Solar energy storage is critical to combatting anthropogenic climate change and transitioning to renewable sources of energy. Billions of years ago, plants evolved the ability to harvest and store
energy from the sun in a process initiated by Photosystems I and II, wherein the oxygen evolving
complex oxidizes water to produce dioxygen. This heterocubane CaMn4O5 cluster serves as a
source of inspiration for the Tilley group’s investigations into the chemistry of water oxidation by
cobalt oxo cubanes. Chapter 1 briefly describes the current understanding of the mechanism for
water oxidation by the oxygen evolving complex, and the challenges posed to synthetic inorganic
chemists by this system. Chapter 2 details the first approach attempted to synthesize new
heterometallic cobalt oxo cubanes starting from simple tricobalt precursors. While the primary aim
of this study was to find rational synthetic routes to a wide library of MCo3O4 clusters, the
electronic structure of the Co3O4 fragment provides insight into the role of the fourth cobalt in the
parent cluster. Chapter 3 presents a near complete investigation into the metal-metal exchange
reaction between the Co4O4 cubane and MnII/III complexes to give the MnCo3O4 cubane. This study
provides mechanistic evidence for a pendant metal intermediate during the exchange process,
details reactions with CoIII and CoIV materials, and also reports an array of substituted benzoate
and pyridine ligated cobalt oxo cubanes. This manuscript is available publicly on ChemRxiv.
Chapter 4 details the synthesis and properties of a vanadium-cobalt oxo cubane through the
principles outlined in the metal-metal exchange study. The isostructural vanadium and ruthenium
cobalt oxo cubanes allow for interrogation of the role of the tricobalt framework. This chapter
continues to describe the oxidative reactivity of the vanadium-cobalt oxo system and attempts to
observe the oxidized intermediate spectroscopically with in situ methods. Theory and experiment
suggest a more localized hole compared to the all-cobalt system, which may have implications for
vanadium-cobalt oxide materials.