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