Theoretical studies on the mechanism for the reaction of CH_3CH_2,CH_3CHCl and CH_3CCl_2 with NO_2

DFT-B3LYP/6-311+G is used to calculate the geometries of reactants,intermediates,transition states and products for CH3CH2,CH3CHCl and CH3CCl2+NO2 reaction.The transition states and intermediates of the reaction are verified by frequency analysis.The intrinsic reaction coordinate(IRC) calculations at the same level were also carried out to check the connection between all the critical structures located on the potential energy surface.Single point energies have been calculated at the CCSD(T)/6-311+G level.The energy barriers,rate constants and thermodynamic quantities of the reaction at T=298 K and T=700 K have also been calculated.The results show that the reaction of the title reactions involve one channel,producing C2H4+HNO2,CH3CHO+ClNO and CH3CClO+ClNO products,respectively.