Computational investigation of the reaction of NO with imine, silanimine, and its substituted derivatives

The reaction mechanisms of HNXH2 (X = C, Si) + NO were studied at the QCISD(T)/6-311++G(d,p)//B3LYP/6-311++G(d,p) level. The result indicated that the most favorable pathway of HNCH2 + NO would lead to the formation of CH2N2 + OH with the calculated barrier of 44.41 kcal/mol, while in the reaction of HNSiH2 + NO the most preferable pathway shifted to the production of H2SiOH + N2, a direct reduction of NO into a stable and nontoxic nitrogen molecule. The barrier of rate-determining step was calculated to be 18.90 kcal/mol, and it could be further decreased to 14.42 kcal/mol in the N-methyl substituted silanimine (CH3NSiH2). It could be advantageous if it would act as a reactant in converting the reactive and toxic NO into a harmless N2 gas in several NO-producing combustion systems. The possible explanation to the differences between imine and silanimine toward the reaction with NO was provided.