Predicting Infinite Dilution Activity Coefficients of Chlorinated Organic Compounds in Aqueous Solution Based on Three-Dimensional WHIM and GETAWAY Descriptors

The ability of the Weighted Holistic Invariant Molecular (WHIM) and GEometry, Topology, and Atom-Weights AssemblY (GETAWAY) descriptors to represent the effect of molecular structure on the infinite dilution activity coefficients (gamma(infinity)) of chlorinated organic compounds in aqueous solution was investigated. To this end, the dataset of 45 chlorinated organic compounds was randomly divided into a training set (35) and a test set (10). The genetic algorithm was employed for descriptor selection and model development. A five-parameter correlation equation for ln(gamma(infinity)) was obtained, with a squared correlation coefficient (R(2)) of 0.9609 and a standard error of estimation (s) of 0.599 for the training set. The reliability of the proposed model was further illustrated by means of the leave-one-out cross-validation procedure and validation through an external test set. All descriptors involved in the model can be derived directly from the structures of the compounds, which makes it very useful in predicting gamma(infinity) of other chlorinated organic compounds not involved in the present dataset.