The kinetic method of making thermochemical determinations

This critical examination of the kinetic method is carried out as part of a dialog-in-print with Peter Armentrout and László Drahos and Károly Vékey. We summarise the characteristics of the kinetic method and try to place it in the context of other thermokinetic methods of making thermochemical determinations, especially the threshold collision-induced dissociation method. We cover the approximations made in deriving the method and tabulate five forms of the method which have been used over the past 21 years. We show that many criticisms of the method apply to the simplest forms and, conversely, that a great deal of information can be obtained from those forms which do not assume that entropy effects cancel. A number of cases of apparent failure of the method are examined, including the alcohol/Li+ case described by Armentrout. We encourage continued use of each of the thermochemical methods but recommend that these uses be informed by knowledge of the subtleties of deriving thermochemical information from relative rate measurements.