Browsing by Author "Aharonovich, I"

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    Hydrothermal synthesis, structures and properties of two uranyl oxide hydroxyl hydrate phases with Co(II) or Ni(II) ions
    (Royal Society of Chemistry., 2016-04-11) Zhang, YJ; Čejka, J; Lumpkin, GR; Tran, TT; Aharonovich, I; Karatchevtseva, I; Price, JR; Scales, N; Lu, KT
    Two new iso-structured uranyl oxide hydroxyl hydrate (UOH) phases with the incorporation of cobalt(II) or nickel(II) ions have been synthesised under hydrothermal conditions and structurally characterised. Both K4Co(OH)3(H2O)9[(UO2)12(O)7(OH)13] (1) and K4Ni(OH)3(H2O)9[(UO2)12(O)7(OH)13] (2) have two-dimensional (2D) polymeric uranyl oxohydroxyl layers with either potassium and hydroxyl cobalt(II) (1) or potassium and hydroxyl nickel(II) (2) ions between layers via uranyl–cation interactions. This work highlights the feasibility of making new UOH phases via a hydrothermal route at relatively higher solution pHs. It also demonstrates that other transition metal ions which are readily available in the environment may also be incorporated into such UOH phases during the natural weathering of uraninite as well as during the storage and disposal of spent nuclear fuels. © 2016 The Royal Society of Chemistry
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    Solvothermal synthesis of uranium(VI) phases with aromatic carboxylate ligands: a dinuclear complex with 4-hydroxybenzoic acid and a 3D framework with terephthalic acid
    (Elsevier B.V., 2016-02-01) Zhang, YJ; Karatchevtseva, I; Bhadbhade, MM; Tran, TT; Aharonovich, I; Fanna, DJ; Shepherd, ND; Lu, KT; Li, F; Lumpkin, GR
    With the coordination of dimethylformamide (DMF), two new uranium(VI) complexes with either 4-hydroxybenzoic acid (H2phb) or terephthalic acid (H2tph) have been synthesized under solvothermal conditions and structurally characterized. [(UO2)2(Hphb)2(phb)(DMF)(H2O)3]·4H2O (1) has a dinuclear structure constructed with both pentagonal and hexagonal bipyramidal uranium polyhedra linked through a µ2-bridging ligand via both chelating carboxylate arm and alcohol oxygen bonding, first observation of such a coordination mode of 4-hydroxybenzoate for 5 f ions. [(UO2)(tph)(DMF)] (2) has a three-dimensional (3D) framework built with pentagonal bipyramidal uranium polyhedra linked with µ4-terephthalate ligands. The 3D channeled structure is facilitated by the unique carboxylate bonding with nearly linear C–O–U angles and the coordination of DMF molecules. The presence of phb ligands in different coordination modes, uranyl ions in diverse environments and DMF in complex 1, and tph ligand, DMF and uranyl ion in complex 2 has been confirmed by Raman spectroscopy. In addition, their thermal stability and photoluminescence properties have been investigated. © 2015 Elsevier Inc.
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    Uranium(VI) hybrid materials with [(UO2)3(µ3‐O)(µ2‐OH)3]+ as the sub–building unit via uranyl–cation interactions
    (John Wiley and Sons, 2016-01-14) Zhang, YJ; Clegg, JK; Lu, KT; Lumpkin, GR; Tran, TT; Aharonovich, I; Scales, N; Li, F
    The hydrothermal reaction of uranyl nitrate with 1,4-benzenedicarboxylic acid (H2bdc) in the presence of strontium or potassium hydroxides and nitrates afford the formation of two new uranyl hybrid materials featuring extensive uranyl-strontium or uranyl-potassium interactions with [(UO2)3(µ3-O)(µ2-OH)3]+ as the sub-building unit. Sr1.5[(UO2)12(O)3(OH)13(bdc)4]⋅6H2O (1) contains one-dimensional (1D) uranyl oxohydroxyl ribbons made of trinuclear pentagonal bipyramidal uranyl units. The ribbons are linked together via uranyl-strontium interactions to form 2D inorganic domains which are further connected through µ4-bdc anions forming a 3D hybrid structure. This is the first reported uranyl-strontium interaction in extended hybrid solid with the shortest Sr-O−yl bond length of 2.596 (8) Å. K3[(UO2)12(O)3(OH)13(bdc)4]⋅8H2O (2) has a similar 3D hybrid structure built up through extensive K-O−yl interactions with the shortest K-O−yl bond length of 2.620 (6) Å. Raman spectroscopy has confirmed the presence of oxo-bridging (U−O−U) vibrations. Thermal stabilities and photoluminescent properties are reported. © 2016 Wiley‐VCH Verlag GmbH & Co.