在高效液相色谱(HPLC)测定方法的基础上,采用摇瓶法,准确测得25℃时16个取代苯硫酚类化合物的水溶解度(-lgSw)和19个正辛醇/水分配系数(lgKow)数据.采用密度泛函理论(DFT)中的B3LYP方法,在6-311G**基组上全优化计算得到24个取代苯硫酚...在高效液相色谱(HPLC)测定方法的基础上,采用摇瓶法,准确测得25℃时16个取代苯硫酚类化合物的水溶解度(-lgSw)和19个正辛醇/水分配系数(lgKow)数据.采用密度泛函理论(DFT)中的B3LYP方法,在6-311G**基组上全优化计算得到24个取代苯硫酚的结构参数和热力学参数,采用SPSS12.0 for windows程序,分别求得-lgSw和lgKow值与这些参数之间的相关方程,相关系数R2分别为0.958和0.946.用交叉验证法对方程的稳定性进行了验证(q2分别为0.925和0.930),并用t检验和变异膨胀因子(Variance Inflation Factors,VIF)对两个方程中各变量的显著性和自相关性进行了检验.结果表明:所建方程具有较强的预测能力,并用其预测了8个没有实验数据的取代苯硫酚的-lgSw值和5个lgKow值.展开更多
The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It ...The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the compounds.The thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted congeners.PCXT congeners with one phenyl ring fully chlorinated are found to be the least stable among the analogues.The effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.展开更多
Structural and thermodynamic parameters of 56 oxygen-containing and 56 sulfur- containing organic compounds were computed at the B3LPY/6-311G** level using density functional theory (DFT) method. Furthermore,the depen...Structural and thermodynamic parameters of 56 oxygen-containing and 56 sulfur- containing organic compounds were computed at the B3LPY/6-311G** level using density functional theory (DFT) method. Furthermore,the dependent equations between the experimental data of boiling points (Tb) and theoretical parameters were proposed with SPSS12.0 for windows software,whose correlation coefficients R2 are 0.933 and 0.945. These dependent equations were validated by cross-validation method (q2 are 0.923 and 0.929,respectively). VIF (variance inflation factors) and t-value methods were also used to verify the significance and self-correlationship of each variable. Results indicate that our dependent equation exhibits good prediction ability,and molecular polarizability (α) is the main factor affecting the Tb of oxygen- and sulfur-containing organic compounds. To our interest,obvious dependence could also be found among the oxygen- and sulfur-containing organic compounds’ experimental data of boiling points (Tb) with R2 of 0.857.展开更多
文摘在高效液相色谱(HPLC)测定方法的基础上,采用摇瓶法,准确测得25℃时16个取代苯硫酚类化合物的水溶解度(-lgSw)和19个正辛醇/水分配系数(lgKow)数据.采用密度泛函理论(DFT)中的B3LYP方法,在6-311G**基组上全优化计算得到24个取代苯硫酚的结构参数和热力学参数,采用SPSS12.0 for windows程序,分别求得-lgSw和lgKow值与这些参数之间的相关方程,相关系数R2分别为0.958和0.946.用交叉验证法对方程的稳定性进行了验证(q2分别为0.925和0.930),并用t检验和变异膨胀因子(Variance Inflation Factors,VIF)对两个方程中各变量的显著性和自相关性进行了检验.结果表明:所建方程具有较强的预测能力,并用其预测了8个没有实验数据的取代苯硫酚的-lgSw值和5个lgKow值.
基金Supported by the National Natural Science Foundation of China （20977046, 20737001）.
文摘The gas phase thermodynamic properties of 135 polychlorinated xanthones(PCXTs)are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G**level.It is found that the chlorine substitution pattern strongly influences the thermodynamic properties of the compounds.The thermodynamic properties of congeners with the same number of chlorines also depend on the chlorine substitution pattern,especially for ortho-substituted congeners.PCXT congeners with one phenyl ring fully chlorinated are found to be the least stable among the analogues.The effect of the chlorine substitution pattern is quantitatively studied by considering the number and position of Cl atom substitution(NPCS).The results show that the NPCS model may be used to predict the thermodynamic properties for all 135 PCXT congeners. In addition,the values of molar heat capacities at constant pressure(cp,m)from 200 to 1000 K for PCXT congeners are calculated,and the temperature dependence relation of this parameter is obtained using the least-squares method.
基金Supported by the State Science Foundation of China (No. 20737001)
文摘Structural and thermodynamic parameters of 56 oxygen-containing and 56 sulfur- containing organic compounds were computed at the B3LPY/6-311G** level using density functional theory (DFT) method. Furthermore,the dependent equations between the experimental data of boiling points (Tb) and theoretical parameters were proposed with SPSS12.0 for windows software,whose correlation coefficients R2 are 0.933 and 0.945. These dependent equations were validated by cross-validation method (q2 are 0.923 and 0.929,respectively). VIF (variance inflation factors) and t-value methods were also used to verify the significance and self-correlationship of each variable. Results indicate that our dependent equation exhibits good prediction ability,and molecular polarizability (α) is the main factor affecting the Tb of oxygen- and sulfur-containing organic compounds. To our interest,obvious dependence could also be found among the oxygen- and sulfur-containing organic compounds’ experimental data of boiling points (Tb) with R2 of 0.857.
