Synthesis of site-differentiated Fe₄S₄ and Fe₂S₂ clusters supported by bi- and tridentate ligands

Abstract

Iron-sulfur clusters in various geometries have crucial roles in a diverse array of biological transformations. In an attempt to expand the diversity of synthetic analogues, we have prepared a tris(amido) ligand intended to support a site-differentiated [Fe4 S4] cluster. We have similarly synthesized two bis(pyrazolyl)borate ligands envisioned for [Fe₂S₂] clusters. None of these ligands were found to metallate productively. Two bidentate diphosphine ligands have been shown to support an [Fe₄S₄] cluster with an extremely distorted core geometry.