Surface-induced reactions and decomposition of the benzene molecular ion C 6H 6+: Product ion intensities, angular and translational energy distributions

Abstract

Surface-induced decomposition of benzene molecular ions (impact energy range 19–30 eV) and hydrogen atom abstraction from surface adsorbates leading to the production of a protonated benzene ion, were investigated using two different types of scattering apparatus. In addition to determining relative abundances of the product ions (mass spectra), we have measured the angular and translational energy distributions of the major product ions. All product ions show a strongly inelastic scattering behavior, with a maximum in translational energy distribution at 2–6 eV and a maximum in angular distribution at angles (70–75°) lower than the specular angle (90°). For the projectile ion, besides inelastic scattering reactions, we also observed an elastic scattering channel of substantial abundance exhibiting its maximum at scattering angles (55–60°) lower than that for the other scattered ions. Differences in the translational energy spectra for C 6H 6 + and C 6H 7 + were used to deduce the reaction sequences leading to the various fragment ions observed in the product ion mass spectra.