Crystal structure of dimethylgold(III) 8-hydroxyquinolinate and 8-mercaptoquinolinate

A crystal-chemical study of dimethylgold(III) complexes with 8-hydroxyquinoline (CH₃)₂Au(OR) and 8-mercaptoquinoline (CH₃)₂Au(SR) (R = C₉H₆N) was performed. Crystal data for (CH₃)₂Au(OR): a = 8.7133(17) Å, b = 27.875(6) Å, c = 8.6688(17) Å, β = 102.76(3)°, Z = 8, ρ(calc) = 2.401 g/cm³, space group P2₁/c, R = 0.0909; for (CH₃)₂Au(SR): a = 3.5401(7) Å, b = 15.689(3) Å, c = 19.910(4) Å, β = 99.81(3)°, Z = 4, ρ(calc) = 2.361 g/cm³, space group P2₁/c, R = 0.0712. Both structures are molecular and involve neutral (CH₃)₂Au(L) molecules, L = C₉H₆NO or C₉H₆NS. In the structures, the molecules are arranged in stacks joined by van der Waals interactions. The average Au…Au intrastack distances are 3.57 Å and 4.34 Å for (CH₃)₂Au(OR) and 3.5 Å for (CH₃)₂Au(SR).     

A restudy of the crystal structure of tetraaquastrontium dicitratoborate trihydrate

The crystal structure of Sr(H₂O)₄[(C₁₂H₁₁O₁₄)B] · 3H₂O (I) has been restudied and determined with a higher accuracy. The crystals are monoclinic, space group P2₁/n, a = 11.405(1) Å, b = 18.814(1) Å, c = 11.987(1) Å, β = 110.79(1)°; Z = 4. The structure was refined by full matrix least-squares calculation to R = 0.0547 on 5343 unique reflections with R _int = 0.0419. The structural units of crystal I are the Sr²⁺ cation, seven water molecules, and doubly charged dicitratoborate anion, which is not equivalent to the singly charged complex dicitratoborate anion identified previously in the crystal structures of complexes of boric and citric acids. The coordination polyhedron of the Sr²⁺ cation is a distorted dodecahedron composed of four O atoms of coordinated water molecules and four O atoms of two complex anions. The crystal packing of I is layered. Thirteen independent O-H…O and O-H…, O′ contacts form an intricate system of hydrogen bonds.     

Synthesis and crystal structure of lithium 8-hydroxyquinoline-5-sulfonate tetrahydrate

A lithium salt of 8-hydroxyquinoline-5-sulfonic acid, Li₂(C₉H₅NO₄S)·4H₂O, has been synthesized and characterized by X-ray diffraction techniques. The salt is monoclinic, space group P2₁/c, with a?=?10.323(3), b?=?10.088(9), c?=?11.792(6)?Å and β?=?92.21(3)°. Li ions adopt two different distorted tetrahedral geometries. Li(1) is surrounded by a water molecule, N,O atoms of the oxine ring and one of the oxygen atoms of the sulphonate group. Li(2) is surrounded by three water molecules and an oxygen atom of the sulphonate group. The two lithium ions are bridged by a water molecule, leading to a polymeric network.     

Synthesis and crystal structure of dibenzo-18-crown-6 oxonium perchlorate trihydrate

A hydrated crystalline ionized adduct of dibenzo-18-crown-6 and perchloric acid DB18C6 · H₃O⁺ · CiO ₄ ^? · 3H₂O (I) is synthesized and characterized by X-ray diffraction. The crystals of I are monoclinic: a = 17.760 Å, b = 12.922 Å, β = 124.27°, Z = 4, space group Cc. The structure of I is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.079 for 3294 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). A DB18C6 molecule has a butterfly conformation with the rough symmetry C _2v . An H₃O⁺ · H₂O dimer is situated on one side of the DB18C6 macrocycle, and the ClO ₄ ^? anion and two other water molecules are on the other side. In the crystal of I, the DB18C6 molecules, H₃O⁺ and ClO ₄ ^? ions, and water molecules are linked through intermolecular (interionic) hydrogen bonds to form broad infinite chains running along the z axis.     

The crystal structure of U5Re3C8

U₅Re₃C₈ crystallizes tetragonal in space group P4/mbm with the lattice constantsa=1 131.3(1) pm,c=330.29(7) pm,V=0.4227 nm³ andZ=2 formula units per cell. The structure was determined from single-crystal counter-data and refined to a residual ofR=0.032 for 649 structure factors and 24 variable parameters. It is of a new type with carbon atoms on three different sites with approximately octahedral environment of five uranium and one rhenium or four uranium and two rhenium atoms. The positions of the metal atoms correspond to those of a (slightly distorted) cubic body centered structure as is also found for Ho₂Cr₂C₃, UCr₄C₄, UMoC₂, YCoC, and U₂IrC₂.     

Thermal properties of dimethylgold(III) 8-hydroxyquinolinate and 8-mercaptoquinolinate

Dimethylgold(III) complexes with 8-hydroxyquinoline Me₂Au(Ox) (I) and 8-mercaptoquinoline Me₂Au(Tox) (II) were synthesized and studied. Complex II obtained for the first time was identified from the elemental analysis, IR, ¹H NMR, and mass spectrometry data. The thermal properties of complexes I, II in condensed state were investigated by thermography. The temperature dependences of the saturated vapor pressure over crystals were measured by the Knudsen effusion method with mass spectrometric recording of the gas phase composition and the thermodynamic characteristics of the sublimation process were determined: for I, log P[Torr] = (14.6 ± 0.3) ? (6.34 ± 0.10) × 10³/(T, K), Δ H _subl ^o = 121.2 ± 1.9 kJ^?1, Δ S _subl ^o = 224.1 ± 4.6 J mol^?1 K^?1 (the temperature interval under study 80–115°C); for II, log P [Torr] = (13.3 ± 0.2) ? (6.30 ± 0.09) × 10³/(T, K), Δ H _subl ^o = 120.5 ± 1.7 kJmol^?1, ΔS _subl ^o = 199.3 ± 3.0 J mol^?1 K^?1 (86–145°C).     

Synthesis and crystal structure of sodium borosilicide, Na8B74.5Si17.5

Ternary sodium borosilicide, Na(8)B(74.5)Si(17.5), was newly synthesized by heating a mixture of sodium, silicon and amorphous or crystalline boron at 1073-1273 K. The crystal structure of the black hexagonal prismatic single crystal obtained at 1273 K was analyzed. The X-ray diffraction reflections of the crystal were indexed with hexagonal cell parameters a = 10.2392(3) ? and c = 10.9215(4) ? (space group P6(3)/mmc, No. 194). The structural formula could be represented as Na(8)(B(12))(6)Si(16)[BSi](1.5)[B(2)](0.5). B(12) icosahedra form a three-dimensional framework having small triangular and large hexagonal channels along the c axis. Chains of [-Si-(Si-Si)(3)-Si-] surrounded by Na atoms are located in the large channels. Trigonal prism cages for Na atoms and for atom pairs of Si-B or B-B are alternately arrayed in the small channels. The ratio of Si-B and B-B pairs in the cage is around 3:1.     

Molecular and crystal structure of tetrahydroneosophoramine

The structure of tetrahydroneosophoramine has been studied by x-ray structural analysis. Rings A, B, and C have the chair conformation, and ring D the half-chair conformation. On the basis of a semiquantitative analysis it has been shown that the strains in the molecules of tetrahydroneosophoramine and of matrine are of the same order of magnitude.     

Molecular and crystal structure of tert-butylphosphaethyne

The crystal and molecular structure of tert-butylphosphaethyne, Bu^tCP, liquid at room temperature, has been determined by X-ray diffraction at 108 K. Main geometrical parameters are as follows: PC 1.542(2), C(sp)–C(sp³) 1.470(3) Å, PCC 179.3(2)°.     

Molecular and crystal structure of luteidine

The crystal structure of luteidine has been deciphered by x-ray structural analysis; there are two molecules in the independent part of its elementary cell. These symmetrically independent molecules differ in structure. The position of the olefinic methoxy group of luteidine has been established. Its structure has been determined as 1-hydroxy-2,12-dimethoxy-9,10-dihydrohomoaporphine.Institute of Biorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent, and V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 348–352, May–June, 1986.     

Molecular and crystal structure of sophoridine

The three-dimensional structure of the alkaloid sophoridine C₁₅H₂₄ON₂ has been studied by x-ray structural analysis; the parameters of the elementary cell are: a=5.458, b=10.640, c=11.989 Å; =99.7°; z=2; space group P2₂. The experimental set was obtained on a Sinteks-P2₁ diffractometer, the structure being determined by the direct method with refinement by the method of least squares in the anisotropic approximation taking the hydrogen atoms into account to R=0.059. Ring A has the chair conformation, rings B and C the boat conformation, and ring D the half-chair conformation. The linkages of rings A/B, B/C, and C/D are trans, and of B/C cis. There are no shortened intermolecular contacts in the crystal structure of the compound.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Crystallography, Academy of Sciences of the USSR, Moscow. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 355–362, May–June, 1979.