Setschenow Constant Prediction Based on the IEF-PCM Calculations

The Setschenow constant K-salt of a compound in NaCl solution is an important parameter. The solvent environment influences the geometries, energies, charge distributions, and other properties of solutes. The integral equation formalism polarizable continuum model (IEF-PCM) for solvent effects was used to optimize molecular geometries with the density functional theory method combined with Becke's three-parameter hybrid functional and Lee-Yang-Parr's gradient-corrected correlation functional at 6-31G(d) level. Single-point energy calculations and natural bond orbital analyses were carried out with the same method. After 1672 molecular descriptors generation, four descriptors were selected to develop models for K-salt of 101 organic compounds, by using the genetic algorithm method together with multiple linear regression (MLR) technique. The optimal MLR and support vector machine models of K-salt have the mean root-mean-square errors of 0.0287 and 0.0227, respectively. Compared with previous models, the two models in this work have better predictive performance. Results of the study suggest that calculating molecular descriptors from IEF-PCM to predict the Setschenow constants K-salt of organic compounds in NaCl solution is feasible.