Reaktionen von Re2O7 mit Iminophosphoranen - Kristallstruktur von ( O3ReN = PPh2)2C2H4/Reactions of Re2O7 with Iminophosphoranes - Crystal Structure of (O3ReN = PPh2)2C2H4

1990 ◽  
Vol 45 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Herbert W. Roesky ◽  
Detlev Hesse ◽  
Mathias Rietzel ◽  
Mathias Noltemeyer
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractRe2O7 reacts with (Me3SiN = PPh2)2CH2, (Me3SiN = PPh2)2C2H4 and Me3SiN = PPh3 to give (O3ReN = PPh2)2CH2 (3), (O3ReN = PPh2)2C2H4 (6) and Ph3P= NReO3 (7). 6 has been characterizedby X-ray crystallography. The complex crystallizes in the space group P 1̄ with unit cell dimensions a = 837.4(4), b = 873.0(5), c = 1102.5(6) pm, ɑ = 112.53(4), β = 98.54(4), γ = 100.59(4)°, and Z = 1. The structure demonstrates that the bis(diphenylphosphinimino)-ethane group is bridging two ReO3 units.

Crystal structure of Al5O3N3 (15R)

2017 ◽  
Vol 32 (S1) ◽  
pp. S2-S5 ◽  
Author(s):  
Jacek Podwórny ◽  
Alicja Pawełek ◽  
Jerzy Czechowski
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Structural Model ◽  
Stoichiometric Composition ◽  
Unit Cell ◽  
Second Phase ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Having synthesised an AlON-bonded ceramic corundum material, Al5O3N3 (15R) polytype coexisting with α-Al2O3 was identified. The sample was prepared from an alumina-rich mixture of Al2O3 and AlN substrates and fired at 1650 °C in a nitrogen atmosphere. Using the X-ray external standard quantitative method, one of the reaction products, α-Al2O3, was quantified. From the remaining substrates the stoichiometric composition of the second phase was calculated. The applied method of crystal structure determination consisted of three stages. In the first stage, the Le Bail method of X-ray pattern decomposition was used for the extraction of Al5O3N3 (15R) diffraction lines from a two-phase diffractogram. The space group and unit-cell dimensions from the isostructural SiAl4O2N4 SiAlON phase, producing the same X-ray pattern, were used as input data. Next, the direct structure determination in real space was applied for initial structural model derivation, which was followed by Rietveld refinement. The solved crystal structure of Al5O3N3 (15R), except the stacking sequence, proved to be closely related to the structure of Al7O3N5 (21R) polytype. The Al5O3N3 (15R) is trigonal with space group R-3m, unit-cell dimensions a0 = 3.0128 Å, c0 = 41.8544 Å, and volume V = 329.00 Å3. The model of Al5O3N3 (15R) polytype structure has positional disordering in one of three (6c) Al sites, which leads to stacking faults in six tetrahedral layers. Every third tetrahedron from LR3 and LR4, LR8 and LR9, LR13 and LR14 layers is rotated by 180°.

Synthesis and crystal structure of Na3.5Cr1.5Co0.5(PO4)3 phosphate

2006 ◽  
Vol 21 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Mohamed Chakir ◽  
Abdelaziz El Jazouli ◽  
Jean-Pierre Chaminade
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Hexagonal Unit Cell ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

A new Nasicon phosphates series [Na3+xCr2−xCox(PO4)3(0⩽x⩽1)] was synthesized by a coprecipitation method and structurally characterized by powder X-ray diffraction. The selected compound Na3.5Cr1.5Co0.5(PO4)3 (x=0.5) crystallizes in the R3c space group with the following hexagonal unit-cell dimensions: ah=8.7285(3) Å, ch=21.580(2) Å, V=1423.8(1) Å3, and Z=6. This three-dimensional framework is built of PO4 tetrahedra and Cr∕CoO6 octahedra sharing corners. Na atoms occupy totally M(1) sites and partially M(2) sites.

X-Ray Crystal Structure of [Rh(OH2)6](ClO4)3.3H2O

1989 ◽  
Vol 42 (11) ◽  
pp. 2051 ◽  
Author(s):  
GD Fallon ◽  
L Spiccia
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Octahedral Sites ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal structure of [Rh(OH2)6](ClO4)3.3H2O has been determined by single-crystal X-ray diffraction and found to be isomorphous with that of M(ClO4)2.6H2O (M= Fe, Zn, Mn, Co, Ni) and LiClO4.3H2O. Crystal: are hexagonal, space group P63mc with unit cell dimensions a 7.817(2) and c 5.208(1) �. The lattice consists of a uniform arrangement of H2O and ClO4- groups with the RhIII centre occupying 1/3 of the octahedral sites formed by the H2O groups. The RhIII is not situated at the centre of the octahedron. However, the two Rh-O distances [2.128(6) and 2.136(6) �] may be considered identical, i.e. within the errors.

Crystal data and X-ray powder diffraction data of 2,4-diiodo-4-nitrophenol (disophenol), C6H3I2NO3. More precise X-ray powder diffraction data of p-nitrophenol, C6H5NO3

1996 ◽  
Vol 11 (4) ◽  
pp. 301-304
Author(s):  
Héctor Novoa de Armas ◽  
Rolando González Hernández ◽  
José Antonio Henao Martínez ◽  
Ramón Poméz Hernández
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Monoclinic Cell

p-nitrophenol, C6H5NO3, and disophenol, C6H3I2NO3, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for p-nitrophenol was a=6.159(2) Å, b=8.890(2) Å, c=11.770(2) Å, β=103.04(2)°, Z=4, space group P21 or P2l/m, Dx=1.469 Mg/m3. The monoclinic cell found for disophenol has the dimensions a=8.886(1) Å, b=14.088(2) Å, c=8.521(1) Å, β=91.11(1)°, Z=4, space group P2, P2, Pm or P2/m, Dx=2.438 Mg/m3.

Crystallization and preliminary X-ray crystallographic analysis of the Pseudomonas aeruginosa cyclohexadienyl dehydratase

1999 ◽  
Vol 55 (2) ◽  
pp. 539-541
Author(s):  
Palangpon Kongsaeree ◽  
Jun Liang ◽  
Roy A. Jensen ◽  
Jon Clardy
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crystal Form ◽  
High Energy ◽  
Crystallographic Analysis ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The title protein has been crystallized in a new crystal form. The crystals belong to the cubic space group P4132 (or P4332) with unit-cell dimensions a = b = c = 126.1 Å at 100 K and typically diffract beyond 1.6 Å at the Cornell High Energy Synchotron Source (CHESS) A1 beamline.

Die Kristallstruktur von Methyltriphenylphosphoniumhexachlorotitanat [MePh3P]2TiCl6 / The Crystal Structure of Methyltriphenylphosphonium Hexachlorotitanate

1981 ◽  
Vol 36 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Evamarie Hey ◽  
Ulrich Müller
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Unit Cell ◽  
Distorted Octahedron ◽  
Inversion Center ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions

The crystal structure of [MePh3P]2TiCl6 was determined from X-ray diffraction data and refined to a residual index of R = 0.065. It crystallizes in the space group P2i/n with two formula units per unit cell; the cell dimensions are a - 921, b = 1314, c = 1648 pm and y - 100.87°. The TiCl62- ion occupies an inversion center and has the shape of a slightly distorted octahedron with Ti-Cl distances between 233 and 235 pm.

Crystal structures of phenacylkojate (2-(hydroxymethyl)-5-phenacyloxy-4H-pyran-4-one) and its complex with sodium chloride: bis(phenacylkojate)sodium chloride

1976 ◽  
Vol 54 (17) ◽  
pp. 2723-2732 ◽  
Author(s):  
Simon E. V. Phillips ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Sodium Chloride ◽  
Potassium Iodide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Hydroxyl Groups ◽  
Space Group ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Iodide Complex

The structures of the title compounds have been determined by three dimensional X-ray crystal structure analysis.Crystals of anhydrous phenacylkojate are monoclinic, space group P21/c, with unit cell dimensions a = 9.087(4), b = 11.764(3), c = 12.714(4) Å, β = 116.57(2)°, Z = 4. The structure was solved by direct methods and refined by full-matrix least-squares to R = 0.044 for 1225 independent diffractometer observations. The crystal structure is held together by hydrogen bonding between carbonyl and hydroxyl groups and [Formula: see text] interactions.Crystals of the sodium chloride complex are monoclinic, space group C2/c, with unit cell dimensions a = 11.3714(6), b = 15.796(1), c = 14.487(1) Å, β = 97.241(5)°, Z = 4. The structure was solved by heavy atom and Fourier methods and comparison with the previously determined structure of the potassium iodide complex. It was refined to R = 0.040 for 1670 independent diffractometer observations. The structure closely resembles that of the potassium iodide complex (P21/n), but in C2/c, the alkali metal ion being eight co-ordinate in each. Na+—O distances are in the range 2.558–2.674 Å and the [Formula: see text] hydrogen bonded distance is 3.266 Å.

scholarly journals Synthesis And Structural Characterization Of 1-Butyl-2,3-Dimethylimidazolium Bromide And Iodide

2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  
Keyword(s):  
Unit Cell ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
X Ray ◽  
Crystal System ◽  
H Nmr ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å

Refinement of the structure of Mg2As2O7

1970 ◽  
Vol 48 (6) ◽  
pp. 890-894 ◽  
Author(s):  
C. Calvo ◽  
K. Neelakantan
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Unit Cell ◽  
Full Matrix ◽  
Space Group ◽  
Cell Dimensions ◽  
Central Oxygen ◽  
R Value ◽  
Unit Cell Dimensions

The crystal structure of Mg2As2O7 has been refined by full matrix least squares procedures using 587 observed reflections. The structure of Mg2As2O7 is of the thortveitite type, as reported by Łukaszewicz, with space group C2/m and unit cell dimensions a = 6.567(2) Å, b = 8.524(4) Å, c = 4.739(1) Å, β = 103.8(1)°, and Z = 2. The As—O—As group in the anion appears to be linear but the central oxygen atom undergoes considerable disorder in the plane perpendicular to this group. The AsO bond distances uncorrected for thermal motion are 1.67 Å for the As—O(—As) bond and 1.66 and 1.65 Å for the terminal As—O bonds. The final R value obtained is 0.088.

The Crystal Structure of Indium Monobromide

1950 ◽  
Vol 3 (4) ◽  
pp. 581 ◽  
Author(s):  
NC Stephenson ◽  
DP Mellor
Keyword(s):  
Crystal Structure ◽  
Layer Structure ◽  
Unit Cell ◽  
Space Group ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal structure of indium monobromide has been determined using powder and complete rotation photographs. The unit cell dimensions are ������������ a= 4.46�0.005 Ǻ������������ b=12.39�0.02 Ǻ ������������ c= 4 73�0.01 Ǻwith four molecules per cell. The space group is D172h:: -Cmcm. The structure is a layer structure isomorphous with that of thallium iodide TlI. Each indium has five bromine atoms arranged about it at the corners of a rectangular pyramid with one In-Br bond of 2.80 Ǻ and four In-Br bonds of 3.29 Ǻ. Indium atoms are similarly arranged about bromine atoms.

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