Smoluchowski equation for systems which do not obey the Stokes-Einstein relation

Abstract

Experimental rate constants for the transfer of electronic excitation energy from naphthalene, phenanthrene and chrysene to biacetyl were obtained in hexadecane, from the measured quenching coefficients and the directly measured lifetimes. These rate constants were compared with rate constants calculated from the Smoluchowski equation using measured diffusion coefficients and assuming that the transfer radii are of similar magnitude as the kinetic radii. Diffusion coefficients for biphenyl, acetone, methyl ethyl ketone and diethyl ketone were also measured in hexadecane at 30°C and compared with values estimated by various theoretical and semi-empirical relations.