In this paper,Topological Electronegativity Index (TEI) was developed to express the relatively power of an group in a molecule to attract electrons to itself.The charge effect,the relaxation effect and the electrosta...In this paper,Topological Electronegativity Index (TEI) was developed to express the relatively power of an group in a molecule to attract electrons to itself.The charge effect,the relaxation effect and the electrostatic field effect on the C 1s core ionization energies of saturated molecules were evaluated,based on the topological electronegativity index TEI,the atomic electronegativity χP and the polarizability α.The charge effect was scaled by the topological electronegativity index discrepancy between the C and X (X is atom or group) in the C-X bond.The relaxation effect (induced dipole) was scaled by the charge on the ionized carbon atom together with the polarizabiliy of the X.The electrostatic field effect was scaled by the charges on the atoms attached directly to the ionized carbon atom.Further,the shielding effect ΔSi of the C 1s electron in the saturated molecules was expressed by the charge effect and the relaxation effect together with the electrostatic field effect.By introducing the ΔSi into the Slater model,a Slater-like model was obtained for calculating the C 1s core ionization energy E1,C of saturated molecules,whose correlation coefficient r is 0.99943 and the average absolute error between the calculated and the experimental C 1s core ionization energies is only 0.094eV for 81 saturated molecules.Also the cross-correlation was tested by the leave-one-out (LOO) cross-validation method,and the obtained model has good predictive ability and stability (the correlation coefficient rcv is 0.99928,the average absolute error between the predicted and the experimental values is only 0.105 eV).展开更多
研究了硫醚、硫醇在不同极性固定相上色谱保留指数与结构之间的关系,得到了影响硫醚、硫醇化合物Kov a ts保留指数的四个结构参数：分子极化效应指数MPEI、有效拓扑立体效应指数ETSEI、碳原子个数N及Wiener的路径数P_3．并用这4个参数...研究了硫醚、硫醇在不同极性固定相上色谱保留指数与结构之间的关系,得到了影响硫醚、硫醇化合物Kov a ts保留指数的四个结构参数：分子极化效应指数MPEI、有效拓扑立体效应指数ETSEI、碳原子个数N及Wiener的路径数P_3．并用这4个参数建立定量模型,预测硫醚、硫醇在不同极性固定相上Kov a ts保留指数,其相关系数均在0．98以上,预测值与实验值较为吻合．表8。展开更多
文摘In this paper,Topological Electronegativity Index (TEI) was developed to express the relatively power of an group in a molecule to attract electrons to itself.The charge effect,the relaxation effect and the electrostatic field effect on the C 1s core ionization energies of saturated molecules were evaluated,based on the topological electronegativity index TEI,the atomic electronegativity χP and the polarizability α.The charge effect was scaled by the topological electronegativity index discrepancy between the C and X (X is atom or group) in the C-X bond.The relaxation effect (induced dipole) was scaled by the charge on the ionized carbon atom together with the polarizabiliy of the X.The electrostatic field effect was scaled by the charges on the atoms attached directly to the ionized carbon atom.Further,the shielding effect ΔSi of the C 1s electron in the saturated molecules was expressed by the charge effect and the relaxation effect together with the electrostatic field effect.By introducing the ΔSi into the Slater model,a Slater-like model was obtained for calculating the C 1s core ionization energy E1,C of saturated molecules,whose correlation coefficient r is 0.99943 and the average absolute error between the calculated and the experimental C 1s core ionization energies is only 0.094eV for 81 saturated molecules.Also the cross-correlation was tested by the leave-one-out (LOO) cross-validation method,and the obtained model has good predictive ability and stability (the correlation coefficient rcv is 0.99928,the average absolute error between the predicted and the experimental values is only 0.105 eV).
文摘研究了硫醚、硫醇在不同极性固定相上色谱保留指数与结构之间的关系,得到了影响硫醚、硫醇化合物Kov a ts保留指数的四个结构参数：分子极化效应指数MPEI、有效拓扑立体效应指数ETSEI、碳原子个数N及Wiener的路径数P_3．并用这4个参数建立定量模型,预测硫醚、硫醇在不同极性固定相上Kov a ts保留指数,其相关系数均在0．98以上,预测值与实验值较为吻合．表8。
