JPH075718B2 - Dialkoxy-bis (2-thienyl) silane polymer and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a conductivity and a redox property, and is useful as a conductive polymer material for various electric parts and electronic parts and as a redox electric element in the electrochemical field. The present invention relates to an alkoxy-bis (2-thienyl) silane polymer and a method for producing the same.

[0002]

2. Description of the Related Art Conjugative polymers such as polyacetylene-based polymer compounds, polyphenylene-based polymer compounds, polypyrrole-based polymer compounds, polythiophene-based polymer compounds and polyselenophene-based polymer compounds have hitherto been used as conductive polymer compounds. In the form of electron transfer through a double bond,
Polymers such as polyacene-based polymer compounds, polyperinaphthalene-based polymer compounds that transfer electrons through condensed aromatic rings, and ionized atoms such as polyaniline and poly (3-methyl-4-carboxypyrrole) It is known that electron transfer is carried out through atomic groups, but in either case, most of them are insoluble and infusible, so they lack workability and are inferior in terms of mechanical properties. The range of use is unavoidable.

Therefore, it has been a major problem in this field to develop a conductive polymer compound having a novel structure and to expand the field of application according to its physical properties.

By the way, recently, a conductive polymer compound having a structure in which a heterocycle is linked via a silicon atom has been studied, and so far, a general formula has been used.

[Chemical 3] (Wherein R is a methyl group, a phenyl group or a p-tolyl group) having a repeating unit [“Macromolecules”
s) ", Vol. 24, No. 8, pp. 2106-2107 (1991)] and general formula

[Chemical 4] (X in the formula is S, O, Se or Te, and R and R '
Is a hydrogen atom, an alkyl group or an aryl group), and is a polymer of a compound represented by JP-A-3-76714.
However, all of them are difficult to put into practical use because they lack workability.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made for the purpose of providing a novel conductive polymer compound obtained in the form of a film that can be put to practical use and showing excellent conductivity and heat resistance. is there.

[0006]

By the way, there is an electrolytic polymerization method as one of the methods for producing a conductive polymer compound.
This has the advantage that a film-like conductive polymer compound can be obtained, but its application range is limited to the polymerization of five-membered ring compounds such as thiophene and pyrrole, and arylamines such as aniline, and is universal. Is not applicable to.

For example, when this electropolymerization method is applied to 2,5-bis (trimethylsilyl) thiophene, the silyl group is eliminated to give polythiophene, which is referred to as “J. Electroanalytical Chem. .) ”, Second
81, p. 293], and when applied to bis (2-thienyl) silane, polythiophenes having no silyl group are produced (40th Annual Meeting of the Polymer Society of Japan, Masuda, Taniki,
Return home report). Therefore, it has been considered so far that a conductive polymer compound having a structure in which heterocycles are linked via a silicon atom cannot be produced by an electrolytic polymerization method.

However, the inventors of the present invention have conducted various studies on conductive polymer compounds having a structure in which thiophene rings are linked via a silicon atom, and as a result, dialkoxy-bis (2-thienyl) silane was electrolyzed. It was found that, when polymerized, poly [dialkoxy-bis (2-thienyl) silane] was formed into a film without polymerization of the basic structure. The present invention has been made based on this finding.

That is, the present invention has the general formula

[Chemical 5] The average molecular weight of the repeating unit represented by the formula (R1 and R2 in the formula are alkyl groups) is 1,000 to
Dialkoxy-bis (2-
A thienyl) silane polymer is provided.

R1 and R2 in the general formula may be the same or different from each other, and each has 1 carbon atom.
-8 straight-chain or branched alkyl groups are preferred. Examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, a heptyl group and an octyl group. Since the polymer of the present invention does not dissolve in a solvent, its molecular weight cannot be accurately measured. However, the molecular weight of a polymer having a similar structure known so far and its polymerization conditions are about 1,0.
It is estimated to be in the range of 00 to 100,000.

The conductive polymer of the present invention has the general formula

[Chemical 6] It can be produced by electropolymerizing a dialkoxy-bis (2-thienyl) silane represented by the formula (R1 and R2 have the same meaning as described above).

At this time, the dialkoxy-bis (2-thienyl) silane used as a raw material is a novel compound which has not been published in the literature, and is a thiophene substituted with an alkali metal at the 2-position such as 2-lithiothiophene and dihalodialkoxysilane. Can be obtained by reacting at a molar ratio of 2: 1.

This reaction is carried out under an inert atmosphere in an inert solvent at 0 ° C. or lower, preferably − in order to suppress side reactions.
Preference is given to carrying out at temperatures between 10 and -40 ° C. Nitrogen, argon, etc. are used as the inert atmosphere at this time. In addition, examples of the inert solvent include ethers such as diethyl ether, methyl ethyl ether, dipropyl ether and tetrahydrofuran, and liquid hydrocarbons such as hexane, pentane and cyclohexane.

The raw material for the conductive polymer of the present invention is obtained in this manner. Diethoxybis (2-thienyl) silane, dimethoxybis (2-thienyl) silane,
Dipropoxybis (2-thienyl) silane, dibutoxybis (2-thienyl) silane, dipentyloxybis (2-thienyl) silane, dihexyloxybis (2-
Thienyl) silane, dioctyloxybis (2-thienyl) silane, methoxyethoxybis (2-thienyl) silane, methoxypropoxybis (2-thienyl) silane, methoxybutoxybis (2-thienyl) silane, ethoxypropoxybis (2- Thienyl) silane, ethoxybutoxybis (2-thienyl) silane, methoxypentyloxybis (2-thienyl) silane, methoxyhexyloxybis (2-thienyl) silane, methoxyoctyloxybis (2-thienyl) silane, propoxybutoxybisbis (2-thienyl) silane and the like can be used.

Next, the electropolymerization for obtaining the conductive polymer of the present invention is carried out in the presence of a suitable electrolyte in an aprotic polar solvent such as nitrobenzene, acetonitrile or propylene carbonate.

At this time, the anode is formed of an electrode that does not participate in redox, for example, a noble metal such as platinum, and the cathode is formed of an appropriate electrode material such as iron, carbon, aluminum, gold, platinum, and conductive glass. To be done. The electrolytic oxidation reaction is preferably carried out at a reaction temperature of −30 to 50 ° C. under a constant current of a current density of 1 to 50 mA / cm 2. In addition, the concentrations of the raw material dialkoxybis (2-thienyl) silane and the above electrolyte are each 0.01 to 0.5.
It is preferably in the range of mol / liter and 0.05 to 0.1 mol / liter.

As the above-mentioned electrolyte, a quaternary ammonium salt commonly used in electrolytic reactions, for example, a general formula

[Chemical 7] (R3, R4 and R5 are the same or different alkyl groups, or R3 forms a pyridinium group together with R4 and R5, R6 is an alkyl group, Z is PF6, BF4 or Cl.
A compound represented by O4) is used. Examples of the compound of the formula (III) include tetraethylammonium hexafluorophosphate, tetraethylammonium tetrafluoroborate, tetrabutylammonium perchlorate and the like.

In this way, the desired conductive polymer is obtained on the surface of the anode as a black film having a thickness of 0.1 to 20 μm.

As a result of cyclic voltammetry measurement, the conductive polymer film thus obtained was capable of reversibly undergoing oxidation-reduction, and its oxidation potential showed a value equivalent to that of polythiophene. Also, the conductivity of the one doped with PF 6 − was 10 S · cm −1.

[0020]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Reference Example A mixture of 5.05 (60.0 mmol) of thiophene and 50 ml of diethyl ether was added under nitrogen atmosphere at -40 ° C.
-Butyllithium 60.0 mmol in hexane was added dropwise, and dry ice-acetone refrigerant was used at -40 ° C for 2 hours.
Stir the time. A solution of 5.67 g (30.0 mmol) of dichlorodiethoxysilane dissolved in 5 ml of diethyl ether was added dropwise thereto at -20 ° C, and the mixture was stirred at room temperature for 12 hours. After the reaction mixture was neutralized with 4N-hydrochloric acid, it was poured into 200 ml of ice water, and a colorless oily substance was obtained from the ether extract by a conventional method. This was further purified by silica gel column chromatography (Wako Gel C-200), and 5.31 g of diethoxybis (2-thienyl) silane as a colorless oil was obtained from the hexane eluate (yield 62.0).
%) Was obtained. The identification data for this item are as follows.

1H-NMR (CDCl3, δ): 1.27
(T, J = 10.6 Hz, 6H), 3.93 (g, J =
6.9 Hz, 4H), 7.22 (dd, J = 3.4H)
z, J = 4.6 Hz, 2H), 7.48 (dd, J =
1.0 Hz, J = 3.4 Hz, 2H), 7.68 (d
d, J = 1.0 Hz, J = 4.6 Hz, 2H) 13 C-NMR (CDCl 3, δ): 18.2, 59.
4, 128.2, 132.4, 137.3 IR (KBr, ν, cm -1): 3102 (w), 297.
4 (m), 1406 (m), 1215 (m), 1166
(M), 1078 (s), 1008 (m), 962
(M), 785 (m), 713 (s), 528 (m)

Example Diethoxybis (2-thienyl) silane 1 obtained in Reference Example
42 mg (0.1 mmol) and supporting electrolyte tetraethylammonium hexafluorophosphate 41 mg
(0.03 mmol) as a solvent, nitrobenbene,
Acetonitrile and 5 ml of propylene carbonate were added, and argon was bubbled for 15 minutes, and then bubbling was continued on the liquid. Platinum plate electrodes were inserted as an anode and a cathode into this solution, and the solution was kept at a temperature of 30 ° C. and a current was applied at a constant current of a current density of 5 mA / cm 2 to obtain a desired conductive polymer on the anode. The amount of electricity applied was 8.1 C / cm2, and the observed inter-electrode potential was 7.2.
Was about 7.9V.

The electroconductive polymer thus obtained was immediately washed with n-hexane and the electric conductivity was measured by the four-terminal method. As a result, the measured value was 12 S · cm −1.

[0025]

INDUSTRIAL APPLICABILITY The present invention is a novel conductive polymer which exhibits high electric conductivity and can be redox-reduced. Since it is obtained in the form of a film which is easy to put into practical use, it is suitable for various electric parts and electronic parts. It can be suitably used as a conductive material and an electric element in the field of electrochemistry.

Claims (2)

[Claims] 1. A general formula: The average molecular weight of the repeating unit represented by the formula (R1 and R2 in the formula are alkyl groups) is 1,000 to
Dialkoxy-bis (2-
Thienyl) silane polymer. 2. A general formula: 2. A dialkoxy-alkoxy-silane according to claim 1, characterized in that a dialkoxy-bis (2-thienyl) silane represented by the formula: wherein R1 and R2 are alkyl groups is electropolymerized.
Process for producing bis (2-thienyl) silane polymer.