O++C60 - C60O+ PRODUCTION AND DECOMPOSITION, CHARGE-TRANSFER, AND FORMATION OF C59O+ - DOPEYBALL OR [CO-AT-THE-COST-OF-C58]+

The reaction of O+ with C60 has been studied over a collision energy range from 2 to 77 eV. At collision energies below 10 eV, we observe formation of the metastable C60O+ adduct, as well as charge transfer and chemically driven fragmentation processes. As energy increases, the adduct decomposes to form C60+, C59+ and C58+. At higher collision energies, in addition to the expected series of C60-2n+ fragments, we observe odd-sized fullerene oxides, C59-2nO+, n = 0-4. These could be either O-substituted fullerenes (dopeyballs) or endohedral CO complexes of the form [CO@C58-2n]+. Our evidence is most consistent with the endohedral CO structure, which would be the first example of a molecule collisionally trapped inside a fullerene. We also examined collisions of CO+ with C60, however only C60-2n+ fragment ion production is observed.