A theoretical study of CH3ONOÂ +Â H reaction

A detailed theoretical study is performed at the UMP2/6-311++G(d,p) and CCSD(T)/aug-cc-pVTZ (single-point) levels in order to explore the mechanism of the reaction between cis-CH3ONO/trans-CH3ONO and H. For cis-CH3ONO + H reaction, six products are obtained. P1 (CH3OH + NO), and P6 (CH3O + HNO) are the most feasible products. P3 (CH3 + trans-HONO), P4 (CH3 + cis-HONO), and P5 (cis-CH2ONO + H2) are the second feasible products, followed by the least feasible product P2 (CH4 + ONO). For trans-CH3ONO + H reaction, five dissociation products are obtained. P1 (CH3OH + NO), P6 (CH3O + HNO), and P7 (trans-CH2ONO + H2) are the most feasible products, the lesser followed competitive product is P4 (CH3 + cis-HONO), while P2 (CH4 + ONO) is even much less feasible. Our theoretical results are in consistent with the available experiments. Because the rate-determining transition states involved in the feasible pathways lie above the reactant R, the title reactions may be important at higher temperatures. The present paper may be helpful for modeling of methyl nitrite-hydrogen combustion chemistry.