Preparation and Partial Characterization of Two New Hexavalent Uranium Metal Uranates

1996 ◽  
Vol 49 (7) ◽  
pp. 817 ◽  
Author(s):  
M Sterns ◽  
RL Withers ◽  
P Midgeley ◽  
R Vincent
Keyword(s):  
Electron Diffraction ◽  
Structural Investigation ◽  
Chemical Characterization ◽  
Unit Cell ◽  
Tetragonal Symmetry ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The preparation, chemical characterization and structural investigation by X-ray and electron diffraction of two uranates (VI), namely Sr5U3O14 and of Pb11U5O26, are reported. The strontium compound, the unit cell of which is metrically tetragonal with a = 11.248(5), c = 11.086(5) Ǻ, Z = 4, was shown by electron diffraction to be orthorhombic, space group Pbca with a = b. Crystals of Sr5U3O14 are invariably submicroscopically twinned and, because of the identity of a and b, mimic tetragonal symmetry. The lead uranate , Pb11U5O26, was shown to be a long-period superstructure with unit cell dimensions a = 44.54, b = 15.586, c = 8.241 Ǻ, Z = 8.

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

Re-examination of the mineral tuhualite

1956 ◽  
Vol 31 (232) ◽  
pp. 96-106 ◽  
Author(s):  
C. Osborne Hutton
Keyword(s):  
New Zealand ◽  
Unit Cell ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Goniometric Measurements ◽  
Unit Cell Dimensions

SummaryX-ray study of tuhualite from Mayor Island, New Zealand, has shown it to be orthorhombic, space-group either . Unit-cell dimensions are a = 14·31 Å, b = 17·28 Å., c = 10·11 Å., and a : b : c = 0·828 : 1 : 0·585. Goniometric measurements give a : b : c = 0·8243 : 1 : 0·5658. a{100} dominant with forms s{011}, p{021}, c{001}, b{010}, n{101}, m{110}, q{111}. Crystals with b{010} dominant are rare. Three good cleavages, a (100), b (010), c (001). α = 1·608, β = 1·612, γ = 1·621; γ-α = 0·013. , positive; β = b, γ = c, α = colourless to pale lavender, β = violet, lavender, γ = intense purplish-blue; γ > β > α. Sp. gr. 2·89 (measured), 2·86 (calculated).An analysis of carefully purified material leads to the possible formula:H9(Na,K,Mn)12Fe″6(Al,Fe‴,Mg,Ti)9[Si8O8]15.Details of alteration phenomena and associated minerals are given. Occurrence is held to result by crystallization from magma quite impoverished in lime due to early fractionation of aegirine-hedenbergite, and perhaps aegirine-augite, in the intratelluric stage.

Crystallization and preliminary X-ray characterization of VanA from Enterococcus faecium BM4147: towards the molecular basis of bacterial resistance to the glycopeptide antibiotic vancomycin

1999 ◽  
Vol 55 (8) ◽  
pp. 1481-1483 ◽  
Author(s):  
Trevor Huyton ◽  
David I. Roper
Keyword(s):  
Ammonium Sulfate ◽  
Enterococcus Faecium ◽  
Molecular Basis ◽  
Bacterial Resistance ◽  
Glycopeptide Antibiotic ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

A recombinant form of Enterococcus facieum BM4147 D-alanine-D-lactate ligase (VanA) has been prepared and crystallized. VanA was found to crystallize only in the presence of a phosphinate inhibitor analogue of D-alanine-D-alanine. The crystals grow in 40–45% ammonium sulfate, 0.1 M 3-(N-morpholino)-propanesulfonic acid pH 6.0 and reach dimensions of 0.4 × 0.2 × 0.1 mm. The crystals diffract to at least 2.5 Å and are in the centred orthorhombic space group C2221, with unit-cell dimensions a = 123.2, b = 225.4, c = 72.4 Å.

The External Shape of Human γ GI Immunoglobulin from Crystal Sections

1971 ◽  
Vol 29 ◽  
pp. 428-429
Author(s):  
L. W. Labaw
Keyword(s):  
Molecular Weight ◽  
Sodium Phosphate ◽  
Osmium Tetroxide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Large Molecular Weight ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

Structural and vibrational studies of 1,1,3,3-tetracyanopropane and 2,2,4,4,6-pentacyanocyclohexenamine

1987 ◽  
Vol 65 (2) ◽  
pp. 261-270 ◽  
Author(s):  
R. A. Bell ◽  
B. E. Brown ◽  
M. Duarte ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock
Keyword(s):  
Unit Cell ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
New Methods ◽  
Cell Dimensions ◽  
Cell Data ◽  
Unit Cell Data ◽  
Monoclinic Cell ◽  
C Nmr

1,1,3,3-Tetracyanopropane, 1, was prepared in low yields by a literature method with 2,2,4,4,6-pentacyanocyclohexenamine, 2, as a major by-product. The products were examined by X-ray crystallography. 1 has an orthorhombic space group, Pbcn (No. 60) with cell dimensions, a = 7.158(2), b = 10.510(3), c = 9.733(2) Å and has four formula units in the unit cell. 2 has a monoclinic cell, P21/c (No. 14) with cell dimensions a = 14.368(3), b = 6.626(1), c = 12.300(2) Å, β = 115.60(1)° and has 4 formula units in the unit cell. Data were collected with use of MoKα radiation and a Nicolet P3 diffractometer. The crystal structures were determined by standard methods and refined to Rw = 0.037 (1) and Rw = 0.040 (2) on the basis of 782 and 2108 unique reflections. Bond lengths and angles in the two compounds are normal. 2 has what has been considered to be the less likely tautomeric structure. Both compounds were examined by 1H, 13C nmr, vibrational spectroscopy, and mass spectroscopy. For 2 there was no evidence of the alternative tautomeric structure. New methods were developed for the preparation of both compounds and the mechanism of the original reaction rationalized.

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.

Synthesis and Structure of cis-Dioxobis(pyrimidine-2-thiolato-N,S)molybdenum(VI)

1992 ◽  
Vol 45 (11) ◽  
pp. 1933 ◽  
Author(s):  
PR Traill ◽  
AG Wedd ◽  
ERT Tiekink
Keyword(s):  
Least Squares ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Distorted Octahedral ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The characterization of two MoVI complexes, cis -[MoO2(2-pymS)2] and cis -[MoO2(2-pyS)2] (where 2-pymSH is pyrimidine-2-thiol and 2-pySH is pyridine-2-thiol), and their reaction with Ph3P are reported. The X-ray structure of cis -[MoO2(2-pymS)2] shows the molybdenum atom to exist in a distorted octahedral geometry defined by two mutually cis oxygen atoms and two chelating 2-pymS ligands so that the two sulfur atoms occupy approximate trans positions. Crystals of cis -[MoO2(2-pymS)2] are monoclinic, space group P 21/n, with unit cell dimensions: a 9.301(3), b 12.121(2), c 11.303(3) �, β 112.62(3)�, V 1176.3 �3, Z 4. The structure was refined by a full-matrix least-squares procedure to R 0.067 for 1858 reflections with I ≥ 2.5 (I).

scholarly journals ReNF4 · ReF5(NCl), ein Nitrido-Nitrenokomplex von Rhenium(VII)/ ReNF4 · ReF5(NCl), a Nitrido Nitrene Complex of Rhenium (VII)

1984 ◽  
Vol 39 (8) ◽  
pp. 1114-1117 ◽  
Author(s):  
Willi Kafitz ◽  
Kurt Dehnicke ◽  
Eberhard Schweda ◽  
Joachim Strähle
Keyword(s):  
Ir Spectrum ◽  
Fluorine Atom ◽  
Structural Investigation ◽  
Unit Cell ◽  
Trans Position ◽  
X Ray ◽  
Bond Lengths ◽  
Direct Fluorination ◽  
Cell Dimensions ◽  
In Trans

AbstractReNF4 · ReF5(NCl) is prepared by direct fluorination of ReNCl4 with fluorine between 80 °C and 130 °C. The red crystals are extremely sensitive to moisture. The complex is characterized by the IR spectrum and by an X-ray structural investigation. ReNF4 · ReF5(NCl) crystallizes orthorhombically in the space group Pnma with 4 formula units per unit cell and with the cell dimensions a = 1440, b = 848, c = 776 pm (419 observed, independent reflexions, R = 13.9%). The complex consists of the molecules ReNF4 and ReF5(NCl), which are linked by a linear asymmetric fluorine bridge. The bridging fluorine atom is in trans-position to the nitrido ligand Re -F - 228 pm) and to the nitreno ligand (Re -F = 159 pm and Re= N - Cl 164 pm) correspond to triple 188 pm). The Re ≡ N bond lengths Re= N bonds.

ZrSiO4 mit monokliner Baddeleyitstruktur?.

1976 ◽  
Vol 31 (9) ◽  
pp. 1175-1178 ◽  
Author(s):  
Kurt Walenta
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Limits Of Error ◽  
Zircon Particles

A new compound having the same composition as zircon, ZrSiO4, but differing from it in its structure has been obtained by heating zircon particles to a temperature of 5000 to 10000°K. According to X-ray powder diffraction data the structure and within limits of error also the unit-cell dimensions are identical with that of monoclinic baddeleyite, ZrO2. This suggests that the baddeleyite lattice can not only accommodate 10 molecular % SiO2 as is already known for some time, but substantially more, unless it is assumed that some kind of submicroscopic exsolution of amorphous SiO2 has taken place.

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