UranyI Phosphonates with Multiple UranyI Coordination Geometries and Low Temperature Phase Transition

Main observation and conclusion Two new uranium(VI)phosphonate compounds,namely K_(8)[N(C_(2)H_(5))_(4)]_(2)(UO_(2))_(17)(H_(2)O)_(4)[CH_(2)(PO_(3))_(2)]_(8)[CH_(2)(PO_(3))(PO_(3)H)]_(4)·16(H_(2)O)(1)and[N(C_(2)H_(5))_(4)]_(4)(H_(3)O)_(2)(UO_(2))_(10)[CH_(2)(PO_(3))_(2)]_(5)[CH_(2)(PO_(3))(PO_(3)H)]_(2)·10H_(2)O(2),have been synthesized under mild hydro/solvothermal condition.The structural analysis of the two compounds reveals that they both contain all three typical coordination geometries of the U(VI)ions,including UO;tetragonal,UO,pentagonal,and UOg hexagonal bipyramids.Moreover,compound 1 displays a tempera-ture-induced single crystal to single crystal phase transformation as confirmed by the Single-crystal X-ray diffraction data collected at different temperatures.Temperature-dependent fluorescence spectra presented herein illustrate the perturbation of the electronic structure of uranyl centers.

Diversity of supramolecular architecture of H_2salpn coordination compounds based on its flexibility

Two complexes, [ Cu （salpn） ] · NH （ CH3 ）2 （ 1 ） and [Ni （ salpn ）·H20] （ 2 ） （ H2 salpn = N, N-bis（salicylidene）-propane-1,3-diamine） were characterized by IR, element analysis and single crystal X-ray diffraction analysis. Crystal data for complex 1 ： monoclinic, P21/C, a = 1. 097 4×10^-7 cm, b=1.4806x10-7 cm, c=1.0315×10^-7 cm, β=94.43（3）°. The Cu （II） ion in complex 1 is four coordinated with distorted square planar coordination geometry. The crystal structure of com- plex 1 consists of [ Cu（salpn）] coordination complex and a guest molecule NH（ CH3 ）2 that can act as both H-bonding donor and acceptor and plays an important role in constructing supramolecular ar- chitecture. Crystal structure data for complex 2： orthorhombic, Pnma, a = 8. 676 3 ×10^-8 cm, b = 2. 414 5 ×10^-7 cm, c = 7. 538 8×10^-8 cm. The Ni（II） ion in complex 2 is five-coordinated with a but- terfly coordination geometry. The coordinated water molecule plays a key role in hydrogen-bonded networks.

Structure of Tetra[β-(1,2,4-triazole-1-yl)propiophenone] Dichloro Nickel(II) Solvate Hexahydrate Complex: [NiCl_2(C_2H_2N_3CH_2CH_2COPh)_4]·6H_2O

The mononuclear complex, [NiCl 2(trzCH 2CH 2COPh) 4]·6H 2O (trz=1,2,4-triazole), was synthesized and its structure was determined by single crystal X-ray determination. It crystallizes in the monoclinic system, space group P2 1/c, with lattice parameters: a= 0.80391(2) nm, b= 1.08215(2) nm, c=2.90133(2) nm, β=94.792 (1)° and Z=2. Each nickel atom is coordinated by four N atoms of triazole from four β-(1,2,4-triazole-1-yl)propiophenone ligands and two chloride anions in trans arrangement with octahedral coordination geometry. In addition to the coordinating nickel complex, there are six uncoordinated water molecules. The Ni-Cl distance is 0.24865(8) nm and the Ni-N distances are in the range of 0.2072(2) to 0.2099(2) nm, respectively. In the solid state, the title compound forms three dimensional network structure through hydrogen bonds. The intermolecular hydrogen bonds connect the [NiCl 2(C 2H 2N 3CH 2CH 2COPh) 4] and H 2O moieties. The deep green crystals were also examined by elemental analysis, FT-IR and UV spectra, which are in agreement with the structural data.