A new reaction path for the C + NO reaction: dynamics on the 4A″ potential-energy surface

Abstract

We present a new reaction path without significant barriers for the C + NO reaction, forming ground state N(⁴S) and CO. Electronic structure (CASPT2) calculations have been performed for the two lowest ⁴A″ states of the CNO system. The lowest of these states shows no significant barriers against reaction in the C + NO or O + CN channels. This surface has been fitted to an analytical function using a many-body expansion. Using this surface, and the previously published ²A′ and ²A″ surfaces [Andersson et al., Phys. Chem. Chem. Phys., 2000, 2, 613; Andersson et al., Chem. Phys., 2000, 259, 99], we have performed quasiclassical trajectory (QCT) calculations, obtaining rate coefficients for the C(³P) + NO(X²Π) → CO(X¹Σ⁺) + N(⁴S,²D) and C(³P) + NO(X²Π) → O(³P) + CN(X²Σ⁺) reactions. We have also simulated the crossed molecular beam experiments of Naulin et al. [Chem. Phys., 1991, 153, 519] The inclusion of the ⁴A″ surface in the QCT calculations gives excellent agreement with experiments. This is the first time an adiabatic pathway from C(³P) + NO(X²Π) to CO(X¹Σ⁺)+N(⁴S) has been reported.