Computational Chemistry and Molecular Modeling
Atomic, Molecular and Optical Physics
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Solvation effect on the tunneling rates in the case of coupled motion of two protons along the reaction coordinate was semiempirically, CNDO/2, computed. The following molecular transition-state complexes (TSC) were studied: +AH - BH - A, where A was either NH3 or H2O and BH was HF. Solvation was modeled with water molecules attached to each side of the perpendicular axis, through the bridge HF at different distances F/O. FN and FO (on-line) distances were also varied. Lower and narrower barriers were observed with the close positioning of the solvating molecules. This effect is reflected in higher tunneling probabilities. Thus, solvation favors the tunnel phenomenon in proton-transfer processes. © 1992 John Wiley & Sons, Inc.
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