VEH ELECTRONIC BAND-STRUCTURE OF POLY(PHENYLSILANE)

The electronic structure of all-trans syndiotactic and isotactic poly( phenylsilane) has been calculated using the valence effective Hamilton ian (VEH) method. The effects of attachment of the phenyl group on the electronic properties of polysilane are analysed in detail. The VEH r esults show a decrease of ionization potential and an increase of elec tron affinity which determine an important reduction of the bandgap. T hese features are correlated with sigma-pi and sigma-pi* interactions between the silicon backbone and the phenyl group.