Laser Flash Photolysis Study of Photophysical and Photochemical Properties of a Higher Fullerene, C₇₆

Photophysical and photochemical properties of C 76 have been investigated by using nano- and picosecond laser flash photolysis methods. In the nanosecond laser flash photolysis of C 76, transient absorption ascribable to the triplet excited state of C 76 ( T C 76 *) was observed in the visible and near-IR regions. From the generation of the absorption band of T C 76 *, the lifetime of the singlet excited state was estimated to be 1.7 ns. Under the presence of β-carotene in toluene, T C 76 * was deactivated by energy transfer to β-carotene at a 2.6 × 10 9 M -1 s -1 rate constant. Electron-transfer reaction to T C 76 * was also confirmed in a benzonitrile solution containing C 76 and tetramethyl- p -phenylenediamine (TMPD) as an electron donor. A bimolecular rate constant for quenching of T C 76 * by TMPD was estimated to be 7.8 × 10 8 M -1 s -1 .