Microsolvation effect on chlorination reaction of simple alcohols

Abstract

AbstractThe microsolvation effect was investigated on bimolecular nucleophilic substitution () mechanism for chlorination of methanol, ethanol, and propanol using water as explicit solvent. Based on theoretical calculations, within Density Functional Theory (DFT) combined with polarizable continuum model (PCM) and explicit solvent molecules, it was possible to compare the effect of hydration on the nucleophile and on the leaving group, for the main extremal points of potential surfaces, that is, pre‐complex, transition state (TS), and post‐complex. The possible disposition of water molecules was also investigated raging from one to four explicit molecules. This study was carefully and systematically done for methanol and the main conclusions were used to guide the corresponding study for ethanol and propanol. The results point out to an increase of activation energy with the number of explicit water molecules, showing the importance of hydrogen bond on the stabilization of structures, effect not captured by PCM alone.