Mechanistic Insight into Synergistic Catalysis of Olefin Hydrogenation by a Hetero-Dinuclear RuII-CoII Complex with Adjacent Reaction Sites

We have designed and synthesized a hetero-dinuclear Ru-II-Co-II complex with a dinucleating ligand inspired by hetero-dinuclear active sites of metalloenzymes. A synergistic effect between the adjacent Ru-II and Co-II sites has been confirmed in catalytic olefin hydrogenation by the complex, exhibiting a much higher turnover number than those of mononuclear Ru-II or Co-II complexes as the components. A Ru-II-hydrido species was detected by H-1 NMR and electrospray ionization (ESI)-time-of-flight (TOF)-MS measurements as an intermediate to react with olefins, and Co-II-bound methanol was suggested to act as a proton source.