Electrochemical synthesis and properties of poly(3-methylthiophene): Novel synthesis of poly(3-methylthiophene) with pentachlorostannate and hexachloroantimonate

Poly(3-methylthiophene) (P3-MeT) doped with different anions were prepared electrochemically in the presence of tetraalkylammonium salts. The new poly(3-methylthiophene) SnCl5- and SbCl6- (P3-MeT SnCl5 and P3-MeT SbCl6) were prepared electrochemically using tetra-n-butylammonium pentachlorostannate and tetra-n-butylammonium hexachloroantimonate as the supporting electrolytes. The effect of current density, salt concentration, reaction temperature, and the nature of solvents on the polymer yield and polymer conductivities have been investigated. Cyclic voltammetry of poly(3-methylthiophene) has been examined at platinum electrode in 1,2-dichloroethane medium containing n-Bu4NSnCl5, Bu4NSbCl6, and Bu4NClO4 as the supporting electrolytes in the range of -1.0 to 1.7 V versus SCE in the presence and absence of 3-methylthiophene. Electrical conductivity, magnetic susceptibility measurements, and structural determination by elemental analysis and infrared studies were also made. Scanning electron microscopy revealed a globular, branched, fibrous and a spongy, fibrous morphology of poly(3-methylthiophene) SnCl5-, ClO4-, and SbCl6-, respectively. The thermal analysis of the polymers was also investigated. Possible causes for the observed lower conductivity of these polymers have also been discussed. (C) 1999 John Wiley & Sons, Inc.