Structural properties of synthetic ionophore GL 2 E 4 diastereomers, 18-membered cyclic lactone tetraepoxides, by X-ray crystal analyses: possible relation between crystal structure and Ca2+-transportation ability. Addendum

1996 ◽  
Vol 52 (1) ◽  
pp. 215-215
Author(s):  
M. Doi ◽  
Y. In ◽  
T. Nishino ◽  
T. Ishida ◽  
M. Inoue ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Properties ◽  
International Union ◽  
Acta Cryst ◽  
X Ray ◽  
Structure Factors ◽  
Synthetic Ionophore ◽  
Anisotropic Displacement Parameters

Structure factors, anisotropic displacement parameters, H-atom coordinates and complete geometry for the paper by Doi, In Nishino, Ishida, Inoue, Shibuya, Ohashi, Narita & Kitagawa [Acta Cryst. (1995), B51, 1045–1050] have been deposited with the IUCr (Reference: AS0697). Copies may be obtained through The Mangaging Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England.

Li+/Na+ β-alumina: a combined single-crystal neutron and X-ray diffraction study. Erratum

1997 ◽  
Vol 53 (5) ◽  
pp. 849-849
Author(s):  
K. Edström ◽  
T. Gustafsson ◽  
J. O. Thomas ◽  
G. C. Farrington
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
International Union ◽  
Acta Cryst ◽  
X Ray ◽  
Structure Factors ◽  
Anisotropic Displacement Parameters ◽  
Atomic Coordinates

Lists of atomic coordinates, anisotropic displacement parameters and structure factors have been deposited with the IUCr (Reference: AB0365) for this article [Edström, Gustafsson, Thomas & Farrington, Acta Cryst. B53, 631–638]. Copies may be obtained through The Managing Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England.

Accurate unrestrained DDM refinement of crystal structures from highly distorted and low-resolution powder diffraction data

2016 ◽  
Vol 72 (5) ◽  
pp. 738-743 ◽  
Author(s):  
Leonid A. Solovyov
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
Acta Cryst ◽  
Functional Theory ◽  
Interatomic Distances ◽  
X Ray ◽  
Anisotropic Displacement Parameters ◽  
Xrpd Pattern

The structure of benzene:ethane co-crystal at 90 K is refined with anisotropic displacement parameters without geometric restraints from high-resolution synchrotron X-ray powder diffraction (XRPD) data using the derivative difference method (DDM) with properly chosen weighting schemes. The average C—C bond precision achieved is 0.005 Å and the H-atom positions in ethane are refined independently. A new DDM weighting scheme is introduced that compensates for big distortions of experimental data. The results are compared with density functional theory (DFT) calculations reported by Maynard-Caselyet al.[(2016).IUCrJ,3, 192–199] where a rigid-body Rietveld refinement was also applied to the same dataset due to severe distortions of the powder pattern attributable to experimental peculiarities. For the crystal structure of 2-aminopyridinium fumarate–fumaric acid formerly refined applying 77 geometric restraints by Donget al.[(2013).Acta Cryst.C69, 896–900], an unrestrained DDM refinement using the same XRPD pattern surprisingly gave two times narrower dispersion of interatomic distances.

scholarly journals Redetermination of Sr2PdO3 from single-crystal X-ray data

2019 ◽  
Vol 75 (1) ◽  
pp. 30-32
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Structure Type ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.

scholarly journals Redetermination of the crystal structure of RhPb2 from single-crystal X-ray diffraction data, revealing a rhodium deficiency

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Takashi Mochiku ◽  
Yoshitaka Matsushita ◽  
Nikola Subotić ◽  
Takanari Kashiwagi ◽  
Kazuo Kadowaki
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Type ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters ◽  
Slight Deficiency

RhPb2 (rhodium dilead) is a superconductor crystallizing in the CuAl2 structure type (space group I4/mcm). The Rh and Pb atoms are located at the 4a (site symmetry 422) and 8h (m.2m) sites, respectively. The crystal structure is composed of [RhPb8] antiprisms, which share their square faces along the c axis and the edges in the direction perpendicular to the c axis. We have succeeded in growing single crystals of RhPb2 and have re-determined the crystal structure on basis of single-crystal X-ray diffraction data. In comparison with the previous structure studies using powder X-ray diffraction data [Wallbaum (1943). Z. Metallkd. 35, 218–221; Havinga et al. (1972). J. Less-Common Met. 27, 169–186], the current structure analysis of RhPb2 leads to more precise unit-cell parameters and fractional coordinates, together with anisotropic displacement parameters for the two atoms. In addition and likewise different from the previous studies, we have found a slight deficiency of Rh in RhPb2, leading to a refined formula of Rh0.950 (9)Pb2.

scholarly journals Diosgenin hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o2357-o2357 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
Gabriel Guerrero-Luna ◽  
Anselmo A. Martínez-Gallegos
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Dimethyl Sulfoxide ◽  
Starting Material ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
X Ray ◽  
Hydroxy Groups ◽  
Hydrogen Bonded

Diosgenin [or (22R,25R)-spirost-5-en-3β-ol] is the starting material of the Marker degradation, a cheap semi-synthesis of progesterone, which has been designated as an International Historic Chemical Landmark. Thus far, a single X-ray structure for diosgenin is known, namely its dimethyl sulfoxide solvate [Zhanget al.(2005).Acta Cryst.E61, o2324–o2325]. We have now determined the structure of the hemihydrate, C27H42O3·0.5H2O. The asymmetric unit contains two diosgenin molecules, with quite similar conformations, and one water molecule. Hydroxy groups in steroids and water molecules form O—H...O hydrogen-bondedR54(10) ring motifs. Fused edge-sharingR(10) rings form a backbone oriented along [100], which aggregates the diosgenin molecules in the crystal structure.

Two Modifications of Hg5Re2O10

1995 ◽  
Vol 50 (9) ◽  
pp. 1335-1339 ◽  
Author(s):  
Marietta S. Schriewer-Pöttgen ◽  
Wolfgang Jeitschko
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Elemental Mercury ◽  
Oxidation States ◽  
X Ray ◽  
Structure Factors ◽  
Oxygen Atoms

AbstractThe previously reported mercury perrhenate Hg5Re2O10, prepared hydrothermally, has now been obtained by reaction of HgO with the mercury(II) metaperrhenate Hg(ReO4)2 in sealed silica tubes. A second modification of this compound can be obtained by reaction of elemental mercury with Hg(ReO 4)2 also in sealed silica tubes. Its crystal structure has been determined from single-crystal X-ray data: P21/c, a - 861.5(1), b = 1200.9(2), c = 1203.9(2) pm, β = 97.15(1)°, Z = 4, R = 0.024 for 1733 structure factors and 105 variables. Both modifications may be represented by the formula Hg2+-2Hg2O - 2ReO4-, indicating that mercury occurs in oxidation states I and II. In both modifications the mercury and some oxygen atoms form two-dimensionally infinte, puckered, cationic nets of the composition (Hg2+-2Hg2O)n , which are separated by the ReO4- tetrahedra. In the modification reported earlier the mercury oxygen nets consist of condensed 16-membered rings, while the nets of the present modification contain 10- and 22-membered rings.

scholarly journals `Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31

2015 ◽  
Vol 71 (7) ◽  
pp. 807-809 ◽  
Author(s):  
Wilhelm Klein ◽  
Hanpeng Jin ◽  
Viktor Hlukhyy ◽  
Thomas F. Fässler
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Original Structure ◽  
Site Symmetry ◽  
Structure Model ◽  
Reaction Route ◽  
X Ray ◽  
Anisotropic Displacement Parameters ◽  
Solid State Reaction Route ◽  
Atomic Coordinates

The crystal structure of the title compound was previously reported with composition `Pd20Sn13' [Sarahet al.(1981).Z. Metallkd,72, 517–520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtainedviaa solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3):0.62 (3). One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3aand 3b).

Preparation, Crystal Structure, and Properties of the Lanthanoid Carbides Ln4C7 with Ln = Ho, Er, Tm, and Lu

1996 ◽  
Vol 51 (5) ◽  
pp. 646-654 ◽  
Author(s):  
Ralf Czekalla ◽  
Wolfgang Jeitschko ◽  
Rolf-Dieter Hoffmann ◽  
Helmut Rabeneck
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Magnetic Ordering ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Neutron Powder Diffraction Data ◽  
Monoclinic Crystal Structure ◽  
Arc Melting ◽  
Structure Factors ◽  
Hydrolysis Of

The isotypic carbides Ln4C7 (Ln = Ho, Er, Tm, Lu) were prepared by arc-melting of the elemental components, followed by annealing at 1300 °C. The positions of the metal and of some carbon atoms of the monoclinic crystal structure of LU4C7 were determined from X-ray powder data, and the last carbon positions were found and refined from neutron powder diffraction data: P21/c, a = 360.4(1), b = 1351.4(3), c = 629.0(2) pm, β = 104.97(2)°, Z = 2, R = 0.026 for 429 structure factors and 15 positional parameters. The structure contains isolated carbon atoms with octahedral lutetium coordination and linear C3-units, with C-C bond lengths of 132(1) and 135(1) pm. This carbide may therefore be considered as derived from methane and propadiene. The hydrolysis of LU4C7 with distilled water yields mainly methane and propine, while the hydrolyses of the corresponding holmium and erbium carbides resulted in relatively large amounts of saturated and unsaturated C2-hydrocarbons in addition to the expected products methane and propine. The structure comprises two-dimensionally infinite NaCl-type building elements, which are separated by the C3-units. It may be described as a stacking variant of a previously reported structure of HO4C7, now designated as the a-modification. The Lu4C7-type β -modification was obtained at higher temperatures. Its structure was refined by the Rietveld method from X-ray powder data to a residual R = 0.037 for 320 F values and 15 positional parameters. Lu4C7 is Pauli paramagnetic; β -HO4C7 and Er4C7 show Curie-Weiss behavior with magnetic ordering temperatures of less than 20 K.

Structural Properties of a Dimeric Phenylcyanamidocopper(I) Complex, [{Cu(PPh3)2(C6H5NCN)}2]

2000 ◽  
Vol 53 (12) ◽  
pp. 971 ◽  
Author(s):  
Eric W. Ainscough ◽  
Andrew M. Brodie ◽  
Peter C. Healy ◽  
Joyce M. Waters
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Structural Properties ◽  
Structure Determination ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
X Ray ◽  
Angle Spinning

The X-ray crystal structure determination of bis[-(phenylcyanamido)bis(triphenylphosphine)copper(I)], [{Cu(PPh3)2(C6H5NCN)}2], (1) is reported. The complex has a centrosymmetric dimeric structure with the phenylcyanamide ligands bridging the copper atoms in a -1,3-fashion. The structure is compared with that of the 4-methylphenylcyanamido complex, [{Cu(PPh3)2(4-MeC6H4NCN)}2] (2), and the differences observed in the Cu–P bond lengths compared with changes in the solid state 31P cross-polarization magic-angle spinning (CPMAS) spectra of the two complexes.

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