Photophysical properties of higher fullerenes C-76 and C-84 were investigated in toluene by steady-state and transient absorption spectroscopy. Lifetimes of 75 and 35 ps were measured for the lowest excited state of C-76 and C-84, respectively, which are much shorter than the values estimated from previous triplet-triplet absorption studies. It was found that the internal conversion rate constants, k(IC), increased as the size of fullerene increased, and that k(IC) was strongly correlated with the HOMO-LUMO energy gap, DeltaE(g). From this correlation, an empirical relationship was obtained: log k(IC) (s(-1)) = 14.59 - 3.39 DeltaE(g) (eV). (C) 2003 Elsevier Science B.V. All rights reserved.