Estimation of the aqueous solubility (−lgSw) of all polychlorinated dibenzo-furans (PCDF) and polychlorinated dibenzo-p-dioxins (PCDD) congeners by density functional theory

Optimized calculations of 76 polychlorinated dibenzo-p-dioxins and 136 polychlorinated dibenzo-furans were carried out at the B3LYP/6-31G* level in gaussian 98 program. Based on the theoretical linear solvation energy relationship (TLSER) model, the obtained structural parameters were taken as theoretical descriptors to establish a novel QSPR model for predicting aqueous solubility (−lgSw) of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans. The new model of −lgSw achieved in this work contains two variables, dipole moment of the molecules (μ) and the polarizability (α), of which R2=0.9403, SD=0.40. And the results of cross-validation test (q2=0.9153) and method validation also showed that the model of this study exhibited optimum stability and better predictive power than semi-empirical method.