'Holy grails' of chemistry: the transition state in chemical reaction

Abstract

In discussions of chemical reactions, particularly their rates, the concept of a 'transition state' appears frequently. In all undergraduate textbooks in chemistry, the notion of a transition state (henceforth abbreviated as TS) or an activated complex (synonymous) is used in describing the passage of a reaction from reactants to products. However, everyone understands and interprets the exact meaning of the term, TS, in one’s own way. In this article, I shall attempt to develop the concept and try to provide a working definition for the TS in a chemical reaction.