ELECTROCHEMICAL CHARACTERISTICS OF STABLE POLYACETYLENE DERIVATIVES - POLY(O-TRIMETHYLSILYLPHENYLACETYLENE)

Activation phenomena have been observed in the cyclic voltammogram of the film of poly(o-trimethylsilylphenylacetylene) (PTMSiPA) prepared by the solution casting method. Upon electrochemical doping in PTMSiPA the absorption peak in the visible range due to the interband transition is suppressed and a new broad peak appears in the infrared range. Corresponding to this spectral change, the film changes from red to colorless. Spin density evaluated by ESR decreases with electrochemical doping and becomes negligibly small. These doping characteristics have been interpreted in terms of the solition model just as for the case of nonsubstituted polyacetylene, and the electronic energy scheme of this polymer has been evaluated. A relatively large diffusion coefficient (9.2 x 10(-8 cm2/s) of anion dopant (BF4-) was obtained in this film. It was also found to exhibit high Coulombic efficiency in the charge-discharge characteristics as a secondary battery.