Crystal structure of the 4 + 2 cycloadduct of photooxidized anthracene and C60fullerene

The structure of the title compound, 5,6-[(1R,10S)-2,9-dioxatricyclo[8.6.03,8.011,16]hexadecane-1,10-diyl]-(C60–Ih)[5,6]fullerene methanedithione 0.1-solvate, C74H10O2·0.1CS2, has tetragonal (P42/n) symmetry at 100 K. It has a unique eight-membered ring, with two incorporated O atoms in place of the original central ring of the anthracene. The distortion of the molecular geometry around the cycloadduct bonds corresponds to that seen in related fullerene derivatives. Close packing of the adduct forms cavities partially filled with disordered carbon disulfide solvent molecule. The 41% occupancy of the cavities yields an overall 1:0.103 adduct–solvent ratio. Reaction steps are described as light-assisted singlet-oxygen generation, peroxide, epoxide and dioxocin derivative formation and the final step of thermally activated cycloaddition.