New framework hydrous silicate K3Sc[Si3O9] · H2O related to the high-temperature anhydrous silicate K3Ho[Si3O9] and symmetry analysis of a phase transition with prediction of structures

Crystals of a new framework silicate K₃Sc[Si₃O₉] · H₂O, space group Pm2₁ n (nonstandard setting of space group Pmn2₁ = C _2v ⁷), are obtained under hydrothermal conditions. The structure is determined without preliminary knowledge of the chemical formula. The absolute configuration is determined. The structure is close to that of the high-temperature K₃Ho[Si₃O₉] phase, which was obtained upon the heating of K₃HoSi₃O₈(OH)₂. This structural similarity is due to the specific conditions of synthesis and an analogous formula, where holmium is replaced by scandium. A symmetry analysis shows that the high local symmetry of a block (rod) is responsible for the first-order phase transition of both the order-disorder (OD) and displacement type. The number of structures in which the simplest and high-symmetry layers are multiplied by different symmetry elements are predicted.     

Synthesis and structure determination of a new layered zincophosphate: [H2N2C6H16]0.5[Zn2(PO4)(HPO4)(H2O)]·H2O

The synthesis and crystal structure of a new microporous zincophosphate are described. [H₂N₂C₆H₁₆]_0.5[Zn₂(PO₄)(HPO₄)(H₂O)]·H₂O crystallizes in the triclinic space group P1¯ with a = 8.822(4), b = 9.236(4), c = 8.451(3) Å, = 67.19(3), = 91.32(3), = 111.10(3)°, V = 586.7(4) ų and Z = 2. This new material consists of infinite two-dimensional anionic layers alternated with planes containing organic diprotonated templates, N, N, N, N-tetramethylethylenediamine [H₂N₂C₆H₁₆]²⁺ molecules. The framework structure is built up of ZnO₄, ZnO₃OH₂, PO₄, and PO₃OH tetrahedra, linked through oxygen vertices. The presence of terminal OH₂ and OH groups, leads to an open structure containing four- and eight-rings. The organic molecules are interconnected to the framework through hydrogen bonds.     

Synthesis, crystal structure, and thermal property of a novel supramolecular assembly: (NH4)2(C8H10N4O2)4 [H4V10O28]·2H2O, constructed from decavanadate and caffeine

A novel 3D supramolecular assembly constructed from decavanadate and caffeine building blocks, (NH₄)₂(C₈H₁₀N₄O₂)₄[H₄V₁₀O₂₈]·2H₂O (1), has been synthesized in aqueous solution and characterized by elemental analysis, IR, ¹H NMR, ⁵¹V NMR, TG-DTA, and single crystal X-Ray diffraction. The compound 1 crystallizes in monoclinic system, space groupP2 ₁/n, a = 15.801(1) Å, b = 12.914(1) Å, c = 15.913(2) Å, = 113.55°,V = 2976.4 (5)ų, Z = 2, R = 0.0498 with 6818 reflections. Water molecules, ammonium ions, and caffeine act as cement linking the polyanions into 1D chain along the c-axis by hydrogen bonding. In compound 1, extensive hydrogen-bond contacts and strong – interactions lead to an ordered 3D supramolecular framework. TG-DTA curves indicate that the weight loss of the complex can be divided into three stages.     

K8Gd3Si12O32Cl · 2H2O,a new member of the family of porous silicates with K and RE elements

Crystals of K₈Gd₃Si₁₂O₃₂Cl · 2H₂O (space group $P\bar 1$ ), a new member of the family of porous silicates containing rare earths, are obtained under hydrothermal conditions. The structure retains the main features of the family in which original one-story layers of Si-tetrahedra formed by 6-membered rings of two types and large-in-diameter 8-membered and 12-membered rings are bound by Gd-octahedra to form a framework. Large pores in the interlayer space of the mixed framework are filled with K⁺ ions. The penetration of Cl^? ions from a concentrated mineralizing solution into the centers of the eight-membered rings of the layer corroborates the ion-exchanging properties of the crystals of this structural type. The filling of rings and pores of different types in different members of the family by K⁺ and Cl^? ions, hydroxyl groups, and water molecules is analyzed.     

Hydrothermal crystallization and X-ray structure determination of a new decavanadate with mixed cations [Mn(H2O)6]2[N(CH3)4]2[V10O28]·2H2O

A new decavanadate with mixed cations, [Mn(H₂O)₆]₂[N(CH₃)₄]₂[V₁₀O₂₈]·2H₂O (1), was crystallized from a hydrothermal reaction between MnCO₃ and V₂O₅ in the presence of N(CH₃)₄Br at 100°C. The structure of 1, as determined by x-ray single crystal analysis, consists of cations and anions of hexa-aqua manganese [Mn(H₂O)₆]²⁺, tetramethyl ammonium [N(CH₃)₄]⁺ and decavanadate [V₁₀O₂₈]^6–. The extended H-bonding between the [Mn(H₂O)₆]²⁺ and [V₁₀O₂₈]^6– ions gives rise to a pseudo- two-dimensional network in the crystal lattice x-ray crystallographic data for 1: monoclinic P2₁/n, a = 9.1499(5), b = 12.8725(7), c = 18.625(1) Å, = 92.252(1)°, V = 2192.0(2) ų, MZ = 2, and D _calcd = 2.22 g cm^–3.     

Crystal structure of triaquamaleatostrontium(II) monohydrate, [Sr(C4H2O4)(OH2)3]·H2O

[Sr(C₄H₂O₄)(OH₂)₃]·H₂O is monoclinic, P2₁/n, witha=11.476(2),b=7.027(1),c=12.344(2) Å, =115.74(3)°,V=896.67 ų,Z=4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. The Sr–O distances range from 2.546(2) to 2.808(2) Å. The C–O distances are equal within the standard deviation 1.263(3) to 1.258(3) Å). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9)°. Both carboxylate groups deviate significantly from planarity. The different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.     

Synthesis and crystal structure of a new bimetallic complex of diethylenetriamine pentaacetic acid: [YbAg2(dtpa)(H2O)]·3H2O

The reaction between Yb(III) nitrate, Ag(I) nitrate, and the diethylenetriamine pentaacetate (dtpa) ligand gives rise to a bimetallic complex. [YbAg₂(dtpa)(H₂O)]·3H₂O is triclinic, space group P-1, with a = 8.768 (3), b = 9.862 (2), c = 13.055 (2) Å, = 75.40 (1), = 83.00 (2) and = 87.46 (2)°. Each dtpa is coordinated to one ytterbium and six silver atoms. The resulting crystal structure can be described as 2D packing. In the layers, the ytterbium atoms are connected through [Ag(COO)]₂ dimers. Strong hydrogen bonds, involving the noncoordinated water molecules, ensure crystal cohesion.     

Molecular structure of [trans-FeCl2(imidazole)4]Cl·THF·H2O

The structure of [trans-FeCl₂(imidazole)₄]Cl has been determined as the THF/H₂O solvate. The Fe-Cl and Fe-N distances in the cation are shorter than analogous trans-FeCl₂(L)₄ compounds, concomitant with the decreased ionic radius of Fe³⁺ versus Fe²⁺. Crystal data: orthorhombic, Pnma, a = 8.456(2), b = 20.991(4), c = 13.288(3) Å, V = 2358.6(8), andZ = 4.     

Synthesis and crystal structure of hexaaquamagnesium hydrogen phosphododecatungstate tetrahydrate [Mg(H2O)6][HPW12O40]·4H2O

Crystals suitable for X-ray structure analysis were obtained after the slow evaporation of the reaction mixture containing equimolar quantities of magnesium chloride and dodecatungstophosphoric acid aqueous solution insuring pH of the solution between 1.0 and 1.2. This simple synthetic route yielded stability of Keggin anion and high quality [Mg(H₂O)₆][HPW₁₂O₄₀]·4H₂O single crystals. The obtained compound belongs to the group of heteropoly compounds and its structure is composed of Keggin [PW₁₂O₄₀]^3– anions, [Mg(H₂O)₆]²⁺ cations and lattice water molecules. Zigzag arrangement of Keggin anions along c-axis creates irregular channels occupied by [Mg(H₂O)₆]²⁺ cations and lattice H₂O molecules. The calculation of the total potential solvent volume indicated the presence of 4.1 lattice H₂O lattice molecules per formula unit, which is in agreement with the here presented structural model. The position of one lattice water molecule is well defined, while each of three other molecules is statistically distributed over two locations. Hydrogen bonds involve all coordinated and lattice H₂O molecules, as well as some oxygen atoms from the Keggin anion. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure of N-benzylmethylammonium dihydrogen-monophosphate monohydrate, [C6H5CH2NH2CH3]H2PO4·H2O

The salt N-benzylmethylammonium dihydrogenmonophosphate monohydrate is monoclinic with the following unit cell dimensions: a = 6.356(1)Å, b = 8.385(7)Å, c = 11.472(5)Å, = 104.32(1)°, space group P2₁ with Z = 2. The structure consists of infinite parallel two-dimensional [110] planes built of mutually connected ions and water molecules by strong O–H···O and N–H···O hydrogen bonding. There are no contacts other than normal van der Waals interactions between the layers.     

Silicogermanate Ba2K2In2[(Si0.8Ge0.2)6O18] · 2H2O As an Analogue of the Natural Zirconosilicate Kostylevite K4Zr2[Si6O18] · 2H2O

Crystallography Reports - Crystals of new silicogermanate Ba2K2In2[(Si0.8Ge0.2)6O18] · 2H2O were prepared by the hydrothermal synthesis; sp. gr. P21/n, a = 6.5548(6) Å, b = 11.6946(10)...     

Synthesis,crystal structure and spectral studies of the complex [Ni(C3H4N2)4(H2O)2]·(C6H4COSO2N)2

The title compound has been synthesized and its crystal structure determined at room temperature.M _r =731.39, triclinic, space groupP¯1,a=9.020(3),b=11.280(7),c=7.784(2)Å,=97.05(4),=97.08(2), =105.32(4)°, U=748(1)ų,Z=1,D _calc.=1.624 g/cm³. The finalR is 0.030 for 3095 independent observed reflections withI3(I). The crystal structure consists of repeated [Ni(im)₄(H₂O)₂]²⁺ cations and noncoordinated saccharin anions. In the complex cation [Ni(im)₄(H₂O)₂]²⁺, Ni² is bonded to four N atoms from four imidazole molecules and two O atoms from two water molecules forming an approximately square octahedral stereochemistry. The d-d transition spectrum of the title compound is also reported and is explained perfectly with the scaling radial theory which was proposed by us.     

Crystallographic analysis of Royline monohydrate [C25H41NO7 · H2O]

The crystal and molecular structures of the alkaloid Royline {(1α,6β,14α, 16β)-20-ethyl-4-hydroxymethyl)-1,6,14,16-tetramethoxyaconitane-7,8-diol} with a water molecule has been determined by X-ray diffraction analysis. The compound crystallizes in the space group P2₁ with the unit cell parameters a = 10.985(1) Å, b = 7.898(1) Å, c = 14.956(1) Å, β = 102.96(1)°, V = 1264.52 ų, Z = 2, λMoK _α = 0.71073 Å, and R = 0.033 for 2067 observed reflections. Rings A, B, and C adopt a chair conformation, ring D is a half-boat, ring E is a half-chair, and ring F is in an envelope conformation with C(14) at the flap. Molecules are linked together in the crystal by hydrogen bonds.     

Synthesis and crystal structure of 3-ammoniumphenyl sulfone selenate, 3-aminophenyl sulfone [C12H14N2O2S]SeO4 · [C12H12N2O2S]

The crystal structure of [C₁₂H₁₄N₂O₂S]SeO₄ · [C₁₂H₁₂N₂O₂S] was determined by X-ray diffraction on single crystal. Crystals are orthorhombic, space group Pbca, with cell parameters a = 11.545 (1), b = 8.143 (1), c = 55.783(1)Å, V = 5244.2 (8)ų and Z = 8. The structure can be described as organic layers built by [C₁₂H₁₄N₂O₂S]²⁺ cations and [C₁₂H₁₂N₂O₂S] molecules, parallel to ab plane, between which the inorganic groups SeO ₄ ^2? are inserted. In this atomic arrangement, H-bonds between the different species play an important role in the three-dimensional network cohesion.     

Crystal structure of a new double salt hydrate SrCd2Cl6⋅8H2O

SrCd₂Cl₆8H₂O crystallizes in the space group and has the unit cell dimensions a = 9.688(2) Å, b = 11.212(2) Å, c = 7.732(3) Å, = 99.85(21)°, = 89.95(22)°, = 75.81(13)°, and Z = 2. After refinement through full-matrix least-squares methods, the reliability factor R in the final cycle is 4.65%. A very persistent occurrence of twinning by pseudosymmetry was observed. The twin element is a twofold axis [001]. The title compound exhibits five endothermic peaks, which have been detected by differential scanning calorimetry and interpreted from thermogravimetry.     

Synthesis and physicochemical characterization of a porous coordination polymer of Sn-Cu xylarate: The structure of [Sn4Cu8.5(HL)2(L)4O2(OH)(H2O)12.5] · 17.2H2O

A porous coordination polymer of Sn-Cu xylarate [Sn₄Cu_8.5(HL)₂(L)₄O₂(OH)(H₂O)_12.5] · 17.2H₂O (H₅ L is xylaric acid) is synthesized for the first time and characterized by chemical analysis, IR spectroscopy, and X-ray diffraction. Centrosymmetric heterometallic fragments [Sn₄Cu₆(HL)₂(L)₄O₂(H₂O)₆] (A) including copper Cu1–3 and tin Sn1,2 atoms are distinguished in the structure. The Cu4(OH)_0.5(H₂O)_2.5 bridges connect A units into chains running along the c axis, and the Cu5(OH)(H₂O) bridges connect A fragments into layers perpendicular to the c axis. The Cu4,5 atoms form a framework whose voids accommodate the crystallization water molecules.     

Crystal and molecular structure of complex compound [Fe3O(CH3COO)6(H2O)3]2[ZnCl4] ⋅ 2H2O

The X-ray crystal structure of trinuclear iron acetate [Fe₃O(CH₃COO)₆(H₂O)₃]₂ [ZnCl₄] ? 2H₂O was determined. The crystal has a ionic structure. It is monoclinic, a = 25.363(7), b = 14.533(4), c = 15.692(4) Å, β = 103.11(2)°, space group _C2/c, and R = 0.0685. The structure of the cationic complex [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ is typical of trinuclear iron(III) compounds containing a μ₃-O bridge: the iron atoms are situated at the vertices of an almost equilateral triangle with the O atom at the center. Each Fe atom is coordinated by four O atoms of bridging carboxy groups, the μ₃-bridging O atom, and the water molecule in the trans position to the latter O atom. Mössbauer spectroscopy evidence indicates the high-spin state (_S = 5/2) of the iron(III) ions.     

Crystal structure of new synthetic calcium pentaborate Ca[B5O8(OH)] · H2O and its relation to pentaborates with similar boron-oxygen radicals

A new representative of pentaborates with the composition Ca[B₅O₈(OH)] · H₂O was synthesized under hydrothermal conditions within the framework of the study of phase formation in the CaCl₂-Na₂CO₃-B₂O₃ system. The crystal structure of the new pentaborate was established (a = 6.5303(9) Å, b = 19.613(3) Å, c = 6.5303(9) Å, β = 119.207(2)°, V = 2513(2) ų, sp. gr. P2₁/c, Z = 4, d _calcd = 2.74 g/cm³, automated Brucker SMART CCD diffractometer, 6871 reflections, λMo radiation, anisotropic refinement by least-squares, R _hkl = 0.076). The structure of calcium pentaborate is built by isolated B-Ca-B stacks parallel to the (010) plane. The central fragments of these stacks consists of nine-vertex Ca polyhedra. The Ca layers are located between loose B-O networks composed of [B ₂ ^t B ₃ ^Δ O₈(OH)]^2? pentaborate groups. The arrangement of the polyhedra around large cations in pentaborates with groups of two B tetrahedra and three B triangles was analyzed in terms of crystal chemistry. It is established that the structures of these compounds consist of large isolated polyhedra, columns, layers, and three-dimensional frameworks.     

Temperature-induced changes in the single-crystal structure of K9H7(SO4)8 · H2O

Interest in superprotonic crystals of M _m H _n (XO₄)_{(m + n)/2} is associated with the solution to the fundamental problem of modern condensed matter physics: investigations of structural phase transitions and the stabilization of phases with high proton conductivity with the aim of designing new functional materials. The available data suggest that changes in the physical properties in these crystals can occur through different structural mechanisms. To reveal the structural conditionality for anomalies in the physical properties, the crystals of K₉H₇(SO₄)₈ · H₂O were studied by X-ray diffraction in the temperature range of 25–463 K, and the crystal structure of the high-temperature phase was determined at 418 K (sp. gr. Pcan). The results of the study indicate that the occurrence of high conductivity in K₉H₇(SO₄)₈ · H₂O crystals at high temperatures is associated with the diffusion of water of crystallization, the hydrogen-bond network rearrangement, and the motion of K ions. The hydrogen-bond rearrangement and the hindered back diffusion of water to the crystal stabilize the high-temperature phase and ensure its supercooling to low temperatures.     

The synthesis and crystal structure of [La(OH2)5(phen)2]Cl3·4H2O·phen

[La(OH₂)₅(phen)₂]Cl₃·4H₂O·phen is centric, Pnna, witha=19.946(7),b=16.458(5),c=12.207(4)Å andD _calc=1.57 g cm^–3 forZ=4. The La(III) ion resides on a crystallographic twofold axis and is coordinated to four nitrogen atoms (from two phen molecules) and five water molecules resulting in a distorted tricapped trigonal prismatic geometry. An uncoordinated phen molecule, two chloride anions, and four uncoordinated water molecules are hydrogen bonded to the coordinated water molecules. The coordinated and uncoordinated phen molecules -stack diagonally through the unit cell.