Coupling conversion of CO 2 and N 2 molecules under mild conditions to form useful N-C bond-containing products has attracted significant attention. However, the activation and direct coupling of such very inert molecules are quite challenging. Herein, we determined that this coupling reaction can be realized by AuNbBO - quaternary anions at room temperature. The well-defined AuNbBO - anions can cleave the N≡N bond in N 2 and two C═O bonds in CO 2 to form a novel product NCNBO - . To the best of our knowledge, the NCNBO - anion has been experimentally synthesized for the first time by coupling N 2 and CO 2 . Comparative studies with Nb 2 BO - /N 2 and NbBO - /N 2 systems further indicate that the presence of a Au atom in AuNbBO - is indispensable for this N 2 and CO 2 coupling reaction, because the Au atom can decrease the active orbital energies of AuNbBO - anions to facilitate the π-back-donating interaction between AuNbBO - and N 2 .