scholarly journals Synthesis and Crystal Structure of Hg2V8O20 – the First Ternary Mercury Vanadate with Mixed-valent Vanadium (IV/V)

2007 ◽  
Vol 62 (11) ◽  
pp. 1390-1396 ◽  
Author(s):  
Matthias Weil ◽  
Berthold Stöger ◽  
Annemarie L. Wessels ◽  
Wolfgang Jeitschko
Keyword(s):  
Crystal Structure ◽  
Structure Type ◽  
Vanadium Oxides ◽  
Near Neighbor ◽  
The Other ◽  
Intermediate Valence ◽  
Oxidation Number ◽  
Coordination Polyhedra ◽  
Variable Parameters ◽  
Synthesis And Crystal Structure

Black needle-shaped single crystals of Hg2V8O20 were obtained by heating amorphous precipitates resulting from mixing aqueous solutions of HgNO3OH and NH4VO3 (Hg :V ratios between 1 : 2.0 and 1 : 2.5) in evacuated silica ampoules at 450 °C for two weeks. Their crystal structure was determined from single crystal diffractometer data [C2/m, Z = 2, a = 22.375(1), b = 3.6312(2), c = 9.6113(4) Å, β = 91.708(5)°, R[F2 ≥ 2σ (F2)] = 0.0681, 807 F2 values, 61 variable parameters]. Two of the four independent vanadium atoms are surrounded by six close oxygen atoms whereas the other two have five oxygen neighbors. These coordination polyhedra share edges and corners resulting in puckered layers with an overall composition [V4O10]− extending parallel to (100). The layers are linked by Hg22+ dumbbells (d(Hg-Hg) = 2.510(2) Å) with a short Hg-O distance of 2.13(2) Å(∠(O9−Hg-Hg) = 173.8(5)°). Although Hg2V8O20 crystallizes in a new structure type, it resembles the structures of other layered vanadium oxides with open frameworks and can be classified as being of the Q-UD-type. The near-neighbor environments of the four vanadium positions of this reduced vanadate with an average oxidation number of +4.75 of the vanadium atoms are similar with respect to V-V bonding and it is suggested that the vanadium atoms have delocalized V-V bonding with intermediate valence.

Preparation and Crystal Structure of the Calcium Rhenate(VI, VII) Ca5Re3O15-x

1999 ◽  
Vol 54 (12) ◽  
pp. 1483-1488 ◽  
Author(s):  
Wolfgang Jeitschko ◽  
Horst A. Mons ◽  
Ute Ch. Rodewald
Keyword(s):  
Crystal Structure ◽  
The Other ◽  
Oxidation Number ◽  
Variable Parameters ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Oxygen Coordination ◽  
Structure Factors ◽  
Oxygen Site ◽  
Elemental Calcium

The title compound was prepared by reaction of elemental calcium with the calcium metaperrhenate Ca(ReO4)2. Its crystal structure was determined from single-crystal X-ray data: Amm2, a = 560.31 (5)pm, b = 1572.4( 1)pm, c = 719.91 (6)pm ,Z = 2 ,R = 0.033 for 930 structure factors and 46 variable parameters. The calcium atoms occupy three atomic sites, all with seven oxygen neighbors. Of the two different rhenium atoms one has square-pyramidal oxygen coordination with an average oxidation number +6.25. The other rhenium site (oxidation number +7) was refined as a split position with trigonal-bipyramidal (75%) and tetrahedral oxygen coordination (25%). One oxygen site remains unoccupied, whenever the tetrahedral rhenium site is occupied, resulting in the composition Ca5Re3O14.75. A test for superconductivity of this black compound down to 1.5 K was negative.

Synthesis and crystal structure of (Ag,Pd)22Se6

2013 ◽  
Vol 28 (1) ◽  
pp. 13-17 ◽  
Author(s):  
F. Laufek ◽  
A. Vymazalová ◽  
D.A. Chareev ◽  
A.V. Kristavchuk ◽  
J. Drahokoupil ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Glass Tube ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Cell Parameters ◽  
Silica Glass Tube

The (Ag,Pd)22Se6 phase was synthesized from individual elements by silica glass tube technique and structurally characterized from powder X-ray diffraction data. The (Ag,Pd)22Se6 phase crystallizes in Fm$\overline3$m symmetry, unit-cell parameters: a = 12.3169(2) Å, V = 1862.55(5) Å3, Z = 4, and Dc = 10.01 g/cm3. The crystal structure of the (Ag,Pd)22Se6 phase represents a stuffed 3a.3a.3a superstructure of the Pd structure (fcc), where only 4 from 108 available octahedral holes are occupied. Its crystal structure is related to the Cr23C6 structure type.

scholarly journals Synthesis and crystal structure of (E)-1,2-bis[2-(methylsulfanyl)phenyl]diazene

2019 ◽  
Vol 75 (11) ◽  
pp. 1808-1811
Author(s):  
Jonas Hoffmann ◽  
Thomas J. Kuczmera ◽  
Enno Lork ◽  
Anne Staubitz
Keyword(s):  
Crystal Structure ◽  
Dimethyl Disulfide ◽  
Hirshfeld Surface ◽  
The Other ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
Synthesis And Crystal Structure ◽  
Compound C ◽  
Azo Group ◽  
Subsequent Quenching

The title compound, C14H14N2S2, was obtained by transmetallation of 2,2′-bis(trimethylstannyl)azobenzene with methyl lithium, and subsequent quenching with dimethyl disulfide. The asymmetric unit comprises two half-molecules, the other halves being completed by inversion symmetry at the midpoint of the azo group. The two molecules show only slight differences with respect to N=N, S—N and aromatic C=C bonds or angles. Hirshfeld surface analysis reveals that except for one weak H...S interaction, intermolecular interactions are dominated by van der Waals forces only.

Synthesis and Crystal Structure of Tetraphenylarsonium Pentachlorocarbonylosmate(IV), (Ph4As)[OsCl5(CO)]

1997 ◽  
Vol 52 (8) ◽  
pp. 978-980 ◽  
Author(s):  
M Höhling ◽  
W Preetz
Keyword(s):  
Crystal Structure ◽  
Complex Anion ◽  
Structure Type ◽  
Close Packing ◽  
Cation Sublattice ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Positional Disorder ◽  
Intermolecular Contacts

The structure of tetraphenylarsonium pentachlorocarbonylosmate(IV), (Ph4As)[OsCl5(CO)], the first example of a halogenocarbonyl complex with osmium in the oxidation state +IV, has been determined at 208 K by single crystal X-ray diffraction: tetragonal, space group P4/n with a = 12.821 , c = 8.084 Å, Z = 2. There are short intermolecular contacts between neighbouring anions along the tetragonal axis c and unusually large displacement ellipsoids of the carbonyl group and the four equatorial Cl ligands arising from a positional disorder of the complex anion. By analogy with a variety of reported structures of the (Ph4As)[RuNCl4] structure type this is attributed to the close packing of the cation sublattice. Compared to other monocarbonylosmates the Os-C bond of 1.94(2) Å is extraordinaryly long while the bond between Os and the trans coordinated Cl ligand of 2.286(3) Å is rather short.

Analysis of the environment of beryllium, magnesium and alkaline earth atoms in oxygen-containing compounds

1999 ◽  
Vol 55 (2) ◽  
pp. 139-146 ◽  
Author(s):  
V. A. Blatov ◽  
L. V. Pogildyakova ◽  
V. N. Serezhkin
Keyword(s):  
Crystal Structure ◽  
Alkaline Earth ◽  
Organometallic Compounds ◽  
Alkaline Earth Metals ◽  
The Other ◽  
Crystal Chemical ◽  
Coordination Polyhedra ◽  
Coordination Numbers ◽  
Coordination Spheres

About 2100 inorganic and organometallic compounds containing beryllium, magnesium and alkaline earth atoms (M) were investigated with Voronoi–Dirichlet polyhedra (VDPs). It is shown that the coordination numbers (CNs) of the M atoms in MO n coordination polyhedra can be determined by means of VDPs without crystal-chemical radii. The distributions of the M—O distances in the coordination spheres of the M atoms are bimodal for M = Be or Mg and monomodal for the other alkaline earth metals. Beryllium and magnesium coordination polyhedra containing weak M—O contacts were classified by variants of their distortions. It is found that the volume of the domains of the Mg, Ca, Sr and Ba atoms is independent of their CNs at CN \ge 6 (up to 16 for barium). The possibility of using the model of deformable spheres to describe the crystal structure of the compounds investigated is suggested.

Ca10V5.2Fe0.8O24, a Novel Oxometalate with Discrete Complex Anions

2003 ◽  
Vol 58 (11) ◽  
pp. 1112-1116 ◽  
Author(s):  
Kurt O. Kleppa ◽  
Norbert A. Harringer ◽  
Hubert Preßlinger
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Bond Distance ◽  
Structure Type ◽  
The Other ◽  
Nominal Composition ◽  
Average Bond ◽  
Complex Anions ◽  
Trigonal Prismatic ◽  
Discrete Complex

Abstract Lustrous needle shaped prismatic single crystals of the new compound Ca10V5.2Fe0.8O24 were obtained out of a sample with nominal composition Ca2Fe1.6V0.4O5 prepared at 1400 °C. The crystals are opaque and stable to humid air. Ca10V5.2Fe0.8O24 crystallizes with a new structure type, space group Pnma with a = 6.803(3), b = 16.015(8), c = 10.418(7)Å , Z = 2, R = 0.041. The crystal structure is characterized by two mononuclear tetrahedral species, MO4, which differ significantly from each other with respect to their M-O bond lengths. One with an average bond distance of 1.709(8)Å represents an orthovanadate ion. The other with a significantly larger value d(M-O) = 1.744(6) Å corresponds to a mixed occupation of its centre according to [V0.8Fe0.2O4]3.5−. In the crystal structure the complex anions are arranged in separate sheets parallel to the (010) plane. They are separated from each other by three crystallographically independent Ca2+ ions which are each coordinated by 7 oxygen atoms in distorted pentagonal bipyramidal and trigonal prismatic configurations, respectively.

Darstellung und Kristallstruktur von K2Pd02 / Synthesis and Crystal Structure of K2Pd02

1974 ◽  
Vol 29 (1-2) ◽  
pp. 10-12 ◽  
Author(s):  
Horst Sabrowsky ◽  
Welf Bronger ◽  
Dieter Schmitz
Keyword(s):  
Crystal Structure ◽  
Structure Type ◽  
Chain Structure ◽  
Unit Cell ◽  
One Dimension ◽  
Ternary Oxide ◽  
Orthorhombic Unit Cell ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
A Chain

The ternary oxide K2PdO2 has been prepared by a reaction between K2O and PdO. X-ray investigations suggest a chain-structure-type which corresponds to that of K2PtS2. The planar oxygen coordinations of the palladium atoms are connected laterally in one dimension. The orthorhombic unit cell (a = 8.523, b = 6.089, c = 3.119 Å) contains two formula units.

Synthesis and Crystal Structure of 4,7-bis (2-thienylethynyl)-2,1,3-benzothiadiazole

2002 ◽  
Vol 2002 (10) ◽  
pp. 511-513 ◽  
Author(s):  
Chitoshi Kitamura ◽  
Kakuya Saito ◽  
Mikio Ouchi ◽  
Akio Yoneda ◽  
Yoshiro Yamashita
Keyword(s):  
Crystal Structure ◽  
Thiophene Ring ◽  
The Other ◽  
Sonogashira Coupling ◽  
Synthesis And Crystal Structure

4,7-Bis(2-thienylethynyl)-2,1,3-benzothiadiazole was prepared by Sonogashira coupling. The crystal structure showed that one thiophene ring is coplanar and the other is perpendicular to the benzothiadiazole ring.

Hydrothermal synthesis and crystal structure of Na(Na,Mn)7Mn22(PO4)180.5H2O, a new compound of fillowite structure type

2006 ◽  
Vol 18 (6) ◽  
pp. 765-774 ◽  
Author(s):  
Paul Keller ◽  
Frédéric Hatert ◽  
Falk Lissner ◽  
Thomas Schleid ◽  
André-Mathieu Fransolet
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Structure Type ◽  
Synthesis And Crystal Structure

Multianvil High-Pressure Synthesis And Crystal Structure Of β-YbBO3

2001 ◽  
Vol 56 (8) ◽  
pp. 697-703 ◽  
Author(s):  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Title Compound ◽  
Variable Parameters ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Oxygen Coordination ◽  
Distorted Octahedral ◽  
Pressure Synthesis ◽  
Octahedral Oxygen

β-Ytterbium borate (β-YbBO3) was synthesized under high-pressure in a Walker-type multianvil apparatus at 2.2 GPa and 1400 °C. The title-compound crystallizes in the trigonal calcite structure, space group R3̄̄c. Single crystal X-ray data yielded a = 492.1(2), c = 1630.5(9) pm, wR2 = 0.0344 for 165 F2 values and 11 variable parameters. Within the trigonal planar BO3 groups the B-O distance is 137.8(4) pm. The ytterbium atoms have a slightly distorted octahedral oxygen coordination (Yb-O: 224.4(2) pm)

Sign in / Sign up

Export Citation Format

Share Document