Reaction of Ar 2+ with C 60 to produce C 60 3+ : first observation of double electron-transfer ionization?

Abstract

The gas-phase reaction of translationally cold Ar2+ ( 1S0) ions with C60 has been studied using a selected-ion flow tube (SIFT) apparatus. Amongst several product channels detected, which arose from competing reactions of contaminants (N2, O2, H2O) and from the He buffer gas itself as well as from the target process Ar2++C60, we observed an apparently minor but unambiguous signal due to a C603+ product ion. We surmise that this product channel arises from Ar2+ ( 1S0)+C60 in a bimolecular fashion, most probably by an initial (and highly exothermic) direct double electron transfer leading to the generation of either highly excited (C602+)* or of electronically excited (Ar) *. Trication formation from either of these possible high-energy intermediates would then follow according to either an autoionization or a Penning ionization mechanism. Show more