Strukturverfeinerung von Kalium - periodat bei 297 und 150 K/Structure Refinement of Potassium Periodate at 297 and 150 K

1996 ◽  
Vol 51 (3) ◽  
pp. 444-446 ◽  
Author(s):  
Danita de Waal ◽  
Klaus-Jürgen Range
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Structural Parameters ◽  
Structure Refinement ◽  
Potassium Periodate ◽  
Space Group ◽  
X Ray ◽  
Two Temperatures

Abstract The scheelitetype structure of potassium perio­date, KIO4, has been confirmed and refined from single-crystal X-ray data at two temperatures. The compound crystallizes tetragonally, space group I41/a, with a = 5.726(1), c = 12.607(4) Å at 297(1) K, and a = 5.704(3), c = 12.478(8) Å at 150(1) K, respectively. Except for a significant decrease in the anisotropic displacement factors, the changes in the structural parameters at low temperature are rather small.

Structure Refinement of Rubidium Periodate at 297 and 150 K

1996 ◽  
Vol 51 (9) ◽  
pp. 1365-1367 ◽  
Author(s):  
Danita de Waal ◽  
Klaus-Jürgen Range
Keyword(s):  
Single Crystal ◽  
Low Temperatures ◽  
Structural Parameters ◽  
Structure Refinement ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Two Temperatures

The scheelite-type structure of rubidium periodate, RbIO4, has been confirmed and refined from single-crystal X-ray data at two temperatures. The compound crystallizes tetragonally, space group I41/a, with a = 5.897(1), c = 12.876(3) Å at 150 K and a = 5.910(1), c = 13.021(3) Å at 297 K, respectively. Only small changes are observed for the structural parameters at low temperatures, but a significant decrease could be observed in the anisotropic displacement factors.

Strukturverfeinerung von Rubidiumperrhenat bei 297 und 159 K / Structure Refinement of Rubidium Perrhenate at 297 and 159 K

1993 ◽  
Vol 48 (2) ◽  
pp. 233-234 ◽  
Author(s):  
Peter Rögner ◽  
Klaus-Jürgen Range
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Structure Refinement ◽  
Type Structure ◽  
Space Group ◽  
X Ray

AbstractThe scheelite-type structure of rubidium perrhenate, RbReO4, has been confirmed and refined from single-crystal X-ray data at two tempera­tures. The compound crystallizes tetragonally, space group I41/a,with a = 5,8401(5), c = 13,265(2) Å at 297(1) K, and a = 5,8289(7), c = 13,109(2) Å at 159(3) K, respectively. Except for a significant decrease in the anisotropic displace­ment factors, the changes in the structural para­meters at low temperature are rather small.

Aragonite-type lanthanum orthoborate, LaBO3

2006 ◽  
Vol 62 (4) ◽  
pp. i103-i105 ◽  
Author(s):  
Akihiko Nakatsuka ◽  
Osamu Ohtaka ◽  
Hiroshi Arima ◽  
Noriaki Nakayama ◽  
Tadato Mizota
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Single Crystal ◽  
General Position ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Thermal Vibrations

The crystal structure of the low-temperature (LT) modification of LaBO3 has been redetermined from single-crystal X-ray data; the resulting structure confirms the previous study [Abdullaev, Dzhafarov & Mamedov (1976). Azerbaidzhanskii Khim. Zh. pp. 117–120], but with improved precision. LT-LaBO3 crystallizes in space group Pnma and adopts the aragonite-type structure. Except for one O atom, which is situated on a general position, all other atoms (one La, one B and a second O atom) lie on mirror planes. The structure is composed of LaO9 polyhedra with an average La—O distance of 2.593 Å and trigonal BO3 groups with an average B—O distance of 1.373 Å. Slight anisotropies of the thermal vibrations of La and B atoms suggest that the electrostatic La...La and La...B interactions across the shared edges are weak.

Die Synthese und Struktur von Clusteraziden: A4[Nb6Cl12(N3)6](H2O)2 mit A=Rb. Cs / Synthesis and Structure of the Cluster Azides: A4Nb6Cl12(N3)6](H2O)2 with A=Rb, Cs

1995 ◽  
Vol 50 (9) ◽  
pp. 1377-1381 ◽  
Author(s):  
Olaf Reckeweg ◽  
H.-Jürgen Meyer
Keyword(s):  
Single Crystal ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Crystal Data ◽  
Mechanical Pressure ◽  
Space Group ◽  
X Ray ◽  
Methanolic Solution ◽  
New Compounds

AbstractThe new compounds A4[Nb6Cl12(N3)6](H2O)2 (A = Rb, Cs) were synthesized from In4[Nb6Cl12Cl6] by substituting six terminal Cl ligands and the In+ ions in methanolic solution. An X-ray structure refinement was performed on single-crystal data of Rb4[Nb6Cl12(N3)6](H2O)2 (1) (space group P1̄, Z = 1, a = 912.5(1) pm, b = 937.2(1) pm, c = 1062.0(1) pm, α = 96.88(2)°, β = 101.89(1)°, γ = 101.44(2)°) and Cs4[Nb6Cl12(N3)6](H2O)2 (2) (space group PI, Z = 1, a = 920.9(5) pm, b = 947.9(7) pm, c = 1091.8(7) pm, α = 96.89(6)°, β = 103.35(5)°, γ = 101.60(5)°. Each of the centrosymmetric [Nb6Cl12(N3)6]4- ions of the isotypic compounds contains six terminal azide groups at the corners of the octahedral niobium cluster (d̄Nb-N = 226(1) pm (1), 225(1) pm (2), bond angles Nb-N-N 120-127°). The [Nb6Cl12(N3)6]4- ions are linked via Rb-N and Rb-Cl interactions of the Rb+ ions to form a three-dimensional structure. Crystals of the compounds react explosively on heating or mechanical pressure.

scholarly journals Crystal structure and XANES investigation of petzite, Ag3AuTe2

2019 ◽  
Vol 75 (2) ◽  
pp. 273-278
Author(s):  
Hidetomo Hongu ◽  
Akira Yoshiasa ◽  
Massimo Nespolo ◽  
Tsubasa Tobase ◽  
Makoto Tokuda ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Chemical Bonding ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Absolute Structure ◽  
Golden Mile

Petzite, Ag3AuTe2, crystallizes in the space group I4132, which is a Sohncke type of space group where chiral crystal structures can occur. The structure refinement of petzite reported long ago [Frueh (1959). Am. Mineral. 44, 693–701] did not provide any information about the absolute structure. A new single-crystal X-ray diffraction refinement has now been performed on a sample from Lake View Mine, Golden Mile, Kalgoorlie, Australia, which has resulted in a reliable absolute structure [a Flack parameter of 0.05 (3)], although this corresponds to the opposite enantiomorph reported previously. The minimum Te–Te distance is 3.767 (3) Å, slightly shorter than the van der Waals bonding distance, which suggests a weak interaction between the two chalcogens. XANES spectra near the Au and Te L III edges suggest that the chemical-bonding character of Au in petzite is more metallic than in other gold minerals.

Crystal data of the low-temperature solid form of 2-methyl-2-nitro-propanol(MNP)

1994 ◽  
Vol 9 (2) ◽  
pp. 84-86 ◽  
Author(s):  
J. Ll. Tamarit ◽  
N. B. Chanh ◽  
P. Négrier ◽  
D. O. López ◽  
M. Barrio ◽  
...  
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Solid Form

By means of X-ray single crystal Weissenberg photographs, the crystal of the low-temperature solid form of 2-methyl-2-nitro-propanol, (CH3)2C(NO2)(CH2OH), has been determined and found to be of the monoclinic type, space group P21/c. The cell constants were refined from X-ray powder diffraction data: a=6.195(3) Å, b=19.116(7) Å, c=16.598(7) Å, and β = 90.12(2)° with Z = 12. The indexed pattern at 293 K is given.

Space-Group Determination of the Orthorhombic Form of NaV6O11

1995 ◽  
Vol 28 (5) ◽  
pp. 599-603 ◽  
Author(s):  
Y. Kanke ◽  
H. Shigematsu ◽  
K. Ohshima ◽  
K. Kato
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Single Crystal ◽  
Diffraction Study ◽  
Structural Phase ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
Space Group ◽  
X Ray

The unit cell and space group of orthorhombic NaV6O11 (low-temperature form) are found by an X-ray single-crystal diffraction study at 300 K (hexagonal, P63/mmc), 100 K (hexagonal, P63 mc) and 20 K (orthorhombic). The orthorhombic form (o) shows no superstructure and its unit cell is related to the hexagonal one (h): a o ≃ a h + b h , a o ≃ −a h + b h and c o ≃ c h . Bijvoet-pair examination confirms that it crystallizes in the noncentrosymmetric space group Cmc21. The hexagonal (P63 mc)-orthorhombic (Cmc21) structural phase transition is proved to be of second order.

scholarly journals Zirconium tetrachloride revisited

2018 ◽  
Vol 74 (3) ◽  
pp. 307-311
Author(s):  
Rosendo Borjas Nevarez ◽  
Samundeeswari Mariappan Balasekaran ◽  
Eunja Kim ◽  
Philippe Weck ◽  
Frederic Poineau
Keyword(s):  
Phase Transformation ◽  
Single Crystal ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Zirconium Tetrachloride ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Temperature Range ◽  
Crystallographic Study

Zirconium tetrachloride, ZrCl4, is a strategic material with wide-ranging applications. Until now, only one crystallographic study on ZrCl4has been reported [Krebs (1970).Z. Anorg. Allg. Chem.378, 263–272] and that was more than 40 years ago. The compound used for the previous determination was prepared from ZrO2and Cl2–CCl4, and single-crystal X-ray diffraction (SCXRD) studies on ZrCl4obtained from Zr metal have not yet been reported. In this context, we prepared ZrCl4from the reaction of Zr metal and Cl2gas in a sealed tube and investigated its structure at 100, 150, 200, 250, and 300 K. At 300 K, the SCXRD analysis indicates that ZrCl4crystallizes in the orthorhombic space groupPca21[a= 6.262 (9),b= 7.402 (11),c= 12.039 (17) Å, andV= 558.0 (14) Å3] and consists of infinite zigzag chains of edge-sharing ZrCl6octahedra. This chain motif is similar to that observed previously in ZrCl4, but the structural parameters and space group differ. In the temperature range 100–300 K, no phase transformation was identified, while elongation of intra-chain Zr...Zr [3.950 (1) Å at 100 K and 3.968 (5) Å at 300 K] and inter-chain Cl...Cl [3.630 (3) Å at 100 K and 3.687 (9) Å at 300 K] distances occurred.

scholarly journals Use of a miniature diamond-anvil cell in a joint X-ray and neutron high-pressure study on copper sulfate pentahydrate

IUCrJ ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Giulia Novelli ◽  
Konstantin V. Kamenev ◽  
Helen E. Maynard-Casely ◽  
Simon Parsons ◽  
Garry J. McIntyre
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Diamond Anvil Cell ◽  
Structural Parameters ◽  
Structure Refinement ◽  
Neutron Data ◽  
X Ray ◽  
Sulfate Pentahydrate ◽  
Diamond Anvil

Single-crystal X-ray and neutron diffraction data are usually collected using separate samples. This is a disadvantage when the sample is studied at high pressure because it is very difficult to achieve exactly the same pressure in two separate experiments, especially if the neutron data are collected using Laue methods where precise absolute values of the unit-cell dimensions cannot be measured to check how close the pressures are. In this study, diffraction data have been collected under the same conditions on the same sample of copper(II) sulfate pentahydrate, using a conventional laboratory diffractometer and source for the X-ray measurements and the Koala single-crystal Laue diffractometer at the ANSTO facility for the neutron measurements. The sample, of dimensions 0.40 × 0.22 × 0.20 mm3 and held at a pressure of 0.71 GPa, was contained in a miniature Merrill–Bassett diamond-anvil cell. The highly penetrating diffracted neutron beams passing through the metal body of the miniature cell as well as through the diamonds yielded data suitable for structure refinement, and compensated for the low completeness of the X-ray measurements, which was only 24% on account of the triclinic symmetry of the sample and the shading of reciprocal space by the cell. The two data-sets were combined in a single `XN' structure refinement in which all atoms, including H atoms, were refined with anisotropic displacement parameters. The precision of the structural parameters was improved by a factor of up to 50% in the XN refinement compared with refinements using the X-ray or neutron data separately.

Adiponitrile at 100 K

2017 ◽  
Vol 73 (11) ◽  
pp. 937-940 ◽  
Author(s):  
Rüdiger W. Seidel ◽  
Richard Goddard ◽  
Nils Nöthling ◽  
Christian W. Lehmann
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Low Temperature ◽  
Single Crystal ◽  
Large Scale ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Intermolecular Contacts

Adiponitrile, C6H8N2, is a key intermediate in the synthesis of the polyamide Nylon 66 and is produced industrially on a large scale. We have determined the crystal and molecular structure of adiponitrile by single-crystal X-ray analysis at 100 K, a suitable crystal (m.p. 275 K) having been grown from the melt at low temperature. The compound crystallizes in the monoclinic space group P21/c with Z = 2. In the crystal structure, the molecule adopts an exact C i-symmetric gauche–anti–gauche conformation of the C—C—C—C skeleton about an inversion centre. The molecules are densely packed, with short intermolecular contacts between the α-H and nitrile N atoms.

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