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.