Bond-forming and electron-transfer reactivity in the collisions of CF₂²⁺ with NH₃

Abstract

The ionic products formed in collisions between CF₂²⁺ and NH₃ have been detected and identified as a function of the centre-of-mass collision energy (0.5–4 eV). Electron-transfer reactivity is found to be responsible for the major proportion of these product ions (CF₂⁺, CF⁺, NH₃⁺, NH₂⁺ and C⁺) and their relative intensities can be rationalised by the use of Landau–Zener theory. This analysis indicates, in common with previous studies, that CF₂²⁺ beams contain ions in more than one long-lived electronic state. In addition to electron-transfer reactivity, a bond-forming reaction producing HNCF⁺ is also detected and isotopic labelling confirms that this weak product ion signal is indeed a result of collisions between CF₂²⁺ and NH₃. The variation in the HNCF⁺ ion yield as a function of collision energy suggests that this bond-forming reaction proceeds via a different mechanism to the previously investigated ‘chemical’ reaction between CF₂²⁺ and D₂.

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