New crystals of the CsHSO<Subscript>4</Subscript>–CsH<Subscript>2</Subscript>PO<Subscript>4</Subscript>–H<Subscript>2</Subscript>O system

Cs₆H(HSO₄)₃(H₂PO₄)₄ crystals, grown for the first time based on an analysis of the phase diagram of the CsHSO₄–CsH₂PO₄–H₂O ternary system, have been investigated by structural analysis using synchrotron radiation. The atomic structure of the crystals is determined and its specific features are analyzed.     

Untersuchungen zur Wärmeleitfähigkeit von Bi?Sb-Einkristallen

Theoretical and experimental values of the total thermal conductivity are presented for Bi_xSb_1-x single crystals. An analysis of the electronical part and the lattice conductivity in function of Sb-concentration (0 ⩽ (1−x) ⩽ 0.30) on the basis of theoretical models is made. The anisotropy of crystal properties is taken into consideration. It sustains the arguments above the scattering of phonons.     

Crystal structure of Сu<Subscript>4</Subscript>SeTe

Сu₄SeTe compound has been synthesized. A Сu₄SeTe sample was homogenized by annealing at 750 K for five days. An X-ray diffraction analysis based on powder diffraction data has revealed that the sample crystallizes into the trigonal system with lattice parameters а = 4.178 Å and с = 41.921 Å, sp. gr. \(R\overline 3 m\), Z = 6. Its crystal structure has been determined and refined by the Rietveld method. The final value of the reliability factor R _Bragg is found to be 0.0246.     

The first layer potassium–bismuth-nickel oxophosphate KBi<Subscript>4</Subscript>Ni<Subscript>2</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>O<Subscript>4</Subscript>: Synthesis,crystal structure,and expected magnetic properties

The new potassium–bismuth–nickel oxophosphate obtained by hydrothermal synthesis in the Bi(OH)₃–NiCO₃–K₂CO₃–K₃PO₄ system is studied by X-ray diffraction, IR spectroscopy, and Raman spectroscopy. Parameters of the orthorhombic cell are as follows: a = 13.632(1) Å, b = 19.610(2) Å, and c = 5.4377(3) Å; V = 1452.64(2) ų; and space group Pnma. The structure is solved and refined to the final discrepancy factor R ₁ = 5.76% in the anisotropic approximation of atomic displacements using 3606 reflections with I > 2σ(I). The crystal-chemical formula (Z = 4) is KBi₄{Ni₂O₄(PO₄)₃}, where the composition of the layer nickel–phosphate polyanion is enclosed in braces. Theoretical calculations show that all exchange spin interactions between Ni²⁺ ions are antiferromagnetic and very weak (J < 0.1 cm^–1) because of the polyatomic character of bridging Ni–O–P–O–Ni and Ni–O–Bi–O–Ni groups. Thus, this compound is expected to be paramagnetic with very weak antiferromagnetic exchange interactions and appreciable energy of zero-field splitting of the spin levels of Ni²⁺ ions.     

Solvothermal Syntheses and Crystal Structures of Rare Earth Thioantimonates [Y(en)<Subscript>4</Subscript>]SbS<Subscript>4</Subscript>·0.5en and [Tm(en)<Subscript>4</Subscript>]SbS<Subscript>4</Subscript>·0.5en

Abstract  

Two rare earth metal thioantimonates [RE(en)₄]SbS₄·0.5en (RE = Y(1), Tm(2); en = ethylenediamine) were synthesized under mild solvothermal conditions. Compounds 1 and 2 are isostructural, and both crystallize in monoclinic space group P2₁/n. Crystallographic data for 1: a = 11.0894(19), b = 12.905(2), c = 16.000(3) ?, β = 91.792(4), V = 2288.7(7) ?³, Z = 4. For 2: a = 11.0870(14), b = 12.8977(16), c = 15.986(2) ?, β = 91.879(3), V = 2284.7(5) ?³, Z = 4. The four-en coordinated rare earth complex cation [RE(en)₄]³⁺ formed in situ balances the charge of the [SbS₄]³⁻ anion in the crystal structure. The RE³⁺ ion is in an eight-coordinated environment involving eight N atoms of four en ligands forming a bicapped trigonal prism. Hydrogen bonds link [RE(en)₄]³⁺, [SbS₄]³⁻ and en species into a three-dimensional structure. The structure determination of 1 and 2 implies that the ionic radii of rare earth metal ions play an important role on the structures of the rare earth metal thioantimonates.     

Crystal structure of the solid solution NH<Subscript>4</Subscript>Al<Subscript>0.62</Subscript>Cr<Subscript>0.38</Subscript>(SO<Subscript>4</Subscript>)<Subscript>2</Subscript> · 12H<Subscript>2</Subscript>O

The solid solution NH₄Al_0.62Cr_0.38(SO₄)₂ · 12H₂O was studied by X-ray diffraction. The crystal structure was determined in a series of the maximal subgroups Pa3? > R3? > P1? > P1. Reflections forbidden in sp. gr. Pa3? are indicative of symmetry lower than cubic. In the centrosymmetric models under consideration, all sulfate groups are oppositely oriented with respect to each other. In non-centrosymmetric sp. gr. P1, four of the eight sulfate groups have the same orientation, whereas the other four groups are oriented in an opposite direction.     

Growth and ionic conductivity of γ-Li<Subscript>3</Subscript>PO<Subscript>4</Subscript>

Single crystals of γ-Li₃PO₄ have been grown from flux. The 4 × 8 × 9-mm crystals have the cleavage along the [010] and [120] directions. The anisotropy in ionic conductivity in the grown crystals, ((σ ‖ a)/(σ ‖ b) = 2.5 and (σ ‖ a)/(σ ‖ c) = 1.3), is explained by specific features of the γ-Li₃PO₄ structure.     

Crystal structure and properties of [OsO<Subscript>2</Subscript>(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>]SO<Subscript>4</Subscript> · H<Subscript>2</Subscript>O

The structure of a single crystal of tetraammindioxoosmium(VI) sulfate [OsO₂(NH₃)₄]SO₄ · H₂O, which is synthesized by the reaction of K₂[OsO₂(OH)₄] with (NH₄)₂SO₄ in an aqueous solution, is investigated using X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system, space group P2₁/c, a = 13.102(2) Å, b = 6.158(3) Å, c = 11.866(2) Å, β = 98.13(2)°, and Z = 4. The [OsO₂(NH₃)₄]SO₄ · H₂O compound has an island structure. Two crystallographically independent osmium atoms are situated at the centers of symmetry, and their octahedral coordination includes two oxygen atoms and four nitrogen atoms of the ammonia molecules. In both octahedra, the osmyl group is linear. The Os-O distances in the octahedra are identical within the standard deviations [Os(1)-O, 1.762(2) Å; Os(2)-O, 1.769(2) Å]. The Os-N bond lengths vary from 2.082(3) to 2.101(3) Å. The cationic complexes, SO₄ groups, and water molecules are linked via the system of hydrogen bonds. The assignment of the absorption bands in the IR spectrum of the compound synthesized is performed, and its thermal behavior in air is studied.     

Synthesis,crystal structure,and conducting properties of a new molecular metal, (<Emphasis Type="Italic">BEDO</Emphasis>)<Subscript>4</Subscript>Ni(CN)<Subscript>4</Subscript> · 4CH<Subscript>3</Subscript>CN

A new radical cation salt based on bis(ethylenedioxy)tetrathiafulvalene (BEDO) with the planesquare anion Ni(CN) ₄ ^2? is synthesized. The molecular and crystal structures of the radical cation salt are determined, and the conducting properties are investigated. In the structure, the BEDO radical cations have a β″-type packing. It is shown that the temperature dependence of the conductivity of (BEDO)₄Ni(CN)₄ · 4CH₃CN crystals exhibits metallic behavior.     

Synthesis and crystal structure of binuclear molecule Ho<Subscript>2</Subscript>(2-FC<Subscript>6</Subscript>H<Subscript>4</Subscript>COO)<Subscript>6</Subscript>⋅4H<Subscript>2</Subscript>O

The complex Ho₂(2-FC₆H₄COO)₆?4H₂O has been synthesized and structurally characterized by single crystal X-ray diffraction methods. The complex crystallizes in the triclinic system with space group P \(\bar 1\), lattice parameters a = 9.293(8) Å, b = 9.845(8) Å, c = 12.703(11) Å, α = 85.470(14)^°, β = 87.537(12)^°, γ = 62.485(11)^°, V = 1027.5(15) ų, Z = 1, D_calc = 1.998 Mg/m³. The Ho³⁺ ion is in distorted monocapped square-antiprism coordination environment and is coordinated by nine oxygen atoms, seven from five 2-FC₆H₄COO^2? groups, two from two water molecules. Two Ho³⁺ ions are linked together by four bridging carboxylate groups to form a binuclear molecule with inversion center.     

Growth and dielectric properties of KTiOPO<Subscript>4</Subscript> and K<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Rb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>TiOPO<Subscript>4</Subscript> crystals

Methods of growth of KTiOPO₄ and K_{1 ? x} Rb _x TiOPO₄ crystals of high optical quality have been optimized. The dielectric properties (permittivity and conductivity) of the crystals grown have been investigated at frequencies from 10² to 10⁶ Hz in the temperature range from 100 to 350 K, along the [001] crystallographic direction. It is established that partial substitution of K⁺ ions with Rb⁺ ions leads to a decrease in the permittivity and conductivity.     

Synthesis,Crystal Structure and NLO Properties of a Mixed Crystal K<Subscript>1−x</Subscript>(NH<Subscript>4</Subscript>)<Subscript>x</Subscript>H<Subscript>2</Subscript>PO<Subscript>4</Subscript> (x = 0.5)

Abstract  

A new mixed crystal K_1−x(NH₄)_xH₂PO₄ (KADP) of ammonium dihydrogen phosphate (ADP) of ADP–KCl system has been synthesized with x = 0.5 by slow evaporation of the mixture of equimolar aqueous solution at room temperature. Crystal composition determined by single crystal X-ray diffraction analysis reveals that it belongs to the tetragonal system with noncentrosymmetric space group I-42d and it is structurally similar to ADP crystals with the following parameters: a = 7.418(3) ?; c = 7.2284(6) ?; v = 404.63(4) ?³; z = 4. The substitution results in defect centers which influence the physical properties. Mixed crystal has a superior NLO activity, twice that of KH₂PO₄ (KDP), a well known NLO material and the enhanced NLO activity is rationalized. The structural analysis of KADP and the influence of partial cationic substitution in ADP by K⁺ ions on the NLO properties are reported.     

Anisotropy of microhardness and fracture of (NH<Subscript>4</Subscript>)<Subscript>2</Subscript>Ni(SO<Subscript>4</Subscript>)<Subscript>2</Subscript> · 6H<Subscript>2</Subscript>O (ANSH) crystals

The Vickers hardness of the (010) and (001) planes in (NH₄)₂Ni(SO₄)₂ · 6H₂O (ANSH) crystals has been measured. Anisotropy hardness of the first kind is revealed for the (010) plane in ANSH. The hardness anisotropy coefficient k ₂ was determined to be 1.5. The temperature dependence of the microhardness of the (001) face of ANSH crystals was investigated in the temperature range from 20 to 80°C. The character of fracture of the (100), (010), and (001) planes during indentation with a spherical indenter has been qualitatively determined.     

Synthesis and Crystal Structure of [Ni(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(pdc)(4-CNpy)] · 2H<Subscript>2</Subscript>O (pdc = Pyridine-2,6-dicarboxylate, 4-CNpy = 4-cyanopyridine)

Abstract A new complex containing two different substituted pyridine ligands, viz. 4-CNpy (4-cyanopyridine) and pdc (pyridine-2,6-dicarboxylate), [Ni(H₂O)₂(pdc)(4-CNpy)] · 2H₂O (1), has been prepared using [Ni(4-CNpy)₂(H₂O)₃(SO₄)] · H₂O (2) as the starting compound. Crystal data on 1 are: monoclinic, P2₁/c, a = 11.533(2) ?, b = 20.114(4) ?, c = 7.306(1) ?, β = 93.777(3)°, V = 1,691.1(5) ?³, Z = 2, D _calc. = 1.57 g cm⁻³, R ₁ = 0.0585, w R ₂ = 0.1236 for reflections with I > 4σ(F ₀) and 268 parameters (R ₁ = 0.0859, wR ₂ = 0.1336 for all 4,024 reflections). The discrete molecules of the title complex remain hydrogen-bonded to assemble into supramolecular layers interleaved by disordered water molecules. In an attempt to obtain the cationic complex species cis-[Ni(H₂O)₄(4-CNpy)₂]²⁺ we have isolated the compound [Ni(H₂O)₄(4-CNpy)₂] · (BPh₄)₂ · 2(4-CNpy) · 4H₂O (3) by adding NaBPh₄ to an aqueous solution of 2. Crystal data on 3 are: monoclinic, P2₁/n, a = 10.5002(1) ?, b = 21.1692(3) ?, c = 15.3249(2) ?, β = 95.120(1)°, V = 3392.84(7) ?³, Z = 2, D _calc. = 1.231 g cm⁻³, R ₁ = 0.0453, wR ₂ = 0.1217 for reflections with I > 4σ (F ₀) and 556 parameters (R ₁ = 0.0688, wR ₂ = 0.1364 for all 9,257 reflections). Index Abstract Synthesis and Crystal Structure of [Ni(H₂O)₂(pdc)(4-CNpy)] · 2H₂O (pdc = Pyridine-2,6-dicarboxylate, 4-CNpy = 4-cyanopyridine) Manjit K. Bhattacharyya, Sanchay J. Bora and Birinchi K. Das Crystal structure of a new nickel(II) complex displaying a supramolecular layered structure is described. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

C(4) helices,Br⋅<Emphasis Type="Italic">s</Emphasis>Br interaction and <Emphasis Type="Italic">R</Emphasis><Stack><Subscript>4</Subscript><Superscript>2</Superscript></Stack> (10) ring in bromoipriflavone

The title compound, 8-bromo-7-isopropoxyisoflavone (bromoipriflavone), C₁₈H₁₅O₃Br, crystallizes in tetragonal crystal system, space group I4₁/a with cell constants a = 21.396(2) Å, c = 13.588(2) Å, V = 6220.2(14) ų and Z = 16. Bromoipriflavone is composed of a benzopyranone moiety, a phenyl moiety, an isopropoxy group and a bromine atom. The benzopyranone ring is not coplanar with the phenyl ring with a dihedral angle of 55.1. The molecules are stacked into a C(4) helices down [001] via – stacking and hydrogen bonds, the C(4) helices are assembled into three-dimensional network via strong BrsBr interactions and synthons R₄²(10) formed by two tri-centered C–HsO hydrogen bonds, resulting in a distinctive high-symmetry supramolecule. The title compound was also characterized by IR and ¹H NMR.     

Synthesis and Crystal Structures of 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate and 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate

Abstract  

Two new hydrazone compounds, 4-chloro-N′-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate (1) and 4-chloro-N′-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate (2), were synthesized and characterized by physico-chemical methods and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 23.257(3) ?, b = 4.829(1) ?, c = 12.763(2) ?, β = 96.017(2)°, V = 1425.5(5) ?³, Z = 4, R ₁ = 0.0525, and wR ₂ = 0.1120. Compound 2 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 8.103(3) ?, b = 21.321(3) ?, c = 10.594(3) ?, β = 120.281(2)°, V = 1580.5(8) ?³, Z = 4, R ₁ = 0.0480, and wR ₂ = 0.1078. Both compounds contains a hydrazone molecule and a water molecule. The crystals of the compounds are stabilized by N–H···O, O–H···O, and O–H···N hydrogen bonds.     

Calcio-olivine γ-Ca<Subscript>2</Subscript>SiO<Subscript>4</Subscript>: I. Rietveld refinement of the crystal structure

The structure of the natural mineral calcio-olivine (γ-Ca₂SiO₄) found in skarn xenoliths in the region of the Lakargi Mountain (North Caucasus, Kabardino-Balkaria, Russia) is refined by the Rietveld method [a = 5.07389(7) Å, b = 11.21128(14) Å, c = 6.75340(9) Å, V = 384.170(5) ų, Z = 4, ρ_calcd = 2.98 g/cm³, space group Pbnm]. The X-ray diffraction pattern of a powdered sample is recorded on a STOE STADI MP diffractometer [λCuK _α1; Ge(111) primary monochromator; 6.00° < 2θ < 100.88°; step width, 2.5° in 2θ; number of reflections, 224]. All calculations are performed with the WYRIET (version 3.3) software package. The structural model is refined in the anisotropic approximation to R _p = 6.44, R _wp = 8.52, R _exp = 5.85, R _B = 4.98, R _F = 6.90, and s = 1.46. It is shown that the sample under investigation is a mixture of several mineral phases, among which calcio-olivine (the natural analogue of the γ-Ca₂SiO₄ compound) (83%), hillebrandite (13%), and wadalite (4%) are dominant. Only the scale factors and the unit cell parameters are refined for hillebrandite Ca₂SiO₃(OH)₂ [a = 3.63472(16) Å, b = 16.4140(10) Å, c = 11.7914(8) Å, space group Cmc2₁, Z = 6] and wadalite Ca₆Al₅Si₂O₁₆Cl₃ (a = 12.0088 Å, space group, I \(\bar 4\)3d Z = 4). The results of the structure refinement of the main component of the sample confirm that the mineral calcio-olivine is isostructural to the synthetic compound γ-Ca₂SiO₄. The structure of this compound is formed by the heteropolyhedral framework composed of Ca octahedra joined together into olivine-like ribbons and isolated Si tetrahedra.     

X-ray diffraction study of Rb<Subscript>2</Subscript>[(UO<Subscript>2</Subscript>)<Subscript>2</Subscript>(CrO<Subscript>4</Subscript>)<Subscript>3</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The compound Rb₂[(UO₂)₂(CrO₄)₃(H₂O)₂] · 4H₂O was studied by X-ray diffraction. The crystals are monoclinic, a = 10.695(2) Å, b = 14.684(3) Å, c = 14.125(3) Å, β = 108.396(4)°, sp. gr. P2₁/c, Z = 4, V = 2104.9(7) ų, and R = 0.0491. The main structural units are layers consisting of [(UO₂)₂(CrO₄)₃(H₂O)₂]^2? anions belonging to the crystal-chemical group A ₂ T ₂ ³ B ²M ₂ ¹ (A = UL ₂ ²⁺ , T ³ and B ² are CrO ₄ ^2? , and M ¹ is H₂O) of uranyl complexes. The uranium-containing layered groups are held together by electrostatic interactions with rubidium cations, as well as by hydrogen bonds with the participation of inner- and outer-sphere water molecules.     

Behavior of ammonium ion in β-LiRb<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>(NH<Subscript>4</Subscript>)<Subscript>x</Subscript>SO<Subscript>4</Subscript> mixed crystals (0.5 ≤ <Emphasis Type="Italic">x</Emphasis> ≤ 1.0)

The influence of replacement of an ammonium ion by rubidium on the x-T phase diagram in the concentration range 0.50 ≤ x ≤ 1.0 has been studied by X-ray and neutron powder diffraction over a wide temperature range. It is shown that a decrease in the ammonium concentration is accompanied by an increase in the temperature of the II ? I phase transition and stabilization of phase II up to low temperatures (20 K). The changes occurring in the dynamics of mixed crystals are studied by inelastic incoherent neutron scattering. The spectra of the generalized vibrational density of states obtained allowed one to establish the difference in the phonon modes corresponding to phase III of β-LiNH₄SO₄ and phase II of β-LiRb_1?x(NH₄)_xSO₄ mixed crystal with x = 0.91 and x = 0.77 at 20 K. It is shown that a mixed crystal with x = 0.77 at 20 K is in the orientational glass state.     

Molecular structure of [(<Superscript>t</Superscript>Bu)<Subscript>2</Subscript>Al(μ-OC<Subscript>6</Subscript>H<Subscript>4</Subscript>-2-Me)]<Subscript>2</Subscript>

The molecular structure of [(^tBu)₂Al(-OC₆H₅-2-Me)]₂ has been determined. Both the ortho-tolyl methyl groups are oriented towards Al(2). The intramolecular steric interaction between the ortho-methyl groups and the tert-butyl ligands results in the geometry about the bridging oxygen being significantly distorted while the geometries about the aluminum centers show a distortion from tetrahedral that is less than the sterically less hindered [(^tBu)₂Al(-OPh)]₂. Crystal data: group C2/c, a = 13.733(3) Å, b = 15.135(3) Å, c = 15.420(3) Å, = 104.24(3), V = 3106(1) ų, Z = 4, R = 0. 0612, wR₂ = 0.1787.