ION-BEAM STUDIES OF ATOMIC ION COLLISIONS WITH C-60 - CHEMISTRY AT SURFACE, SUBSTITUTIONAL, AND ENDOHEDRAL SITES

Results are presented for scattering of B+, F+, Fe+, and C-2(+) from C -60, and comparisons are made with similar results for other atomic io n-C-60 systems. The experiments were carried out in a guided-ion beam tandem mass spectrometer, over a collision energy range from 2 to 80 e V. All these species undergo efficient charge transfer with C-60, but their tendency toward chemical reaction was observed to vary dramatica lly. For B+, C+, C-2(+), and 0(+), no activation barrier is observed f or formation of AC(60)(+) adducts (A = B, C, C-2 etc), which are stabl e enough to survive our millisecond time, N+ reacts to form abstractio n and substitutional products, but with a substantial activation barri er. Aside from charge transfer, F+ does not react at all. Fe+ appears to form two distinct FeC60+ complexes, with different activation energ ies and stabilities. At higher collision energies, a variety of both c hemical and dissociative charge transfer products are observed.