Quantum molecular similarity measures are used together with structural proximity and isosynchronicity parameters as interpretative tools to understand better how a reaction proceeds along the reaction coordinate. Both Hammond and anti-Hammond behavior can be easily predicted and interpreted by means of the analysis presented. Further, this methodology shows that the effect of a uniform electric field on the reaction coordinate of a Walden inversion reaction should be regarded from the transition state point Of view, in such a way that one can say that the reactant complex is becoming transition state-like.