Halogen and interhalogen reactions with [60]fullerene: Preparation and characterization of C60Cl24 and C60Cl18F14

U.V. irradiation of a solution of [60]fullerene in carbon tetrachloride saturated with chlorine gave a yellow solid, the negative ion FAB mass spectrum of which is consistent with the presence of C60Cl24. When a solution of [60]fullerene in CCl4 was mixed with IF5, a yellow solid was deposited in the denser IF5 layer. The negative ion FAB mass spectrum of this material indicated it to be C60Cl18F14. This result provides the first confirmation that halogenation of fullerenes is a radical process. Fluorination of C60Br8 gave a range of fluorinated products, having a maximum fluorine content of ca. 36 fluorines per cage, and with either C60F18 or its mono-oxide as major species. EI mass spectrometry of the products at various temperatures indicates that the more highly fluorinated fullerenes are either less stable to heat, or are more volatile.