The triplet excited state behavior of C-84 has been probed by the triplet-triplet energy transfer method using pulse radiolytically generated biphenyl triplets in benzene. The tripler excited state has a weak absorption in the UV (difference absorption maxima at 310 and 345 nm) but no significant absorption in the visible. The rate constants for energy transfer from (BP)-B-3* and 3C(60)* are 4 x 10(9) and 4.7 x 10(9) M(-1) s(-1) respectively. Tripler excited state properties of C-3(84)* are compared with other fullerenes. A photocatalytic method has also been successfully employed to reduce C-84 in a UV-irradiated colloidal TiO2 suspension.