Synthesis of Octadecahydroxylated C₇₀

Abstract

Synthesis of novel hydrophilic [70]fullerenols was described. The reaction involved an oleum-induced oxidative sulfation of the C₇₀ molecules with a product yield of 86%. The rate of fullerene sulfation was accelerated either moderately or greatly by the addition of P₂O₅ or SeO₂, respectively. Hydrolysis of the resulting polycyclosulfated C₇₀ in H₂O at 80°C afforded [70]fullerenols in a yield of more than 72%. The negative ion MALDI-TOF mass spectrum of [70]fullerenols showed a well-defined pattern of ion fragmentations with a nearly constant, consecutive weight increase in 17 mass units from the mass of C₇₀. Detection of a molecular ion at m/z 1146 was indicative for the composition of [70]fullerenols as octadecahydroxyfullerenes, containing 18 hydroxy addends per C₇₀ cage. That correlates the structure of their polycyclosulfated precursors to nonacyclosulfated [70]fullerenes, C₇₀(SO₄)₉.