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Estimation of Thermodynamic Properties of PBTAs Using the Molecular Electronegativity Distance Vector

CHEN Yan， DU Xi-hua

Abstract （1810）

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Based on the molecular electronegativity distance vector, the quantitative structure-property relationship (QSPR) models of the thermodynamic properties (standard enthalpy H ⁰，free energy G ⁰，heat capacity at constant volume C ⁰ _V and standard entropy S ⁰) were constructed for TA and 75 PBTAs. From the four parameters of the model, it was known that the molecular structure fragents: [CDS1]CH—,[CDS1]Ｃ＜,－S－,－Br were all the dominant influencing factors of thermodynamic properties. The optimal bivariate correlation (R ²) of these QSPR models were all 1.000, and the calculated values were in good agreement with experimental data and favorable with literature data. The results show that the possess better predictability and robustness by Jackknifed method and cross-validation procedure. It can be expected that the molecular electronegativity distance vector will be used widely in quantitative structure-property/activity relationship research.

2009, 22 (4): 29-33. DOI: 10.3696/j.issn.1006-396X.2009.04.008

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The QSPR Research on t he Olfactory Thresholds of Alip hatic Alcohols

DU Xi-hua, CHEN Yan

Abstract （1967）

PDF （198KB）（653）

Atomic characteristic value f i of aliphatic alcohols were defined and calculated for QSPR research of aliphatic alcohols, then topological parameter and hydrogen line index H were acquired by the technique of molecule graphics and AM1. QSPR for estimating olfactory thresholds ( POL ) of aliphatic alcohols were achieved based on multiple regression. The regression equations were proposed. The mean error between estimated values and experimental value of 50 aliphatic alcohols is
0. 46 ,while the olfactory thresholds of other 49 aliphatic alcohols molecules were predicted by the regression equation , the mean error is 0. 67. The result s show that the model developed can make a better agreement among estimated values ,predicted values and experimental value.

2009, 22 (3): 28-32. DOI: 10.3696/j.issn.1006-396X.2009.03.008

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The QSPR Research of Photolysis Half-Lives of PCDD/Fs Adsorbed on Spruce Needles Foliage

DU Xi-hua, FENG Chang-jun

Abstract （272）

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The quantitative relationships between photolysis half-lives（t _1/2） and molecular structures of dioxins (PCDD/Fs) was described. Atomic characteristic value δi of PCDD/Fs were defined. The topological descriptor Km and orientating group bedeck index mXJ were acquired by the technique of molecule graphics and AM1. The QSPR model，which could predict photolysis half-lives of PCDD/Fs adsorbed to spruce needle surfaces，were established using the index，the regression equations was proposed with mean deviation was 0.056. A modified leave-one-out procedure test was performed to validate model robustness，predicted the t _1/2 of other some PCDD/Fs molecules by the regression equation，and the error analysis were discussed. The results show that the model developed can make a better agreement between predicted and observed values of t _1/2.

2008, 21 (2): 29-32.

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Correlativity Research Between Topological Dyeing Index and Gas Chromatography Retention Index of Fatty Esters

DU Xi-hua, FENG Chang-jun

Abstract （280）

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In order to study on the QSRR of fatty esters, 100 fatty esters were optimized by semiempirical calculations AM1，then calculated them by quantum chemistry algorithnl and the technique of molecule graphics and AM1 to acquire the Kier index and Kappa shape index. Based on the molecular topological thoery， introduced a modified topological dyeing index ^mL and use these index to study on the correlational relationship of gas chromatography retention index of 100 esters，the correlation coefficient was 0.999 and the mean relative error was 1.02%. These models can better indicate the change rule of retention indices for the fatty esters，and the QSRR models have high relative coefficients，good stability and good predictability.

2008, 21 (1): 16-20.