Ion cyclotron resonance studies on the reaction of H2+ and D2+ ions with various simple molecules and hydrocarbons

Abstract

The rate constants and product distributions for the reactions of H2+ ions with N2, O2, and CO, and for the reactions of both H2+ and D2+ ions with CH4, CD4, NH3, H2O, H2S, C2H2, C2H4, and C2H6 have been measured by ion cyclotron resonance methods. Proton transfer dominates in the reaction with diatomic molecules, and charge transfer dominates in the reaction with polyatomic molecules. However, a significant amount of charge transfer was observed in the reaction of H2+ ions with O2 and CO, and a significant amount of proton transfer was observed in the reaction of H2+ ions with H2O. The reaction with methane to form methyl cations appears to involve a superposition of both dissociative charge transfer and proton transfer followed by H2 elimination. The extent of fragmentation resulting from H2+ charge exchange to CH4 is on the order of that observed in photoionization and Penning ionization of CH4 at 16 eV total available energy, and much larger than is observed in electron impact of CH4 at 16 eV.