Transition metal-oxo complexes: how theory influences reactivity

Metal-oxo complexes are ubiquitous in nature; these structural motifs are central to key reactions that support all life, from the evolution of oxygen from water to the functionalization and oxidation of small molecules. There has been a significant amount of research into the electronic structure of these complexes with a keen eye on structure-activity relationships, and much of the chemistry by metal-oxos can be distilled down to acid-base (or electrophile-nucleophile) chemistries based on the oxidation state, ligand architecture, and geometry of the complex. Herein, we review metal-oxos and their various properties, importance in chemical transformations, and potential applications. In the first half, we detail the electronic structure of metal-oxos––the molecular orbital theory, orbital overlap analysis, and energetics of one-electron excitations. In the second, we apply the fundamental theory to two reactions crucial to modern chemistry research: water oxidation and organic molecule oxidation. Through the lens of structural inorganic chemistry (detailed in this review), we can view how the fundamental theory can be translated to complex reactivity in an intuitive way.