No abstract

The synthesis and structural characterization of the compounds K[(UO(2))(2)(UO(4))(OH)(NO(3))(2)]H(2)O (1) and Ba[(UO(2))(4)(UO(4))(2)(OH)(2)(NO(3))(4)]H(2)O (2) have revealed that each contains sheets that are based upon the beta-U(3)O(8)-type topology and that these sheets are linked through low-valence interlayer cations. Consistent with other uranium(VI) compounds that have topologically identical sheets, one of the uranium(VI) sites exhibits a highly unusual (UO(4))(2-) tetraoxido core that is further coordinated by two bidentate (NO(3))(-) groups.

Uranium(VI) Tetraoxido Core Coordinated by Bidentate Nitrate. -The structures of (III) (orthorhombic, space group Pbca, Z = 8) and (V) (Pbca, Z = 4) are determined by single crystal XRD. Both compounds contain corrugated layers with β-U3O8 topology. Each sheet contains three U VI sites. Two of these sites are typical (UO2) 2+ uranyl ions, while the third U VI site exhibits a highly unusual (UO4) 2tetraoxido core that is further coordinated by two bidentate (NO 3 )groups. Adjacent layers are interconnected via the K + and Ba 2+ cations and through a hydrogen bonding network. -(UNRUH, D. K.; BARANAY, M.; BARANAY, M.; BURNS*, P. C.; Inorg. Chem. 49 (2010) 15, 6793-6795,

Synthesis and Characterization of Uranyl Chromate Sheet Compounds Containing Edge-Sharing Dimers of Uranyl Pentagonal Bipyramids. -Eight uranyl chromate compounds are synthesized and characterized by single crystal XRD. The uranyl chromates (V), (VII), (X), (XI), and (XIV) crystallize in the monoclinic space group P21/c, (III) crystallizes in the orthorhombic space group Cmcm, (XIII) in the monoclinic space group P2 1 /n, and (XVI) in the orthorhombic space group P2 1 2 1 2 1 . The structural units of the compounds are sheets of uranyl pentagonal bipyramids and [Cr VI O4] 2tetrahedra. The uranyl pentagonal bipyramids share an equitorial edge, resulting in a dimer that is linked into the sheet through corner-sharing with CrO4 tetrahedra. -(UNRUH, D. K.; BARANAY, M.; PRESSPRICH, L.; STOFFER, M.; BURNS*, P. C.; J. Solid State Chem. 186 (2012) 158-164, http://dx.