of thiophene.
g was obtained.

Example 3 0.22 g of polyazothiophene of the general formula (3) was obtained in the same manner as in Example 1 except that silver perchlorate was used as the oxidizing agent during the polymerization reaction.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Kenji Seki 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Prefecture Osaka Gas Co., Ltd.

Claims (7)

[Claims] 1. A general formula (1): Azothiophene represented by. 2. A general formula (2): (In formula, n shows the integer of 5-10,000) The polyazo thiophene shown. 3. A general formula (3): (In the formula, n represents an integer of 5 to 10000; m represents 0.0
1 to 2; a is 1, 2 or 3; X- ^a represents an anion), and polyazothiophene doped with an anion. 4. A general formula (1): wherein 2-aminothiophene, a salt thereof or a metal complex thereof is oxidized in the presence of manganese dioxide in an organic solvent. A method for producing azothiophene represented by. 5. A compound represented by the general formula (1): The azothiophene represented by the formula (3) is oxidized in the presence of an oxidizing agent in an organic solvent, and the general formula (3): (In the formula, n represents an integer of 5 to 10000; m represents 0.0
1 to 2; a is 1, 2 or 3; X- ^a represents an anion), and a method for producing polyazothiophene doped with an anion. 6. A compound represented by the general formula (3): (In the formula, n represents an integer of 5 to 10000; m represents 0.0
1 to 2; a is 1, 2 or 3; X ^−a represents an anion), and polyazothiophene doped with an anion represented by the general formula (2): Chemical 8] (In formula, n shows the integer of 5-10,000) The manufacturing method of the polyazo thiophene shown by these. 7. A compound represented by the general formula (2): (In the formula, n represents an integer of 5 to 10000) or the general formula (3): (In the formula, n represents an integer of 5 to 10000; m represents 0.0
1 to 2; a is 1, 2 or 3; X- ^a represents an anion), and a secondary battery characterized by using an anion-doped polyazothiophene as an electrode active material. .