Visible light facilitates a solid-to-solid aerial oxidation of a hunter-green oxidovanadium (IV) complex to form a black powder of cis-dioxidovanadium (V) complex. The tridentate sulfur- containing ligand used in this study is a siderophore. This irreversible transformation of a metal oxo species to a metal dioxo in the presence of oxygen extends solid matrix chemistry to include oxidation reactions and is the first example of its class.