Effective way of modeling chemical catalysis: Empirical valence bond picture of role of solvent and catalyst in alkylation reactions

A general methodology for the study of chemical catalysis is presented and demonstrated. in a study of Friedel-Crafts-type alkylation reactions that a re constrained to collinear configurations. Ab initio potential energy surf aces in solution and relevant experimental results are used to calibrate ge neral empirical valence bond (EVB) potential surfaces for studies of such r eactions. The EVE surfaces allow one to interpolate the ab initio results t o studies of the effect of different solvents, substituents, and catalysts on the alkylation reactions. This implicit approach introduces such effects by shifting the diagonal energies of the corresponding resonance structure s. Such an EVB/shift approach appears valuable for assessing the effects of different catalysts and solvents on complex chemical reactions. (C) 2000 J ohn Wiley & Sons, Inc.