Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some struct...Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some structural parameters. Consequently, Cl substitution positions were taken as theoretical descriptors to establish a novel QSPR model for predicting –lgSw of all PCB congeners. The model achieved in this work contains four variables, of which r^2 = 0.9527, q^2 = 0.9490 and SD = 0.25 with large t values. In addition, the variation inflation factors （VIFs） of variables in this model are all less than 5.0, suggesting high accuracy of the –lgSw predicting model. And the results of cross-validation test and method validation also show that the model exhibits optimum stability and better predictive capability than that from the AM1 method.展开更多
基金This work was supported by the 973 National Basic Research Program of China (2003CB415002)the China Postdoctoral Science Foundation (No. 2003033486)
文摘Optimization calculations of 209 polychlorinated biphenyls （PCBs） were carried out at the B3LYP/6-31G^＊ level. It was found that there is significant correlation between the Cl substitution position and some structural parameters. Consequently, Cl substitution positions were taken as theoretical descriptors to establish a novel QSPR model for predicting –lgSw of all PCB congeners. The model achieved in this work contains four variables, of which r^2 = 0.9527, q^2 = 0.9490 and SD = 0.25 with large t values. In addition, the variation inflation factors （VIFs） of variables in this model are all less than 5.0, suggesting high accuracy of the –lgSw predicting model. And the results of cross-validation test and method validation also show that the model exhibits optimum stability and better predictive capability than that from the AM1 method.
