Quantitative structure activity relationship (QSAR) of chlorine effects on ELUMO of disinfection by-product: Chlorinated alkanes

Chlorinated Alkane (CA) is one of the major classes of Disinfection By-Products (DBPs) in chlorinated drinking water. Multi-multivariate regression methods have been used to develop Quantitative Structure-Activity Relationship (QSAR) models between the Energy of the Lowest Unoccupied Molecular Orbital (ELUMO) and three molecular descriptors: namely, number of chlorine (NCl), number of carbon (NC) and the Energy of the Highest Occupied Molecular Orbital (EHOMO). Among different linear QSAR models, the most robust model is ELUMO = −0.1474NCl – 0.003766NC + 1.9528EHOMO + 1.0664 (N = 30, R2 = 0.956, F = 188.498, RMSE = 0.00762, P = 0.000). The model is validated by using internal and external cross validation techniques. The model uncertainties are also quantified through the Bootstrapping and the Taylor methods. Among all the molecular descriptors, number of chlorine (NCl) contributes to the most to the ELUMO of chlorinated alkanes.