Bimetallic Cooperativity and Hydrogen Bonding Allow Efficient Reduction of CO2.

Abstract

Reducing CO2 selectively to one of the several C1 products is challenging, as the thermodynamic reduction potentials for the different n e- /n H+ reductions of CO2 are similar and so is the reduction potential for H+ reduction. Recently, Halime, Aukauloo, and co-workers have taken inspiration from the active site of nickel CO dehydrogenase (Ni-CODH) to design bimetallic iron porphyrins bridged by a urea moiety. These complexes show fast and selective reduction of CO2 to CO and the results suggest a Ni-CODH type mechanism at play where one of the two metals binds and reduces the CO2 while the other stabilizes the reduced species by forming a bridged complex, facilitating the C-O bond cleavage.