ABSTRACTFive cyclic adducts C60C4H6, C60C5H6, C60NHCO2, C60NCO2Et, and C60CHCO2Et have been synthesized and their absorption and fluorescence spectral properties investigated and compared with those of the parent. Breaking the structural symmetry of C60 apparently resulted in enhancing the quantum yield two to three-folds in some adducts and thus made fluorescence much easier to be measured at room temperature. New absorption bands and altered fluorescence spectra were observed in the adducts. The Stokes' shifts of the adducts were small, about 4-5 nrm, compared to 68 nm for the parent compound. All the adducts exhibited a single fluorescence lifetime about the same as C60 (ca. 1.3 ns). Aliphatic solvents had little influence on the absorption or fluorescence spectral profile except on the molar absorptivity whereas aromatic and polar solvents strongly interacted with the adducts causing a peak broadening effect.