Hydrothermal Synthesis and Structure of Neptunium(V) Oxide

2006 ◽  
Vol 985 ◽  
Author(s):  
Tori Z. Forbes ◽  
Peter C. Burns ◽  
L. Soderholm ◽  
S. Skanthakumar
Keyword(s):  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Single Crystals ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Unique Data ◽  
Ccd Detector

AbstractSingle crystals of Np2O5 have been synthesized by low-temperature hydrothermal reaction of a Np5+ stock solution with natural calcite crystals. The structure of Np2O5 was solved by direct methods and refined on the basis of F2 for all unique data collected on a Bruker X-ray diffractometer equipped with an APEX II CCD detector. Np2O5 is monoclinic, space group P2/c, with a = 8.168(2) Å, b = 6.584(1) Å, c = 9.3130(2) Å, β = 116.01(1)˚, V = 449.8(2) Å3, and Z = 1. The structure contains chains of edge-sharing neptunyl pentagonal bipyramids linked into sheets through cation-cation interactions with distorted neptunyl square bipyramids. Additional cation-cation interactions connect the sheets into a three-dimensional framework. The formation of Np2O5 on the surface of calcite crystals has important implications for the precipitation of isolated neptunyl phases in natural aqueous systems.

Benzo-18-krone-6 -Acetonitril (1/2): Kristallisation und Tieftemperatur- Röntgenstrukturanalyse / Benzo-18 -crown-6 -Acetonitrile (1/2): Crystallization and Low-Temperature X-Ray Analysis

1998 ◽  
Vol 53 (12) ◽  
pp. 1528-1530 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Data Collection ◽  
Single Crystals ◽  
Title Complex ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
Mecn Solution

Abstract Benzo-18 -crown-6 -Acetonitrile (1/2), Crystal Structure Single crystals of the title complex resulted fortuitously during an attempt to co-crystallise MeN(SO2Me)2 with benzo-18-crown-6 from an MeCN solution at -30 °C. The crystal structure has been determined via data collection at -100 °C (monoclinic, space group P21/n, Z = 4). The nitrile molecules are located with their me­ thyl groups above and below the plane of the 18-membered crown ring, the Me hydrogen atoms being rotationally disordered about the MeCN axes; C(methyl)···O(crown) distances range from 309.4(3) to 384.9(3) pm.

Crystal structures of two lactones of the bicyclo[2,2,2]octane series

1982 ◽  
Vol 35 (2) ◽  
pp. 457 ◽  
Author(s):  
RM Carman ◽  
SS Smith ◽  
CHL Kennard ◽  
G Smith ◽  
AH White ◽  
...  
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
A Cell

The crystal structures of two γ-lactones of the bicyclo[2,2,2]octane series, endo-3-carboxy-exo-5- iodobicyclo[2,2,2]octane-2,6-carbolactone (2; R = CO2H) and exo-3-methoxycarbonyl-endo-5-acetoxybicyclo[2,2,2] octane-2,6-carbolactone (7b), have been determined by direct methods from three-dimensional X-ray data and refined by least-squares to final residuals of 0.033 (2; R = CO2H) and 0.036 (7b) for 1918 and 630 'observed' reflections respectively. Crystals for (2; R = CO2H) are monoclinic, space group P21/c with Z 8 in a cell of dimensions a 7.192(2), b 23.785(8), c 13.199(5) �, β 105.35(2)�, while (7b) crystallizes in the orthorhombic space group P212121 with Z 4 in a cell of dimensions a 13.347(7), b 11.839(7), c 8.227(11) �.

Crystal structure of 9-Oxofluorene-4-carboxylic acid

1981 ◽  
Vol 34 (5) ◽  
pp. 1143 ◽  
Author(s):  
CHL Kennard ◽  
G Smith ◽  
GF Katekar
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
A Cell

The crystal structure of 9-oxofluorene-4-carboxylic acid has been determined by direct methods using three-dimensional X-ray diffraction data, and refined to R0·068 for 1323 'observed' reflections. Crystals are monoclinic, space group P21/c with 24 in a cell of dimensions a 3·843(3), b 7·986(5), c 3269(2) �, β 96·64(4)�. The molecules form centrosymmetric hydrogen-bonded cyclic dimers [O···O 2·642(3) �] with the plane of the carboxylic acid making an angle of 26·5� with that of the 9-oxofluorene group. Stacks of molecules form down the a axis with 3.843 �. separation.

Comparison of σ-acyl and σ-perfluoroacyl groups as ligands: Crystal and molecular structures of the platinum(II) complexes trans-PtCl(COR)(PMePh2)2 (R = Me,CF3)

1982 ◽  
Vol 35 (7) ◽  
pp. 1311 ◽  
Author(s):  
MA Bennett ◽  
K Ho ◽  
JC Jeffery ◽  
GM Mclaughlin ◽  
GB Robertson
Keyword(s):  
Three Dimensional ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Unique Data ◽  
Trans Influence ◽  
Small Deformations

Crystal and molecular structures of the title compounds have been determined from three dimensional X-ray diffraction data recorded on a four-circle diffractometer. Crystals of the acetyl complex, trans-PtCl(COMe)(PMePh2)2,(1), are monoclinic, space group P2,1/c, with a 12.9709(5), b 11.1024(5), c 277535(9) Ǻ, β 94.75(1)° and Z 6. Crystals of the trifluoroacetyl complex, trans-PtCl(COCF3)- (PMePh2)2, (2), are monoclinic, space group P21/n (non-standard setting of P21c), with a 11.4246(7), b 15.5750(7), c 15.4200(8) Ǻ, β 90.54(1)° and Z 4. For (I), with Z 6, the unit cell contains one set of four equivalent molecules in the general equipoint and one set of two equivalent (disordered) molecules located at inversion centres. The four molecules in (2) comprise a single equivalent set in the general equipoint. Least-squares analyses converge with R 0.042 for (1) (5696 unique data) and R 0.025 for (2) (3933 unique data). Molecules of both complexes exhibit small deformations from planar towards tetrahedral platinum geometry; the acyl and coordination planes are approximately orthogonal. The phosphine substituents in (2) and in the 'general' molecules in (1) are approximately eclipsed, and approximately eclipse the Pt-C (acetyl) bonds. In the 'special' molecules in (1) the phosphines are constrained to adopt the mutually staggered conformation found in the alkyl analogues trans-PtClR(PMePhM2)2 (R = Me, CF3, C2F2). Important comparative lengths in (1) (general molecule) and in (2) (in square brackets) are: Pt-C 2.028(6) [1.960(4)] A, Pt-Cl 2.430(2) [2.390(1)] Ǻ, Pt-P 2.301(2), 2.297(2) [2.316(1), 2.321(1)] A, C-O 1.182(8) [1.210(5)] 8, and C C (acetyl) 1.488(10) [1.547(6)] A. The trifluoroacetyl ligand forms a shorter and presumably stronger bond with platinum, and exerts a larger cis- and a smaller trans-influence than the acyl ligand. The smaller trans-influence of the trifluoroacetyl ligand is consistent with the expectation from platinum-chlorine stretching frequencies (v(Pt-Cl)).

The first proof of protonated anion tetrahedra in the tsumcorite-type compounds

2004 ◽  
Vol 68 (5) ◽  
pp. 757-767 ◽  
Author(s):  
T. Mihajlović ◽  
H. Effenberger
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Single Crystal ◽  
Diffraction Data ◽  
Title Compound ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Synthetic Compounds ◽  
X Ray

AbstractHydrothermal synthesis produced the new compound SrCo2(AsO4)(AsO3OH)(OH)(H2O). The compound belongs to the tsumcorite group (natural and synthetic compounds with the general formula M(1)M(2)2(XO4)2(H2O,OH)2; M(1)1+,2+,3+ = Na, K, Rb, Ag, NH4, Ca, Pb, Bi, Tl; M(2)2+,3+ = Al, Mn3+, Fe3+, Co, Ni, Cu, Zn; and X5+,6+ = P, As, V, S, Se, Mo). It represents (1) the first Sr member, (2) the until now unknown [7]-coordination for the M(1) position, (3) the first proof of (partially) protonated arsenate groups in this group of compounds, and (4) a new structure variant.The crystal structure of the title compound was determined using single-crystal X-ray diffraction data. The compound is monoclinic, space group P21/a, with a = 9.139(2), b = 12.829(3), c = 7.522(2) Å, β = 114.33(3)°, V = 803.6(3) Å3, Z = 4 [wR2 = 0.065 for 3530 unique reflections]. The hydrogen atoms were located experimentally.

Three-dimensional visualization of the inner structure of single crystals by step-scanning white X-ray section topography

2006 ◽  
Vol 13 (6) ◽  
pp. 484-488 ◽  
Author(s):  
Taihei Mukaide ◽  
Kentaro Kajiwara ◽  
Takashi Noma ◽  
Kazuhiro Takada
Keyword(s):  
Single Crystals ◽  
Three Dimensional ◽  
X Ray ◽  
Section Topography

A New POM-Based Supramolecular Compound: Synthesis, Structure and Adsorptive Property of [Cu(phen)2]3[W6O19]

2014 ◽  
Vol 919-921 ◽  
pp. 2013-2016 ◽  
Author(s):  
Ya Bing Liu ◽  
Hong Jie Wang ◽  
Hong Kai Zhao
Keyword(s):  
Three Dimensional ◽  
Building Blocks ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hybrid Compound ◽  
Adsorptive Property ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Compound Synthesis ◽  
Metal Organic

A POM - based organice - inorganic hybrid compound with the chemical formula of[Cu (phen)2]3[W6O19] (phen = 1,10-phenanthroline) (1) has been hydrothermally synthesized andstructurally characterized by the elemental analysis, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space groupC2/c witha=18.319(4) Å,b= 17.311(4) Å,c= 22.248(4) Å,β= 112.40(3) o,V= 6523(2) Å3,Z= 4, R1= 0.0448, andwR2=0.1218. Compound 1 consists of the [W6O19]3-building blocks and [Cu (phen)2]+metal organic cationic moieties, which are packed together via the extensive hydrogen-bonding interactions to form a three-dimensional supramolecular framework. The adsorption of methylene blue (MB) under UV irradiation with 1 as the heterogeneous adsorbent has been investigated, showing a good adsorptive property of 1 for MB degradation.

Structure of 3α,4α:5β,6β-Diepoxyandrostan-17-one

1983 ◽  
Vol 36 (11) ◽  
pp. 2333 ◽  
Author(s):  
B Kamenar ◽  
RA Pauptit ◽  
JM Waters
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray

The X-ray crystal structure of 3α,4α:5β,6β-diepoxyandrostan-17-one has been determined. Crystals of the title compound (C19H26O3)are monoclinic, space group P21, with a 9.208(2), b 9.620(4), c 9.312(3) �, β 99.14(2)�, V 814.5 Ǻ3 and Z 2. The structure was solved by direct methods and refined to R 0.039 for 887 observed reflexions. The 3α,4α:5β,6β configuration of the epoxide rings confirms the assignment based on proton n.m.r. studies.

The Crystal Structure of KIO3.HIO3

1971 ◽  
Vol 49 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Lilian Y. Y. Chan ◽  
F. W. B. Einstein
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray ◽  
R Factor ◽  
Octahedral Environment ◽  
Distorted Octahedral ◽  
Potassium Hydrogen ◽  
A Cell ◽  
Least Squares Techniques

The crystal structure of potassium hydrogen di-iodate (bi-iodate) KIO3.HIO3 was determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.0 % for the 1392 observed reflexions. The salt crystallizes in the monoclinic space group P21/c with eight formula units in a cell of dimension a = 7.028(1) Å, b = 8.203(1) Å, c = 21.841(3) Å, β = 98.03(1)°.The iodate units are all basically pyramidal; weak interionic I—O contacts complete a very distorted octahedral environment around three iodine atoms. There is a capped octahedral (7-coordinate) environment around the remaining iodine atom. The I—O bonds are in the range 1.75–1.82 Å and the I—OH bonds are 1.91 and 1.95 Å, variations in length can be correlated with differences in the degree of involvement in (a) hydrogen bonding and (b) interaction with adjacent iodine atoms.

The crystal structure of gatehouseite

2011 ◽  
Vol 75 (6) ◽  
pp. 2823-2832
Author(s):  
P. Elliott ◽  
A. Pring
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Direct Methods ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manganese Phosphate ◽  
Phosphate Mineral ◽  
Unit Formula

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space group P212121, a = 17.9733(18), b = 5.6916(11), c = 9.130(4) Å, V= 933.9(4) Å3, Z = 4, has been solved by direct methods and refined from single-crystal X-ray diffraction data (T = 293 K) to an R index of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6 octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6 octahedra coupled by PO4 tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.

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