scholarly journals The crystal structure of brunogeierite, Fe2GeO4 spinel

2001 ◽  
Vol 65 (3) ◽  
pp. 441-444 ◽  
Author(s):  
M. D. Welch ◽  
M. A. Cooper ◽  
F. C. Hawthorne
Keyword(s):  
Crystal Structure ◽  
Close Packing ◽  
Unit Cell Dimension ◽  
Unit Cell ◽  
Cell Dimension ◽  
Bond Lengths ◽  
Exact Agreement ◽  
Oxygen Parameter ◽  
Oxygen Atoms

AbstractBrunogeierite, Fe2GeO4, a = 8.4127(7) Å, V = 595.4(1) Å3, is a rare germanate spinel from Tsumeb, Namibia. Its structure has been refined to an R index of 2.2%. The oxygen parameter, u, is 0.2466(1), indicating nearly ideal cubic close-packing of oxygen atoms. There is exact agreement between the observed a unit-cell dimension and that calculated from the observed Ge–O and Fe–O bond lengths. The cations Ge and Fe are fully ordered at tetrahedral (A) and octahedral (B) sites, respectively, in keeping with synthetic germanate spinels, all of which are fully-ordered normal spinels.

Crystal structure of Cu3(AsO4)2

1968 ◽  
Vol 46 (6) ◽  
pp. 917-927 ◽  
Author(s):  
Sandra J. Poulsen ◽  
C. Calvo
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Bond Distance ◽  
Unit Cell ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Bond Lengths ◽  
Oxygen Distance ◽  
Atom Bond ◽  
Oxygen Atoms

Cu3(AsO4)2 forms a monoclinic crystal with lattice parameters a = 6.327(5) Å, b = 8.642(5) Å, c = 11.313(5) Å, β = 92.04(4)°, and Z = 4. The space group is P21/c. The two orthoarsenate anions in the unit cell have average AsO bond lengths of 1.68 Å and 1.70 Å with mean deviations of 0.02 Å and 0.01 Å respectively. The three cations are fivefold coordinated to oxygen atoms with mean cation oxygen atom bond lengths of 2.005 Å, 2.053 Å, and 2.017 Å for the three independent cations. The range of bond distances extends from 1.892 Å to 2.362 Å. Only one additional cation oxygen distance of less than 3 Å occurs and this lies at 2.76 Å. The cation polyhedra form sheets parallel to the ab plane by corner and edge sharing of common oxygen atoms. Adjacent sheets are bonded through the long Cu—O bond distance cited above and by the AsO43− anions. Each of the arsenic atoms shares three oxygen atoms with one sheet and one with the adjacent one.

Study of Garnets by ALCHEMI

2001 ◽  
Vol 7 (S2) ◽  
pp. 358-359
Author(s):  
János L. Lábár ◽  
Lajos Tόth ◽  
István Dόdony ◽  
Jerzy Morgiel
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
High Sensitivity ◽  
Unit Cell ◽  
Previous Literature ◽  
The Other ◽  
Axial Orientation ◽  
Partial Substitution ◽  
X Ray ◽  
Oxygen Atoms

Garnets were one of the first materials in which an occupation of separate lattice sites by different atomic species was determined with an ALCHEMI technique proposed by Spence and Tafto in l982. The reason of so much interest in this material was twofold, i.e. first its known high sensitivity of X-ray generation depending on orientation especially in the axial orientation and second its complicated crystal structure allowing different atomic arrangements in the unit cell depending on its chemical composition. The dodecahedral (X), octahedral (Y) and tetrahedral (Z) sites between the relatively large oxygen atoms can be filled with a variety of small cations in accordance with the formula X3Y2Z3O12. Partial substitution of one cation with another is common in this structure. The results presented in the previous literature indicated that ALCHEMI can only separate the Y-sites from the sum of the other two (X+Z), while the latter has to remain unresolved.

scholarly journals Crystal Structure and Cyclic Voltammetric Studies on the Metal Complexes of N-(Dimethylcarbamothioyl)-4-fluorobenzamide

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Gun Binzet ◽  
Ersan Turunc ◽  
Ulrich Flörke ◽  
Nevzat Külcü ◽  
Hakan Arslan
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Analysis Data ◽  
Complex Compounds ◽  
Planar Geometry ◽  
Cyclic Voltammetric ◽  
Bond Lengths ◽  
H Nmr ◽  
Cyclic Voltammetric Studies ◽  
Oxygen Atoms

We synthesized N-(dimethylcarbamothioyl)-4-fluorobenzamide compound and its copper(II) and nickel(II) complexes. The structures of compounds have been characterized by elemental analysis and spectral data (IR, 1H NMR). Furthermore, crystal and molecular structure of the synthesized complexes have been identified by using single crystal X-ray diffraction data. In the complexes formation the metal atom was coordinated via two sulfur atoms and two oxygen atoms. The single crystal structure of copper(II) and nickel(II) complex exhibits slightly distorted square planar geometry. The oxygen atoms are in a cis configuration. It appeared that the lengths of the thiocarbonyl and carbonyl bonds are longer than the average for C=S and C=O; meanwhile the C‐N bonds in the complex ring appeared to be shorter than the average for C‐N single bonds. These data show that C-O, C-S, and C-N bond lengths of the complexes suggest considerable electronic delocalization in the chelate ring. All bond lengths and angles obtained as a result of the analyses are found to be within experimental error limits. The obtained crystal analysis data shows that the structure of complex compounds is compatible with similar compounds in literature. Electrochemical behavior of complexes has been investigated by cyclic voltammetry technique in aprotic media. From the cyclic voltammetric investigation, both of the complexes have demonstrated electroactive properties.

Die Kristallstruktur von Gadolinium (III)-sulfit Trihydrat Gd2(S03)3∙ 3H2O / Crystal Structure of Gadolinium(III)-sulfite Trihydrate Gd2(SO3)3 ∙3H2O

1994 ◽  
Vol 49 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Petra Joerg ◽  
Gerhard Pezzei ◽  
Alexander Wolski
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Room Temperature ◽  
Triclinic Space Group ◽  
Space Group ◽  
Bond Lengths ◽  
Clear Solution ◽  
Oxygen Atoms

Abstract Gd2(SO3)3 • 3 H20 is obtained by passing gaseous SO2 through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Single crystals are obtained by heating to 70(2) °C for 6 days. The compound crystallizes in the triclinic space group P 1 with a = 6.499(6), b = 6.621(3), c = 6.954(3) Å, α = 110.71(5), β = 90.54(3), γ = 106.05(1)° and Z = 1. The two crystallographically different gadolinium atoms are both coordinated by eight oxygen atoms forming distorted square antiprisms. Gd(l) is coordinated by six O atoms of sulfite ligands and two O atoms of water, while Gd(2) is surrounded by seven O atoms of SO3 and one of H2O. Gd-O-bond lengths vary between 2.31(3) and 2.50(3) Å.

scholarly journals Crystal structure of bis{μ-(E)-2-[(2-oxidophenylimino)methyl]quinolin-8-olato-κ4O,N,N′,O′}bis[dibutyltin(IV)]

2017 ◽  
Vol 73 (1) ◽  
pp. 4-7
Author(s):  
Camacho-Camacho Carlos ◽  
Ortiz-Pastrana Naytzé ◽  
Garza-Ortiz Ariadna ◽  
Rojas-Oviedo Irma
Keyword(s):  
Crystal Structure ◽  
Schiff Base ◽  
Metal Atom ◽  
Title Complex ◽  
Unit Cell ◽  
Type Structure ◽  
Triclinic Space Group ◽  
Space Group ◽  
Centrosymmetric Dimers ◽  
Oxygen Atoms

Condensation of 8-hydroxyquinoline-2-carbaldehyde with 2-aminophenol gave the (E)-2-[(2-hydroxyphenylimino)methyl]quinolin-8-ol derivative that reacted with di-n-butyltin oxide with release of H2O to yield the chelate title complex, [Sn2(C4H9)4(C16H10N2O2)2]. The compound crystallizes in the triclinic space groupP-1, with two independent centrosymmetric dimers in the unit cell. Each features a typical pincer-type structure where the dianionic ligand is tetradentate, coordinating to the central tin atom through both phenolate oxygen atoms, as well as through the quinoline and imine N atoms. Each metal atom adopts a distorted pentagonal–bipyramidal SnC2N2O3coordination arising from theN,N′,O,O′-tetradentate deprotonated Schiff base, one bridging phenolate O atom of the neighbouring ligand and two butyl groups in the axial sites.

N-TrimethylsilyMminotriphenylphosphoran-Kupfer(II)-chlorid, [Me3 SiNPPh3 · CuCl 2 ]2 Synthese und Kristallstruktur / N-Trimethylsilyl-iminotriphenylphosphorane Copper(II) Chloride, [Me3 SiNPPh3 · CuCl 2] 2 Synthesis and Crystal Structure

1988 ◽  
Vol 43 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Dieter Fenske ◽  
Eberhard Böhm ◽  
Kurt Dehnicke ◽  
Joachim Strähle
Keyword(s):  
Crystal Structure ◽  
Coordination Number ◽  
Structure Determination ◽  
Ir Spectrum ◽  
Title Compound ◽  
Unit Cell ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Bond Lengths ◽  
Moisture Sensitive

Abstract The title compound has been prepared by the reaction of N-trimethylsilyl-iminotriphenylphos-phorane with copper(II) chloride in boiling CCl4 /C2H5OH, and forms moisture sensitive crystals, which are green in transmittance and black in reflexion. [Me3SiNPPh3 · CuCl2 ] 2 was characterized by its IR spectrum as well as by a crystal structure determination (4197 observed, independent reflexions, R = 0.049). The lattice dimensions are at 20 °C: a = 1102.7. b = 1407.3. c = 1560.2 pm; β = 94.27°; space group P21/n with two formula units in the unit cell. The complex consists of centrosymmetric, dimeric molecules with a planar Cu2 Cl2 ring (Cu-CI bond lengths 229 and 231 pm). A terminally bonded CI atom (Cu-CI = 221 pm) and the N atom of the Me3SiNPPh3 ligand (Cu-N = 198.5 pm) complete the coordination number four of the nearly planar surroundings of the Cu atoms.

scholarly journals Die Kristallstruktur von Gadolinium-(III)-hydrogensulfat Gd(H SO4)3 / Crystal Structure of Gadolinium-(III)-hydrogensulfate Gd(HSO4)3

1994 ◽  
Vol 49 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Petra Joeg ◽  
Gerhard Pezzei ◽  
Alexander Wolski
Keyword(s):  
Crystal Structure ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Lattice Constants ◽  
Bond Lengths ◽  
Moisture Sensitive ◽  
Oxygen Atoms

Abstract Gd(HSO4)3 is obtained on treatment of Gd2(SO4)3 in conc. H2SO4 in closed vessels at 200 °C. The extremely moisture-sensitive crystals belong to the orthorhombic space group Pbca. Lattice constants are a = 12.080(8), b = 9.574(8), c = 16.513(8)Å and Z = 8. Gadolinium is coordinated by eight oxygen atoms of the hydrogensulfate ligands forming a distorted square antiprism. There are three different HSO4- anions within the structure. One of them is coordinated with two Gd atom s while two HSO4- anions bridge three Gd atoms. The Gd-O bond lengths vary in the range of 2.334(6)-2.423(5)Å .

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