The crystal structure of dihydrazinium uranyl dioxalate monohydrate, (N2H5)2 [UO2(C2O4)2(H2O)], has been determined by x-ray diffraction. The structure was solved by heavy-atom method and refined to an R value of 0–059 using 2312 reflections. The N2H5+ ions are not coordinated to the metal. In the anion [UO2(C2O4)2(H2O)]2−, the linear UO22+ group is coordinated by two chelating bidentate oxalate oxygens and a water oxygen. The coordination polyhedron around the uranium atom is an approximate pentagonal bipyramid.
