PRODUCTION OF ENDOHEDRAL YTTRIUM FULLERENE CATIONS BY DIRECT LASER VAPORIZATION

Direct laser vaporization of samples containing graphite, yttrium oxide, and fullerenes is used to generate gas-phase yttrium-fullerene adduct ions, Y(x)C(n)+ (x = 1, 2 with even-numbered n = 60-100), in a Fourier transform ion cyclotron resonance mass spectrometer. Collision-induced dissociation and oxidation reactions are used to compare these species with externally-bound adducts, Y(C(n))+, generated by gas-phase association reactions. The stability toward fragmentation and the remarkable oxidative stability suggest that the laser-generated species have endohedral structures, Y(x) @ C(n)+. Possible mechanisms are considered for the production of these endohedral metal-containing fullerene cations.