Gas phase ion thermochemistry based on ion-equilibria From the ionosphere to the reactive centers of enzymes

The discovery that ion-molecule equilibria can be determined in the gas phase with mass spectrometers, which was made accidentally with a high-pressure mass spectrometer constructed for other purposes, has led to the development of a vast field of gas-phase ion-equilibria determinations with mass spectrometers. Data have been obtained for many thousands of important reactions, such as the ion-solvent molecule and ion-ligand bonding interactions, basicities of bases B and acidities of acids AH in the gas phase, stabilities of carbocations, and electron affinities of molecules. The data have applications in many areas of chemistry. Examples of such applications are given. (C) 2000 Elsevier Science B.V.