Stabilisation and characterisation of a trinuclear uranyl complex by ligand-radical formation

Redox-active ligands can play an important role in the chemistry of actinide complexes by facilitating alternative reaction pathways or modifying electronic properties. In this regard, we report here the synthesis of the first trinuclear uranyl complex of a bridging radical ligand, [K(18-c-6)][(UO₂Cl₂)₃(TPymT)] 4.25THF (1). Structural and electronic characterisation reveals delocalisation of the radical across the bridging ligand and that the stability of the complex is entirely dependent on radical formation, with oxidation resulting in uranyl decomplexation. This study highlights the interplay between radical chemistry and actinide complexes and opens up new avenues for further research in this area.