1998 J.C. Polanyi Award Lecture Fullerene ions in the gas phase: chemistry as a function of charge state

Abstract

Results of recent measurements in the Ion Chemistry Laboratory at York University using the Selected-Ion Flow Tube (SIFT) technique are surveyed for reactions of singly, doubly, and triply charged buckminsterfullerene C60n+ cations proceeding at room temperature in helium buffer gas at 0.35 Torr (1 Torr = 133.3 Pa). Measured rate coefficients and observed product channels for reactions with a variety of inorganic and organic molecules depend strongly on the charge state of the reactant ion. The measured rate coefficients span more than four orders of magnitude. Primary product channels observed include attachment, dissociative attachment, dissociative attachment with charge separation, single-electron transfer, dissociative single-electron transfer, and two-electron transfer. A qualitative description of the potential-energy profiles associated with these reaction channels is provided. The observed higher order chemistry of derivatized C60n+ cations and of atomic exohedral adduct ions is also described. This chemistry includes cation-transfer reactions, surface derivatization, and "ball-and-chain" polymerization. Finally, results are presented that provide insight into the influence of surface strain on the reactivities of fullerene ions.Key words: fullerenes, ions, electron transfer, charge separation, surface derivatization.