Tuneable Electronic Coupling in Linked Bis(cubane) Cobalt-Oxo Clusters

Abstract

A family of cobalt-oxo bis(cubane) complexes wherein each subunit is derived from the Co₄O₄ cubane, a known water oxidation catalyst, was synthesized. Both 4,4’-bipyrdine and pyrazine were demonstrated to serve as viable bridging ligands. Through an analysis of their half-wave splitting potentials, it was determined that pyrazine-bridged bis(cubane)s exhibit inter-cubane electronic coupling, and that this coupling may be tuned through ligand substitution. Electrostatic contributions to the half-wave splitting potentials were evaluated and found to result in “non-conformist” behavior related to the ion-pairing ability of the electrolytes.