LAUSR

Capture and activation of the water-soluble uranyl dication (UO22+) remains a challenging problem, as few rational approaches are available for modulating the reactivity of this species. Here, we report the divergent synthesis of heterobimetallic complexes in which UO22+ is held in close proximity to a range of redox-inactive metals by a tailored macrocyclic ligand. Crystallographic and spectroscopic studies confirm assembly of homologous UVI(μ-OAr)2Mn+ cores with a range of mono-, di-, and tri-valent Lewis acids (Mn+). Cyclic voltammetry data demonstrate that the UVI/UV reduction potential in these complexes is modulated over a span of nearly 600 mV, depending linearly on the Lewis acidity of the redox-inactive metal with a sensitivity of 61±9 mV/pKa unit. These findings suggest that interactions with Lewis acids could be effectively leveraged for rational tuning of 5f elements, reminiscent of strategies more commonly employed with 3d transition metals.