Direct Conversion of N and O to Nitric Oxide at Room Temperature Initiated by Double Aromaticity in the YBO Cation.

The conversion of dinitrogen to more useful and reactive molecules has been the focus of intense research by chemists. In contrast to reductive N fixation, direct oxidation of N by O to nitric oxide under mild conditions via a thermochemical process is extremely challenging. Herein, we report the first example of N and O activation and coupling under thermochemical conditions through the remarkable ability of YBO to react with one N and two O molecules. Detailed mechanistic studies using mass spectrometry and quantum chemical calculations revealed that the N activation by YBO is facilitated by the double aromatic character of the YBON intermediate. Subsequent oxidation with O releases NO in a dearomatization process driven by the formation of stronger Y-O bonds over the Y-N bonds. Our findings represent the first example of N and O activation and coupling under thermochemical conditions at room temperature, providing a novel strategy for small-molecule activation.