Gas-phase hydrogen abstraction reactions have been compared using the popular density functional theory （DFT） functional BHandHLYP/aug-cc-pVTZ/RECP level of theory, on the basis of the model reaction CHCI-/CCl2- ＋ ...Gas-phase hydrogen abstraction reactions have been compared using the popular density functional theory （DFT） functional BHandHLYP/aug-cc-pVTZ/RECP level of theory, on the basis of the model reaction CHCI-/CCl2- ＋ CX3H （X = F, Cl, Br and I）. Our theoretical findings suggest the efficiency of the H-abstraction reactions induced by either CHCl- or CCl2- increases as the substrate is changed from CF3H to Cl3H, and that CHCI＇-has a higher activity in hydrogen abstraction than CCl2- for a given substrate. The entropy effect at 298 K does not significantly change the trend in reactivity of the various reactions, which is in general controlled by the heights of activation energies △E＂. Therefore, we have explored the origin of the energy barriers △E＂ of the reactions using the activation strain model of chemical reactivity.展开更多
基金the Fundamental Research Funds for the Central Universities (zyz2011059)
文摘Gas-phase hydrogen abstraction reactions have been compared using the popular density functional theory （DFT） functional BHandHLYP/aug-cc-pVTZ/RECP level of theory, on the basis of the model reaction CHCI-/CCl2- ＋ CX3H （X = F, Cl, Br and I）. Our theoretical findings suggest the efficiency of the H-abstraction reactions induced by either CHCl- or CCl2- increases as the substrate is changed from CF3H to Cl3H, and that CHCI＇-has a higher activity in hydrogen abstraction than CCl2- for a given substrate. The entropy effect at 298 K does not significantly change the trend in reactivity of the various reactions, which is in general controlled by the heights of activation energies △E＂. Therefore, we have explored the origin of the energy barriers △E＂ of the reactions using the activation strain model of chemical reactivity.
