Crystal growth and structure of KBi(WO4)2 single crystals

Potassium bismuth tungstate [KBi(WO₄)₂] single crystals have been grown by the top‐seeded solution growth technique. Bulk crystal with dimensions up to several centimeters is obtained for the first time. Several self‐flux systems have been used for the growth from the solution and the experiments using K₂W₂O₇ as a solvent are detailed. Powder and single crystal X‐ray diffraction of this crystal are reported. The structure refinement shows that KBi(WO₄)₂ crystallizes in the monoclinic space group C2/c, with a=10.837(3), b=10.586(3), c=7.622(2)Å, β=130.860(3)°, V=661.4(3)ų, and Z=4. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structure and spectra character of cobalt nickel sulfate twelvehydrate (CNSH) single crystal

The title compound CoNi(SO₄)₂ · 12H₂O has been prepared and its crystal structure determined by single crystal X‐ray differaction at room temperature. The CNSH crystal structure belongs to the monoclinic space group C2/c,a = 9.966(2) Å, b = 7.2265(14) Å, c = 24.218(5) Å, β = 98.32(3)°, V = 1725.9(6) ų, z = 4, Dc = 2.024 gcm⁻³. The optical transmission character of CNSH crystal in aqueous solution is discontinuous in the range from ultraviolet to near IR wavelengths. The relationship between the structure and the optical transmission property is further discussed. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterisation of potassium cobalt nickel sulfate hexahydrate for UV light filters

A new single crystal for ultraviolet light filter, KCNSH (Potassium Cobalt Nickel Sulfate Hexahydrate) was designed and its crystal structure was studied using X‐ray diffraction in this paper. The empirical of the title compound is K₂Co_0.1Ni_0.9(SO₄)₂.6H₂O with formula weight 437.15. KCNSH crystal belongs to the monoclinic space group P2(1)/c, a=6.1390(3)Å, b=12.1839(6)Å, c=9.0095(4)Å, α=γ=90°, β=105.060(2)°, V=650.74(5)ų, Z=2, Dc=2.231g/cm³. Using the cooling solution method, we have grown a deep green KCNSH crystal with dimension of 12×12×40mm³. The transmission spectrum of KCNSH in the range from UV to near IR wavelengths, its thermal properties, and the relationship between the structure and optical transmission properties are also studied and further discussed in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Crystal and Molecular Structure of 11,12‐dibromo‐ 7,8—benzo‐1,5‐di(p—tolylsulphonyl)‐1,5‐diazacyclononan

The crystal structure of the title compound, C₂₅H₂₆Br₂N₂O₄S₂ was determined by single crystal X‐ray diffraction technique. The crystals are monoclinic, space group C 2/c, with a=20.7142(2) Å b=11.7910(2) Å, c= 10.6735(3) Å, β=98.549(2)°, V=2577.94(9) ų, Z=4. The structure was solved by direct methods and refined by least‐squares methods to a final R=0.046 for 1866 observed reflections with I>2sigma(I). The title compound, displays disordered geometry around the C1 atom located almost on twofold axis. The nine‐membered heterocylic ring is close to the half‐chair conformation. The dihedral angle between phenyl rings is 34.2(1)°.     

Crystal structure of 3‐hydroxy methyl 4,6‐dimethoxy‐9‐phenylsulfonyl‐carbazole

The crystal structure of 3‐Hydroxy methyl 4,6‐dimethoxy‐9‐phenylsulfonyl‐carbazole. (C₂₁H₁₉NO₅S) has been determined [CCDC 194425]. The compound crystallizes from methanol in the monoclinic system, space group I2/c, with unit cell parameters: a = 20.498(2), b = 9.258(2), c = 21.866(3)Å, β = 116.450(10)°, Z = 8, V = 3715.2(10)ų. The crystal structure was solved by direct methods and refined by full‐matrix least squares to a final R‐value of 0.050 with 3508 unique reflections. The planar carbazole ring fragment is inclined at an angle of 79.9(1)° to the phenylsulfonyl group. The sum of the angle about N is 351.6(2)°. The atoms linked to the central hexavalent S atom are arranged in a tetrahedral configuration with the larger deviations in the O‐SO angles [O1‐S‐O2 = 119.7(2)°] and the O1‐S‐N and O2‐S‐N angles [106.1(2) and 106.9(1)°, respectively].     

Three‐Dimensional Structure Constructed via Hydrogen Bonds and π‐π Stacking Interaction. Crystal Structure of [Cu(AFO)2(H2O)2](ClO4)2.2(AFO).2H2O (AFO = 4,5‐Diazafluoren‐9‐one)

The structure of the title complexes [Cu(AFO)₂(H₂O)₂](ClO₄)₂.2(AFO).2H₂O (AFO = 4,5‐Diazafluoren‐9‐one)has been established by single‐crystal X‐ray diffraction. The complex crystallizes in the triclinic space group P‐1 with cell constants a = 7.659(3) Å, b = 11.066(3) Å, c = 14.203(5) Å, alpha = 75.16(3)°, β = 79.87(3)°, gamma = 85.71(3)°, Z = 1. The structure was solved by direct methods and refined to R₁ = 0.0595 (wR₂ = 0.1164). The X‐ray analysis reveals that a pair of AFO ligands chelate to a Cu(II) atom in an asymmetric fashion with one Cu‐N bond being much longer than the other, the Cu(II) atom is further coordinated by a pair of aqua ligands to form an elongated octahedral geometry. In the crystal of the complex, the mononuclear complex cations [Cu(AFO)₂(H₂O)₂]²⁺, uncoordinated AFO molecules, lattice water molecules and perchlorate anions are assembled into 3‐D structure via hydrogen bonds and π‐π stacking interaction.     

Structure,growth and optical properties of Zn0.24Ni0.76(SO4)·7H2O single crystal

A new crystalline complex zinc nickel sulfate heptahydrate (ZNSH) has been prepared. The crystal structure was investigated by x‐ray single crystal diffraction method and the empirical formula is Zn_0.24Ni_0.76(SO₄)·7H₂O. The ZNSH crystal belongs to the orthorhombic space group P2₁2₁2₁ with cell parameters a = 6.7742(14) Å, b = 11.748(2) Å, c = 12.009(2) Å. The deep‐green ZNSH single crystal with dimension of 30 × 25 × 25 mm³ has been grown by the cooling solution method. The constituent ratio of ZNSH crystal grown from various compounding solutions at temperature range 40‐50 °C is approximate invariant. The crystal absorption spectra with theoretical analysis are reported. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Flux growth of straw‐like rutile monocrystals

Millimetric straw‐like rutile monocrystals were grown by the flux growth technique. A suitable mixture of flux (MoO₃, V₂O₅, Li₂CO₃) and amorphous TiO₂ gel was slowly cooled down to 750°C from 1250°C or 1350°C. The best yields of straw‐like rutile were obtained with a nutrient/flux ratio and a cooling rate in the range 0.015‐0.006 and 1.8‐1.9 K h^‐1, respectively. The hollowed crystals were characterized by powder and single‐crystal X‐ray diffraction, scanning electron microscopy, microthermometry, and µ‐Raman spectroscopy. As for skeletal crystal, the formation of axial canals in rutile is attributed to a lack of nutrient due to the viscosity of the melt and the high growth rate along [001]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,growth and characterization of a new nonlinear optical crystal: l‐arginine maleate dihydrate

A new nonlinear optical material L‐arginine maleate dihydrate, C₆H₁₄N₄O₂,C₄H₄O₄,2H₂O (LAMD) was synthesized and single crystals were grown by slow cooling and also by slow evaporation method at constant temperature from its aqueous solution. Quality and size of the crystals are found to be dependent on pH of the solution and best crystals were obtained at pH = 4. Single crystal X‐ray diffraction analysis reveal that the crystal lattice of LAMD is triclinic with unit cell parameters a = 5.264(3)Å, b = 8.039(3)Å, c = 9.784(3)Å, α = 106.19(3)°, β = 97.24(3)°, γ = 101.66(2)°. Second harmonic generation efficiency is found to be about 6.8 times that of quartz. It is optically transparent down to 300 nm and possesses a large optical window between 300–2000 nm. The compound is thermally stable up to 93.4 °C. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,structural and thermal studies of tetrathioureacopper(I) chloride crystals

Tetrathioureacopper(I) chloride, hereafter abbreviated as TCC, was synthesised and single crystals were obtained from saturated aqueous solution by slow evaporation (solution growth) method at room temperature. The crystals obtained are bright, colourless and transparent having well defined external faces. The grown crystals were characterized through elemental analysis, single crystal X‐ray diffraction study, thermal analysis, electron spin resonance spectroscopy and Fourier Transform infrared spectroscopy. The elemental analysis confirms the stoichiometry of the compound. The single crystal diffraction studies indicate that TCC crystallises in the tetragonal lattice and the unit cell parameters are a = b = 13.4082 Å, c = 13.8074 Å, V = 2482.29 ų, α = β = γ = 90°. Space group and the number of molecules per unit cell (Z) are found to be P4₁2₁2 and 8 respectively. The TG curve of the sample shows a prolonged decomposition from 210 to 628.3 °C, from which the decomposition pattern has been formulated. The endothermic peaks in the DTA curve indicate melting and decomposition of the compound at 165.2 and 633.8 °C respectively. An exothermic peak in high temperature DSC indicates a phase transition in the compound at 274.8 °C. Thermal anomalies observed in the low temperature DSC at –163.3, –152.0, –141.5, –108.3, 1.0 and 12.1 °C in the heating run and –157.1 and –153.9 °C in the cooling run reveal first order phase transitions in the crystal. The peaks observed at –146.2 °C in both the heating and cooling runs suggest occurrence of a second order phase transition in this compound. The IR spectroscopic data were used to assign the characteristic vibrational frequencies of various groups present in the compound. The ESR study confirms that the copper is in the +1 oxidation state in the complex. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Holographic Studies of Diffusivities of KDP and DKDP in the Solutions

The solution diffusivities of KDP and DKDP are measured accurately and conveniently by holography with a reference-fringe system being introduced into the hologram. The influences of solutions with different concentrations, concentration gradients, deuterium concentrations and at different temperatures on the diffusivities have been studied in detail for KDP-H₂O and DKDP-D₂O systems. The problems of how to measure diffusivity accurately are discussed on the basis of diffusion mechanism and experimental technique. The activation energies for the diffusion of KDP and DKDP around the saturated solution in the temperature range of 20–50 °C are about 16 · 10³J/mole and 25 · 10³J/mole, respectively.     

Crystal growth and spectral properties of Nd:Ca5(BO3)3F

A neodymium doped Ca₅(BO₃)₃F single crystal with size up to 51×48×8 mm³ has been grown by the top seeded solution growth (TSSG) technique with a Li₂O‐B₂O₃‐LiF flux. The spectra of absorption and fluorescence were measured at room temperature. According to Judd‐Ofelt (J‐O) theory, the spectroscopic parameters were calculated and the J‐O parameters Ω₂, Ω₄, Ω₆ were obtained as follows: Ω₂ = 1.41×10⁻²⁰cm², Ω₄ = 3.18×10⁻²⁰cm², Ω₆ = 2.11×10⁻²⁰cm². The room temperature fluorescence lifetime of NCBF was measured to be 51.8 μs. According to the J‐O paramenters, the emission probabilities of transitions, branching ratios, the radiative lifetime and the quantum efficiency from the Nd^{3+ 4}F_3/2 metastable state to lower lying J manifolds were also obtained. In comparasion with other Nd‐doped borate crystals, the calculated and experimental parameters show that NCBF is a promising SFD crystal.     

Single‐crystal growth and characterization of mullite‐type orthorhombic Bi2M4O9 (M = Al3+, Ga3+, Fe3+)

Pure and homogeneous single crystals of orthorhombic mullite‐type Bi₂M₄O₉ (M = Al³⁺, Ga³⁺, Fe³⁺), and a mixed Bi₂Fe_1.7Ga_2.3O₉ crystal from an equimolar Ga/Fe composition were grown by the top seeded solution growth (TSSG) method. All these compounds melt incongruently in the range of about 800 and 1100 °C. In case of bismuth gallate and ferrate inclusion‐free crystals with dimensions up to several cubic centimeters can be grown. Limited solubility in Bi₂O₃ and the high steepness of the liquidus curve are the reasons for getting only small imperfect bismuth aluminate crystals. In contrast to ceramic materials preparation reported in literature, divalent calcium and strontium could not be incorporated into the mullite‐type structure during the melt growth process. Several fundamental physical properties like heat capacity, thermal expansion, heat conductivity, elastic constants, high‐pressure behavior and oxygen diffusivity were determined by different research groups using single‐crystalline samples from the as‐grown materials. Furthermore, the refractive indices of Bi₂Ga₄O₉ were measured in the range of 0.430 and 0.700 μm. Such as many other bismuth containing compounds the refractive indices of Bi₂Ga₄O₉ are larger than 2, and Bi₂Ga₄O₉ is an optic biaxial positive crystal. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Flux growth and characterization of Ti‐ and Ni‐doped forsterite single crystals

Forsterite monocrystals doped with Ti and Ni were grown by the flux growth technique. A suitable mixture of flux (MoO₃, V₂O₅, Li₂CO₃) and nutrient was slowly cooled down to 750 °C from 1250 °C or 1350 °C. The crystals were then characterized by powder and single‐crystal X‐ray diffraction, scanning electron microscopy and differential scanning calorimetry (DSC). Variations observed in crystal size were attributed by both the varying experimental conditions in which they had been obtained, and to the amount of Ni substituted for Mg in the structure. High abundances of doped forsterite required a cooling rate of 1.8 K h^‐1. These synthetic, well‐characterized Ti and Ni doped forsterite crystals may have potential for exploitation in industrial fields. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Two organic‐inorganic hybrids with Keggin polyanions

Two new Keggin polyoxometalates [Co(phen)₃]₂[SiW₁₂O₄₀]·6H₂O (1) and (ppy)₆ H₄SiMo₁₂O₄₀·0.4H₂O (2) (phen = 1,10′‐phenanthroline, ppy = 4‐(5‐phenylpyridin‐2‐yl)pyridine) have been synthesized by the hydrothermal method. Single crystal X‐ray analysis revealed that compound 1 crystallizes in the monoclinic crystal system with cell parameters of a = 13.344(2) Å, b = 17.191(3) Å, c = 22.002(4) Å, α = 90.00°, β = 99.566(2)°, γ = 90.00°, V = 4977 ų, Z = 2, and compound 2 crystallizes in the triclinic crystal system with cell parameters of a = 11.297(2) Å, b = 12.341(3) Å, c = 19.354(4) Å, α = 107.60(3)°, β = 95.80(3)°, γ = 94.16(3)°, V = 2543.7(9) ų, Z = 1. Both 1 and 2 represent organic ligand molecules and inorganic Keggin anions, which are further interconnected to a 3D framework by supramolecular interactions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth of ZnO single crystals by an induced nucleation from a high temperature solution of the ZnO‐PbF2 system

To grow ZnO single crystals from a high temperature solution of the ZnO‐PbF₂ system, a gas cooling system was assembled at the bottom of the crucible to induce nucleation in the initial growth stage. The growth experiments were carried out in a homemade vertical Bridgman furnace and Pt crucible of 28 mm in diameter was used. The furnace temperature was set to 1100°C and the flow rate of the oxygen gas was optimized as 3.0 l/min. ZnO crystal up to 5∼8mm in the thickness was obtained with the lowering rate of 0.3 mm/h. XRD patterns showed that the as‐grown crystal was pure ZnO Wurtzite phase. The impurity ions were analyzed by the glow discharge mass spectroscopy (GDMS) as 390.0 ppm and 40.0 ppm for Pb²⁺ and F^‐, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structure of [Ru(phen)3](ClO4)2.(C2H5)2O

The title solvated complex, in which phen denotes 1,10‐phenanthroline, crystallizes in the monoclinic space group P2₁/n with a = 13.313 (3), b = 15.980 (3), c = 18.392 (4) Å, α = 96.76 (3)°, Z = 4, V = 3885.4 (14) ų, D_cal = 1.564 Mg m^‐3. The crystal is composed of racemic layers of complex cations, with the ether solvents located near, and the perchlorate anions sandwiched between, indicating the hydrophobic environment in the complex layer and the stacking interaction between the enantiomeric cations. The average length of the Ru‐N bonds is 2.064 (2) Å and the average ligand bite angle is 80.00 (7)°.     

Temperature‐concentration oscillations as a result of nanoheterophase structure of concentrated aqueous solutions of salts

Detailed precision investigation of aqueous solutions of NaBr·2H₂O, KBr, RbNO₃, and K₂SO₄ salts showed oscillations of crystal‐solution phase equilibria in the temperature range of 15–45 °C. The maximum deviations from the smooth correlation between the saturation temperature and the salt concentration (up to 4% of concentration and up to 10 °C) were found to correspond to simplest salt‐water ratios. Recently, similar trends were observed for NaNO₃, KNO₃ and K₂CrO₄ solutions. Oscillation amplitudes for saturation temperature in the investigated series decreased in the following orders: Na⁺→K⁺, Rb⁺, NH₄⁺ (nitrate systems), CrO₄^2–→SO₄^2– and Br^–→NO₃^– (potassium systems), and NO₃^–→Br^– (sodium systems). Increase in total content of impurities (2‐4‐fold) in solution results in 1.5‐2‐fold elevation of the oscillation amplitudes. A concept of nanoheterophase solution was suggested to account for the observed temperature‐concentration oscillations. The concept is based on the original experimental data on interrelated variation of different properties of aqueous salt solutions depending on their concentrations. Characteristic features of the phase diagrams are discussed and influence of the oscillations on crystal growth is elucidated. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal and molecular structure of 3‐phenyl‐4‐(p‐chlorobenzylamino)‐4,5‐dihydro‐1‐H‐1,2,4‐triazol‐5‐on

The structure of the title compound, C₁₅H₁₃N₄OCl was determined by single crystal X‐ray diffraction technique. The structure consists of a p‐chlorobenzylamino moiety and triazol and phenyl rings. The title compound crystallizes in the monoclinic space group P2₁/c with a = 14.368(3), b = 6.255(3), c = 17.631(3) Å, β = 113.24(3)°, Z = 4, V = 1455.8(8) ų and D_x = 1.372 gcm^‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R=0.0477). The dihedral angle between the triazole moiety and the phenyl ring is 28.8(3)°. The molecular packing is stabilized by N‐H…N and N‐H…O types of inter molecular hydrogen bonds. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and characterization of single crystals of the layered copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O

Single‐crystals of the layered copper hydroxide acetate Cu₂(OH)₃(CH₃COO)·H₂O were synthesized by heating copper acetate solution at 60 °C. The standard synthesis of the title compound based on slow titration of copper acetate solution with NaOH yielded materials with worse morphology and an additional phase present. The obtained products were characterized with powder X‐ray diffraction, high temperature powder X‐ray diffraction, scanning electron microscopy and infrared spectroscopy. The crystal structure was determined from single‐crystal X‐ray diffraction data, collected both at 120 K and at 293 K. The title compound crystallizes in the monoclinic botallackite‐type layered structure, space group P 2₁, with the lattice parameters a = 5.5776(3) Å, b = 6.0733(2) Å, c = 18.5134(8) Å, β = 91.802(4)° and a = 5.5875(4)Å, b = 6.0987(4) Å, c = 18.6801(10)Å, β = 91.934(5)° for 120 K and for 293 K, respectively. Acetate groups and water molecules are interlayered between corrugated sheets of edge‐sharing CuO6 octahedra exhibiting strong distortion resulted from the Jahn‐Teller effect. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)