Bond-forming and electron transfer reactions following collisions of CF22+ with H2X (X = O, S)

Abstract

The ionic products of the electron transfer and chemical reactions which occur following collisions of CF₂²⁺ with H₂X (X = O, S) have been identified by time-of-flight mass spectrometry. The integral reaction cross sections, in arbitrary units, for forming the CF⁺ and CF₂⁺ ions which are products of electron transfer reactions and the XCF⁺ products of the chemical reactions, have been determined. In collisions of CF₂²⁺ with H₂O the electron transfer reactions favour the formation of H₂O⁺, together with approximately equal amounts of CF⁺ and CF₂⁺. Electron transfer reactions between CF₂²⁺ and H₂S, on the other hand, favour the formation of H₂S⁺ together with CF⁺, with CF₂⁺ and C⁺ generated in significantly smaller quantities. A Landau–Zener model has been employed to account for the relative abundances of the product ions from electron transfer. The chemical reaction forming OCF⁺ from collisions between CF₂²⁺ and H₂O is distinctly more probable than the formation of SCF⁺ from collisions with H₂S. The partner ion formed together with the XCF⁺ ion in both chemical channels appears to be H⁺. Such significant rearrangement in the atomic connectivity between reactants and products is strongly indicative of a mechanism involving a collision complex.