Capture and Characterization of High-Valent Uranium on Carbon Electrodes with a Hybrid Molecular Platform

Thermodynamic adsorption isotherm measurements, along with computational structural predictions, demonstrate that uranium is held tightly to the graphite surface in a manner that is enhanced by the presence of uranium in the ligand. In accord with these findings, Laviron analysis shows that the uranium redox on this platform is characterized by fast heterogeneous electron-transfer kinetics (<i>k</i>⁰ = 5 s^–1).

X-ray photoelectron spectroscopy (XPS) reveals rather intense U 4f satellite features for the on-surface molecular species, an effect originating in covalency between U and the hybrid ligand but not previously explored for molecular coordination complexes. Extended cathodic polarization can reversibly release uranium from the electrode, showcasing the potential of noncovalent immobilization strategies for studies of fundamental and applied actinide chemistry.