Uranyl-Promoted Peroxide Generation: Synthesis and Characterization of Three Uranyl Peroxo [(UO2)2(O2)] Complexes

Three novel uranyl(VI) peroxide complexes, [(UO2)2(CH3COO)2(O2)(C10H8N2)] (1), [(UO2)2(CH3COO)2(O2)(C12H12N2)] (2), and [(UO2)3(CH3COO)4(O2)(C15H11N3)2] (3), have been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and luminescence spectroscopy. Each of these structures feature a [(UO2)2(O2)] dimer with additional coordination by acetate, 2,2'-bipyridine (BPY), 5,5'-dimethyl-2,2'-bipyridine (MeBPY), or 2,2':6,2″-terpyridine (TPY). Compound 3 consists of an additional uranyl unit functionalized with a TPY donor ligand. The presence of the peroxo ligand in 1-3 is due to in situ generation of peroxide when preparative solutions of 1-3 were exposed to ambient light and/or sunlight.