P-TYPE DOPING PROPERTIES AND ELECTRONIC STATES OF CONDUCTING POLY(TRANS-1,2-DI(2-THIENYL)ETHYLENE AND POLY(1,4-DI(2-THIENYL)-1,3-BUTADIENE)

The electrochemical and optical properties in poly(trans-1,2-di(2-thie nyl)ethylene),trans-PTE, and poly(1,4-di(2-thienyl)-1,3-butadiene), PT B, in comparison with those of polythiophene, PT, during electrochemic al p-type doping have been investigated by the cyclic voltammetry and in situ optical-absorption-spectrum measurements. The evolution of loc alized states is evidenced by the spectral change associating with dop ing. Preparation of high quality conducting poly(cis-1,2-di(2-thienyl) ethylene), cis-PTE, from the electrochemical polymerization of cis-1,2 -di(2-thienyl)ethylene was also tried. However, the synthesized polyme r was not cis-PTE but trans-PTE. These results are discussed in terms of polaron and/or bipolaron models.