Structure and Reactivity of an Asymmetric Synthetic Mimic of Nitrogenase Cofactor

The Mo nitrogenase catalyzes the ambient reduction of N-2 to NH3 at its M-cluster site. A complex metallocofactor with a core composition of [MoFe7S9C], the M-cluster, can be extracted from the protein scaffold and used to facilitate the catalytic reduction of CN-, CO, and CO2 into hydrocarbons in the isolated state. Herein, we report the synthesis, structure, and reactivity of an asymmetric M-cluster analogue with a core composition of [MoFe5S9]. This analogue, referred to as the Mo-cluster, is the first synthetic example of an M-cluster mimic with Fe and Mo positioned at opposite ends of the cluster. Moreover, the ability of the Mo-cluster to reduce C-1 substrates to hydrocarbons suggests the feasibility of developing nitrogenase-based biomimetic approaches to recycle C-1 waste into fuel products.