Prediction of solvation free energies from computed properties of solute molecular surfaces

✍ Scribed by Peter Politzer; Jane S. Murray; Fakher Abu-Awwad

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 182 KB
• Volume: 76
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(2000)76:5<643::aid-qua6>3.0.co;2-f

✦ Synopsis

We have shown that the solvation energies of a group of 12 solutes in 7 different solvents can be presented analytically in terms of quantities computed at the density functional B3P86/6-31+G * * level for the isolated solute molecules. These quantities include the molecular surface area and several properties of the electrostatic potential on the surface, e.g., the most positive and negative values, the average deviation of the potential, the positive and negative portions of the surface, and their average potentials. Overall, the average absolute deviation of the predicted from the experimental solvation free energies is 0.25 kcal/mol; the poorest results are obtained for the solute butanone, for which the average absolute deviation is 0.63 kcal/mol. The forms of the relationships reflect the natures of the solute-solvent interactions; for the solvents with low dielectric constants, these are primarily global, involving extended portions of the molecular surfaces, whereas for the more polar solvents, site-specific interactions also play key roles.