Dissolving Metal Reductions of Fullerenes

Treatment of fullerenes with reducing metals and a proton source leads to the formation of hydrogenated fullerenes (C₆₀H_n and C₇₀H_n). The reaction of C₆₀ with a variety of metals was investigated, using metals that span a broad range of reducing power, from tin (E° = -0.14 V) to magnesium (E° = -2.36 V). We report useful synthetic routes to a number of reduced fullerenes, including C₆₀H₂, C₆₀H₄, and C₆₀H₆, and we have determined that, despite the huge number of isomers that are possible, a small number are actually formed in these cases. For example, only two isomers of C₆₀H₆ are obtained in the Zn(Cu) reduction of C₆₀, in a 6:1 ratio. Three isomers of C₇₀H₁₀ are produced, in ratios that are dependent on reaction time.