Rapid sulfation kinetics of fullerene in oleum-oxide mixtures

Fast kinetics of fullerene sulfation reaction was observed in H2SO4-SO3 (28-30%) in the presence of metal oxides, such as V2O5 and, to a lesser extent, SeO2, showing nearly spontaneous production of hexacyclosulfated C-60. Detection of dodecahydroxylated C-60 in the reaction products revealed formation of hexacyclosulfated C-60 even at an early stage of reaction. Partially sulfated C-60 molecules exhibit a higher reactivity toward further sulfation than the parent fullerene molecules. A much faster sulfation rate of C-60 in comparison with that of C-70 under similar reaction conditions allows one to produce relatively pure dodecahydroxy[60]fullerene from a mixture of C-60 and C-70.