Molecular interaction in langmuir-blodgett films of amphiphilic polysilanes

Chemically modified amphiphilic polysilanes with ammonium side chains showed quite new emission bands in the visible region other than the fluorescence of polysilanes via singlet σ^*. The new emission bands are ascribed to the exciplex formation between an ammonium site and a side chain phenyl ring or a silicon conjugated segment. The exciplex emission bands basically consisted of two bands (450nm and 560nm) in ion beam induced emission spectra. Both two bands were observed for random casted films of this amphiphilic polysilane, though only shorter one was observed for the films oriented by means of Langmuir-Blodgett technique, This emission spectral difference is explained by the difference in the degree of molecular orientation of these films. The changes in the inter- and intramolecular interaction are discussed in the present paper comparing the microstructures in LB films with that in random casted films of the amphiphilic polysilanes.