Quenching of diphenylmethane triplet by energy transfer to diphenylmethyl radical in solution

Abstract

Energy transfer from the diphenylmethane triplet to the diphenylmethyl radical in n-heptane solution has been studied by nanosecond fluorescence and absorption spectroscopy. Both the triplet and the radical are produced by excitation of diphenylmethane with a 266 nm pulse, and the sensitized fluorescence of the radical is observed. A unimolecular rate of (2.9±0.1)×105 s-1 for decay of the triplet and a bimolecular rate of (1.8±0.5)×1010 d mol-1 s-1 for quenching of the triplet by the radical are obtained.