In the two decades since the discovery of elementary reactions at low temperatures, numerous specialized reviews of separate lines of research into these phenomena have emerged. A substantial body of experimental data has enabled the development of models that shed light on the multidimensional character of tunneling and the effects of non-tunneling intra- and inter-molecular vibrational modes. Theoretical work concerning similar ideas in the quantum transition state theory has been applied to gasphase reactions in the region below the energy threshold. Supersonic jet cooling and high-resolution spectroscopy have revealed multidimensional tunneling in isolated molecules and dimers. As a consequence of this rapid proliferation of research data, the need has never been greater for a survey of the entire field. Offering an examination of multidimensional tunneling and its manifestations in the various branches of chemical physics, Chemical Dynamics at Low Temperatures fulfills that need. It presents a comprehensive overview of the subject, including developmental history; formulation of general problems and the main approximations used to solve them; specific features of tunneling chemical dynamics; one-dimensional tunneling in the path integral formalism; special problems of two- and multidimensional tunneling; and an extended presentation of pertinent experimental results. The purpose of this book is to stimulate further research, as well as to provide a graduate level introduction to low-temperature chemistry.

All topics are treated in sufficient detail for researchers to identify promising areas for new investigation. For chemical physicists there is an untamed wilderness of unsolved problems to which modern quantum mechanical methods can be applied. Experimentalists, meanwhile, will find deep analogies between seemingly unrelated tunneling phenomena being discovered by researchers working in a variety of fields.