Ion–Molecule Reactions

Abstract

Ionized matter is ubiquitous in Nature, occurring over a large range of length scales and energy densities, in environments ranging from plasmas to condensed phases. In the gas phase, collisions that occur between ions and neutral atoms and molecules provide important microscopic routes for the formation of species that influence the macroscopic behavior of chemical and physical systems such as flames and planetary atmospheres. The term “ion–molecule” reactions generally applies to an entire class of gas phase collision phenomena in which electrons and atoms can be transferred among the approaching reactants to form products with new chemical bonds and distributions of charge. Such reactions are generally regarded as low energy phenomena, occurring over a collision energy range from thermal up to several eV.