H₂ Production Mediated by CO₂ via Initial Reduction to Formate

A Ru­(NH-NHC) complex with an open coordination site on the metal center adjacent to ligand N–H moieties has been synthesized and characterized. This complex exhibits unique reactivity upon reaction with either CO₂ or NaHCO₃, yielding a formate-bridged bimetallic complex via a spontaneous deoxygenation reaction and formal reduction at carbon. Dehydrogenation of the formate complex leads to a Ru–carbamate species following carbon–nitrogen bond formation between the CO₂ moiety and the NHC ligand. This reactivity opens up new pathways for CO₂ reduction and is relevant to H₂ storage.