Extension of a Temperature-Dependent Aqueous Solvation Model to Compounds Containing Nitrogen, Fluorine, Chlorine, Bromine, and Sulfur

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• 作者：Adam C. Chamberlin ; Christopher J. Cramer ; Donald G. Truhlar
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：March 13, 2008
• 年：2008
• 卷：112
• 期：10
• 页码：3024 - 3039
• 全文大小：204K
• 年卷期：v.112,no.10(March 13, 2008)
• ISSN：1520-5207

文摘

Most methods for predicting free energies of solvation have been developed or validated exclusively forroom temperature. Recently, we developed a model called SM6T for predicting aqueous solvation free energiesas a function of temperature for solutes composed of C, H, or O, and here we present solvation model 8 withtemperature dependence (SM8T) for predicting the temperature dependence of aqueous free energies ofsolvation for compounds containing H, C, N, O, F, S, Cl, and Br in the range 273-373 K. We also describethe database of experimental aqueous free energies of solvation used to parametrize the model. SM8T partitionsthe temperature dependence of the free energy of solvation into two components: the temperature dependenceof the bulk electrostatic contribution to the free energy of solvation, which is computed using the generalizedBorn equation, and the temperature dependence of first-solvation-shell effects, which is modeled by termsproportional to the solvent-exposed surface areas of atoms in functional groups determined entirely by geometry.SM8T predicts the temperature dependence of aqueous free energies of solvation with a mean unsigned errorof 0.08 kcal/mol over a database of 4403 measurements on 348 compounds at various temperatures. We alsodiscuss the accuracy of SM8T for predicting the temperature dependence of aqueous free energies of solvationfor ions and present free energies of solvation as a function of temperature for two sample ions.