Exploring the Redox Properties of Bench-Stable Uranyl(VI) Diamido-Dipyrrin Complexes

The uranyl complexes UO₂(OAc)(L) and UO₂Cl(L) of the redox-active, acyclic diamido-dipyrrin anion L are reported and their redox properties explored. Because of the inert nature of the complexes toward hydrolysis and oxidation, synthesis of both the ligands and complexes was conducted under ambient conditions. Voltammetric, electron paramagnetic resonance spectroscopy, and density functional theory studies show that one-electron chemical reduction by the reagent CoCp₂ leads to the formation of a dipyrrin radical for both complexes [Cp₂Co][UO₂(OAc)(L^•)] and [Cp₂Co][UO₂Cl(L^•)].