Theoretical study of the migration of electronic excitation along the polymer chains in conformation motion

Abstract

The approach of the effective medium approximation (EMA) has been used for the description of incoherent migration of electronic excitation. The migration takes place among the chromophores linked into a polymer chain which is in conformational motion. The polynomial equation, corresponding to two relative positions of neighbouring chromophores, yields the hypersurface of the effect rate coefficients W eff( Z) of the migration, where z is the parameter of the Laplace transformation. The inverse Laplace transformation of functions of W eff( Z) gives the mean-square distance and the diffusion coefficient D( t) of the migration of excitation. The dependence of D( t) as well as of its limit value for long time D(∞) on the rate of the trans⇄ gauche (T⇄G) conformational motion has been outlined for the polyvinylnaphthalene (PVN) chain.