Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The scattering of the hydrocarbon radical cation C₂D₄^•+ from room-temperature carbon (highly oriented pyrolytic graphite, HOPG) surface was investigated at low incident energies of 6-12 eV. Mass spectra, angular and translational energy distributions of product ions were measured. From these data, information on processes at surfaces, absolute ion survival probability, and kinematics of the collision was obtained. The projectile ion showed both inelastic, dissociative and reactive scattering, namely the occurrence of H-atom transfer reaction with hydrocarbons present on the room-temperature carbon surface. The absolute survival probability of the ions for the incident angle of 30° (with respect to the surface) decreased from about 1.0% (16 eV) towards zero at incident energies below 10 eV. Estimation of the effective surface mass involved in the collision process led to m(S)_eff of about 57 a.m.u. for inelastic non-dissociative collisions of C₂D₄^•+ and of about 115 a.m.u. for fragment ions (C₂D₃⁺, C₂D₂^•+) and ions formed in reactive surface collisions (C₂D₄H⁺, C₂D₂H⁺, contributions to C₂D₃⁺ and C₂D₂^•+). This suggested a rather complex interaction between the projectile ion and the hydrocarbon-covered surface during the collision.

Keywords: Ion-surface scattering; Low-energy collisions; Ethylene cation; Carbon surface; Ion survival probability.

References: 24 live references.