Synthesis,Structure and Characterization of Three Metal Molybdate Hydrates: Fe(H2O)2(MoO4)2·H3O,NaCo2(MoO4)2(H3O2)and Mn2(MoO4)3·2H3O

Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray...     

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O] n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC₆F₄COOH · H₂O (H₂L · H₂O), [Tb₂(H₂O)₄(L)₃ · 2H₂O] _n (I), and Tb₂(Phen)₂(L)₃ · 2H₂O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H₂L · H₂O is built of centrosymmetric molecules H₂L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb₂(H₂O)₄(L)₃] _n and molecules of water of crystallization. The ligands are the L^2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO₉ is a distorted three-capped trigonal prism. Acid H₂L manifests photoluminescence in the UV region (??_max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb³⁺ ions, and the band with ??_max = 545 nm (transition ⁵ D ₄?? ⁷ F ₅) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.     

Oxidation of coordinated ethylenediamine in platinum(IV) complexes with bromine. Crystal structures of [Pt(en)Py2Br2]Br2 · H2O, [Pt(HN-C(O)-C(O)-NH)Py2Br2] · H2O, and [Pt(en)PyBr3]NO3

Heating of an aqueous solution of [Pt(en)Py₂Cl₂]Cl₂ · 2H₂O (I) with KBr excess leads to the formation of [Pt(en)Py₂Br₂]Br₂ · H₂O (II). The interaction of a solution of II with bromine water results in the precipitation of polybromide ([Pt(en)Py₂Br₂]Br₂ · Br₂), which within a few days in the reaction solution partly transforms into oximide platinum(IV) complex, [Pt(HN-C(O)-C(O)-NH)Py₂Br₂] · H₂O (III). Complex [Pt(en)PyBr₃]Br · H₂O (IV) with an impurity of II was prepared by reacting KBr excess and the product of [Pt(en)Py₂]Cl₂ oxidation with chlorine in 0.05 N HCl. The action of HNO₃ on the solution of IV produced a nitrate derivative ([Pt(en)PyBr₃]NO₃, V). Complex IV, unlike II, does not react with bromine. The IR spectra of all the obtained compounds were recorded. Complexes II, III, and V were studied by X-ray crystallography. The crystals of II are monoclinic, space group P2₁/c, a = 15.640(2) Å, b = 9.345(1) Å, c = 14.167(2) Å, β = 102.63(1)°, V = 2020.5(5) ų, Z = 4, R _hkl = 0.033. The crystals of III are triclinic, space group P $\bar 1$ , a = 7.108(1) Å, b = 10.946(1) Å, c = 11.020(2) Å, α = 83.63(1)°, β = 80.31(1)°, γ = 75.02(1)°, V = 814.4(2) ų, Z = 2, R _hkl = 0.033. In the near-planar five-membered chelate ring (torsion angle NCCN is 7°), the C-O distances (1.23(1) Å) correspond to double bonds; the C-C (1.53(1) Å) and C-N (1.31(1) Å), distances correspond to ordinary bonds. The crystals of V are monoclinic, space group P2₁/c, a = 8.306(2) Å, b = 8.995(2) Å, c = 20.231(4) Å, β = 97.48(2)°, V = 1498.6(6) ų, Z = 4, R _hkl = 0.037.     

Synthesis and crystal structure of [UO2(L)(OH)], (CN3H6)2[(UO2)2CrO4(L)4 · 2H2O and [UO2(H2O)5][(UO2)2Cr2O7(L)4] (where L is picolinate ion)

[[UO₂(L)(OH)] (I), (CN₃H₆)₂[(UO₂)₂CrO₄(L)₄] · 2H₂O (II), and [UO₂(H₂O)₅][(UO₂)₂Cr₂O₇(L)₄] (III) crystals, where L is picolinate ion C₅H₄NCOO^?, have been synthesized and studied by X-ray diffraction and IR spectroscopy. Complex I crystallizes in triclinic system with the unit cell parameters a = 6.2858(5) Å, b = 7.9522(5) Å, c = 8.3598(6) Å, α = 79.527(6)°, β = 87.760(6)°, γ = 79.126(6)°, space group P $\bar 1$ , Z = 2, R = 0.0306, and complexes II and III crystalize in monoclinic system with a = 8.8630(9) Å, b = 13.4540(13) Å, c = 31.266(3) Å, β = 93.118(3)°, space group C2/c, Z = 4, R = 0.0187 (II), and a = 7.3172(4) Å, b = 15.4719(8) Å, c = 16.6534(10) Å, β = 98.943(4)°, space group P2₁/m, Z = 2, R = 0.0588 (III). The structure of complex I is built of electronegative [UO₂(L)(OH)] chains, which belong to the AT¹¹M² crystallochemical group (A = UO ₂ ²⁺ , T¹¹ = L, M² = OH^?) of uranyl complexes. The structure of complexes II and III contains [(UO₂)₂(L′)(L)₄]^2? dimers (L′ = CrO ₄ ^2? or Cr₂O ₇ ^2? ), which belong to the A₂B²B ₄ ⁰¹ group (A = UO ₂ ²⁺ ,B² = L′, B⁰¹ = L). The specifics of intermolecular interactions in the structures of complexes I–III and some their analogues have been considered using molecular Voronoi-Dirichlet polyhedra.     

Rhenium complexes with pyrazoles. Synthesis and crystal structure of trans-[Re(O)(OMe)L4]Br2·L·4H2O (L is 3,5-dimethylpyrazole)

The first mononuclear Re^V complex with four pyrazole ligands, viz., [Re(O)(OMe)L₄]Br₂ (L is 3,5-dimethylpyrazole), and its molecular adduct with L, viz., [Re(O)(OMe)L₄]Br₂·L·4H₂O, were synthesized. The complex is resistant to hydrolysis in a neutral aqueous solution. The structure of the adduct was established by X-ray diffraction analysis.     

On the infrared spectra of libratory modes of H2O molecules in SrX2 · 6H2 O (X = Cl,Br)

A detailed study of the libratory modes of H₂O molecules in the i.r. spectra of SrX₂ · 6H₂O (X = Cl, Br) is reported. The rocking, wagging and twisting libratory modes of (H₂O)_b (bridging type bonding) and (H₂O)_t (terminal type bonding) molecules are assigned at 705, 552, 658 and 460, 400, 438 cm⁻¹ and at 687, 532, 625 and 448, 370, 405 cm⁻¹ in the respective spectra. Using a semi-empirical relation reported by the authors in an earlier communication, the barrier height for (H₂O)_b is estimated to be 22.16 and 20.04 kcal/mole and that for (H₂O)_t to be 10.04 and 8.64 kcal/mole in the respective salts. The value of the force constants K_H and K_H′ for H₂O molecules are also reported.     

Two fumarato-bridged Co(II) coordination polymers: syntheses,crystal structures and properties of Co(H2O)4L and [Co3(H2O)4(OH)2L2]·2H2O with H2LHOOCCHCHCOOH

Two fumarato-bridged Co(II) coordination polymers Co(H₂O)₄L 1 and [Co₃(H₂O)₄(OH)₂L₂]·2H₂O 2 with H₂LHOOCCH CHCOOH were prepared. Complex 1 consists of polymeric chains _∞¹[Co(H₂O)₄(C₄H₂O₄)_2/2], which result from octahedrally coordinated Co atoms bridged by bis-monodentate fumarate anions and are assembled by interchain hydrogen bonds. Within 2, the edge-shared Co₂O₁₀ bi-octahedra are connected to the CoO₆ octahedra to form 1D cobalt oxide chains and 3D open framework generated from the chains inter-linked by bis-bidentate fumarate anions displays rhombic tunnels, which are filled with the lattice H₂O molecules. Thermal and magnetic behaviors of both the title coordination polymers are discussed. Crystal data: (1) monoclinic, P2₁/c, Z=4, a=7.493(1) Å, b=14.377(1) Å, c=7.708(1) Å, β=99.54(1)°, V=818.9(2) Å³, R₁=0.0304, and wR₂=0.0669 for 1487 observed reflections (I⩾2σ(I)) out of 1877 unique reflections; (2) monoclinic, P2₁/c, Z=2, a=6.618(1) Å, b=8.172(2) Å, c=15.578(3) Å, β=96.30(3)°, V=837.4(3) Å³, R₁=0.0360 and wR₂=0.0663 for 1442 observed reflections (I⩾2σ(I)) out of 1927 unique reflections.     

Synthesis and crystal structure characterization of supramolecular complex [Cd2(Bipy)2(L)2(H2O)2] · 9H2O (H2L = 2,2′-bipyridyl-6,6′-dicarboxylic acid)

In the complex [Cd₂(Bipy)₂(L)₂(H₂O)₂] · 9H₂O, the center atom Cd(II) presents a seven-coordinated pentagonal bipyramidal geometry with seven coordination bonds, four Cd-N bonds, and three Cd-O bonds. X-ray structural analysis shows that nineteen water molecules formed a large water cluster, the cluster and the composition connected to form 2D plane areolar framework and 3D zigzag networks structure through π-π-stacking and hydrogen bonding. This composition in the previous report is rare.     

Far infrared spectra of K2Pt(CN)4Br0.3·3.2H2O

Polarized far i.r. reflection spectra of K₂Pt(CN)₄Br_0.3·3.2H₂O were measured at 220, 150 and 80 K for the frequency range 15–400 cm⁻¹. The E|c and E ⊥ c spectra were analysed on the basis of the one- and four-oscillator model, respectively. Observed bands were interpreted based on the average structure (C¹_4υ, Z = 2), not taking into account Peierls distortion.     

Synthesis and Crystal Structure of [Ni(H2O)6][Ni(H2O)2(C4H2O4)]·4H2O

Reaction of a freshly prepared Ni(OH)_{2?2 x} (CO₃) _x ·yH₂O with maleic acid in H₂O at room temperature afforded [Ni(H₂O)₆][Ni(H₂O)₂(C₄H₂O₄)]·4H₂O, which consists of [Ni(H₂O)₆]²⁺ cations, [Ni(H₂O)₂(C₄H₂O₄)]^2? anions and lattice H₂O molecules. Ni atoms in cations are octahedrally coordinated and Ni atoms in anions are each octahedrally coordinated by bidentate chelating maleato ligands and two water molecules at trans positions. Cations and anions are interlinked by hydrogen bonds to form 1D chains, which are hexagonally arranged and connected by the lattice water molecules. When heated in a flowing argon stream, the compound decomposes, with complete dehydration being followed by dissociation of nickel maleate into NiO and maleic anhydride.     

Synthesis, crystal structure, and photophysical properties of acid (H3O)2[{W6Br8}Br6] · 4H2O

Compound (H₃O)₂[{W₆Br₈}Br₆] · 4H₂O is synthesized by the reaction of polymeric tungsten bromide W₆Br₁₂ with hydrobromic acid in an ethanolic solution. The structure of the compound is a packing of counterions H₃O⁺ and [{W₆Br₈}Br₆]^2? and crystallization water molecules joined with each other by an extended system of hydrogen bonds. The finely crystalline sample of the complex exhibits luminescence, whose spectrum has a broad profile from ??500 nm to more than 950 nm with a maximum at ??715 nm, with an absolute quantum yield of ??0.225. The emission is characterized by the biexponential decay with lifetimes of ??2.2 and ??8.4 ??s.     

Tansition metal complexes with 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL): Synthesis and crystal structure of [Co(L)2(H2O)4] · 6H2O and [Cu(L)2(H2O)2] · 4H2O

Transition metal complexes of 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL), namely [Co(L)₂(H₂O)₄] · 6H₂O (I) and [Cu(L)₂(H₂O)₂] · 4H₂O (II), have been synthesized by a hydrothermal procedure and characterized by X-ray crystallography, CIF files CCDC nos. 1007524 (I), 1007525 (II). Both I and II are mononuclear molecules. In I, the Co²⁺ ion is in octahedral coordiantion environment and surrounded by four O atoms from water molecules and two carboxylate O atoms of two deprotonated ligand (L^?) occupied six culmination. While in II, the Cu²⁺ ion is located in a square-planar geometry, bounded to two aqua O atoms and two carboxylate O atoms from L^?.     

Synthesis and Crystal Structure of Ammonium Dimolybdatouranylate Monohydrate (NH4)2[UO2(MoO4)2] · H2O

The crystal structure of the complex (NH₄)₂[UO₂(MoO₄)₂] · H₂O is determined. The unit cell parameters are a= 7.916, b= 10.885, c= 13.476 Å, = 98.40°, V= 1148.8 ų, space group P2₁/c, Z= 4, (calcd) = 3.452 g/cm³, R= 0.0406, R _w= 0.0850. The coordination polyhedron of the uranium atom is a pentagonal bipyramid with its equatorial plane formed by oxygen atoms of five MoO₄groups.     

Supramolecular Assemblies via Hydrogen Bonding and π-π Stacking Interactions: Crystal Structures of [Co(phen)(H2O)4]L·0.5H2O and [CO2(phen)2(H2O)2L2] with H2L = Adipic Acid

Reaction of freshly-prepared CoCO₃, phenanthroline monohydrate and adipic acid (H₂L) in CH₃OH/H₂O produced a mixture of [Co(phen)(H₂O)₄]L·0.5H₂O (1) and [CO₂(phen)₂(H₂O)₂L₂] (2). Complex 1 crystallizes in the orthorhombic space group Pbcn with cell dimensions a = 23.380(2), b = 12.347(1), c = 12.821(1) Å, and D _calc = 1.390 g/cm³ for Z = 8, and complex 2 in the triclinic space group P1; with cell dimensions a = 8.203(1), b = 9.809(1), c = 11.827(1) Å, α = 70.34(1), β = 74.81(1), γ = 71.54(1)° and D _calc = 1.592 g/cm³ for Z = 1. Complex 1 consists of [Co(phen)(H₂O)₄]²⁺ complex cations, adipate anions and crystal H₂O molecules. The Co atoms are each octahedrally coordinated by one chelating phen ligand and four water molecules with d(Co-O) = 2.041-2.097 Å and d(Co-N) = 2.144, 2.160 Å. Through hydrogen bonds, the [Co(phen)(H₂O)₄]²⁺ complex cations and adipate anions are interconnected into 2D layers, whose assembly could be ascribed to weak π-π stacking interactions between interdigitating phen ligands. Complex 2 is composed of centrosymmetric dinuclear [Co₂(phen)₂(H₂O)₂L₂) molecules, in which the Co atoms are each coordinated by two N atoms of one chelating phen ligand and four O atoms of one H₂O molecule and two adipato ligands to form distorted octahedra with d(Co-O) = 2.027-2.248 Å and d(Co-N) = 2.112, 2.162 Å. The centrosymmetric molecules are assembled via intermolecular hydrogen bonds and π-π interactions into 2D layers.     

Structure of (C3H5NH3)2H2P2O7·H2O

The bis(cyclopropylammonium)dihydrogenodiphosphate monohydrate is a new diphosphate associated with the organic molecule C₃H₅NH₂. We report the chemical preparation and the crystal structure of this organic cation diphosphate. (C₃H₅NH₃)₂H₂P₂O₇.H₂O is orthorhombic (S.G. : P2₁2₁2₁), with Z = 4 and the following unit-cell parameters : a = 4.828(1) Å, b = 11.011(1) Å, c = 25.645(2) Å. The P₂O₇ groups and H₂O water molecules form a succession of bidimensional layers perpendicular to the c axis. The organic cations ensure the three-dimensional cohesion by NH-O hydrogen bonds.     

Synthesis and characterization of [PtMe3L(H2O)]BF4·H2O (L=3-O-acetyl-1,2-O-isopropylidene-α-D-glucofuranose)

Reaction of [PtMe₃(Me₂CO)₃]BF₄ (1) with 3-O-acetyl-1,2;5,6-di-O-isopropylidene--D-glucofuranose in acetone affords [PtMe₃L]BF₄ (2) (L=3-O-acetyl-1,2-O-isopropylidene--D-glucofuranose). In wet methylene chloride, complex2 transforms to [PtMe₃L(H₂O)]BF₄·H₂O (3). Complex3 was characterized by microanalysis and NMR spectroscopy (¹H,¹³C,¹⁹⁵Pt). The X-ray structure analysis (monoclinic, P2¹, a=10.529(3) , b=7.322(2) , c=14.668(4) , Z=2) reveals that 3-O-acetyl-1,2-O-isopropylidene--D-glucofuranose acts as a neutral bidentate ligand which is coordinated via two hydroxyl groups (²O^5,6 coordination). The five-membered 1,3,2-dioxaplatina rings exhibit an envelope conformation. The coordination sphere of platinum is completed by H₂O ligand.Institut für Anorganische Chemie, Martin-Luther-Universität; Halle-Wittenberg, Kurt-Mothes Str. 2, D-06120 Halle/Saale, Germany. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1119–1126, August, 1999.     

Crystal structure of a tantal cluster with tetraphenylborate-anion: [Ta6Br12(H2O)6](BPh4)2·4H2O

The crystal structure of the [Ta₆Br₁₂(H₂O)₆](BPh₄)₂·4H₂O salt (1), obtained from Ta₆Br₁₄·7H₂O and NaBPh₄, is determined by X-ray crystallographic analysis. The structure contains a network of hydrogen bonds, which organizes the cluster cations into layers.