Fates of the molecular anions of SF6 and C7F14 upon recombination with positive ions

Experiments are described by which the fates of the molecular anions of sulfur hexafluoride, SF6, and perfluoromethylcyclohexane, C7F14, upon recombination with positive ions are determined in nitrogen buffer gas at a pressure of 1.33 atm from 30°C to 180°C. It is shown that C7F14- is converted primarily back to the parent molecule, C7F14, by its ion/ion recombination (IIR) reactions, while SF6- is converted primarily to unknown altered neutrals by its IIR reactions. These results are in very good agreement with those previously obtained by Valkenburg et al. [J. Chem. Phys., 86 (1987) 6782] using a different experimental method. The implications of the present results with respect to the fates of SF6 and C7F14 in the Earth's atmosphere are discussed.