Physicochemical Mechanics Instead of Transition State Theory.

Abstract

This article initially reminds the basics of transition state theory (TST) and gives a textbook example illustrating the often-forgotten problems with TST-based description of reversible reactions. Then, we briefly describe a suggested by us approach called physicochemical mechanics. It was initially developed to describe both the rates and equilibria of chemical mass transport. Here, we show that the same classical mechanics-based approach is working for the kinetics of elementary mono-, bimolecular, and electrochemical reactions. Traditional assumptions regarding pseudoequilibrium for transition state formation are not necessary anymore. A simple interpretation of compensation and tunneling effects is given. The inversion zone for rate constants of strongly exothermic redox reactions is also explained.