Novel Oxidative Nucleophilic Chemistry Enroute to The Synthesis of C60 Fullerols

ABSTRACTWe have demonstrated a novel cyclosulfation chemistry for the functionalization of C60 Molecules and a new route to the synthesis of fullerol. The cyclosulfation reaction of C60 was performed in neat fuming sulfuric acid at 55–60 °C under N2. Hydrolysis of these derivatives in the presence of water at 85–90 °C or in aqueous NaOH solution at ambient temperature gave the corresponding polyhydroxylated fullerenes (fullerols) in high yield. Various spectroscopie methods were used to resolve the chemical structure of fullerol. An average of 10 to 12 hydroxyl addends was found in fullerols that can be correlated to the structure of polycyclosulfated fullerene precursors containing 5 to 6 cyclosulfate units. The cyclosulfation chemistry is, presumably, initiated by an one-electron oxidation reaction on C60 Molecules, followed by the attack of nucleophilic anionie sulfate species onto the resulting cationic C60 radical intermediates. Further electron oxidation and intramolecular cyclization of the resulting hydrogen sulfated C60 yielded the desired polycyclosulfated C60 products.