Gas-phase ion chemistry is a broad field which has many applications and which encompasses various branches of chemistry and physics. An application that draws together many of these branches is the synthesis of molecules in interstellar clouds. This was part of the motivation for studies on the neutralization of ions by electrons and on isomerization in ion-neutral associations. The results of investigations of particular aspects of ion dynamics are presented in this volume. Solvation in ion-molecule reactions is discussed and extended to include multiply charged ions by the application of electrospray techniques. This volume also provides a wealth of information on reaction thermodynamics which is critical in determining reaction spontaneity and availability of reaction channels. More focused studies are also presented towards the end of this volume, relating to the ionization process and its nature.