Photoinduced electron transfer of the triplet states of C 60 and C 70 from oxotitanium(IV) tetra- t-butyl-phthalocyanine as an electron-donor in polar solvent

Abstract

Excited triplet state properties of oxotitanium(IV) tetra- t-butyl-phthalocyanine (OTiPc) were investigated by the laser flash photolysis observing the transient absorption bands in the near-IR region. Photoinduced energy and electron transfer processes of the excited triplet states of C 60 and C 70 in the presence of OTiPc take place depending on the solvent polarity. In PhCN, slower formations of the ion radicals after the rapid decays of the triplet excited states of C 60 and C 70 were observed, suggesting the presence of the intermediates (i.e. triplet exciplex) for electron transfer. In longer time-scale, freely solvated radical ions show second-order back electron transfer.