Application of solvaton model to quantum-chemical study of influence of solvation on the chemical process NH3 + HF → NH+4 + F-

Influence of solvent (H2O) on the system NH3 + HF NH+4 + F- has been studied with the use of the solvaton model at the level of the semiempirical CNDO/2 method. The solvent has been found to cause changes in equilibrium geometries and charge distributions particularly in the polar components of the system. Hydration stabilizes much more the charged components, hence the reaction equilibrium should be shifted to the right in aqueous medium. Hydration also facilitates the proton-transfer from HF to NH3, and the ion pair H3NH+...F- should be the most stable intermediate in aqueous medium according to the calculations.