Synthesis and characterization of exohedrally silylated M@C82 (M = Y and La).

The silylation of endohedral mono-metallofullerenes (Y@C(82) and La@C(82)) and isolation of the corresponding adducts by HPLC separation have been accomplished. The redox properties of the silylated mono-metallofullerene were first clarified by CV and DPV measurements, indicating that the bis-silylated mono-metallofullerenes have lower oxidation and higher reduction potentials than the parent mono-metallofullerenes. These results reveal that bis-silylation is very effective for producing the electronegatively mono-metallofullerene derivatives as well as empty fullerenes.