Molecular Theory of Hydration at Different Temperatures.

Abstract

Solvation plays an important role in diverse chemical processes ranging from reaction kinetics to molecular recognition, solubility, and phase separations. Despite a long-history of theoretical exploration, quantitative prediction of solvation remains a theoretical challenge without relying on the macroscopic properties of the solvent as an input. Here we present a molecular density functional theory that provides a self-consistent description of the solvation structure and thermodynamic properties of small organic molecules in liquid water at different temperatures. Based on the solute configuration and force-field parameters generated from first-principles calculations, the theoretical predictions are found in good agreement with experimental data for the hydration free energies of 197 organic molecules in a temperature range from 0 to 40 °C. In addition to calibration with experimental results, the theoretical predictions are compared with recent molecular dynamics simulations for the hydration of five highly explosive nitrotoluenes. This work demonstrates the potential of the classical density functional theory for high-throughput prediction of solvation properties over a broad range of temperatures.