Analysis of solvent effect on S<inf>N</inf>2 reactions by different theoretical models

The solvent effect on two SN2 reactions was evaluated by discrete, continuum and discrete–continuum models. The potential energy profiles were found to change dramatically on introduction of the solvent effect. The double‐well shape which characterizes the F− + CH3F → FCH3 + F− reaction in the gas phase becomes unimodal when the solvent is introduced, in good agreement with experimental data. The solvation parameters are found to intervene in the reaction coordinate. Recent Monte Carlo and molecular dynamics calculations are discussed. Copyright © 1989 John Wiley & Sons Ltd.