Localization of excitations in silicon chains by electron donating side groups

Abstract

The fluorescence decay kinetics in the copolymer, poly(phenylmethyl-co-p-dimethylanilinemethyl silane) have been studied by steady state and time correlated fluorescence spectroscopy and three absorbing and emitting species are proposed to explain the complex fluorescence decay behaviour. In the case of poly(phenyl methyl silane) homopolymer, excitations have been shown to delocalize over several tens of monomer units, however, in the copolymers discussed here the extent of the delocalization has been shown to be dependent on the degree of substitution of the dimethylaniline side group. In the more highly substituted copolymers the excitations are shown to be confmed to almost a single monomer unit by the electron donating nature of the dimethylaniline side group. A simple geometric distribution of chain lengths is used to predict the delocalization length of the excitations.