Mass Spectrometric Studies of Ion–Neutral Reactions in Perfluoroethane

Autor: T. O. Tiernan, R. E. Marcotte
Rok vydání: 1971
Předmět:
Zdroj: The Journal of Chemical Physics. 54:3385-3394
ISSN: 1089-7690
0021-9606
DOI: 10.1063/1.1675355
Popis: Ion–molecule reactions in perfluoroethane have been investigated using mass spectrometric techniques. Reaction trends observed in the high‐pressure mass spectrum of C2F6 are not consistent with kinetic data for the elementary fragment ion reactions determined in a tandem mass spectrometer. At very low kinetic energies (∼ 0.3 eV), C2F5+ undergoes collision‐induced dissociation while CF3+ reacts principally by a F− transfer process, both reactions being endothermic for ground state reactants. Charge transfer experiments with CF3+ and C2F5+ indicate that these ions have excess internal energies up to 2.9 and 2.4 eV, respectively, which can account for their endothermic reactions. Apparently, at higher pressures, some of the internal energy is degraded by nonreactive collisions, leading to unexpected differences in the reactivity of the fragments. Other reactions observed in the perfluoroethane system are F‐atom transfer and F2 transfer. The generally small rate constants (∼ 10−11 cm3/molecule·sec) determined...
Databáze: OpenAIRE