Flowing Afterglow Studies of the Reactions of the Rare-Gas Molecular Ions He2+, Ne2+, and Ar2+ with Molecules and Rare-Gas Atoms

Abstract

The flowing afterglow technique has been used to measure rate coefficients and product channels for the reactions of He2+, Ne2+, and Ar2+ with the rare-gas atoms Ne, Ar, and Kr, and with the molecules NO, O2, CO, N2, and CO2 at 200°K. These reactions are found to proceed principally by asymmetric charge transfer. The experimental results for the reactions of the rare-gas molecular ions with rare-gas atoms indicate a correlation between reaction probability and reaction exoergicity analogous to that observed for asymmetric atomic ion–atomic neutral charge-transfer reactions. The reactions with molecules are found to proceed with unit reaction probability with the exception of the reactions Ar2++O2 and Ar2++NO. The reaction probability for the reactions of the molecular rare-gas ions with molecules is not very sensitive to an energy resonance criterion. Finally, rate coefficients and reaction channels for the reaction of the mixed rare-gas molecular ions HeNe+, ArKr+, and ArCO+ with Ne, Kr, and CO, respectively, are reported.