Abstract
Photophysical properties and reactivities of water‐soluble micelle‐like C60 derivative, C60((CH2)4SO3Na)6 (abbreviated as FC4S), at the excited triplet state were investigated using laser flash photolysis. A new transient absorption band appearing at ca. 700 nm was attributed to the triplet–triplet (T‐T) absorption band of FC4S. This absorption was quenched by O2 via energy transfer forming singlet oxygen, which was confirmed by its luminescence emission band; the quantum yield was evaluated to be 0.36.