CONTINUUM ELECTROSTATICS MODEL FOR AN S(N)2 REACTION IN SUPERCRITICAL WATER

The electrostatic free energy of solvation Delta A for the S(N)2 reaction of the chloride ion with methyl chloride is calculated with a continuum model. The predictive capacity of the continuum electrostatic model is evaluated by comparing the results with simulation. This comparison provides insight into the role of clustering (electrostriction) of solvent about the reacting species. The results for Delta A are in reasonable agreement with simulation at high and low densities, but the model underpredicts Delta A significantly in the mid-density region. This behavior is consistent with earlier spectroscopic and simulation studies which demonstrated that clustering (electrostriction) is the most prevalent in the mid-density region.