Mechanism and Kinetics of the Reaction of Acetylene and Nitric Oxide

Abstract

The potential energy surface (PES) of a [C2,H2,N,O] system in its electronic doublet ground state has been investigated using density functional theory method, at B3LYP/6-311++G(3df,2p)// B3LYP/6-311++G(d,p) level. Twelve stable intermediate radicals including trans-nitrosoethenyl 1, cis-nitrosoethenyl 2, iminoketenyl 11, and aminoketenyl 12 radicals have been located. Other stationary points on the PES formed from hydrogen migration and dissociation channels of these intermediates have been identified. Barrier heights, vibrational wavenumbers and moments of inertia were then utilized in the calculations of rate constants using quantum Rice−Ramsperger−Kassel (QRRK) theory. The total rate constant is found to increase with increase of temperature. At temperatures below 1000 K, only a rapid equilibrium is established between the reactants and the trans-nitrosoethenyl 1 radical which, in turn, suggests an absence of a reaction at low temperatures. HCO + HCN is found to be the predominant product at high temp...