Effect of Diffusion on Transfer of Electronic Excitation Energy

Abstract

The transfer of electronic excitation energy between naphthalene, acting as donor, and anthranilic acid, acting as acceptor, in a variety of alcohols, was investigated. The efficiency of energy transfer in all of the solvents used was different from the value to be expected according to the theory of Förster. The transfer efficiency was considerably higher in alcohols of low viscosity than in alcohols of high viscosity. This was attributed to the variation of intermolecular distance between donor and acceptor, as a result of Brownian motion, during the lifetime of the excited donor. Fair agreement was found between the experimental data and the values calculated according to theoretical treatments of nonradiative energy transfer in which diffusion has been taken into consideration.