Pillared and open-framework uranyl diphosphonates

The hydrothermal reactions of uranium trioxide, uranyl acetate, or uranyl nitrate with 1,4-benzenebisphosphonic acid in the presence of very small amount of HF at 200 degrees C results in the formation of three different uranyl diphosphonate compounds, [H3O](2){(UO2)(6)[C6H4(PO3)(PO2OH)](2)[C6H4(PO2OH)(2)](2)[C6H4 (PO3)(2)]}(H2O)(2) (UbbP-1). [H3O](4){(UO2)(4)[C(6)H4(PO3)(2)](2)F-4}. H2O (Ubbp-2), and {(UO2)[C6H2F2(PO2OH)(2) (H2O)}(2). H2O (Ubbp-3). The crystal structures of these compounds were determined by single crystal X-ray diffraction experiments. Ubbp-1 consists of UO7 pentagonal bipyramids that are bridged by the phosphonate moieties to form a three-dimensional pillared structure. Ubbp-2 is composed of UO5F2 pentagonal bipyramids that are bridged through the phosphonate oxygen atoms into one-dimensional chains that are cross-linked by the phenyl spacers into a pillared structure. The structure of Ubbp-3 is a three-dimensional open-framework with large channels containing water molecules with internal dimensions of approximately 10.9 x 10.9 angstrom. Ubbp-1 and Ubbp-2 fluoresce at room temperature. (C) 2011 Elsevier Inc. All rights reserved.