A THEORETICAL INVESTIGATION OF THE 2 LOWEST POTENTIAL-ENERGY SURFACESFOR THE REACTION C(P-3)+NO((2)PI)

The two lowest potential energy surfaces for C(P-3)+NO((II)-I-2) have been investigated. The stationary points were first located using CASS CF gradient calculations and the geometries reoptimized using complete active space second-order perturbation theory. Zero-point corrections have been included in the energetics. In addition to the three linear conformations CNO, NCO and CON, a previously unreported triangular co nformation has been found. We found no barrier to carbon attack to the oxygen end of NO, leading to CON. This channel would lead to direct p roduction of N+CO but is expected to be entropically disfavoured. No b arrier to CNO formation has been found, in accord with experimental pr edictions. Experimentalists found no evidence of CO production and con cluded that CN+O are the main products, but our investigation gives no reason to exclude formation of N+CO. It is suggested that the discrep ancy may be due to the fact that no monitoring of CO production was pe rformed.