The dynamics and kinematics of the electron transfer reactions of CF[image omitted] with Ar

Abstract

The electron transfer reactions between CF [image omitted] and Ar have been studied using a position-sensitive coincidence time-of-flight mass spectrometer. The spectra show the formation of CF [image omitted], CF [image omitted] and CF [image omitted] ions, accompanied by Ar+ ions, by dissociative and non-dissociative electron transfer reactions. Analysis of the PSCO data shows that the CF [image omitted] and CF [image omitted] ions are formed by reactions of ground state CF [image omitted](2B2) ions. The CF [image omitted] product is formed in high lying vibrational states of its ground electronic state, just below the dissociation asymptote to [image omitted]. The formation of CF [image omitted] proceeds via a sequential mechanism, involving the population of highly excited vibrational levels of the ground electronic state of CF [image omitted] which dissociate to CF [image omitted](2A1) + F when the CF [image omitted] is well separated from the Ar+ ion. No evidence of complexation is observed. The energy dependence of the experimental yield of the CF+ ion is consistent with it arising from a reaction of an electronic excited state of CF [image omitted], as proposed in a previous study of this collision system. The unimolecular dissociation of the reactant dications is also observed and indicates that these ions are predominantly in their ground (2B2) electronic state. The kinetic energy release of this unimolecular reaction indicates the metastable well of the CF [image omitted](2B2) state is approximately 3 eV deep and also shows that CF [image omitted](2B2) ions well below the barrier to charge separation can dissociate on the time-scale of the experiment. This observation implicates predissociation, possibly via a repulsive dication state, as the mechanism for the unimolecular charge separation of the ground state of CF [image omitted].