| Abstract
| - A hybrid approach using a combination of explicit solvent molecules and the isodensity polarizable continuummodel (IPCM) method is proposed for the calculation of the solvation thermodynamic properties of ions.This model, denominated cluster−continuum, has been applied to the calculation of the solvation free energyof 14 univalent ions, mainly organic species, and compared with the results obtained with the IPCM, polarizablecontinuum solvation model (PCM), and SM5.42R continuum methods. The average error in our calculatedsolvation free energies with respect to experimental data is 8.7 kcal mol-1. However, the great merit of ourmodel resides in the homogeneous treatment for different ions, resulting in a standard deviation of only 2.9kcal mol-1 for the average error. Our results suggest that the cluster−continuum model must be superior tothe IPCM, PCM, and SM5.42R methods for studying chemical reactions in the liquid phase, because thesecontinuum methods present a standard deviation of ∼8 kcal mol-1 for the average error for the species studiedin this work. The model can also be used to calculate the solvation entropy of ions. Predicted solvationentropies for five ionic species are in good agreement with available experimental data.
|
