Bond-Forming Chemistry in the Gas-Phase Reactions of Atomic and Molecular Dications and Trications

Abstract

Over the last 20 years, an increasing body of experimental work has shown that electron transfer is not the only route that can form product ions following the collisions of atomic and molecular dications with neutral molecules. At low collision energies, reactions forming species with new connectivity can compete effectively with simple electron-transfer processes. This article describes the experimental techniques that are used to investigate molecular dication reactivity. Such experiments have shown that a wide range of reactions can generate products in these dication–neutral collision systems. To illustrate this point, we review a series of representative experimental results, work that illustrates the major classes of dicationic bond-forming reactivity. Following these examples of representative reactivity, a simple model rationalizing the reactions is presented and discussed. The model explains the classes of product formed from dication–neutral collision systems in terms of the reactant and product interactions and energetics. Extending this model to trication–neutral interactions allows an explanation of the recently observed bond-forming reactions of molecular and atomic trications.