Electron-Reservoir Multiple Bond in RhC– for Dinitrogen Cleavage

Abstract

Abstract Multiple bonds involving the main-group element represent a prominent class of interactions whose formation and cleavage involve substantial electron redistribution, yet its functional role in redox processes remains unexplored. Herein, we identify a triple-bond character in the RhC– anion, which was generated in the gas phase and characterized spectroscopically by mass spectrometry and photoelectron spectroscopy. Concurrently, the RhC– species is demonstrated to exhibit dinitrogen cleavage capability. Quantum chemical calculations reveal that the resulting products feature a pronounced weakening of the Rh–C interaction along with concomitant C–N bond formation. Electronic structure analysis further indicates that the Rh–C triple bond acts as an electron reservoir, and nitrogen reduction proceeds primarily through cleavage of the Rh–C bond, which releases stored electrons. This work establishes the functional application of metal–carbon multiple bonds in dinitrogen cleavage, demonstrating their unique capacity to couple structural dynamics with redox chemistry and thereby establishing a transformative mechanism for designing electron-reservoir catalysts in dinitrogen activation and beyond.