Computational Study of the Rate Coefficients for the Reactions of NO₂ with CH₃NHNH, CH₃NNH₂, and CH₂NHNH₂

The reactions of NO₂ with <i>cis</i>-/<i>trans</i>-CH₃NHNH, CH₃NNH₂ and CH₂NHNH₂ have been studied theoretically by quantum chemical calculations and steady-state unimolecular master equation analysis based on RRKM theory. The barrier heights for the roaming transition states between nitro (RNO₂) and nitrite (RONO) isomerization reactions and those for the concerted HONO and HNO₂ elimination reactions from RNO₂ and RONO, affect the pressure dependences of the product-specific rate coefficients. At ambient temperature and pressure, the dominant product of the reactions of NO₂ with <i>cis</i>-/<i>trans</i>-CH₃NHNH and CH₂NHNH₂ would be expected to be HONO with <i>trans</i>-CH₃NNH and CH₂NNH₂, respectively, whereas it is CH₃N­(NH₂)­NO₂ for CH₃NNH₂ + NO₂. The product-specific rate coefficients for the titled and related reactions on the same potential energy surfaces were proposed for kinetics modeling