Crystal structure of the new thorium intermetallics Thin and Th6Cd7

The title phases are orthorhombic: ThIn,oP24, space groupPbcm,a = 10.806(3)A?,b = 9.954(4)A?,c = 6.520(4)A?,Z = 12; Th₆Cd₇,oP26, space groupPbam,a = 11.703(3),A?,b = 9.929(7)A?,c = 6.041(2)A?,Z = 2. Direct methods were used for both structure solutions on data collected with an automated single crystal X-ray diffractometer. Anisotropic refinements gaveR = 0.065for ThIn andR = 0.086for Th₆Cd₇ using 799 and 1015 reflections, respectively. The structure of ThIn is closely related to the hexagonal Ti₅Ga₄ type, from which it can be geometrically derived. Th₆Cd₇ can be regarded as a tetrahedrally close packed structure where the Th atoms present the typical CN 14, CN 15, and CN 16 Frank-Kasper polyhedra and the Cd atoms are icosahedrally coordinated.     

Crystal structure of [Cs2Na(H2O)2(C23H16O3)(C23H15O3)3]

The crystal structure of a double salt of sodium and cesium with 2-diphenylacetyl-1,3-indandione of the composition [Cs₂Na(H₂O)₂(C₂₃H₁₆O₃)(C₂₃H₁₅O₃)₃] (I) was studied by X-ray crystallography. The crystals of I are monoclinic, Z = 2, space group P2₁/n, a = 10.212(2) ?, b = 23.479(5) ?, c = 15.638(3) ?, β = 98.30(03)°. The compound contains [Cs₂NaO₁₀] trimers, in which the central Na atom shares two edges with two Cs atoms through deprotonated bridging ligands. The trimers are connected to adjacent trimers by paired C-H...O contacts to form layers. The layers form an infinite open framework via hydrogen bonds between the oxygen atoms of keto groups of noncoordinated indandione moieties and water molecules that enter the cesium coordination sphere in trimers of the adjacent layers.     

Ca7Au3 and Ca5Au4, two structures closely related to the Th7Fe3 and Pu5Rh4 types

Two new intermetallic compounds have been synthetized and structurally studied by single crystal diffractometric data: Ca₇Au₃ (oP80, space groupPbca,a = 20.742(8), b = 18.036(8), c = 6.665(2) A?,Z = 8, R = 0.051) and Ca₅Au₄ (mP18, space groupP2₁/c, a = 8.028(3), b = 8.019(6), c = 7.727(3) A?, β = 109.16(6)°,Z = 2, R = 0.104). Both atomic arrangements, which represent new structural types, are based on Au-centered Ca trigonal prisms and are geometrically related to the Th₇Fe₃ and Pu₅Rh₄ structures.     

Structure cristalline du metatitanate de thallium Tl2TiO3

A thallium titanate oxide Tl₂TiO₃ has been prepared. It is orthorhombic, space groupPnam, with unit cell dimensions a = 12.41 A?,b = 9.615 A?,c = 3.752 A?. The structure contains double chains of edge sharing TiO₅ trigonal bipyramids, in the z direction. In this compound, thallium I has a stereochemically active lone pair. There are four oxygens bonded to thallium, all to one side.     

Hexagonal tungsten bronze-type FeIII fluoride: (H2O)0.33FeF3; crystal structure,magnetic properties,dehydration to a new form of iron trifluoride

(H₂O)_0.33FeF₃, grown by hydrothermal synthesis, crystallizes in the orthorhombic system with cell dimensions a = 7.423(3) Å, b = 12.730(4) Å, c = 7.526(3)Å, and space group Cmcm, Z = 12. The structure, derived from single crystal X-ray diffraction data (605 independent reflections) is refined to R = 0.019 (R_ω = 0.021). The framework of the Fe^IIIF₆ octahedra is related to that of hexagonal tungsten bronze (HTB) Rb_0.29WO₃. At 122°C, zeolithic water is evolved from hexagonal tunnels without any noticeable change of the fluorine skeleton. The related anhydrous compound represents a new form of iron trifluoride which is denoted HTBFeF₃; at 525°C, it transforms into the cubic form of ReO₃-type. (H₂O)_0.33FeF₃ and HTBFeF₃ are antiferromagnetic, with Néel temperatures of T_N = 128°7 ± 0.5 K and T_N = 97 ± 2 K, respectively.     

Crystal structure of [Cu(en)2](ReO4)2

At T = 150 K the crystal structure of [Cu(en)₂] (ReO₄)₂ (en is ethylenediamine) is studied: a = 6.6229(1) ?, b = 14.2968(3) ?, c = 7.4859(2) ?, β = 102.415(1)°, V = 692.24(3) ?,³, P2₁/c space group, Z = 2, d _x = 3.282 g/cm³. Packing of complex cations is shown to be single layered and pseudohexagonal. Perrhenate anions are located between these layers and additionally coordinate copper atoms with Cu...O distances being 2.504(3) ?.     

The isostructural γ-sulfur phase of selenium-sulfur,SenS8−n

Two new selenium-sulfur species, Se_1.1S_6.9 (yellow) and Se_3.7S_4.3 (orange), have been isolated as single crystals, and the corresponding structures have been determined. The space group is P2c, and the parameters are a = 8.34 A?, b = 13.11 A?, c = 9.30 A?, β = 123.9° and a = 8.40 A?, b = 13.26 A?, c = 9.37 A?, β = 124.5°, respectively. They are isostructural with γ-sulfur, having two distinct pairs of eight membered rings in the unit cell. The selenium and sulfur atoms appear scrambled throughout all atomic positions, but are not scrambled equally. When atomic site occupancy data are combined with other data from the literature, a wide compositional continuum of γ-sulfur isostructures is revealed that extends from γ-sulfur to SeS. It appears unlikely that selenium-sulfur crystals exist having the γ-sulfur structure with more than half the atoms as selenium.     

Recherche d'une description structurale des de´compositions endothermique Solide 1 → Solide 2 + gaz. I. Structure cristalline de l'oxalate de baryum 2BaC2O4, H2O

2BaC₂O₄ · H₂O (M = 468.73) is triclinic, space group P1, with a = 9.312(1) A?, b = 9.649(1) A?, c = 6.188(1) A?, α = 90.13(2)°, β = 95.36(2)°, γ = 125.18(2)°, Z = 2, D_m = 3.48; C_x = 3.51g · cm^?3. The position of the Ba atom was determined from a Patterson function. A subsequent Fourier synthesis clearly revealed the position of all C and O atoms in the structure. Refinement of the MoKα diffractometer data by a least-squares method using full matrix gave R = 0.065. The structure presents two remarkable characteristics: (a) We distinguish two types of (C₂O₄)^2? ions. The first are planar, the second are notably separated from the plane configuration (deviation = 30°); this deformation is of a steric origin. (b) The water molecules are located in channels parallel to [001]. They enter in the coordination of one of the Ba²⁺ ions but do not exchange any strong hydrogen bond with oxygen atoms which surround them.     

Layered structure of the silver coordination polymer with nonrigid aromatic diamine {Ag[CH2(C6H4NH2)2]2(CH3C6H4NH2)}NO3

The complex [Ag(DDM)₂(CH₃C₆H₄NH₂)]NO₃, where DDM is 4,4-diaminodiphenylmethane [CH₂(C₆H₄NH₂)₂], was synthesized and its structure was determined. The crystals are monoclinic, space group P2₁/n, a = 9.543(2) ?, b = 18.056(4) ?, c = 1.901(2) ?, β = 106.94(3)°, V = 1796.8(6) ?³, ρ_calcd = 1.443 g/cm³, Z = 4. The Ag atom (at the inversion center) is coordinated at the vertices of an almost undistorted octahedron by six nitrogen atoms of the primary amino groups from four bridging DDM molecules and two terminal p-toluidine molecules (Ag-N, 2.546(3) ?; NAgN, 89.7–90.3°). Wavelike layers composed of conjugate multiunit metal rings, each containing four Ag⁺ ions and four bridging DDM ligands, are formed in the structure in the [101] direction (a 2D polymer). Uncoordinated NO ₃ ⁻ anions are arranged in the cavities between the layers and link them by N-H⋯O hydrogen bonds. Original Russian Text ? Yu.V. Kokunov, V.V. Kovalev, Yu.E. Gorbunova, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 12, pp. 1992–1998.     

One-and two-dimensional silver-tetramethylpyrazine coordination polymers with uncoordinated anions: Synthesis and structure of [Ag(Me4Pyz)]PF6 and [Ag2(Me4Pyz)3](BF4)2·H2O

Coordination polymers [Ag(Me₄Pyz)] PF₆(I) and [Ag₂(Me₄Pyz)₃](BF₄)₂·H₂O (II) have been synthesized, and their structures have been determined. The crystals of I are monoclinic, space group C2/c, a = 9.440(2) ?, b = 10.587(2) ?, c = 13.165(3) ?, β= 107.19(3)°, V = 1257.0(5) ?³, d = 2.056 g/cm³, Z = 4. The crystals of II are monoclinic, space group P2₁/n, a = 13.062(3) ?, b = 12.259(2) ?, c = 18.996(4) ?, β = 97.73(3)°, V = 3014.1(11)?³, ρ = 1.798 g/cm³, Z = 4. The structure of I is built of linear polymeric cations [Ag(C₈H₁₂N₂)] _∞ ⁺ and octahedral anions [PF₆]⁻. Upon the interaction of tetramethylpyrazine molecule with Ag⁺ ions, intersecting polymeric chains [Ag(C₈H₁₂)] _∞ ⁺ (1D polymer) are formed extending in mutually perpendicular diagonal directions. The structure of II consists of layers (2D polymers) formed by fused sixmembered rings. These rings consist of Ag⁺ ions linked by bridging ligands Me₄Pyz. Original Russian Text ? Yu.V. Kokunov, Yu.E. Gorbunova, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 5, pp. 743–750.     

Structural aspects and magnetic properties of the lamellar compound Cu0.50Cr0.50PS3

Cu_0.50Cr_0.50PS₃ is a new lamellar compound obtained from the elements at 700°C in evacuated silica tubes. The unit cell is monoclinic with a = 5.916 (1) Å; b = 10.246 (2) Å; c = 13.415 (5) Å; β = 107.09 (3)°. The structure is built up with S|Cu_0.33Cr_0.33(P₂)_0.33|S slabs in which copper, chromium, and (P₂) pairs share the octahedral voids between two sulfur layers. Copper is not located at the center of its octahedral sites but is distributed among a continuous series of positions within these sites. This complex distribution has been simulated, attributing to copper two crystallographic eightfold positions with important thermal factors, especially perpendicular to the a-b plane. EPR studies and optical and magnetic measurements show that chromium is present as Cr³⁺ ions. The magnetic study suggests that, below T_N ～ 30 K, this compound is a weakly anisotropic antiferromagnet consisting possibly of ferromagnetic layers which are antiferromagnetically coupled to adjacent layers. A good fit with the experimental results is obtained by means of calculations performed on the basis of a two-dimensional Heisenberg model.     

Synthesis, Crystal Structure, and Characterizations of tetra(N-Benzoylmethyl-benzimidazole)dibromide cadmium(II) Complex: CdBr2(C7H5N2CH2COPh)4

The structure of CdBr₂(C₇H₅N₂CH₂COPh)₄ has been determined by X-ray crystallography. It crystallizes in the tetragonal system, space group P4/n, with lattice parameters a = 14.904(3) ?, b = 14.904(3) ?, c = 11.817(2) ?, and Z = 2. The crystal structure consists of monomeric molecules of [CdBr₂(C₇H₅N₂CH₂COPh)₄] with distorted octahedron geometry for the CdBr₂N₄ chromophore. It is also characterized by elemental analysis, IR spectrum, electronic spectrum, and thermogravimetric-differential scanning calorimetry (TG-DSC).     

Chemical twinning of the pyrochlore structure in the system Bi2O3-Fe2O3-Nb2O5

New ternary bismuth iron niobates having structures based on chemical twinning of pyrochlore are described. Bi_5.67Nb₁₀FeO₃₅ has hexagonal symmetry, P6₃/mmc, , , Z=2 and Bi_9.3Nb_16.9Fe_1.1O_57.8 has rhombohedral symmetry, R-3m, , , Z=3. The structures of both phases were determined and refined to R₁=0.04 using single-crystal X-ray data. They can be described as being derived from the pyrochlore structure by chemical twinning on (111)_py oxygen planes. The chemical twin operation produces pairs of corner-connected hexagonal tungsten bronze (HTB) layers as in the HTB structure, so the structures may alternatively be described as pyrochlore:HTB unit-cell intergrowth structures. In the hexagonal phase the pyrochlore blocks have a width of 12 Å, whereas the rhombohedral phase has pyrochlore blocks of two widths, 6 and 12 Å, alternating with HTB blocks. It is proposed that the previously reported binary 4Bi₂O₃:9Nb₂O₅ phase has a related structure containing pyrochlore blocks all of width 6 Å. A feature of the structures is partial occupancy (∼65%) of the Bi sites and displacement of the Bi atoms from the ideal pyrochlore A sites towards the surrounding oxygen atoms, as observed in Bi-containing pyrochlores.     

Pre´paration chimique et structure cristalline de l'iodate d'argent AgIO3

A new chemical preparation of silver iodate AgIO₃ is given. The crystal structure has been determined by single-crystal X-ray diffraction methods and refined to a finalR value of 0.051 for 1280 independent reflections. The unit cell is orthorhombic witha = 7.265(2), b = 15.17(4), c = 5.786(2)A?,Z = 8. The space group isPbc2₁. IO₃ groups and AgO₆ octaedra form a compact bidimensional framework perpendicular to theb axis.     

Structure cristalline de Cu4(PO4)2O

Cu₄(PO₄)₂O is a new copper-rich phosphate. The preparation is described. The unit cell is triclinic, $\text{P}\text{1}$, with a = 7.528 Å, b = 8.090 Å, c = 6.272 Å; α = 113.68°, β = 81.56°, γ = 105.77°. The structure was solved from 1526 independent reflections using Patterson and Fourier syntheses. The final R value is 0.041 for the 1217 strongest reflections. Copper sites form a three-dimensional framework. The structure consists of homogeneous layers of copper and oxygen atoms parallel to the (012) plane. Phosphorus atoms are inserted between copper and oxygen layers.     

Crystal structures of V3S4 and V5S8

Crystal structures of the ordered phases of V₃S₄ and V₅S₈ were refined with single crystal data. Both are monoclinic. Chemical compositions, space groups and lattice constants are as follows: VS_1.47, $\text{I2}\text{m}$ (No. 12), a = 5.831(1), b = 3.267(1), c = 11.317(2)Å, β = 91.78(1)° and VS_1.64, $\text{F}\text{2}\text{m}$ (No. 12), a = 11.396(11), b = 6.645(7), c = 11.293(4), Å, β = 91.45(6)°. In both structures, short metal-metal bonds were found between the layers as well as within them. In comparison with the structure of Fe₇S₈, the stability of NiAs-type structure was discussed based on the detailed metal-sulfur distances.     

Crystal structure of [Cu(NH3)4](ReO4)2

At T = 150 K, the crystal structure of [Cu(NH₃)₄](ReO₄)₂ is studied: a = 6.5167(3) ?, b = 6.7790(3) ?, c = 7.4627(3) ?, α = 67.336(1)°, β = 80.004(1)°, γ = 70.687(1)°, V = 286.70(2) ?³, P-1 space group, Z = 1, d _x = 3.661 g/cm³. We analyze the packing of ions using the translation sublattice isolation technique.     

Phase transitions in A4Li(HSO4)3(SO4); A = Rb, K: Single crystal X-ray diffraction studies

The crystal structure of ferroelastic Rb₄Li(HSO₄)₃(SO₄) has been determined at two temperatures, which indicates a structural phase transition, tetragonal P4₃ witha = 7.629(1) ?,c = 29.497(2) ? at 293 K and monoclinic P2₁ witha = 7.583(3) ?,b = 29.230(19) ?,c = 7.536(5) ?,β = 90.14(1)° at 90 K. The crystal structure of K₄Li(HSO₄)₃(SO₄)₄ has also been determined at two temperatures, tetragonalP4₁ witha = 7.405(1) ?,c = 28.712(6) ? at 293 K and tetragonalP4₁ witha = 7.371(5) ?,c = 28.522(5) ? at 100 K. The overall coordination features in both the structures have been analysed in terms of bond valence sum calculations. Dedicated to Professor C N R Rao on his 70th birthday     

Tetrahedral complexes of zinc(II) chloride with N- and O-containing organic ligands: Synthesis and crystal structures of [ZnCl2(C12H12N2O)] and [ZnCl2(H2O)2](Me4Pyz)2

New complex chlorides [ZnCl₂(ODA)] (I) (ODA=oxydianiline, C₁₂H₁₂N₂O) and [ZnCl₂(H₂O)₂](Me₄Pyz)₂ (II) (Me₄Pyz = 2,3,5,6-tetramethylpyrazine) were synthesized and crystallographically characterized. Crystals of I are monoclinic, space group C2/c, a = 22.682(2) ?, b = 12.646(1) ?, c = 9.951(1) ?, β = 93.23(2)°, V = 2849.7(5) ?³, ρ_calc = 1.569 g/cm³, Z = 8. Structure I contains cyclic fragments consisting of two tetrahedral complexes (ZnCl₂N₂) and two coordinated bridging oxydianiline ligands. Crystals of II are monoclinic, space group P2(1)/c, a = 8.972(2) ?, b = 13.862(3) ?, c = 17.528(4) ?, β = 101.72(3)°, V = 2134.5(7) ?³, ρ_calc = 1.384 g/cm³, Z = 4. In structure II, supramolecular pseudo-metallocycles are formed due to formation of hydrogen bonds O(w)-H…N between coordinated water molecules and noncoordinated nitrogen atoms of tetramethylpyrazine molecules.     

Preparation and crystal structure of Na2Mn2S3

Na₂Mn₂S₃ was prepared by reacting manganese powder with an excess of anhydrous sodium carbonate and elemental sulfur at 870 K. Extraction of the solidified melt with water and alcohol yielded well developed, bright red crystals. Na₂Mn₂S₃ crystallizes with a new monoclinic structure type, space group $\text{C2}\text{c}\text{, Z = 8}$, with a = 14.942(2)Å, b = 13.276(2)Å, c = 6.851(2)Å, and β = 116.50(1)°. The crystal structure was determined from single crystal diffractometer data and refined to a conventional R value of 0.026 for 1613 observed reflections. The atomic arrangement shows sulfur-manganese-sulfur slabs which are separated from each other by corrugated layers of sodium atoms. A prominent feature of the crystal structure is the formation of short, four-membered zigzag chains built up by MnS₄ tetradedra sharing edges. These chains are further connected by the remaining apices to form an infinite sheet. Short MnMn distances (3.02 and 3.05 Å, respectively) are found within the four membered chains. Susceptibility measurements show antiferromagnetic interactions between the Mn atoms.