Perspective on Diabatic Models of Chemical Reactivity as Illustrated by the Gas-Phase S_N2 Reaction of Acetate Ion with 1,2-Dichloroethane

摘要

A useful starting point for elucidating the factors that determine the activation barrier in many condensed-phase and enzyme-catalyzed reactions is an understanding of the intrinsic reactivity of the uncatalyzed reaction in the gas phase.Subsequently,the effect of solvation and/or catalysis can be considered.For example,a computation of the change of a reaction's activation barrier from aqueous solution to an enzyme can be very informative,although it is not sufficient to generate a complete picture of enzyme catalysis1 nor adequate to validate the potential energy surface and computational techniques.