Photoinduced electron transfer from tetraethoxyethene to C60 and C70 studied by laser flash photolysis

Abstract

The electron transfer from tetraethoxyethene (TEOE), which has high electron-donor ability, to photo-excited C60 or C70 in polar and less polar solvents has been investigated by 532 nm laser flash photolysis with observation of the transient absorption bands in the near-IR region. The transient absorption bands of the triplet states of fullerenes (TC60* and TC70*), which appeared immediately after nanosecond laser exposure, were effectively quenched by TEOE. With the decay of TC60* and TC70*, the absorption bands of C60˙- and C70˙- appeared at 1070 and 1380 nm, respectively, showing that the electron transfer takes place from TEOE to TC60* or to TC70*. Then, C60˙- and C70˙- disappear by back electron transfer to TEOE˙+. The efficiencies and rates of the electron-transfer reactions vary with solvent polarity.