Applications directed toward the remediation and reprocessing of nuclear waste have focused on various redox strategies to immobilize soluble uranyl(VI) to insoluble U(IV), employing microorganisms or chemical, electrochemical or photochemical reduction methods. The photochemical reduction with substrates such as alcohols is considered to proceed through two steps, entailing a one-electron reduction to uranyl(V) followed by the disproportionation of the unstable uranyl(V) intermediate, although mechanistic details remain sparse. Perhaps the most important factor that influences this redox chemistry, the coordination sphere of the precursor uranyl species, has largely been ignored. It is in this context that the photochemical reactivity of well-defined cationic uranyl(VI) complexes is presented under non-aqueous conditions employing systematic control over variable experimental conditions (i.e., reductant, solvent, etc.), with a focus on structural and electronic characterization of the products. The results offer mechanistic insight into alternate pathways of dioxo activation during the photochemical reduction of uranyl(VI) that are operable only under anhydrous conditions. One example (illustrated below) shows an unprecedented reversal of the normal trend in uranyl reactivity, whereby the normally labile equatorial coordination sphere remains intact while the usually robust axial site occupancy cleanly and reversibly interchanges between oxo and alkoxide ligands.