Optimized calculations of 209 polychlorinated diphenyl ethers （PCDEs） and diphenyl ethers were carried out at the B3LYP/6-31G^＊ level with the Gaussian 98 program. Based on the theoretical linear solvation energy r...Optimized calculations of 209 polychlorinated diphenyl ethers （PCDEs） and diphenyl ethers were carried out at the B3LYP/6-31G^＊ level with the Gaussian 98 program. Based on the theoretical linear solvation energy relationship （TLSER） model, the obtained structural parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting aqueous solubility （-lgSw） of PCDEs. The model obtained in this work contains two variables： mean molecular polarizability （a） and the most positive partial charge on a hydrogen atom （qH^＋）, of which RE = 0.9606 and SD = 0.32. And the results of cross-validation test also show that the model exhibits optimum stability and better predictive power. Moreover, the predictive power of the new model is better than that of MCIs method.展开更多
Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity i...Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity index,orientating corresponding index was calculated with the technique of molecule graphics.The orientating corresponding index was combined with five observed thermodynamic properties of PCDEs,i.e.molecular mean polarizability,standard enthalpy,free energy,heat capacity at constant volume and standard entropy,and fifteen quantitative structure-property relationship(QSPR) models(r>0.99)were obtained with the unitary linear regression method,and the relative mean deviations were 1.02%,0.48%,0.48%,0.22% and 0.90%,respectively.In order to test the stability and prediction ability of each model,the jackknifed cross validation was performed and good results(r>0.99)were obtained.These models can better elucidate the change of the thermodynamic properties for the PCDEs,and the QSPR models have satisfactory stability and good predictability.展开更多
基金funded by the 973 National Basic Research Program of China (2003CB415002)China Postdoctoral Science Foundation (No. 2003033486)
文摘Optimized calculations of 209 polychlorinated diphenyl ethers （PCDEs） and diphenyl ethers were carried out at the B3LYP/6-31G^＊ level with the Gaussian 98 program. Based on the theoretical linear solvation energy relationship （TLSER） model, the obtained structural parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting aqueous solubility （-lgSw） of PCDEs. The model obtained in this work contains two variables： mean molecular polarizability （a） and the most positive partial charge on a hydrogen atom （qH^＋）, of which RE = 0.9606 and SD = 0.32. And the results of cross-validation test also show that the model exhibits optimum stability and better predictive power. Moreover, the predictive power of the new model is better than that of MCIs method.
文摘Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity index,orientating corresponding index was calculated with the technique of molecule graphics.The orientating corresponding index was combined with five observed thermodynamic properties of PCDEs,i.e.molecular mean polarizability,standard enthalpy,free energy,heat capacity at constant volume and standard entropy,and fifteen quantitative structure-property relationship(QSPR) models(r>0.99)were obtained with the unitary linear regression method,and the relative mean deviations were 1.02%,0.48%,0.48%,0.22% and 0.90%,respectively.In order to test the stability and prediction ability of each model,the jackknifed cross validation was performed and good results(r>0.99)were obtained.These models can better elucidate the change of the thermodynamic properties for the PCDEs,and the QSPR models have satisfactory stability and good predictability.
