scholarly journals Dimanganese(II) hydroxide vanadate, Mn2(OH)[VO4]

2014 ◽  
Vol 70 (7) ◽  
pp. i33-i33 ◽  
Author(s):  
Kewen Sun ◽  
Angela Möller
Keyword(s):  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Point Group Symmetry ◽  
Distorted Octahedral Coordination ◽  
Trigonal Bipyramidal ◽  
Distorted Octahedral ◽  
Coordination Spheres ◽  
Distorted Trigonal Bipyramidal

Dimanganese(II) hydroxide vanadate was obtained from hydrothermal reactions. The crystal structure of the title compound is isotypic with that of Zn2(OH)[VO4]. Three crystallographically independent Mn2+ions are present, one (site symmetry .m.) with a distorted trigonal-bipyramidal and two (site symmetries .m. and 1) with distorted octahedral coordination spheres. These polyhedra are linked through common edges, forming a corrugated layer-type of structure extending parallel to (100). A three-dimensional framework resultsviaadditional Mn—O—V—O—Mn connectivities involving the two different tetrahedral [VO4] units (each with point-group symmetry .m.). O—H...O hydrogen bonds (one bifurcated) between the OH functions (both with point-group symmetry .m.) and the [VO4] units complete this arrangement.

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 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 alluaudite-type NaMg3(HPO4)2(PO4)

2015 ◽  
Vol 71 (7) ◽  
pp. 813-815 ◽  
Author(s):  
Ahmed Ould Saleck ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Cyrille Mercier ◽  
Claudine Follet ◽  
...  
Keyword(s):  
Point Group ◽  
Three Dimensional ◽  
The Other ◽  
Group Symmetry ◽  
Strong Hydrogen Bond ◽  
Site Symmetry ◽  
Point Group Symmetry ◽  
Hydrogen Phosphate ◽  
Hydrothermal Conditions ◽  
Different Types

The title compound, sodium trimagnesium bis(hydrogen phosphate) phosphate, was obtained under hydrothermal conditions. In the crystal, two types of [MgO6] octahedra, one with point group symmetry 2, share edges to build chains extending parallel to [10-1]. These chains are linked together by two kinds of phosphate tetrahedra, HPO4and PO4, the latter with point group symmetry 2. The three-dimensional framework delimits two different types of channels extending along [001]. One channel hosts the Na+cations (site symmetry 2) surrounded by eight O atoms, with Na—O bond lengths varying between 2.2974 (13) and 2.922 (2) Å. The OH group of the HPO4tetrahedron points into the other type of channel and exhibits a strong hydrogen bond to an O atom of the PO4tetrahedron on the opposite side.

scholarly journals Structure cristalline de type alluaudite KNa5Mn3(MoO4)6

2015 ◽  
Vol 71 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Chahira Bouzidi ◽  
Wafa Frigui ◽  
Mohamed Faouzi Zid
Keyword(s):  
Solid State ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Dimensional Structure ◽  
Site Symmetry ◽  
Structural Description ◽  
Point Group Symmetry ◽  
The Third ◽  
New Phase

The new phase potassium pentasodium trimanganese hexakis(molybdate), KNa5Mn3Mo6O24, has been synthesized using solid-state methods. The structure is composed ofM2O10(M= Mn, Na) dimers and MoO4tetrahedra (point group symmetry 2) sharing corners and forming layers parallel to (100), which are linkedviacommon corners of another type ofMO4tetrahedra, forming a three-dimensional structure with two types of large channels along [001] in which two types of Na+cations (one with site symmetry 2, one with -1) and K+cations (site symmetry 2, half-occupation) are located. Mn2+and the third type of Na+cations are located at the same siteMwith occupancies of 0.75 and 0.25, respectively. A comparative structural description is provided between the structure of the title compound and those of the related phases Cu1.35Fe3(PO4)3and NaAgFeMn2(PO4)3.

scholarly journals Thortveitite-type Tm2Si2O7

2014 ◽  
Vol 70 (7) ◽  
pp. i34-i35 ◽  
Author(s):  
Volker Kahlenberg ◽  
Paul Aichholzer
Keyword(s):  
Ambient Pressure ◽  
Point Group ◽  
Structure Type ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Cation Site ◽  
Bond Lengths ◽  
Flux Synthesis ◽  
Distorted Octahedral ◽  
The Individual

Single crystals of dithulium disilicate, Tm2Si2O7, were obtained in flux synthesis experiments in the system SiO2–Tm2O3–LiF at ambient pressure. The compound belongs to the group of sorosilicates,i.e.it is based on [Si2O7]-units and crystallizes in the thortveitite (Sc2Si2O7) structure type. The Tm3+cation (site symmetry .2.) occupies a distorted octahedral site, with Tm—O bond lengths in the range 2.217 (4)–2.289 (4) Å. Each of the octahedra shares three of its edges with adjacent [TmO6] groups, resulting in the formation of layers parallel to (001). The individual [SiO4] tetrahedra are more regular,i.e.the differences between the bond lengths between Si and the bridging and non-bridging O atoms are not very pronounced. The layers containing the octahedra and the sheets containing the [Si2O7] groups (point group symmetry 2/m) form an alternating sequence. Linkage is provided by sharing common oxygen vertices.

(Hexafluorosilicato-κ2F,F′)bis(1,10-phenanthroline-κ2N,N′)zinc(II) methanol monosolvate

2013 ◽  
Vol 69 (10) ◽  
pp. 1112-1115 ◽  
Author(s):  
Rüdiger W. Seidel ◽  
Christina Dietz ◽  
Jürgen Breidung ◽  
Richard Goddard ◽  
Iris M. Oppel
Keyword(s):  
Density Functional ◽  
Crystal Packing ◽  
Point Group ◽  
Solvent Molecule ◽  
Title Complex ◽  
Group Symmetry ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral

The title compound, [Zn(SiF6)(C12H8N2)2]·CH3OH, contains a neutral heteroleptic tris-chelate ZnIIcomplex,viz.[Zn(SiF6)(phen)2] (phen is 1,10-phenanthroline), exhibiting approximate molecularC2point-group symmetry. The ZnIIcation adopts a severely distorted octahedral coordination. As far as can be ascertained, the title complex represents the first structurally characterized example of a ZnIIcomplex bearing a bidentate-bound hexafluorosilicate ligand. A density functional theory study of the isolated [Zn(SiF6)(phen)2] complex was undertaken to reveal the influence of crystal packing on the molecular structure of the complex. In the crystal structure, the methanol solvent molecule forms a hydrogen bond to one F atom of the hexafluorosilicate ligand. The hydrogen-bonded assemblies so formed are tightly packed in the crystal, as indicated by a high packing coefficient (74.1%).

scholarly journals Point-group symmetry detection in three-dimensional charge density of biomolecules

2019 ◽  
Vol 36 (7) ◽  
pp. 2237-2243
Author(s):  
Cyril F Reboul ◽  
Simon Kiesewetter ◽  
Dominika Elmlund ◽  
Hans Elmlund
Keyword(s):  
Charge Density ◽  
Single Particle ◽  
Statistical Tests ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Density Maps ◽  
Point Groups ◽  
Density Map

Abstract Motivation No rigorous statistical tests for detecting point-group symmetry in three-dimensional (3D) charge density maps obtained by electron microscopy (EM) and related techniques have been developed. Results We propose a method for determining the point-group symmetry of 3D charge density maps obtained by EM and related techniques. Our ab initio algorithm does not depend on atomic coordinates but utilizes the density map directly. We validate the approach for a range of publicly available single-particle cryo-EM datasets. In straightforward cases, our method enables fully automated single-particle 3D reconstruction without having to input an arbitrarily selected point-group symmetry. When pseudo-symmetry is present, our method provides statistics quantifying the degree to which the 3D density agrees with the different point-groups tested. Availability and implementation The software is freely available at https://github.com/hael/SIMPLE3.0.

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 structures of two alkaline earth (M= Ba and Sr) dimanganese(II) iron(III) tris(orthophosphates)

2017 ◽  
Vol 73 (5) ◽  
pp. 767-770
Author(s):  
Ghaleb Alhakmi ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structures ◽  
Alkaline Earth ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Solid State Reactions ◽  
Site Symmetry ◽  
Orthorhombic System ◽  
Group Type ◽  
Alkaline Earth Cations

Two new orthophosphates, BaMn2Fe(PO4)3[barium dimanganese(II) iron(III) tris(orthophosphate)] and SrMn2Fe(PO4)3[strontium dimanganese(II) iron(III) tris(orthophosphate)], were synthesized by solid-state reactions. They are isotypic and crystallize in the orthorhombic system with space group typePbcn. Their crystal structures comprise infinite zigzag chains of edge-sharing FeO6octahedra (point group symmetry .2.) and Mn2O10double octahedra running parallel to [001], linked by two types of PO4tetrahedra. The so-formed three-dimensional framework delineates channels running along [001], in which the alkaline earth cations (site symmetry .2.) are located within a neighbourhood of eight O atoms.

The polar phase of Li2Ge4O9at 298, 150 and 90 K

2013 ◽  
Vol 69 (10) ◽  
pp. 1091-1095 ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt
Keyword(s):  
Three Dimensional ◽  
Group Symmetry ◽  
Site Symmetry ◽  
Polar Phase ◽  
Orthorhombic Space Group ◽  
Ferroelectric State ◽  
Space Group Symmetry ◽  
Space Group ◽  
Coordination Spheres

Dilithium tetragermanate is orthorhombic, space groupP21ca, at 298 K, and is thus in a polar and probably a ferroelectric state. The structure contains two independent Li, four Ge and nine O atoms, all on general positions with site symmetry 1. Three tetrahedrally coordinated Ge positions form crumpled crankshaft-like chains, forming sheets within theacplane, and these are interconnected by the fourth, octahedrally coordinated, Ge sites along thebdirection. The GeO4tetrahedra and GeO6octahedra form a three-dimensional framework containing two different cavities, hosting the two 4+1-coordinated Li sites. Cooling to 90 K does not alter the space-group symmetry; the tetrahedral chains behave as a rigid unit and changes occur mainly within the Li coordination spheres.

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