Unusual triplet state relaxation in C60 oxide

Abstract

Abstract The photophysics of C 60 O has been investigated. The calibrated UV–visible absorption spectrum, fluorescence quantum yield, and triplet–triplet absorption spectrum are compared to those of C 60 . Intrinsic triplet decay is anomalous, with typically weak temperature dependence below 180 K but unusual strong activation ( E A =20 kJ mol −1 ) above. At 295 K, the triplet lifetime is only 4.2 μs, or 34 times shorter than that of C 60 . It is proposed that the activated decay channel involves reversible cleavage of the C–C epoxide bond. C 60 O efficiently quenches triplet C 60 with a rate constant of 3.6×10 9 M −1 s −1 .