Synthesis of an All-Ferric Cuboidal Iron-Sulfur Cluster [Fe S (SAr) ].

An unprecedented, super oxidized all-ferric iron-sulfur cubanoid cluster with all terminal thiolates, Fe S (STbt) (3) [Tbt=2,4,6-tris{bis(trimethylsilyl)methyl}phenyl], has been isolated from the reaction of the bis-thiolate complex Fe(STbt) (2) with elemental sulfur. This cluster 3 has been characterized by X-ray crystallography, zero-field Fe Mössbauer spectroscopy, cyclic voltammetry, and other relevant physico-chemical methods. Based on all the data, the electronic ground state of the cluster has been assigned to be S =0.