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 el ectron-donor ability, to photoexcited C-60 or C-70 in polar and less p olar solvents has been investigated by 532 nm laser flash photolysis w ith observation of the transient absorption bands in the near-IR regio n, The transient absorption bands of the tripler states of fullerenes (C-T(60) and C-T(70)*), which appeared immediately after nanosecond l aser 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(.-) app eared at 1070 and 1380 nm, respectively, showing that the electron tra nsfer 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 effic iencies and rates of the electron-transfer reactions vary with solvent polarity.