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 are constrained to collinear configurations, Ab initio potential energy surfaces in solution and relevant experimental results are used to calibrate general empirical valence bond (EVB) potential surfaces for studies of such reactions. The EVB surfaces allow one to interpolate the ab initio results to 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 structures. Such an E VB/shift approach appears valuable for assessing the effects of different catalysts and solvents on complex chemical reactions. © 2000 John Wiley & Sons, Inc.