Photophysical properties of C60

A number of important photophysical properties of C{sub 60} have been determined, including its lowest triplet-state energy (near 33 kcal/mol), lifetime, and triplet-triplet absorption spectrum. The triplet state is formed in near quantitative yield and produces a very high yield of singlet oxygen by energy transfer. C{sub 60} does not react with singlet molecular oxygen and quenches it only slowly by an unknown mechanism. These results are discussed in terms of the unusual geometry of this molecule.