We were the first to observe two emission bands in the visible region
for some kinds of ammonium-type amphiphilic polysilanes both in soluti
ons and in thin films. One, a broad emission band at 400-500 nm not du
e to a sigma-->sigma transition, was observed only for methylphenylsi
lane-based polymer solutions. The appearance of this low-energy emissi
on is reasonably explained by considering the intramolecular exciplex
formation between a Si-conjugated main chain and an ammonium site in t
he same monomer unit. The other, an emission band at the longer wavele
ngth (around 560 nm), was found in the solvent-cast films where each m
olecule is randomly located, in addition to that observed for the solu
tions. This emission, which was not observed for the oriented LB films
, is considered to originate from an intermolecular interaction. (C) 1
997 Elsevier Science B.V.