scholarly journals Crystal structure of SrGeO3in the high-pressure perovskite-type phase

2015 ◽  
Vol 71 (5) ◽  
pp. 502-504 ◽  
Author(s):  
Akihiko Nakatsuka ◽  
Hiroshi Arima ◽  
Osamu Ohtaka ◽  
Keiko Fujiwara ◽  
Akira Yoshiasa
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Thermal Vibrations ◽  
Perovskite Type ◽  
Pressure Phase ◽  
Perovskite Type Structure ◽  
The Ideal

Single crystals of the SrGeO3(strontium germanium trioxide) high-pressure phase have been synthesized successfully at 6 GPa and 1223 K. The compound crystallizes with the ideal cubic perovskite-type structure (space groupPm-3m), which consists of a network of corner-linked regular GeO6octahedra (point-group symmetrym-3m), with the larger Sr atoms located at the centers of cavities in the form of SrO12cuboctahedra (point-group symmetrym-3m) in the network. The degrees of covalencies included in the Sr—O and the Ge—O bonds calculated from bond valences are 20.4 and 48.9%, respectively. Thus, the Ge—O bond of the GeO6octahedron in the SrGeO3perovskite has a strong covalency, comparable to those of the Si—O bonds of the SiO4tetrahedra in silicates with about 50% covalency. The thermal vibrations of the O atoms in the title compound are remarkably suppressed in the directions of the Ge—O bonds. This anisotropy ranks among the largest observed in stoichiometric cubic perovskites.

scholarly journals Crystal structure of post-perovskite-type CaIrO3reinvestigated: new insights into atomic thermal vibration behaviors

2015 ◽  
Vol 71 (9) ◽  
pp. 1109-1113
Author(s):  
Akihiko Nakatsuka ◽  
Kazumasa Sugiyama ◽  
Akira Yoneda ◽  
Keiko Fujiwara ◽  
Akira Yoshiasa
Keyword(s):  
Crystal Structure ◽  
Atmospheric Pressure ◽  
Structure Refinement ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
X Ray ◽  
Thermal Vibrations ◽  
Perovskite Type ◽  
Shared Edge

Single crystals of the title compound, the post-perovskite-type CaIrO3[calcium iridium(IV) trioxide], have been grown from a CaCl2flux at atmospheric pressure. The crystal structure consists of an alternate stacking of IrO6octahedral layers and CaO8hendecahedral layers along [010]. Chains formed by edge-sharing of IrO6octahedra (point-group symmetry 2/m..) run along [100] and are interconnected along [001] by sharing apical O atoms to build up the IrO6octahedral layers. Chains formed by face-sharing of CaO8hendecahedra (point-group symmetrym2m) run along [100] and are interconnected along [001] by edge-sharing to build up the CaO8hendecahedral layers. The IrO6octahedral layers and CaO8hendecahedral layers are interconnected by sharing edges. The present structure refinement using a high-power X-ray source confirms the atomic positions determined by Hiraiet al.(2009) [Z. Kristallogr.224, 345–350], who had revised our previous report [Sugaharaet al.(2008).Am. Mineral.93, 1148–1152]. However, the displacement ellipsoids of the Ir and Ca atoms based on the present refinement can be approximated as uniaxial ellipsoids elongating along [100], unlike those reported by Hiraiet al.(2009). This suggests that the thermal vibrations of the Ir and Ca atoms are mutually suppressed towards the Ir...Ca direction across the shared edge because of the dominant repulsion between the two atoms.

Point Group Symmetry of NH4LiSO4at High Pressure Phase

1979 ◽  
Vol 18 (3) ◽  
pp. 711-712 ◽  
Author(s):  
Terutaro Nakamura ◽  
Seiji Kojima ◽  
Masaaki Takashige ◽  
Toshiharu Mitsui ◽  
Katsuyuki Asaumi ◽  
...  
Keyword(s):  
High Pressure ◽  
Point Group ◽  
High Pressure Phase ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Pressure Phase

scholarly journals Crystal structure of [Co(NH3)6][Co(CO)4]2

2015 ◽  
Vol 71 (11) ◽  
pp. 1418-1420 ◽  
Author(s):  
Thomas G. Müller ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Hydrogen Bonds ◽  
Liquid Ammonia ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Distorted Tetrahedron ◽  
Carbonyl Ligands ◽  
Set Up

Hexaamminecobalt(II) bis[tetracarbonylcobaltate(-I)], [Co(NH3)6][Co(CO)4]2, was synthesized by reaction of liquid ammonia with Co2(CO)8. The CoIIatom is coordinated by six ammine ligands. The resulting polyhedron, the hexaamminecobalt(II) cation, exhibits point group symmetry -3. The Co-Iatom is coordinated by four carbonyl ligands, leading to a tetracarbonylcobaltate(−I) anion in the shape of a slightly distorted tetrahedron, with point group symmetry 3. The crystal structure is related to that of high-pressure BaC2(space groupR-3m), with the [Co(NH3)6]2+cations replacing the Ba sites and the [Co(CO)4]−anions replacing the C sites. N—H...O hydrogen bonds between cations and anions stabilize the structural set-up in the title compound.

Point group symmetry of NH4LiSO4at high pressure phase

1980 ◽  
Vol 25 (1) ◽  
pp. 435-438 ◽  
Author(s):  
Terutaro Nakamura ◽  
Seiji Kojima ◽  
Masaaki Takashige ◽  
Toshiharu Mitsui
Keyword(s):  
High Pressure ◽  
Point Group ◽  
High Pressure Phase ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Pressure Phase

scholarly journals Crystal structures of isotypic poly[bis(benzimidazolium) [tetra-μ-iodido-stannate(II)]] and poly[bis(5,6-difluorobenzimidazolium) [tetra-μ-iodido-stannate(II)]]

2014 ◽  
Vol 70 (10) ◽  
pp. 178-182 ◽  
Author(s):  
Iwan Zimmermann ◽  
Tony D. Keene ◽  
Jürg Hauser ◽  
Silvio Decurtins ◽  
Shi-Xia Liu
Keyword(s):  
Hydrogen Bonds ◽  
Point Group ◽  
Van Der Waals Interactions ◽  
Group Symmetry ◽  
Layered Perovskite ◽  
Out Of Plane ◽  
Related Compounds ◽  
Perovskite Type ◽  
Inorganic Layers ◽  
Perovskite Type Structure

The isostructural title compounds, {(C7H7N2)2[SnI4]}n, (1), and {(C7H5F2N2)2[SnI4]}n, (2), show a layered perovskite-type structure composed of anionic {[SnI4]2−}nsheets parallel to (100), which are decorated on both sides with templating benzimidazolium or 5,6-difluorobenzimidazolium cations, respectively. These planar organic heterocycles mainly form N—H...I hydrogen bonds to the terminal I atoms of the corner-sharing [SnI6] octahedra (point group symmetry 2) from the inorganic layer, but not to the bridging ones. This is in contrast to most of the reported structures of related compounds where ammonium cations are involved. Here hydrogen bonding to both types of iodine atoms and thereby a distortion of the inorganic layers to various extents is observed. For (1) and (2), all Sn—I—Sn angles are linear and no out-of-plane distortions of the inorganic layers occur, a fact of relevance in view of the material properties. The arrangement of the aromatic cations is mainly determined through the direction of the N—H...I hydrogen bonds. The coherence between organic bilayers along [100] is mainly achieved through van der Waals interactions.

scholarly journals Synthesis, structure determination and characterization by UV–Vis and IR spectroscopy of bis(diisopropylammonium) cis-dichloridobis(oxalato-κ2 O 1,O 2)stannate(IV)

2019 ◽  
Vol 75 (6) ◽  
pp. 742-745
Author(s):  
Bougar Sarr ◽  
Abdou Mbaye ◽  
Cheikh Abdoul Khadir Diop ◽  
Mamadou Sidibe ◽  
Yoann Rousselin
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Point Group ◽  
Chain Structure ◽  
Chloride Ions ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Chloride Dihydrate ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.

scholarly journals Crystal structure of the coordination polymer [FeIII2{PtII(CN)4}3]

2015 ◽  
Vol 71 (1) ◽  
pp. i1-i2
Author(s):  
Maksym Seredyuk ◽  
M. Carmen Muñoz ◽  
José A. Real ◽  
Turganbay S. Iskenderov
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Point Group ◽  
Three Dimensional ◽  
Title Complex ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Rotation Axes ◽  
Square Planar ◽  
Cyanide Ligands

The title complex, poly[dodeca-μ-cyanido-diiron(III)triplatinum(II)], [FeIII2{PtII(CN)4}3], has a three-dimensional polymeric structure. It is built-up from square-planar [PtII(CN)4]2−anions (point group symmetry 2/m) bridging cationic [FeIIIPtII(CN)4]+∞layers extending in thebcplane. The FeIIatoms of the layers are located on inversion centres and exhibit an octahedral coordination sphere defined by six N atoms of cyanide ligands, while the PtIIatoms are located on twofold rotation axes and are surrounded by four C atoms of the cyanide ligands in a square-planar coordination. The geometrical preferences of the two cations for octahedral and square-planar coordination, respectively, lead to a corrugated organisation of the layers. The distance between neighbouring [FeIIIPtII(CN)4]+∞layers corresponds to the lengtha/2 = 8.0070 (3) Å, and the separation between two neighbouring PtIIatoms of the bridging [PtII(CN)4]2−groups corresponds to the length of thecaxis [7.5720 (2) Å]. The structure is porous with accessible voids of 390 Å3per unit cell.

scholarly journals Crystal structure of langbeinite-related Rb0.743K0.845Co0.293Ti1.707(PO4)3

2015 ◽  
Vol 71 (3) ◽  
pp. 251-253 ◽  
Author(s):  
Nataliia Yu. Strutynska ◽  
Marina A. Bondarenko ◽  
Ivan V. Ogorodnyk ◽  
Vyacheslav N. Baumer ◽  
Nikolay S. Slobodyanik
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Point Group ◽  
Three Dimensional ◽  
Type Structure ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Point Group Symmetry ◽  
Crystallization Method ◽  
Temperature Crystallization

Potassium rubidium cobalt(II)/titanium(IV) tris(orthophosphate), Rb0.743K0.845Co0.293Ti1.707(PO4)3, has been obtained using a high-temperature crystallization method. The obtained compound has a langbeinite-type structure. The three-dimensional framework is built up from mixed-occupied (Co/TiIV)O6octahedra (point group symmetry .3.) and PO4tetrahedra. The K+and Rb+cations are statistically distributed over two distinct sites (both with site symmetry .3.) in the large cavities of the framework. They are surrounded by 12 O atoms.

scholarly journals Crystal structure of (NH4)2[FeII5(HPO3)6], a new open-framework phosphite

2014 ◽  
Vol 70 (11) ◽  
pp. 309-311 ◽  
Author(s):  
Teresa Berrocal ◽  
Jose Luis Mesa ◽  
Edurne Larrea ◽  
Juan Manuel Arrieta
Keyword(s):  
Crystal Structure ◽  
Ir Spectrum ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Hydrothermal Conditions ◽  
Open Framework ◽  
Vibrational Bands

Diammonium hexaphosphitopentaferrate(II), (NH4)2[Fe5(HPO3)6], was synthesized under mild hydrothermal conditions and autogeneous pressure, yielding twinned crystals. The crystal structure exhibits an [FeII5(HPO3)6]2−open framework with NH4+groups as counter-cations. The anionic skeleton is based on (001) sheets of [FeO6] octahedra (one with point-group symmetry 3.. and one with .2.) linked along [001] through [HPO3]2−oxoanions. Each sheet is constructed from 12-membered rings of edge-sharing [FeO6] octahedra, giving rise to channels with a radius ofca3.1 Å in which the disordered NH4+cations are located. The IR spectrum shows vibrational bands typical for phosphite and ammonium groups.

scholarly journals Crystal structure of iron(III) perchlorate nonahydrate

2014 ◽  
Vol 70 (12) ◽  
pp. 477-479 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Liquid Phase ◽  
Low Temperatures ◽  
Point Group ◽  
Minor Component ◽  
Group Symmetry ◽  
Water Molecules ◽  
Point Group Symmetry ◽  
Solid Liquid

Since the discovery of perchlorate salts on Mars and the known occurrence of ferric salts in the regolith, there is a distinct possibility that the title compound could form on the surface of Mars. [Fe(H2O)6](ClO4)3·3H2O was crystallized from aqueous solutions at low temperatures according to the solid–liquid phase diagram. It consists of Fe(H2O)6octahedra (point group symmetry -3.) and perchlorate anions (point group symmetry .2) as well as non-coordinating water molecules, as part of a second hydrogen-bonded coordination sphere around the cation. The perchlorate appears to be slightly disordered, with major–minor component occupancies of 0.773 (9):0.227 (9).

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