Structure refinement of an FeCl3 crystal using a thin plate sample

1989 ◽  
Vol 22 (2) ◽  
pp. 173-180 ◽  
Author(s):  
S. Hashimoto ◽  
K. Forster ◽  
S. C. Moss
Keyword(s):  
Thin Plate ◽  
Structure Refinement ◽  
Reliability Factor ◽  
Space Group ◽  
Hexagonal Axis ◽  
Cl Atoms

Positional parameters (x, y, z) and anisotropic Debye–Waller factors B ⊥ (normal to the xy plane) and B|| (parallel to the xy plane) have been determined for the Fe and Cl atoms in FeCl3 within the space group R{\bar 3} with a = 6.065, c = 17.42 Å. These are (0, 0, 1/3), B Fe⊥ = 1.75 and B Fe|| = 1.2 Å2 for the Fe atoms at 6(c) positions in the hexagonal-axis representation, and (0.358, 0, 0.078), B Cl⊥ = 1.6 and B Cl|| = 1.55 Å2 for the Cl atoms at 18(f) positions. In addition to the crystallographic parameters, the observed twinning is discussed using the possible variants of ABC and ACB stacking sequences, each of which has two variants with a 60° rotation of the chlorine lattice. One of the four twin variants is found to be strongly enhanced. The fit for these parameters yields a reliability factor R = \sum_{i} \parallel F^{i}_{\rm cal} \mid - \mid F^{i}_{\rm obs}\parallel / \sum_{i} \mid F^{i}_{\rm obs} \mid = 0.60.

Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine, IV [1]. X-Ray Structure Analyses of Trimethylpentylammonium-chloride and (4-Acetoxybutyl) trimethylammonium-iodide

1986 ◽  
Vol 41 (5-6) ◽  
pp. 618-626
Author(s):  
Alfred Gieren ◽  
Michail Kokkinidis
Keyword(s):  
Structure Refinement ◽  
Pharmacological Action ◽  
Ammonium Nitrogen ◽  
Carbonyl Oxygen ◽  
Type B ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Structure Investigations ◽  
Automatic Diffractometer

The crystal structures of the title compounds which display cholinergic activity at the ganglionic receptor have been determined by X-ray structure analysis. [(CH3)3N+C5H11]Cl- (1) crystallizes in the orthorhombic space group Pbnm with half a formula unit per asymmetric unit, a = 11.381(14). b = 12.871(17), c = 7.316(4) Å. The intensities of 1106 independent reflections were collected with an automatic diffractometer. The structure refinement converged at R = 0.133 for the 355 observed reflections. The cation of 1 is disordered. [(CH3)3N + (CH2)4-O-C(O)-CH3]I- (2) crystallizes in the orthorhombic space group P212121 with four formula units per unit cell, a = 16.783(8), b = 10.276(6), c = 7.427(10) Å. The intensities of 1469 independent reflections were collected. The structure refinement converged at R = 0.071 for 1383 observed reflections. In both compounds the trimethylammonio methyl groups are coordinated nearly tetrahedrally by four anions in the first coordination sphere. Anions which occupy a special face type (B) of the tetrahedron of the (CH3)3N+ -CH2-group may be treated as a “model binding site” of the receptor. In the crystal structure of 2 the anions occupying B-type faces form together with the ammonium nitrogen and the carbonyl oxygen so called “Activity triangles”. The almost equal geometries of these activity triangles are correlated with the mode of pharmacological action.

Betaine arsenate, (CH3)3NCH2COO · D3AsO4: structure refinement using multiple-wavelength synchrotron radiation data

1997 ◽  
Vol 212 (9) ◽  
Author(s):  
S. Kek ◽  
M. Grotepaß-Deuter ◽  
K. Fischer ◽  
K. Eichhorn
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Room Temperature ◽  
Structure Refinement ◽  
Temperature Phase ◽  
Space Group ◽  
Radiation Data ◽  
Multiple Wavelength

AbstractThe crystal structure of deuterated betaine arsenate, (CHThe both paraelectric and ferroelastic room-temperature phase of betaine arsenate crystallizes in space group

Structures and Phase Transitions of the A 7PSe6 (A = Ag, Cu) Argyrodite-Type Ionic Conductors. I. Ag7PSe6

1998 ◽  
Vol 54 (4) ◽  
pp. 376-383 ◽  
Author(s):  
M. Evain ◽  
E. Gaudin ◽  
F. Boucher ◽  
V. Petricek ◽  
F. Taulelle
Keyword(s):  
Phase Transition ◽  
Atomic Displacement ◽  
Ionic Conductors ◽  
Reliability Factor ◽  
Conducting Phase ◽  
Cubic Symmetry ◽  
Space Group ◽  
Ionic Conducting ◽  
Jahn Teller ◽  
Diffusion Paths

The crystal structures of the two polymorphic forms of the argyrodite Ag7PSe6 compound are analysed by means of single-crystal X-ray diffraction. Above the phase transition at 453 K leading to the ionic conducting phase, γ-Ag7PSe6 crystallizes in cubic symmetry, space group F4¯3m, with a = 10.838 (3) Å, V = 1273.1 (12) Å3 and Z = 4 at 473 K. The refinement of the 473 K structure leads to a reliability factor of R = 0.0326 for 192 independent reflections and 33 variables. Diffusion paths for silver d 10 ions are evidenced by means of a combination of a Gram–Charlier development of the atomic displacement factors and a split model. Below the phase transition β-Ag7PSe6 crystallizes again in cubic symmetry, but with the space group P213 and a = 10.772 (2) Å, V = 1250.1 (6) Å3 and Z = 4 at room temperature. The refinement of the 293 K structure leads to a reliability factor of R = 0.0267 for 1125 independent reflections and 68 variables. In the β-Ag7PSe6 ordered phase the silver cations are found in various sites corresponding to the most pronounced probability density locations of the high-temperature diffusion paths. Those positions correspond to low coordination (2, 3 and 4) sites, in agreement with the silver preference for such environments. In addition, the Ag atoms are found slightly displaced from the true linear, triangular or tetrahedral coordination, as expected from second-order Jahn–Teller effects.

Protoenstatite: a crystal-structure refinement at 1100°C

1971 ◽  
Vol 134 (3-4) ◽  
Author(s):  
Joseph R. Smyth
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Single Crystal ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Intensity Data ◽  
Crystal Structure Refinement ◽  
Space Group

AbstractTechniques allowing single-crystal investigations on the precession camera up to the melting point of platinum have been developed. The crystal structure of protoenstatite has been refined from three-dimensional intensity data obtained at 1100°C using a crystal of enstatite from the Norton County, Kansas meteorite. The space group is

The crystal structure of caratiite

1984 ◽  
Vol 48 (349) ◽  
pp. 541-546 ◽  
Author(s):  
Herta Effenberger ◽  
Josef Zemann
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Data ◽  
Space Group ◽  
Atomic Arrangement ◽  
Cl Atoms

AbstractThe crystal structure of caratiite, K4Cu4O2 (SO4)4MeCl (a 13.60(2), c 4.98(1) Å, Z = 2) was solved in space group I4 from single crystal data, and refined to R = 0.035 for 654Fo > 6σ(Fo). The atomic arrangement is characterized by Cu2O(SO4)2 chains parallel to [001], with Cu in (4 + 1) co-ordination and O surrounded tetrahedrally by four Cu atoms. These chains are interconnected by K atoms to a framework, the channels of which house the Me and Cl atoms. The nature of the Me atoms is not completely clear; most probably the position is half occupied by Cu, fully occupied by Na, or occupied by a mixture of the two.

Zur Darstellung und Struktur des 1.3-Dichloro-5-N.N-dimethylamino-1.3-dithia-2.4.6-triazins / Synthesis and Structure of 1,3-Dichloro-5-N,N-dimethylamino-1,3-dithia-2,4,6-triazine

1983 ◽  
Vol 38 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Herbert W. Roesky ◽  
Pierre Schäfer ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick
Keyword(s):  
Structure Analysis ◽  
Nmr Spectra ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cl Atoms ◽  
C Nmr

Abstract The six membered ring of composition (CH3)2NCN3S2Cl2 3 a was prepared from N,N-dimethylguanidinhydrochloride and trithiadiazindichloride. 3 a was characterized on the basis of mass, 1H, 13C NMR spectra and X-ray structure analysis. Crystals of 3 a are monoclinic, space group P21/c, with a = 660.3(6), b = 834.5(7), c = 1774.7(15) pm, β = 112.83(6)° and Z = 4. The C2N unit lies approximately in the plane of the [-CNSNSN-] ring, with both Cl atoms on the same side of the ring.

Synthesen, Kristallstrukturen und magnetische Eigenschaften von [Li(12-Krone-4)2][Li(12-Krone-4)(OH2)]2[Nb6Cl18], [Li(15-Krone-5)2(OH2)]3[Nb6Cl18] und [(18-Krone-6)2(O2H5)]3[Nb6Cl18] / Syntheses, Crystal Structures and Magnetic Behaviour of [Li(12-Krone-4)2][Li(12-Krone-4)(OH2)]2[Nb6Cl18], [Li(15-Krone-5)2(OH2)]3[Nb6Cl18] and [(18-Krone-6)2(O2H5)]3[Nb6Cl18]

2001 ◽  
Vol 56 (10) ◽  
pp. 1025-1034 ◽  
Author(s):  
Markus Ströbele ◽  
H.-Jtirgen Meyer
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Crown Ethers ◽  
Magnetic Measurements ◽  
Structure Refinement ◽  
Magnetic Behaviour ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Paramagnetic Behaviour

The title compounds were prepared through reactions of Li2Nb6Cl16 with the corresponding crown ethers in acetone. All three compounds were obtained as dark brown crystals. Their structures were solved with the means of single-crystal X-ray diffraction.[Li(12-crown-4)2][Li(12-crown-4)(OH2)]2[Nb6Cl18]: space group P21/n, Z =2, a = 1320.4(1), b = 1879.1(1), c = 1321.7(1) pm, ß = 92.515(6)°, R1 = 0.0297 (I>2σ(I)). The crystal structure contains Li+ sandwiched by two 12-crown-4-ethers plus Li+ coordinated by one 12-crown-4- ether and one water molecule.[Li(15-crown-5)2(OH2)]3[Nb6Cl18]: space group R3̅, Z = 3, a = b = 2081.7(1), c = 1991.7(1) pm, R1 = 0.0395 (I > 2σ(I)). In the crystal structure Li+ and one water molecule are sandwiched by two 15-crown-5-ethers.[(18-crown-6)2(O2H5)]3[Nb6Cl18]: space group P1̅, Z = 1 ,a = 1405.1(1), b = 1461.1(2), c = 1492.2(2) pm; α = 98.80(1)°, ß = 98.15(1)°, γ = 97.41(1)°, R1 = 0.0538 (I > 2σ(I)). H5O2+ was found in the structure refinement sandwiched between two 18-crown-6-ethers.All compounds reported contain [Nb6Cl18] clusters with Nb-Nb distances between 299 and 301 pm. The paramagnetic behaviour expected for [Nb6Cl18]3- in all three compounds was confirmed by magnetic measurements.

scholarly journals Die Kristallstruktur des Silbertetrachloroaurats(III) AgAuCl4 und seine kristallchemische Verwandtschaft zum Rubidiumtetrachloroaurat(III) RbAuCl4 / The Crystal Structure of Silver Tetrachloroaurate(III) AgAuCl4 and its Crystal Chemical Relationship to the Rubidium Tetrachloroaurate(III) RbAuCl4

1977 ◽  
Vol 32 (7) ◽  
pp. 741-744 ◽  
Author(s):  
Walther Werner ◽  
Joachim Strähle
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Octahedral Coordination ◽  
Monoclinic Space Group ◽  
Crystal Chemical ◽  
Space Group ◽  
Square Planar ◽  
Cl Atoms

AgAuCl4 crystallizes in the monoclinic space group I2/c with Zi = 4. The crystal structure is built up by Ag+ cations and square planar AuCl4⁻ anions with Au-Cl bond length of 228 pm. The Ag+ ions have an octahedral coordination of Cl atoms. AgAuCl4 is topologically related to RbAuCl4.

Notizen: Molekül- und Kristallstruktur des 2,4-Bis(diisopropylamino)-3-phenyl-1,3,2,4-thiazadiboretidins / Crystal and Molecular Structure of 2,4-Bis(diisopropylamino)-3-phenyl-1,3,2,4-thiazadiboretidine

1989 ◽  
Vol 44 (7) ◽  
pp. 853-856 ◽  
Author(s):  
Carl D. Habben ◽  
Mathias Noltemeyer
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Structure Refinement ◽  
Space Group ◽  
X Ray ◽  
Compound C

The title compound, C18H33B2N3S, isolated from the reaction of 3,5-bis(diisopropylamino)-1,2,4,3,5-dithiazadiborolidine with elemental sodium, crystallizes in space group P1̅ with cell constants a = 1034.3(6), b = 1230.4(8), c = 1728.5(12) pm, α = 97.50(6), β = 97.95(5), γ = 90.17(5)° and Z = 4. X-ray structure refinement converged at R = 0.087, wR = 0.085, w-1 = σ2(F0) + 0.004 Fo2. The fourmcmbered ring B2NS is planar, the angle B—S—B being 70°.

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.

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