Preparation of poly(disilanylenetetracyanobutadienyleneoligothienylene)s as new donor–acceptor type organosilicon polymers

Treatment of poly(disilanyleneethynyleneoligothienyleneethynylene)s with tetracyanoethylene gave new donor–acceptor type organosilicon polymers bearing oligothienylene and tetracyanobutadienylene units as the donor and acceptor units, respectively. The polymers showed red-shifted absorption bands at λmax = 513–565 nm, whose edges reached approximately 800 nm, reflecting the donor–acceptor interaction in the backbone. These polymers exhibited solvatochromic behaviors and the UV–Vis absorption maxima moved to the longer wavelengths as increasing the solvent polarity. It was also found that these polymers were photoactive and irradiation of TiO2 electrodes in the polymer solutions led to attachment of the polymers on the TiO2 surface, likely due to the formation of Si–O–Ti anchor bonds. Applications of the resulting polymer-attached TiO2 electrodes to dye-sensitized solar cells were examined.