Charge recombination in photoexcited charge transfer complexes between fullerenes and triphenylamine. Effect of the solvent polarity

The relaxation of photoexcited charge transfer complexes between C60 and C70 fullerence molecules and triphenylamine was studied by the picosecond laser photolysis technique in solvents of various polarities. A scheme of transitions from the radical-ion pair state to the ground and local-excited states of the complex was proposed. The rate constants of the transition between the radical-ion and local excited states were calculated in terms of the one-mode electron transfer model. The suggested scheme of transitions in excited complexes is sufficient for the description of the main kinetic regularities in this system and the dependence of the yield of triplet fullerene on the polarity of the medium upon the relaxation of the complex.