Cs8UIV(UVIO2)3(Ge3O9)3·3H2O: A Mixed-Valence Uranium Germanate with 9-Ring Channels

A mixed-valence uranium(IV,VI) germanate has been synthesized under high-temperature, high-pressure hydrothermal conditions. The structure contains discrete UIVO6 octahedra and UVIO6 tetragonal bipyramids, which are connected by three-membered single-ring Ge3O96– anions to form a three-dimensional framework with 9-ring channels. The U 4f X-ray photoelectron spectroscopy spectrum was measured to identify the valence states of the uranium.