Zhen-Feng Xu

Direct dynamics study of the reaction path and rate constants of NH2+C2H6 → NH3+C2H5

Abstract The title reaction is studied by ab initio molecular orbital theory. The geometries for the reactants, products and transition state are optimized at the UMP2/6-311+G ∗∗ level, and then the minimum energy path is built up by means of the intrinsic reaction coordinate method. In order to improve the energetics along the minimum energy path, single-point calculation is carried out by using Gaussian-2 theory. Furthermore, the forward and reverse rate constants for the temperature range from 300 to 2100 K are obtained by the canonical variational transition state theory with small-curvature tunneling correction method. It is shown that the calculated rate constants are in good agreement with the experimental values.

Ab initio study on the mechanism of the radical reaction NNH(2A′)+N(4S)→N2+NH(3Σ−)

Abstract The mechanism of the title reaction has been studied at the UHF, UMP2, UMP4(sdq) and UQCISD levels of theory with the 6-311G ** basis set. The results show that the hydrogen-atom abstraction path proceeds without potential energy barrier and the trans and cis nitrogen-atom abstraction reaction paths have quite small potential energy barriers. The heat of reaction calculated at the UQCISD level is −79.83 kcal/mol. Therefore, though the hydrogen-atom abstraction reaction is the most dominant reaction path, the nitrogen-atom abstraction reaction paths should be considered in high temperature reaction kinetics.