Quenching of photoluminescence of solutions by electronic excitation transfer

Abstract

Based on the shell model of a luminescent centre and on the Forster theory of intermolecular energy transfer, an expression for the decrease in sensitizer S quantum yield with increasing acceptor A concentration is derived. The dependence of the probability of resonance excitation energy transfer on mutual orientation of the transition moments of the interacting molecules S and A, as well as the fluctuations of the concentration of the acceptor molecules A was taken into account. The quenching of electronic excitation energy of fluorescein, acting as sensitizer, by rhodamine B, action as acceptor, and 2,5-diphenyloxazole by 9,10-dibromoanthracene in glycerol and cylohexane respectively, was investigated and compared with the theory. Fair agreement was found between the experimental data and the values calculated according to theoretical treatment.