Charge transfer and collision-induced dissociation reactions of CF2+ and CF2+2 with the rare gases at a laboratory collision energy of 49 eV

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Abstract
Multiple product channels are observed for the reactions of CF2+ and CF2+2 with the rare gases at a laboratory collision energy of 49±1 eV. A dication beam is produced in an electron impact ion source and mass selected using a quadrupole mass spectrometer. The ion beam is focused into a collision region and a time‐of‐flight mass spectrometer is used to monitor the reaction products. Reactions of CF2+ produce CF+, C+, and F+ ions and reactions of CF2+2 result in CF+2, CF+, C+, and F+ ion formation accompanied by the corresponding rare gas ions when charge transfer occurs. The relative yields of these products are measured directly. For reactions of both dications, there is a substantial increase in the total reaction cross section as the rare gas collision partner changes from He to Xe. Collision induced dissociation is the primary reaction between CF2+ and He, while charge transfer dominates the reactions involving Ne through Xe. Stable CF+ states are populated during charge transfer between CF2+ and Ar. Dissociative charge transfer to form C+ ions and F atoms is favored for collisions of CF2+ with Ar, Kr, and Xe. Both He and Ne undergo almost exclusively collision induced dissociation reactions with CF2+2. Nondissociative charge transfer to populate stable states of CF+2 is the most important reaction pathway in collisions of Ar with CF2+2, and dissociative charge transfer to form CF+ ions and F atoms is the principal reaction of Kr and Xe with CF2+2. The trends in charge transfer reactivity are successfully modeled using Landau–Zener theory.