The Crystal and Molecular Structure of 4'-Cyanophenyl-4-n-Pentylbenzoate

The crystal and molecular structure of the title compound with the formula C₅H¹¹—C₆H₄—COO—C₆H₄—CN (CPPB) has been determined by X-ray diffraction methods. CPPB crystallizes in the monoclinic space group P2₁/n with eight molecules in a unit cell of dimensions a = 15.268(2) Å, b = 9.165(1) Å, c = 24.031(3) Å, β = 94.67(1)°. The structure has been solved by direct methods and refined to an R value of 0.070.

The CPPB molecules adopt a stretched form and are packed in an approximate parallel imbricated mode, the molecular long axes making an angle of about 5° with the crystal c axis. The molecular geometry and packing are discussed in relation to the mesomorphic behavior of CPPB.     

Crystal structure analysis and refinement of Kalabsha kaolinite (Al2Si2O5(OH)4)

The crystal structure of the kaolinite mineral from Kalabsha, Aswan, Egypt, has been investigated with a two-step procedure of the X-ray powder pattern-fitting. The unit cell is found to be triclinic, P1, a = 5.1577(15), b = 8.9417(23), c = 7.3967(40) Å, α = 91.672(5)°, β = 104.860(2) and γ = 89.898(2)°. The refinements of the non-hydrogen atomic positions showed a reliability factors R_WB = 0.037 and R_B = 0.0417. The average rotation angle in the tetrahedral layer in 10°.     

Crystal and Molecular Structure of an Oligomeric 1:2 Complex of Copper (II) Azide with 4-Methylpyridine

A 1:2 complex of copper (II) azide with 4-methylpyridine has been synthesized and the crystal structure has been determined by X-ray methods. The compound crystallizes in space group P2₁/a with a = 11,062(3), b = 19.310(6), c = 20.547(5) Å, β = 90.83(2)°, V = 4389(1) ų, Z = 12 and R = 0.048 for 959 observed MoKα data. The structure is built up by oligomeric edge-sharing chains of polyhedra. With the exception of a single coordinated azido group, all other azido ligands serve to bridge neighbouring copper centers [at Cu  N bond distances of 1.94(2) to 2.76(2) Å] in the μ(1,1) fashion.     

Solvent-controlled structures. Synthesis and characterization of complexes Cu(L)2(CH3COO)2 and [Cu2(μ-CH3COO)4(L)2](L)2 [L = N-(4′-methylaniline)-4-pyridinecarboxamide]

Two complexes Cu(L)₂(CH₃COO)₂ (1) and [Cu₂(μ-CH₃COO)₄(L)₂](L)₂ (2) (L = N-(4′-methylaniline)-4-pyridinecarboxamide) have been prepared and their crystal structures have been determined by single-crystal X-ray diffraction. The complexes are obtained by using the same raw materials and reaction conditions except solvents. The presence or absence of water controls the coordination mode to give rise to different structures. The structure of 1 has a triclinic space group P-1 with a = 8.381(3) ?, b = 8.545(4) ?, c = 11.357(5) ?, α = 110.654(6)°, β = 102.388(7)°, γ = 97.889(7)°, V = 722.9(5) ?³, and Z = 1. The structure of 2 has a triclinic space group P-1 with a = 9.121(3) ?, b = 9.454(3) ?, c = 17.233(5) ?, α = 77.374(5)°, β = 89.827(6)°, γ = 74.342(6)°, V = 1393.8(7) ?³, and Z = 1. Supramolecular assemblies have also been found via noncovalent bonds such as hydrogen bonds, π–π stacking interactions.     

Crystal structure investigation of [Mn(3-CH3C5H4N)2(N3)2(H2O)2]

The crystal structure of the title compound has been determined by single crystal X-ray diffraction methods. [Mn(3-CH₃C₅H₄N)₂(N₃)₂(H₂O)₂] crystallizes in the space group P 1 with a = 7.444(2) Å, b = 7.691(2) Å, c = 8.926(3) Å, α = 99.82(3)°, β = 108.80(2)°, γ = 114.99(2)° and Z = 1. Least squares refinement gave a R value of R_w = 0.046 for 1414 observed reflections. The manganese atom in the title complex is octahedrally coordinated by two oxygen atoms of the water molecules and four nitrogen atoms; two N-atoms are the end atoms of azide groups and the other two nitrogen atoms belong to the 3-methylpyridine molecules. The polyhedra are linked via hydrogen bonds between the water molecules and the azide groups.     

The crystal structure of zinc azide · 2-methylpyridine at 98 K

The crystal structure of the title compound has been determined by single crystal X-ray diffraction methods at 98 K. Zinc azide · 2-methyl pyridine crystallizes in the space group P1 with a = 6.028(2) Å, b = 7.610(3) Å, c = 10.052(4) Å, α = 92.81(3)°, β = 101.08(2)·, γ = 94.64(3)° and Z = 2. Least-squares refinement gave an R value of R_w = 0.039 for 2096 observed reflections. Each zinc atom is surrounded by four nitrogen atoms of different azide groups and one nitrogen atom of the pyridine adduct in a distorted trigonal bipyramidal fashion. The ZnN₅-polyhedra share common edges to form chains along the crystallographic a-axis.     

Refined Crystal and Molecular Structure of Andrographolide — Diterpene

A refined crystal structure of andrographolide has been obtained by X-ray anaysis using CuKα radiation. It crystallizes in the monoclinic crystal system with unique b-axis in space group P2₁. The unit cell parameters are a = 6.552(2) Å, b = 8.009(1) Å, c = 17.989(1) Å and interaxial angle β = 97.32(1)°. The structure has been solved by direct methods and was refined up to R = 0.041, ωR = 0.0464. Both the cyclohexane rings are in chair conformation with the furan ring in twist conformation. The crystal structure is stabilized by hydrogen bonding.     

Crystal structure of R(–)–1–Tosyl–2–methylpyrrolidine

The crystal structure of R(–)-1-tosyl-2-methylpyrrolidine has been determined by X-ray structure analysis. The compound crystallizes in the monoclinic space group P2₁ with cell parameters a = 7.858(1), b = 14.929(6), c = 11.128(1) Å, β = 105.42(1)°. The structure has been solved by direct methods and refined to R = 0.046. There are two crystallographically independent molecules A and B in the asymmetric unit. The pyrrolidine ring of molecule A is disordered with atom C4 occupying two possible sites. The S atom has a distorted tetrahedral coordination in both the molecules. Two bifurcated hydrogen bonds are observed. Molecules are held together by hydrogen bonds.     

The molecular and crystal structure of the Steroidal Alkaloid Aculeamine

A new solanocapsine-type alkaloid named aculeamine has been isolated from roots of Solanum aculeatum and its structure has been established by X-ray analysis as 22,26-epimino-23β-methoxy-16α,23-epoxy-5α,25αH,25βH-chloestane-3β-ol. The compound crystallizes in the hexagonal space group P6₁ with the lattice parameters a = b = 16.706, c = 17.056 Å, α = β = 90°, γ = 120°. The final residual value was R = 0.079.     

Asymmetric base pairing in the complex 5-fluorocytosinium chloride/5-fluorocytosine monohydrate

The structure of the complex 5-Fluorocytosinium chloride/5-Fluorocytosine monohydrate has been studied by X-ray diffraction methods. It crystallizes in the monoclinic system, space group P 2₁ /n, a = 7.1257 (15), b = 8.351 (3), c = 21.520 (4) ?, β = 92.89 (8)°, V = 1279.0 (6) ?³, Z = 4. The structure consists of triple hydrogen-bonded 5-Fluorocytosine pairs, water molecules and chloride anions. Asymmetric reversed Watson-Crick base pairing occurs between one protonated (5FcytH⁺) and one neutral 5-Fluorocytosine (5Fcyt) molecule.     

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.     

The Crystal and Molecular Structure of Mesogenic Malonates (II)

The crystal and molecular structures of three diethyl-2-{n-[4-(4-nitrophenylazo)-phenoxy]alkyl}malonate with n = 5 (5 PhNO₂), 7 (7PhNO₂), 9 (9 PhNO₂) and an analogous diethyl-2-[4(4-cyanophenylazo)phenoxy]pentylmalonate (5 PhCN) have been determined with CuK_a or MoK_a: 5 PhNO₂: a = 8.007(6) Å, b = 11.960(8) Å, c = 13.516(9) Å, α = 77.10(6)°, β = 81.80(5)°, γ = 83.15(5)°; R = 0.053; 7PhNO₂: a = 8.074(4) Å, b = 11.592(5) Å, c = 14.422(7) Å, α = 87.43(3)°, β = 82.46(3)°, γ = 85.43(3)°; R = 0.072; 9 PhNO₂: a = 5.520(5) Å, b = 13.628(9) Å, c = 20.220(11) Å, α = 100.02(4)°, β = 95.49(4)°, γ = 101.02(4)°; R = 0.042; 5 PhCN: a = 8.018(6) Å, b = 11.960(8) Å, c = 13.566(7) Å, α = 77.82(5)°, β = 81.89(5)°, γ = 82.69(5)°; R = 0.067 (isotropically refined). All these structures belong to the triclinic space groups P1 . The arrangements of the molecules in the crystal of the homologous series of nPhNO₂ suggest two different types of packing independent of n even, odd or large, small. 5 PhCN represents an isomorphous structure to 5 PhNO₂. Isomophism between 7 PhNO₂ and 7 PhCN was confirmed by cocrystallization of these two compounds whose crystal structure was also determined.     

Double Salt Formation in the Cu(HCOO)2–Sr(HCOO)2–H2O System

The solubility in the Cu(HCOO)₂–Sr(HCOO)₂–H₂O system has been studied by the method of physico-chemical analysis at 25 and 50 °C. It has been established that two double salts are formed in the system: CuSr₂(HCOO)₆ · H₂O at 25 °C and CuSr(HCOO)₄ · 4 H₂O at 50 °C. The latter salt has not yet been described in the literature. It has been characterized by X-ray powder diffraction and DT and TG analysis. CuSr(HCOO)₄ · 4 H₂O crystallizes in the triclinic system with lattice parameters a = 12.376(6) Å, b = 13.394(4) Å, c = 11.508(6) Å, α = 93.38(3)°, β = 94.01(3)°, γ = 75.04(3)°. Dehydration proceeds in two stages.     

Structure determination of [tetraethylammonium]-[(1,3-dithiole-2-one-4,5-dithiolato)diphenyl-(thiocyanato-N)stannate]

The title compound (3) has been synthesised and its molecular structure has been elucidated by single crystal X-ray diffraction. Refinement of the complex in space groupP2₁/c witha=11.535(4),b=9.831(2),c=25.217(1) and β=94.23(5)° converged atR=0.064. The geometry at the tin center in the anion is trigonal bipyramidal, with the thiocyanato N atom and a dithiolato S atom in the axial sites. The tetraethylammonium cation exhibtis normal geometry.     

Synthesis and Structure of the Dimeric Copper(II) Complex Tetrakis[<Emphasis Type="Italic">N</Emphasis>-thiazol-2-yl-(4-methylphenyl)sulfonamidate]dicopper(II)

Abstract The coordination chemistry of the ligand N-thiazol-2-yl-toluenesulfonamidate towards the copper(II) ion has been investigated using an electrochemical synthesis method. The X-ray structure of this complex was elucidated and is discussed. The compound crystallised in the monoclinic crystal system, P2₁/c space group with a = 17.3888(9), b = 16.3003(9), c = 18.3679(9) ? and β = 114.3640(10)°. Four bidentate sulfathiazolato anions bridge two metal centers in a paddle-wheel fashion, with the nitrogen atoms as donors to give a dimeric species with a Cu···Cu distance of 2.7859(5) ?. Graphical Abstract The coordination chemistry of the ligand N-thiazol-2-yl-toluenesulfonamidate towards the copper(II) ion has been investigated using an electrochemical synthesis method. The X-ray structure of the product has been elucidated and is discussed. Sulfathiazolato anions act as bridging ligands to give a dimeric species with a Cu···Cu distance of 2.7859(5) ?.      

X-ray Structure Analysis of 4–[(3,3–Dimethyloxiranyl)–methoxy]-7H-furo[3,2-g][1]benzopyran-7-one

The title compound, C₁₆H₁₄O₅, a furanocoumarin crystallizes in the triclinic space group P1 . The unit cell parameters are a = 7.852(2), b = 8.485(1), c = 11.095(1) Å; α = 105.90(1), β = 103.18(2), γ = 95.07(1)°. The structure has been solved by direct methods. Final R = 0.048 for 1943 observed reflections. The furanocoumarin system is almost planar. The epoxide ring makes a dihedral angle with the fused ring system of 98.21(11)°. Molecules are held together by C—H… O hydrogen bonds.     

A Novel Coordination Structure of Dichromates Bonding to Copper (II): [Cu(bipy)2(Cr2O7)] · 2 H2O

Dark-green multimetal compound crystal [Cu(bipy)₂(Cr₂O₇)]· 2 H₂O was obtained from aqueous solution of Cu(NO₃)₂, K₂Cr₂O₇ and bipyridine. The crystal structure was determined by X-ray crystallography: triclinic P1 , a = 7.716(3) Å, b = 9.656(3) Å, c = 15.517(5)Å, α = 77.41(3)°, β = 81.04(3)°, γ = 82.33(3)°, Z = 2. In this compound, two chromium atoms and a copper atom are linked by two oxo bridges (Cu(II) O Cr(VI) O Cr(VI)). The copper coordination polyhedron corresponds to a five-coordinated distorted trigonal bipyramid.     

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 and molecular structure of 2-(1-[alkyl,aryl)-2-acylhydrazino]-4,6-diaryloxy-1,3,5-triazine,C20H19Br2N5O3

The crystal and molecular structure of the title compound has been determined by X-ray diffraction techniques. It crystallizes in the monoclinic space group P 2₁/c with cell parameters a = 8.760 Å, b = 26.863 Å, c = 9.678 Å, and β = 106.03°. The structure was solved by the heavy atom method and refined by least-squares calculations to the conventional R value of 0.075.     

The Crystal and Molecular Structure of 1-Allyl-5-benzoyl-4-phenylpyrimidine-2-one hemihydrate

The crystal structure of C₂₀H₁₆N₂O₂. 0.5 H₂O has been determined from three dimensional X-ray diffraction data. The crystals are monoclinic, space group C 2/c, with a = 24.491(3) Å, b =10.241(2) Å, c = 16.643(2) Å, β =126.63(1)°, V = 3350.0(9) ų, D_calc = 1.290 g. cm⁻³, Z = 8. The structure was solved by direct methods and refined by least-squares methods to a final R = 0.0625 for 1358 observed unique reflections (F² ⩾ 2σ(F²)].