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)     

New schemes for recording electron diffraction patterns of hexagonal and monoclinic crystals

Some new schemes for recording electron diffraction patterns of hexagonal crystals rotating around the axes lying in the (hk0) plane of the reciprocal lattice and monoclinic crystals rotating around the a and b axes of the direct lattice and the a* axis of the reciprocal lattice have been developed. Formulas for interpreting electron diffraction patterns are reported. The electron diffraction patterns obtained based on these schemes were used to solve the 2H and 3R polytypes of CdInGaS₄ crystals and the 3R polytype of Zn_1.5In₃Se₆ crystal with the parameters a = 4.046 and c = 59.292 Å, sp. gr. R3m.     

X-ray Diffraction Study on MgSeO4. 6 H2O at Elevated Temperatures

The dehydration of MgSeO₄. 6 H₂O has been studied using an X-ray powder diffraction method at elevated temperatures. Five different solid phases have been identified in the temperature interval of 20–450 °C: MgSeO₄. 6 H₂O; MgSeO₄. 5 H₂O (with a small amount of MgSeO₄. 4 H₂O), MgSeO₄. 2 H₂O, amorphous MgSeO₄ and crystalline MgSeO₄. MgSeO₄. 5 H₂O crystallizes in the triclinic system with the lattice parameters: a = 6.403(2) Å, b = 10.576(5) Å, c = 6.196(3) Å, α = 98.63(2)°, β = 110.36(2)°, γ = 75.25(3)°, SG P1 . MgSeO₄. 2 H₂O forms orthorhombic crystals with lattice parameters: a = 10.304(1) Å, b = 10.351(9) Å, c = 9.138(9) Å. The crystalline anhydrous magnesium selenate crystallizes in the orthorhombic system with the lattice parameters: a = 4.925(2) Å, b = 9.026(5) Å, c = 6.816(6) Å. Additionally MgSeO₄. 4 H₂O has been prepared and studied roentgenographically: monoclinic system with the lattice constants: a = 6.064(4) Å, b = 13.773(7) Å, c = 8.062(6) Å, β = 91.82(7)°, SG P2₁/n. According to expectation the magnesium selenate hydrates are isomorphous with the corresponding magnesium sulphate hydrates.     

X‐ray powder diffraction study of the semiconducting alloy Cu2Cd0.5Mn0.5GeSe4

The structure of the semiconducting alloy Cu₂Cd_0.5Mn_0.5GeSe₄ was refined from an X‐ray powder diffraction pattern using the Rietveld method. The present alloy crystallizes in the wurtz‐stannite structure, space group Pmn2₁ (N^o 31), and unit cell parameters values of a = 8.0253(2) Å, b = 6.8591(2) Å, c = 6.5734(2) Å and V = 361.84(2) ų. The structure exhibits a three‐dimensional arrangement of slightly distorted CuSe₄, Cd(Mn)Se₄ and GeSe₄ tetrahedras connected by corners. © 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim     

An X-ray diffraction refinement of the crystal structure of natural tetragonal analcime (NaAlSi2O6. H2O)

An X-ray diffraction analysis was performed on a single crystal of natural tetragonal analcime: (Na_0.99K_0.01)/(Al_1.05Si_2.02) O₆/0.99 H₂O, space group I 4₁/acd, a = 13.726(2) Å, c = 13.684(1) Å, V = 2578.1 ų, Z = 16, D_obs = 2.26. Refinement of 260 independent reflections yields R = 0.028 (R_w = 0.033). The mean Si(Al) O distance is 1.636 Å and tetrahedral angle is 109.35°. The framework of tetragonal analcime is topologically the same as the cubic modification.     

Synthesis of L‐valine crystals

L‐valine (C₅H₁₁NO₂), an essential amino acid of monoclinic space group P2₁, Z = 4 and lattice parameters a = 9.688 (2) Å, b = 5.267 (1) Å, c = 11.980 (2) Å and β = 90.75 (1)° and of size: 6.0 mm across and 0.5 mm thick was crystallized in silica gel under suitable pH conditions by reduction of solubility method. Density measurement and single crystal X‐ray diffraction were used to characterize the grown crystals. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopic (SEM) studies were made and crystal packing also discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structural study of the semimagnetic semiconductor Zn0.5Mn0.5In2Te4

The semimagnetic semiconductor alloy Zn_0.5Mn_0.5In₂Te₄ was refined from an X‐ray powder diffraction pattern using the Rietveld method. This compound crystallizes in the space group I42m (Nº 121), Z = 2, with unit cell parameters a = 6.1738(1) Å, c = 12.3572(4) Å, V = 471.00(2) Å3, c / a = 2.00. This material crystallizes in a stannite‐type structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X-Ray Diffraction Studies on Molecular Semiconductors Based on Charge-Transfer Complexes of Substituted Phenothiazines with 2,3-Dichloro-5,6-dicyano-p-benzoquinone

X-ray powder diffraction data on the molecular semiconductors based on the 1:1 charge-transfer complexes of the electron donors, viz. phenothiazine (PTZ), 2-chlorophenothiazine (CPZ), 2-acetyl phenothiazine (APZ) and 2-(trifluoromethyl)-phenothiazine (TPZ) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) have been reported in this paper. The indexing has been done by Ito's method. All the complexes have been found to have orthorhombic crystal structures. The lattice parameters for the individual complexes are as follows: (i) PTZ-DDQ: a = 6.020 Å, b = 9.775 Å, c = 24.280 Å; (ii) CPZ-DDQ: a = 5.830 Å, b = 8.070 Å, c = 20.280 Å; (iii) APZ-DDQ: a = 5.055 Å, b = 7.955 Å, c = 19.520 Å; (iv) TPZ-DDQ: a = 5.130 Å, b = 8.195 Å, c = 19.850 Å.     

Crystal structure characterization of the quaternary compounds CuFeAlSe3 and CuFeGaSe3

The crystal structure of the chalcogenide compounds CuFeAlSe₃ and CuFeGaSe₃, belonging to the system I‐II‐III‐III₃, were characterized using X‐ray powder diffraction data. Both compounds crystallize in the tetragonal space group P42c (N° 112), Z = 1, with unit cell parameters a = 5.609(1) Å, c = 10.963(2) Å for CuFeAlSe₃ and a = 5.6165(3) Å, c = 11.075(1) Å for CuFeGaSe₃. These compounds are isostructural with CuFeInSe₃, and have a normal adamantane structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure of 2‐(2'‐hydroxyphenyl)‐6‐tributylstannyl‐4‐(3H )‐quinazolinone and 2‐(2'‐hydroxyphenyl)‐6‐iodo‐4‐(3H)‐quinazolinone

The structures of the title compounds C₂₆H₃₇N₂O₂Sn ( I ) and C₁₄H₉IN₂O₂ ( II ) were determined by single‐crystal X‐ray diffraction technique. Compound I crystallizes in the triclinic space group P1 with a = 9.560(3) Å, b = 16.899(6) Å, c = 17.872(5) Å, α = 65.957(7)°, β = 83.603(5)°, γ ( = 75.242(5)°, V = 2549.8(13) ų, Z = 4, and D =1.374 g/cm³. The compound consists of a quinazolinone ring with phenol and tributylstannyl moieties. Compound II crystallizes in the monoclinic space group P2₁/c with a = 7.6454(12) Å, b = 5.9270(9) Å, c = 27.975(4) Å; α = 90°, β = 95.081(3)°, γ = 90°, V = 1262.7(3) ų, Z = 4, and D = 1.915 g/cm³. The compound consists of a quinazolinone ring with phenol and iodine substituents. For both I and II , the short intramolecular O–H…N and two long intermolecular N–H…O hydrogen bonds are highly effective in holding the molecular system in a stable state. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and single crystal X‐ray structure of the tetragonal tungsten bronze Pb0.91K1.72Li1.46Nb5O15

Crystals of Pb_0.91K_1.72Li_1.46Nb₅O₁₅, belonging to tetragonal tungsten bronze materials, were grown by the slow cooling technique, and characterized by means of single crystal X‐ray diffraction: the structure was solved in the P4bm tetragonal space group, with the following unit cell parameters: a = 12.548(5), c = 4.042(5) Å, V = 636.4(9) ų. The three‐dimensional framework can be described as a layered structure down crystallographic axis c, with arrays of NbO₆ octahedra, whose corner sharing makes up the formation of tunnels filled up by Li, Pb and K displaying complex cation‐oxygen coordinations. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Investigations of phase relations in the system CaO?Na2O?K2O?P2O5

The lattice constants of the compound Ca₂NaK(PO₄)₂ have been studied at room temperature using an X-ray powder diffractometer and also in the temperature range from 20 up to 1000 °C by Guinier-Lenné-technology. A hexagonal lattice with the parameters a₀ = 5.4367 Å and c₀ = 7.3125 Å and a cell volume of 187.18 ų has been determined for the high temperature phase, existing from 670 °C upward. At temperatures below 670 °C a superlattice structure is formed by tripling the axis a, a ′, and c so that it results in a hexagonal superlattice structure cell with the lattice constants of a₀ = 16.311 Å and c₀ = 21.939 Å and a cell volume of 5054 ų.     

The Crystal and Molecular Structure of 2-(2′-Cyano-2′-amido-ethylenyl)-pyridine

The title compound (C₉H₇N₃O) has been determined from three dimensional X-ray diffraction data. The crystals are monoclinic, a = 4.858(3) Å, b = 15.008(7) Å, c = 11.787(2) Å, ß = 94.107(2)°, V= 857.2(4) ų, z = 4, D_calc = 1.342 g. cm⁻³, space group P2_1/c. The structure was solved by direct methods and refined by full-matrix least-squares method (γ MoK_α′, R = 0.0766).     

Crystal structure of the double magnesium zirconium orthophosphate at temperatures of 298 and 1023 K

Double magnesium zirconium orthophosphate Mg_0.5Zr₂(PO₄)₃ is synthesized by the sol-gel method. The compound prepared is characterized using electron probe microanalysis and X-ray diffraction. The crystal structure of the orthophosphate is refined by the Rietveld method in space group P2₁/n (Z = 4) at temperatures of 298 K [a = 12.4218(2) Å, b = 8.9025(2) Å, c = 8.8218(2) Å, β = 90.466(1)°] and 1023 K [a = 12.4273(5) Å, b = 8.9453(4) Å, c = 8.8405(4) Å, β = 90.320(3)°]. It is demonstrated that an increase in the temperature leads to an anisotropic expansion of the unit cell of the phosphate structure, but the structural type remains unchanged.     

Thermal dehydration of the double salts K2Be(XO4)2·2H2O (X = S,Se)

The thermal dehydration of the title compounds was studied by TG, DTA and DSC methods and the enthalpies of dehydration were calculated (87.6 kJ mol^–1 and 167.5 kJ mol^–1 for the sulfate and selenate compound, respectively). The larger value of ΔH_deh of K₂Be(SeO₄)₂·2H₂O is due to the stronger hydrogen bonds formed in the selenate as compared to those formed in the respective sulfate owing to the stronger proton acceptor capabilities of the SeO₄^2– ions. The enthalpies of formation (ΔH_f⁰) of the dihydrates are also calculated from the DSC measurements (– 4467.4 kJ mol^–1 and – 3447.1 kJ mol^–1 for the sulfate and selenate compound, respectively). The anhydrous double salt, K₂Be(SO₄)₂, forms tetragonal crystals with lattice parameters: a = 7.232(2) Å; c = 14.168(2) Å; V = 741.0 ų, while the anhydrous salt, K₂Be(SeO₄)₂, forms monoclinic crystals with lattice parameters: a = 9.217(3) Å; b = 10.645(3) Å; c = 8.989(2) Å; β = 108.52(4)°; V = 836.2 ų. Vibrational spectra (infrared and Raman) of both the dihydrates and the anhydrous compounds are also presented and discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X-ray mapping in heterocyclic design: XIII. Structure of substituted tetrahydroquinolines

The structures of 4-methyl-2-chloro-5,6,7,8-tetrahydroquinoline [a = 8.138(2) Å, b = 11.127(4) Å, c = 11.234(2) Å, β = 111.30(2)°, Z = 4, space group P2₁/c, 4-methyl-2-methoxy-5,6,7,8-tetrahydroquinoline [a = 5.7651(16) Å, b = 8.530(2) Å, c = 10.455(3) Å, α = 73.76(2)°, β = 86.95(2)°, γ = 83.97(2)°, Z = 2, space group P $\bar 1$ , 4-methyl-2-(4-chlorophenacyl)-5,6,7,8-tetrahydro-1H-quinolin-2-one [a = 8.873(2) Å, b = 17.137(2) Å, c = 24.515(4) Å, Z = 8, space group Pbn2₁], and 2-(4-chlorophenyl)-5-methyl-6,7,8,9-tetrahy-drooxazolo[3.2-a]quinolin-10-ylium perchlorate [a = 8.110(6) Å, b = 17.818(7) Å, c = 17.721(5) Å, β = 100.46(4)°, Z = 4, space group P2₁/c] are studied by single-crystal X-ray diffraction. The structures are solved by direct methods and refined by the full-matrix least-squares procedures in the anisotropic approximation to R = 0.0581, 0.0667, 0.0830, and 0.0607, respectively.     

Crystal structures of copper(II) compounds with racemic threonine

Crystals structures of two modifications of the copper(II) compound with racemic threonine Cu(D-Tre)(L-Tre) are determined by the electron diffraction technique. The unit cell parameters, space group, and number of formula units per unit cell for the crystals of two modifications are as follows: a = 11.10(3) Å b = 9.56(2) Å, c = 5.11(2) Å, γ = 92.6(2)°, space group P2₁/b, and Z = 2 (I); and a = 22.20(3) Å, b = 9.56(2) Å, c = 5.11(2) Å, γ = 92.6(2)°, space group C2₁/b, and Z = 4 (II). The structures are polytypic modifications of the same compound.     

Synthesis and Crystal Structure of Open Framework Zinc‐Cobalt Phosphate with Zeolite DFT Topology

The synthesis and crystal structure of Zn_(2‐x)Co_x(PO₄)₂(NH₃CH₂CH₂NH₃) (x = 0.61) (ZCP‐DFT) is described. ZCP‐DFT is characterized by means of single‐crystal and powder X‐ray diffraction. Crystal data for ZCP‐DFT: tetragonal, space group P4₂ bc (No. 106), a = 14.7236(6) Å, b = 14.7236(6) Å, c = 8.9544(5) Å, V = 1941.17(16) ų, Z = 8. The structure has 3‐D 8‐ring channel system with protonated ethylenediamine cations in the channel junctions. The framework structure type is the same as the zeolite DFT topology. The synthesis of ZCP‐DFT indicates that cobalt can partially substitute the metal sties of zinc phosphate, which can lead to the modification of physical and chemical properties of the parent compounds.     

Synthesis and crystal structure determination of two dispiro compounds from laboratory x‐ray powder diffraction data

The crystal structures of the dispiro compounds 1,3,4,8,10,11‐Hexaphenyl‐13‐methyl‐1,2,8,9,13‐pentaazadispiro[4.1.4.3]tetradeca‐2,9‐dien‐6‐one ( 3a ) and 4,11‐Bis(4‐methoxyphenyl)‐13‐methyl‐1,3,8,10‐tetraphenyl‐1,2,8,9,13‐pentaazadispiro‐[4.1.4.3]tetradeca‐2,9‐dien‐6‐one ( 3b ) have been determined at room temperature from X‐ray powder diffraction data using the method of simulated annealing as implemented in the programs DASH and TOPAS. Subsequent Rietveld refinements using the data collected to 1.5 Å resolution yielded R‐Bragg values of 2.2% for ( 3a ) and 3.7% for ( 3b ). It was found, that both compounds crystallize in the monoclinc space group P 2₁/n with lattice parameters of a = 17.1656(5) Å, b =13.8128(3) Å, c = 16.1016(5) Å, and β = 103.7330(2)° for ( 3a ) and a = 17.2529(8) Å, b = 13.8729(5) Å, c =16.1287(10) Å, and β = 103.6910(3)° for ( 3b ). Both compounds exhibit a distorted hexagonal close type of packing (hcp) of the molecular centers of gravity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structural Phase Transitions in Zinc(II) Perchlorate Hexahydrate

Phase transitions in zinc perchlorate hexahydrate are studied by X-ray powder diffraction method. Structural changes in the vicinity of transitions detected at 364.5 K and 256.3 K are characterized. At the former the orthorhombic Pmn2₁ phase transforms into the Pmna one (a = 7.812(1), b = 13.518(3) and c = 5.279(1) Å at 348.6 K). The latter involves changes of the orthorhombic unit cell (a = 7.7922(9), b = 13.537(2) and c = 5.0588(6) Å at 251.0 K). Temperature dependence of lattice parameters in the range of 180 to 363.3 K are presented.