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 pha se with mass spectrometers, which was made accidentally with a high-pressur e mass spectrometer constructed for other purposes, has led to the developm ent of a vast field of gas-phase ion-equilibria determinations with mass sp ectrometers. Data have been obtained for many thousands of important reacti ons, such as the ion-solvent molecule and ion-ligand bonding interactions, basicities of bases B and acidities of acids AH in the gas phase, stabiliti es of carbocations, and electron affinities of molecules. The data have app lications in many areas of chemistry. Examples of such applications are giv en. (C) 2000 Elsevier Science B.V.