Transition states for inversion and retention of configuration channels inthe reactions of alkyl and silyl fluorides with a water molecule

The potential energy surface of CH3F +/- H2O and SiH3F + H2O systems were s canned by B3LYP and MP2 methods. For each system two channels of reactions, i.e. with retention and inversion of configuration, were explored by model ling the front-side and the back-side attack of the water molecule. In each case the barrier heights for two channels were predicted. The inversion ch annels have similar and high energy barriers for both systems while the sub stantial difference was found for the retention channel barriers between me thyl and silyl fluorides. The lower barrier for silyl fluoride is in keepin g with experimental observations. (C) 2000 Elsevier Science B.V. All rights reserved.