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Estimation of Aqueous Solubility (-lgS_w) of All Polychlorinated Biphenyl (PCB) Congeners by Density Functional Theory and Position of Cl Substitution (NPCS) Method 被引量:3
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作者 WEI Xiao-Yan GE Zhi-Gang WANG Zun-Yao XU Jiao 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第5期519-528,共10页
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
关键词 polychlorinated biphenyls (PCBs) aqueous solubility (-lgSw) quantitativestructure-property relationship (QSPR) position of Cl substitution (NPCS) method
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DFT and Position of Cl Substitution (PCS) Methods Studies on n-Octanol/water Partition Coefficients (lgK_(ow)) and Aqueous Solubility (–lgS_w) of All PCDD Congeners 被引量:5
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作者 谢亚杰 赵惠明 +1 位作者 王遵尧 张雅荣 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第12期1409-1418,共10页
Optimized calculations of 75 PCDDs and their parent DD were carded out at the B3LYP/6-31G* level by density functional theory (DFT) method. The structural parameters were obtained and significant correlation betwee... Optimized calculations of 75 PCDDs and their parent DD were carded out at the B3LYP/6-31G* level by density functional theory (DFT) method. The structural parameters were obtained and significant correlation between the C1 substitution position and some structural parameters was found. Consequently, the number of C1 substitution positions was taken as theoretical descriptors to establish two novel QSPR models for predicting lgKow and -lgSw of all PCDD congeners. The two models achieved in this work contain two variables (Na and Nβ), of which r = 0.9312, 0.9965 and SD = 0.27, 0.12 respectively, and t values are all large. The variation inflation factors (VIF) of variables in the two models herein are both less than 5.0, suggesting high accuracy of the lgKow and -lgSw predicting models, and the results of cross-validation test also show that the two models exhibit optimum stability and good predictive power. By comparison, the correlation and predictive ability of the present work are more advantageous than those obtained using semi-empirical AM1 and GC-RI methods. 展开更多
关键词 polychlorinated dibenzo-p-dioxins (PCDDs) n-octanol/water partition coefficients(lgKow) aqueous solubility (-lgSw) quantitative structure-property relationship (QSPR) DFT position of CI substitution (PCS) method
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Thermodynamic Properties for Polybrominated Dibenzothiophenes by Density Functional Theory 被引量:2
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作者 李加友 柳红霞 +2 位作者 于红霞 王遵尧 王连生 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第6期999-1008,共10页
The thermodynamic properties of 135 polybrominated dibenzothiophenes (PBDTs) in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory (the B3LYP/6-311G^**) wit... The thermodynamic properties of 135 polybrominated dibenzothiophenes (PBDTs) in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory (the B3LYP/6-311G^**) with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation (△fH^θ) and the standard Gibbs energy of formation (△fG^θ) of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents (NPBS) are discussed, and it is found that there exist good correlations between othermody namic parameters (including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ) and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure (Cp,m) for PBDT c ongelaers are calculated. 展开更多
关键词 polybrominated dibenzothiophenes density functional theory method of position of substituted Br atom thermodynamic parameters relative stability
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