Structure cristalline d'un phosphochromate acide de cuivre potassium: CuK2H2(PCrO7)2

CuK₂H₂(PCrO₇)₂ is monoclinic, P2₁/c, with a unit cell: a=9.559(5)Å; b=7.196(5)Å; c=8.983(5)Å;β=93.73(5)°; Z=2; and D=2.87g/cm³.The crystal structure of this compound has been resolved by using 1938 independent reflections with a final R value of 0.03. The main feature of this compound is the existence of the mixed pyro-group CrPO₇, up to now the first to be described.     

Synthesis and Structural Characterization of a Layered Tin(II) Phosphate, [Sn2(PO4)2][C2N2H10]·H2O

A new layered tin(II) phosphate [Sn₂(PO₄)₂]²⁻[C₂N₂H₁₀]²⁺·H₂O was synthesized by hydrothermal technique. It crystallizes in monoclinic space groupP2₁/c(No. 14) with lattice parametersa=9.4112(1) Å;b=8.5998(1) Å;c=15.9921(2) Å;β=100.009(1)°;V=1274.61(2);Z=4;R=2.06%;R_w=2.17%. The structure consists of inorganic layers, comprising a network of strictly alternating SnO₃and PO₄moieties and held together by strong hydrogen bonding between the layers. Protonated ethylenediamine and water molecules are trapped between the layers.     

The crystal and molecular structure of trimethyltin(IV) chloride, a chlorine-bridged, linear polymer

The crystal and molecular structure of trimethyltin(IV) chloride has been determined by the heavy-atom technique, and refined to a final R value of 0.041 for 1375 independent reflections (2θ < 53°; Mo-K_a radiation I > 2σ(I)) recorded at 138 ± 2 K on a Nonius CAD-4 counter diffractometer. The crystals are monoclinic with space group I2/c; a 12.541(8), b 9.618(11), c 11.015(11) Å, β 92.62(7)°, Z = 8, D_calcd 1.994 g cm⁻³. The needle crystals are composed of polymeric chains of chlorine atoms bridging non-planar trimethyltin(IV) units at unequal (2.430(2) and 3.269(2) Å) distances. The zig-zag chains are bent at chlorine (angle Sn---Cl Sn 150.30(9)°), but nearly linear at tin (angle Cl---Sn Cl 176.85(6)°) to describe a distorted trigonal bipyramidal geometry at tin with the trimethyltin groups eclipsed. The interchain d(Sn Cl) distances are greater than 4.1 Å. The angles carbon—tin—carbon (mean 117.1(3)°) are larger than tetrahedral, while the angles carbon—tin—chlorine (mean 99.9(2) Å) are smaller, in accord with isovalent hybridization principles, but more severely distorted than in the gas-phase, monomeric structure. The tin—chlorine distance of 2.430(2) Å is also longer than in the gas phase monomer, and the intermolecular contact of 3.269 Å is shorter than in other organotin chloride bridged systems (sum of Van der Waals radii 3.85 Å).     

An XRPD ab-initio structural determination of La2RuO5

The crystal structure of a new oxide, La₂RuO₅, was determined ab initio using conventional laboratory X-ray powder diffraction. Combining X-ray and electron diffraction techniques, we found that the new phase crystallized in the monoclinic system with the space group P2₁/c (SG no.14) and the cell parameters a=9.1878(2) Å, b=5.8313(2) Å, c=7.9575(2) Å and β=100.773(2)° (V=418.8 ų, Z=4). The structural determination with the Patterson method and Fourier difference syntheses and the final Rietveld refinement were performed by means of the JANA2000 program. The structure is built up from the regular stacking of a two octahedra thick [LaRuO₄]_∞ zigzag perovskite slab and an original 3.4 Å thick [LaO]_∞ slab which constitutes the key feature of this new structure.     

Preparation, crystal structure, vibrational spectra and thermal behavior of selenites of ethylene diamine, 1,3-propylene diamine and 1,4-butylene diamine

Selenites of ethylene diamine, propylene diamine and butylene diamine were prepared by crystallization from aqueous solution. The crystal structure was solved for all the substances. Ethylene diammonium(2+) selenite crystallizes in the orthorhombic space group P2₁2₁2, a=11.3710(2) Å, b=11.4390(5) Å, c= 4.6290(4) Å, V= 602.11(6) ų, Z=4, R=0.0341 for 5729 observed reflections. 1,3-Propylene diammonium(2+) selenite dihydrate crystallizes in the monoclinic space group C2/c, a=16.241(14) Å, b=6.673(5) Å, c=17.731(14) Å, β=110.88(2)°, V=1795(3) ų, Z=8, R=0.0271 for 12,233 observed reflections. 1,4-Butylene diammonium(2+) selenite dihydrate crystallizes in the monoclinic space group P2₁/c, a=6.686(5) Å, b=16.597(14) Å, c=9.282(8) Å, β=96.653(14)°, V=1023.2(14) ų, Z=4, R=0.0465 for 2918 observed reflections. The FTIR an FT Raman spectra of all the compounds were recorded and interpreted. The thermoanalytical properties were studied by the TG, DTG, and DTA methods in the 293–633 K temperature range. DSC measurements were carried out in the range from 98 K to the temperature of decomposition of the compounds. No thermal effect indicating a phase transition was observed in this temperature region.     

New Layered Materials in the K–In–Ge–As System: K8In8Ge5As17and K5In5Ge5As14

Exploratory synthesis in the K–In–Ge–As system has yielded the unusual layered compounds K₈In₈Ge₅As₁₇(1) and K₅In₅Ge₅As₁₄(2), both of which contain In–Ge–As layers with interleaved potassium ions, Ge–Ge bonds, InAs₄tetrahedra, As–As bonds, and rows of Ge₂As₆dimers. Compound 1 has As₃groups, while compound 2 has infinite As ribbons on both faces of each layer. Unlike compound 1, compound 2 has substitutional defects where indium partially occupies each of the three independent germanium sites in the ratio of 1:5 for In:Ge. This partial occupancy makes 2 an electron-precise compound. The Ge(In)–Ge(In) bond of 2 is longer than the Ge–Ge bond of 1, and this bond lengthening effect was confirmed by performing DFT-MO calculations on the model compounds H₃Ge–GeH₃and H₃Ge–InH⁻₃. Possible implications of electron imprecise formulas determined by X-ray crystal structure determinations are discussed. Compound 1: space groupP2₁/cwitha=18.394 (8) Å,b=19.087 (7) Å,c=25.360 (3) Å,β=105.71 (2)°,V=8571 (4) ų, andD_calcd=4.45g/cm³forZ=4. Refinement on 4455 reflections yieldedR(R_w)=6.8%(7.8%). Compound 2: space groupC2/mwitha=40.00 (1) Å,b=3.925 (2) Å,c=10.299 (3),β=99.97 (2)°,V=1592 (1) ų, andD_calcd= 4.55g/cm³forZ=8. Refinement on 1206 reflections yieldedR(R_w)=5.6% (5.7%).     

The Crystal Structure, Vibrational Spectra, and Thermal Behavior of Piperazinium(2+) Selenate Monohydrate and N, N′-Dimethylpiperazinium(2+) Selenate Dihydrate

The crystal structure of piperazinium(2+) selenate monohydrate has been resolved; this substance crystallizes in the monoclinic space group P2₁/n, a=6.4586(8), b=11.8335(7), c=11.8065(7) Å, β=100.990(8)°; V=885.80(13) Å⁵, Z=4, R=0.0446 for 1556 observed reflections. A similar compound, N,N′-dimethylpiperazinium(2+) selenate dihydrate, crystallizes in a triclinic system with space group P and lattice parameters a=6.7370(8), b=7.9845(9), c=12.3802(12) Å, α=92.435(9)°, β=100.219(9)°, γ=114.699(10)°; V=590.34(11) ų, Z=2, R=0.0311 for 2071 observed reflections. While, in the former structure, the cations of piperazinium(2+) in the chair conformation are arranged roughly plane-parallel above one another, in the second substance, the N,N′-dimethylpiperazinium (2+) ions lie approximately perpendicularly above one another. The FTIR and FT Raman spectra of both test substances have been measured and studied. The thermoanalytical properties were studied using TG, DTG, and DTA methods in the temperature range 293–533 K. DSC measurements were carried out in the temperature range 95–343 K. No phase transition was found in this temperature region for either of the compounds.     

The crystal structure, vibrational spectra, and thermal behavior of dilithium piperazinium(2+) selenate tetrahydrate and dilithium N,N′-dimethylpiperazinium(2+) selenate tetrahydrate

The crystal structure of dilithium piperazinium(2+) selenate tetrahydrate has been solved; this substance crystallizes in the triclinic space group , a=7.931(2) Å, b=7.974(2) Å, c=7.991(2) Å, α=106.99(2)°, β=101.83(2)°, γ=119.28(2)° Z=1, R=0.0280 for 1489 observed reflections. A similar compound, dilithium N,N′-dimethylpiperazinium(2+) selenate tetrahydrate crystallizes in a monoclinic system with space group P2₁/c and lattice parameters a=7.338(1) Å, b=8.792(2) Å, c=12.856(1) Å, β=92.04(2)°, Z=2, R=0.0334 for 1462 observed reflections. Both structures are centrosymmetric with center of symmetry in the center of eight membered ring formed with two SeO₄ tetrahedra and two LiO₄ tetrahedra connected through tops. The two remaining oxygens on each Li atom come from water molecules. The FTIR and FT Raman spectra of both natural and N,O-deuterated substances have been measured and studied. The thermoanalytical properties were studied using TG, DTG and DTA methods in the temperature range 293–873 K for piperazinium derivative and in the range 293–523 K for dimethylpiperazinium derivative. DSC measurements were carried out in the temperature range 95–343 K. No phase transition was found in this temperature region for either of the compounds.     

Crystallographic and theoretical study of phenyl 2,3,4,6-tetra-O-acetyl-1-thio-α-D-mannopyranoside

The thiomannoside is a key intermediate in the synthesis of polymannosaccharide. But its crystallographic study has not been reported. X-ray crystal structure analysis shows that the crystal of phenyl 2,3,4,6-tetra-O-acetyl-1-thio-α-D-mannopyranoside is in orthorhombic system, has P2₁2₁2₁ space group. Its unit cell dimensions are a=9.1731(11), b=11.574(2), and c=21.199(3) Å, α=β=γ=90.00°, Z=4, V=2250.6(6) ų, D_c=1.300 g/cm³. The crystallographic study reveals that the thiomannoside is an α-anomer. Most interestingly, the structure provides an evidence of existing C–HO and C–HS intramolecular and intermolecular hydrogen bonds.     

Single-crystal characterization of Co7(OH)6(H2O)3(C4H4O4)47H2O; A new cobalt succinate identified through high-throughput synthesis

A new form of cobalt succinate has been discovered using high-throughput methods and its structure was solved by single crystal X-ray diffraction. Co₇(C₄H₄O₄)₄(OH)₆(H₂O)₃7H₂O crystallizes in the monoclinic space group P2₁/c with cell parameters: a=7.888(2) Å, b=19.082(6) Å, c=23.630(7) Å, β=91.700(5)°, V=3555(2) Å³, R₁=0.0469. This complex structure, containing 55 crystallographically distinct non-hydrogen atoms, is compared to the previously reported nickel phase, characterized using ab initio structure solution from synchrotron powder diffraction data.     

Crystal structure determination of BaNd2Ti3O10 using high-resolution electron microscopy

The crystal structure of BaNd₂Ti₃O₁₀ has been determined by electron diffraction and high-resolution electron microscopy. The unit cell is monoclinic with P2₁/m as the most probable space group and not orthorhombic as previously found by X-ray diffraction. However, the structure has an orthorhomic pseudosymmetry, but due to the small Nd³⁺ cations the octahedra are titled and the structure is monoclinic. The cell dimensions based on X-ray data are: a_m = 7.7310 ± 0.0006 Å; b_m = 7.6661 ± 0.0007 Å; c_m = 14.210 ± 0.002 Å; β_m = 97.82 ± 0.01°.     

Hydrothermal Synthesis and Crystal Structure of [(CH3NH3)1.03K2.97]Sb12S20·1.34H2O

A novel thioantimonate(III) [(CH₃NH₃)_1.03K_2.97]Sb₁₂S₂₀·1.34H₂O was synthesized hydrothermally. It crystallizes in space groupP , witha=11.9939(7) Å,b=12.8790(8) Å,c=14.9695(9) Å,α=100.033(1)°,β=99.691(1)°,γ=108.582(1)°,V=2095.3(2) ų, andZ=2. The structure is determined from single crystal X-ray diffraction data collected at room temperature and refined toR(F)=0.037. In the crystal structure, each Sb(III) atoms has short bonds (2.37–2.58 Å) to three S atoms. The pyramidal [SbS₃] groups share common S atoms forming two types of centrosymmetric [Sb₁₂S₂₀] rings with the same topology. These rings are interconnected by weaker Sb–S bonds (2.92–3.29 Å) into 2-dimensional layers. Adjacent layers are parallel with K⁺and CH₃NH⁺₃ions and H₂O molecules located between them. Variation of bond valence sums calculated for the Sb(III) cations is found to be correlated with the coordination geometry. This is interpreted as due to the stereochemical activity of their lone electron pairs.     

Strontium–copper selenite–chlorides: Synthesis and structural investigation

Two new complex selenite–chlorides of strontium and copper Sr₂Cu(SeO₃)₂Cl₂ (I) and SrCu₂(SeO₃)₂Cl₂ (II) were obtained and characterized by X-ray diffraction technique, DTA and IR spectroscopy. Both compounds crystallize in the monoclinic system I: Sp. gr. P2₁/n, a=5.22996(3) Å, b=6.50528(4) Å, c=12.34518(7) Å, β=91.3643(2)°, Z=2; II: Sp. gr. P2₁, a=7.1630(14) Å, b=7.2070(14) Å, c=8.0430(16) Å, β=95.92(3)°, Z=2. Comparison of the crystal structure of (I) with the structures of Sr₂M(SeO₃)₂Cl₂ (M=Co, Ni) was performed. The substitution of strontium atom in the structure of (I) by Cu²⁺ ion with a 3d⁹ Jahn–Teller distorted surrounding leads to the lowering of the structure symmetry and to the appearance of the noncentrosymmetric structure of (II). The noncentrosymmetric character of the structure of (II) was confirmed by SHG signal (1.2 units relative to an α-quartz powder sample).     

Crystal structure, thermal analysis and IR spectrometric investigation of L-tyrosine hydrazide sulfate

Chemical preparation, X-ray single crystal, thermal analysis and IR spectrometric investigation of (C₉H₁₅N₃O₂)SO₄ denoted LTHS are described. The LTHS crystallizes in the monoclinic system with P2₁ space group. Its unit cell dimensions are a=5.5386(1) Å, b=8.0467(4) Å, c=14.0780(6) Å, β=93.339(3)° with V=626.36(4) Å³ and Z=2. The structure has been solved using direct method and refined to a reliability R factor of 0.0212. The LTHS structure is built up from organic chains parallel to the b axis, linked via N---H…O hydrogen bonds and interconnected by inorganic groups so as to build a three-dimensional arrangement.     

X-ray diffraction studies and phase transformations of CeNbO4+δ using in situ techniques

Investigation of CeNbO_4±δ has revealed that the previously determined phase transformations should be revised. Whereas previous studies have indicated that a reduced tetragonal modification of CeNbO₄ is produced on heating in vacuum the present study shows no evidence for this phase transformation. In contrast, a monoclinic–tetragonal phase transformation on heating in air was observed, indicating that the high temperature phase (800 °C) was a stable, oxygen excess tetragonal phase with a similar structure to the Scheelite mineral, CaWO₄. Lattice parameters for this phase were calculated to be a=5.3839(1) Å and c=11.6168(3) Å.     

Syntheses and characterization of Co(pydc)(H2O)2 and Ni(pydc)(H2O) (pydc = 3,5-pyridinedicarboxylate)

The hydrothermal reaction of 3,5-pyridinedicarboxylic acid (pydcH₂) and Co(NO₃)₂ or Ni(NO₃)₂ in the presence of 4,4′-bipyridine results in two novel compounds Co(pydc)(H₂O)₂ (1) and Ni(pydc)(H₂O) (2). Crystal data: 1, monoclinic, C2/c, a=9.900(2), b=11.984(2), c=7.3748(15) Å, β=105.37(3)°, V=843.7(3) Å³, Z=4; 2, monoclinic, P2₁/c, a=7.7496(6), b=15.0496(11), c=6.4224(5) Å, β=108.437(1)°, V=710.59(9) Å³, Z=4. The structure of 1 is composed of honeycomb layers built up from {CoO₄N} trigonal bipyramids and 3,5-pyridinedicarboxylate bridges. The structure of 2 adopts a three-dimensional framework structure in which the Ni atoms are coordinated by the pydc bridges both within the honeycomb layer and between the layers. The magnetic properties of 1 and 2 have been investigated.     

Self-assembly of two novel bisupporting Keggin-polyoxometalate derivatives: Hydrothermal synthesis and structure characterization of (X = P, m = 1; X = Si, m = 2)

Two novel organic–inorganic hybrid polyoxometalates, (X = P, m = 1 1; X = Si, m = 2 2; 2,2′-bpy = 2,2′-bpyridine), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. They are isostructural, possessing orthorhombic, and the parameters of unit cells for compound 1 are space group Pbca, a = 17.317(4) Å, b = 17.092(3) Å, c = 20.587(4) Å, V = 6445(2) Å³, Z = 4; for compound 2 are space group Pcab, a = 17.181(3) Å, b = 18.198(4) Å, c = 20.672(4) Å, V = 6463(2) Å³, Z = 4. The two compounds show a layer framework constructed from Keggin-polyoxoanion clusters and [Cu (2, 2′-bpy)₂]²⁺ coordination polymer fragments via weak covalent interactions, resulting in a 3D network via supramolecular interactions. Their electrochemical properties are studied in detail.     

Synthesis and crystal structure analysis of Sr8Cu3In4N5 and Sr0.53Ba0.47CuN

Single crystals of new quaternary compounds Sr₈Cu₃In₄N₅ and Sr_0.53Ba_0.47CuN were prepared, respectively, from a Sr–Cu–In–Na melt under 7 MPa of N₂ and from a Sr–Ba–Cu–In–Na melt under 0.5 MPa of N₂ by slow cooling from 1023 to 823 K. The crystal structures were determined by single-crystal X-ray diffraction. Sr₈Cu₃In₄N₅ has an orthorhombic structure (space group, Immm, Z=2, a=3.8161(5) Å, b=12.437(2) Å, c=18.902(2) Å), and is isostructural with Ba₈Cu₃In₄N₅. It contains nitridocuprates of isolated units ⁰[CuN₂] and one-dimensional linear chains _∝¹[CuN_2/2] and one-dimensional indium clusters _∝¹[In₂In_2/2]. Sr_0.53Ba_0.47CuN crystallizes in an orthorhombic cell, space group Pbcm, Z=4, a=5.4763(7) Å, b=9.2274(12) Å, c=9.0772(12) Å. The structure contains infinite zig-zag chains _∝¹[CuN_2/2] which kink at every second nitrogen atom.     

Crystal structure and IR spectrum of 1-O-α- -glucopyranosyl- -mannitol–ethanol (2/1)

1-O-α- -Glucopyranosyl- -mannitol–ethanol (2/1), (C₁₂H₂₄O₁₁)₂–C₂H₅OH, crystallizes in the monoclinic space group P2₁ with unit cell dimensions a=11.4230(8) Å, b=9.525(4) Å, c=15.854(2) Å, β=102.751(7)° and V=1682.4(7) ų, Z=2, D_x=1.45 Mg m⁻³, λ (Mo-K_α)=0.71069 Å, μ=0.128 mm⁻¹, F(000)=788 and T=293(2) K. The structure was solved by direct methods and refined by least-squares calculations on F² to R₁=0.0371[I>2σ(I)], and 0.0930 (all data, 3542 independent reflections, R_int=0.021). There are two molecules of glucopyranosylmannitol (GPM) and one ethanol molecule in the asymmetric unit, and the glucopyranosyl ring adopts a chair conformation in both GPM molecules. Bond lengths and angles accord well with the mean values of related structures. The conformation along the mannitol side chain for one of the GPM molecules was the same as for the known polymorphs of -mannitol, while the conformation of the other molecule was different, indicating different conformational arrangements in the terminal carbon atoms of the mannitol side chains of the two GPM molecules. The structure in 1-O-α- -glucopyranosyl- -mannitol–ethanol (2/1) is held together by a very complex hydrogen bonding system, which consists of an infinte chain propagating along the b-axis and a discontinuous chain, which binds the ethanol molecule to the structure. The FTIR spectra for anhydrous GPM, GPM dihydrate and GPM–ethanol (2/1) were recorded. Both IR and X-ray results indicate the extensive hydrogen bonding in crystalline state.     

Preparation and crystallographic characterization of the polyphosphate TlPO3

Chemical preparation and crystallographic data are specified for thallium polyphosphate. TlPO₃ crystallizes in the monoclinic system, space group P2₁/n, with the following unit-cell parameters: a = 12.270(7) Å; b = 4.263(2) Å; c = 6.328(4) Å; β = 96°.72(3); Z = 4. This compound is isotypic with two previously described polyphosphates, namely RbPO₃ and CsPO₃.