The basic ideas behind transition state theory are as follows:
#Rates of reaction can be studied by examining activated complexes near the saddle point of a potential energy surface. The details of how these complexes are formed are not important. The saddle point itself is called the transition state.
#The activated complexes are in a special equilibrium (quasi-equilibrium) with the reactant molecules.
#The activated complexes can convert into products, and kinetic theory can be used to calculate the rate of this conversion.