A variety of metal oxides can catalyze the oxidation of water to molecular oxygen when polarized by a sufficiently high electrochemical potential. Minimizing the overpotential and increasing the rate of the oxygen-evolving reaction (OER) are key goals in making such materials a component of viable energy storage devices. However, the structural factors that imbue the metal oxides with their catalytic power are difficult to assess as these solids contain many distinct metal-ion sites, have a varying amount of defect sites within the lattice, and can be composed of multiple phases. In the present study, we determined the magnetic properties for a series of dimeric cobalt complexes in which the two metal centers are bridged by a dioxygen moiety. Our spectroscopically validated electronic structure description indicates that each species is best described as two Co(III) ions that are bound to a mu-eta(1)eta(1) superoxide ligand. Intriguingly, we found evidence that the two compounds that possess oxygen-evolving activity coordinate the superoxide ion in an unusual, nonplanar fashion. It appears as if the intermediately long Co...Co distance of 3.9 angstrom is responsible for the unusual superoxide binding geometry. This structural factor may be an important element in the design of solid-state OER catalysts.