Conversion of Dinitrogen and Oxygen to Nitric Oxide Mediated by Triatomic Yttrium Cations: Reversible N-N Bond Switching.

The direct coupling of dinitrogen (N) and oxygen (O) to produce value-added chemicals such as nitric acid (HNO) at room temperature is fascinating but quite challenging because of the inertness of N molecules. Herein, an interesting reaction pathway is proposed for a direct conversion of N and O mediated by all-metal Y cations. This reaction pattern begins with the N≡N triple bond cleavage by Y to generate a dinitride cation YN, and the electrons that lead to N activation in this process mainly originate from Y atoms. In the following consecutive reactions with two O molecules, the electrons stored in the N atoms are gradually released to reduce O through re-formation and re-fracture of the N-N bonds, with concomitant release of two NO molecules. Therefore, the reversible N-N bond switching acts as an efficient electron reservoir to drive the oxidation of the reduced N atoms, leading to the formation of NO molecules. This method of producing NO by direct coupling N and O molecules, which is the reversible N-N bond switching, may provide a new strategy for the direct synthesis of HNO, etc.