Threshold collision-induced dissociations for the determination of accurate gas-phase binding energies and reaction barriers

Over the past two decades, an analysis of the kinetic energy dependence of ion molecule reactions has proven to yield accurate thermochemistry for a wide range of interesting chemical species. In this article, the experimental methods required to collect the data, most notably guided ion beam mass spectrometry, are reviewed along with a comprehensive overview of the details of the requisite data analysis. Although the emphasis of the article is on collision-induced dissociation (CID) reactions, similar methods can also be applied to endothermic bimolecular reactions. For CID studies, the systems are generally chosen such that the threshold corresponds to the bond energy desired, but studies in which reaction barriers have been measured are also reviewed. The range of chemical systems accessible by these techniques is wide and includes small covalently bound molecules (both inorganic and organic), small non-covalently bound complexes, metal ligand complexes, metal clusters, isomeric forms, and systems involving biologically relevant molecules. A fairly comprehensive review of various studies of such systems is included.