Theoretical investigation for the reaction of NO2 with CO catalyzed by Sc+

The mechanism of the reaction NO 2 ( 2 A 1 ) + CO ( 1 ∑ + ) → NO ( 2 ∏ ) + CO 2 ( 1 ∑ g + ) catalyzed by Sc+ has been investigated by means of UB3LYP/6-311+G(2d) level. Our calculated results strongly indicate that both the reactions NO2(2A1) + Sc+(X3D) → NO(2∏) + ScO+(X1∑+) and ScO + ( X 1 ∑ + ) + CO ( 1 ∑ + ) → Sc + ( X 3 D ) + CO 2 ( 1 ∑ g + ) are spin-forbidden reactions. The crossing points (CPs) that are involved and the possible spin inversion processes are discussed using the intrinsic reaction coordinate (IRC) approach. On the basis of Hammond postulate, they are typical ‘two-state reactivity’ (TSR) reactions. And the O-atom affinities (OA) testified that the argumentation is thermodynamically allowed.