ABSTRACT
The effect of the condensed phase environment on chemical reaction rates has been extensively studied over the past few decades. The central framework for understanding these effects is provided by the transition state theory (TST) [1, 2] developed in the 1930s, the Kramers theory [3] of 1940, the Grote-Hynes [4] and related theories [5] of the 1980s and 1990s and the Yamamoto reactive flux correlation function formalism [6] as extended and further developed by a number of workers [7, 8]. Each of these seminal theoretical breakthroughs has, in turn, generated an enormous amount of research in its own right. There are many good reviews of this body of literature, some of which are cited in [5, 9-12]. It therefore serves no useful purpose to review the field again in the present chapter. Instead, the key issues involving condensed phase effects on chemical reactions will be organized around the primary theoretical concepts as they stand at the present time. Even more importantly, the gaps in our understanding and prediction of these effects will be highlighted. From this discussion it will become evident that, despite the large body of theoretical work in this field, there are significant questions that remain unanswered, as well as a need for greater contact between theory and experiment. The discussion here is by no means intended to be exhaustive, nor is the reference list comprehensive.
