Synthesis of a Fe₃-Carbyne Motif by Oxidation of an Alkyl Ligated Iron-Sulfur (WFe₃S₃) Cluster

The presence of a carbide ligand in the active site of nitrogenases remains an unusual example of organometallic chemistry employed by a protein. Carbide incorporation into the MFe₇S₉ C cluster involves complex biosynthesis, but analogous synthetic methodologies are limited. Herein, we present a new synthetic strategy for incorporating carbon based bridging ligands into iron–sulfur clusters. Starting from a halide precursor, a WFe₃S₃ cluster displaying three terminal alkyl ligands and an open Fe₃ face was prepared. Oxidation results in loss of alkane and formation of a μ3-carbyne. Characterization of these clusters and mechanistic studies are presented.