Transfer reactions, exothermic fluoride

A couple of significant examples of the use of halide transfer reactions for the investigation of reaction mechanisms and of the structure of gaseous cations, the second field of application of these processes, are given below. More examples are reported in Section II.B. The first example concerns the reaction of the 2-fluoropropyl cation (1) with its neutral precursor /-butyl fluoride to yield the /-butyl cation, a reaction which could proceed either via F abstraction or via H+ transfer and HF elimination, both routes being exothermic (Scheme l)6. Collection of the neutral products by means of the EBFlow... 

Compton studied the formation of both positive and negative ions by electron ionization and electron attachment in UFs (Compton, 1977). The cross section for the electron ionization of UFe from the threshold electron energy, 14 eV, to 1 keV exhibited a maximum of 18 at 160 eV. Reactions of UFs with electrons and alkali metal atoms to produce uranium fluoride anions confirmed the high electron affinity of UFe and demonstrated that D(UF5 —F) and D(UF5-F ) are similar, to within 1 eV, but are both 2 eV greater than D(UF5-F). That the U—F bonds are stronger in UFe" than in UFs reflects the large electron affinity of UFe. Streit and Newton reported that exothermic electron transfer from halide anions and SFe to UFe occurs close to the collisional rate (Streit and Newton, 1980), a result that renders particularly intriguing the nonoccurrence of thermoneutral Eq. 8 due to an unanticipated barrier. 

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