A five-coordinate [2Fe-2S] cluster.
A unique [2Fe-2S] cluster (1) with genuinely five-coordinate ferric ions has been synthesized and investigated both structurally and spectroscopically. The crystal structure of 1 as well as (1)H NMR data reveal that 2,6-bis(imidazol-2-yl)pyridine binds to the [2Fe-2S] core as a tridentate capping ligand. DFT calculations showing spin density on all coordinating atoms support this finding. Cluster