Based on the experiments, the standard enthalpy△H■of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-21G *(based on semi-empirical method UA...Based on the experiments, the standard enthalpy△H■of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-21G *(based on semi-empirical method UAM1 and ab initio method UHF/3-21G*). The com- putation results with UB3LYP/3-21G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-21G * The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (298, 773, 843, 963 and 1 073 K) were calculated. The thermodynamic computation result shows that when the pyrolysis temperature of toluene is lower than 963 K, the reaction path supported by thermody- namics is that the C-H bond of the methyl on the benzene ring breaks and bitoluene form, while the temperature increases (about 1 073 K), the thermodynamic calculation result turns to support the reaction path producing phenyl radicals and methyl radicals. This mechanism is in accord with the experiments.展开更多
The quantitative structure-activity relationship （QSAR） of 16 pyrazole compounds was studied by ab initio method at the HF/3-21G level using Guassian03 soft. The optimized structures together with some characteristi...The quantitative structure-activity relationship （QSAR） of 16 pyrazole compounds was studied by ab initio method at the HF/3-21G level using Guassian03 soft. The optimized structures together with some characteristic and electric parameters of the title compounds were obtained; some stereo-parameters were calculated by HyperChem software. Stepwise multiple regression method was adopted to establish bi- and tri-parametric models between biological activity and some parameters. The lager △E and logP, the higher biological activity; and the biological activity would be promoted with the smaller μ, QN and QPYRA. It provided a theory direction to synthesize some compounds with high activity.展开更多
基金the Foundation of board of education of Shanxi province(99K1100).
文摘Based on the experiments, the standard enthalpy△H■of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-21G *(based on semi-empirical method UAM1 and ab initio method UHF/3-21G*). The com- putation results with UB3LYP/3-21G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-21G * The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (298, 773, 843, 963 and 1 073 K) were calculated. The thermodynamic computation result shows that when the pyrolysis temperature of toluene is lower than 963 K, the reaction path supported by thermody- namics is that the C-H bond of the methyl on the benzene ring breaks and bitoluene form, while the temperature increases (about 1 073 K), the thermodynamic calculation result turns to support the reaction path producing phenyl radicals and methyl radicals. This mechanism is in accord with the experiments.
基金talents in University (NCET-04-0649)the Natural Science Foundation of Shandong Province (Y2006B07, Z2006B01)
文摘The quantitative structure-activity relationship （QSAR） of 16 pyrazole compounds was studied by ab initio method at the HF/3-21G level using Guassian03 soft. The optimized structures together with some characteristic and electric parameters of the title compounds were obtained; some stereo-parameters were calculated by HyperChem software. Stepwise multiple regression method was adopted to establish bi- and tri-parametric models between biological activity and some parameters. The lager △E and logP, the higher biological activity; and the biological activity would be promoted with the smaller μ, QN and QPYRA. It provided a theory direction to synthesize some compounds with high activity.
