NOVEL SYNTHESIS, SPECTROELECTROCHEMICAL, ELECTROCHEMICAL AND CHRONOVOLTABSORPTOMETRIC CHARACTERIZATION OF POLY(ISOTHIANAPHTHENE)

Poly(isothianaphthene) (PITN, poly(benzo[c]thiophene)) has been synthesized via direct electropolymerization from 1,3-dihydroisothianaphthene (DHITN). The polymer as synthesized shows some small but significant solubility in organic media and can be reprocessed (recast) as films which are electroactive; characterization electrochemical data are reported. Spectroelectrochemical characterization data for virgin and reprocessed films show the characteristic development of IR absorption upon increased doping observed in earlier studies. DMF solutions of the polymer are electroactive and show irreversible reduction of the polymer to its saturated analog. Chronocoulometry and chronoamperometry show highly reversible charging behavior over 1000 cycles for pulses as short as 0.1 s and a characteristic switching time of c. 0.08 s. Chronovoltabsorptometry data (optical transmission at selected wavelength as a function of time and applied potential) at 830 nm show a clear polaron → bipolaron transition with a characteristic time of 0.04 s for 100 nm films. © 1990.