Photoinduced electron transfer from tetraethoxyethene to C-60 and C-70 studied by laser flash photolysis

The electron transfer from tetraethoxyethene (TEOE), which has high electron-donor ability, to photoexcited C-60 or C-70 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 tripler states of fullerenes (C-T(60)* and C-T(70)*), which appeared immediately after nanosecond laser exposure, were effectively quenched by TEOE, With the decay of C-T(60)* and C-T(70)*, the absorption bands of C-60(.-) and C-70(.-) appeared at 1070 and 1380 nm, respectively, showing that the electron transfer takes place from TEOE to C-T(60)* or to C-T(70)*. Then, C-60(.-) and C-70(.-) disappear by back electron transfer to TEOE.+. The efficiencies and rates of the electron-transfer reactions vary with solvent polarity.