Addition of S-Heterocyclic Carbenes to Fullerenes: Formation and Characterization of Dithiomethano-Bridged Derivatives

The reactions of novel S-heterocyclic carbenes (SHCs), which were prepared by the cycloaddition of disilenes and digermenes to CS2, with C-60 and Sc3N@I-h-C-80 afforded the corresponding methano-bridged fullerenes. The [6,6]-closed and [6,6]-open structures were characterized for the SHC adducts of C-60 and Sc3N@I-h-C-80, respectively. These derivatives exhibited relatively low oxidation potentials, indicative of the electron-donating effects of the SHC addends. The electronic properties of the SHC derivatives were clarified by the density functional theory calculations.