Irena Y. Bronstein-Bonte

Photoinduced electron transfer quenching of rhodamine B in polymer films

Abstract Photoinduced electron transfer reactions of rhodamine B with several redox quenchers in solution-cast films of poly(N-vinylpyrrolidone) have been investigated using fluorescence spectroscopy. The quenching of the rhodamine B fluorescence has been used to examine the efficiency of photo-induced electron transfer in a rigid amorphous polymer matrix. The data obtained show that the electron transfer efficiency is a function of the free energy of the transfer and depends on the redox potential of the quencher. The data are analyzed using theories of electron transfer in solid media and are correlated with the redox potentials of the quenchers to derive the distance dependence of the excited state transfer. Photoinduced electron transfer between rhodamine B and both donor and acceptor quenchers in the cast polymer films is observed to occur at distances of up to about 15 A for this system.