scholarly journals Crystal structures of Sr(ClO4)2·3H2O, Sr(ClO4)2·4H2O and Sr(ClO4)2·9H2O

2014 ◽  
Vol 70 (12) ◽  
pp. 510-514 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt
Keyword(s):  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Water Molecules ◽  
Point Group Symmetry ◽  
Rotation Axes ◽  
Dimensional Network ◽  
Tricapped Trigonal Prism ◽  
Trigonal Prismatic Coordination ◽  
Solid Liquid

The title compounds, strontium perchlorate trihydrate {di-μ-aqua-aquadi-μ-perchlorato-strontium, [Sr(ClO4)2(H2O)3]n}, strontium perchlorate tetrahydrate {di-μ-aqua-bis(triaquadiperchloratostrontium), [Sr2(ClO4)4(H2O)8]} and strontium perchlorate nonahydrate {heptaaquadiperchloratostrontium dihydrate, [Sr(ClO4)2(H2O)7]·2H2O}, were crystallized at low temperatures according to the solid–liquid phase diagram. The structures of the tri- and tetrahydrate consist of Sr2+cations coordinated by five water molecules and four O atoms of four perchlorate tetrahedra in a distorted tricapped trigonal–prismatic coordination mode. The asymmetric unit of the trihydrate contains two formula units. Two [SrO9] polyhedra in the trihydrate are connected by sharing water molecules and thus forming chains parallel to [100]. In the tetrahydrate, dimers of two [SrO9] polyhedra connected by two sharing water molecules are formed. The structure of the nonahydrate contains one Sr2+cation coordinated by seven water molecules and by two O atoms of two perchlorate tetrahedra (point group symmetry ..m), forming a tricapped trigonal prism (point group symmetrym2m). The structure contains additional non-coordinating water molecules, which are located on twofold rotation axes. O—H...O hydrogen bonds between the water molecules as donor and ClO4tetrahedra and water molecules as acceptor groups lead to the formation of a three-dimensional network in each of the three structures.

scholarly journals Crystal structure of tin(IV) chloride octahydrate

2014 ◽  
Vol 70 (12) ◽  
pp. 480-482 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt
Keyword(s):  
Crystal Structure ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Water Molecules ◽  
Point Group Symmetry ◽  
Complex Molecules ◽  
Lattice Water ◽  
Dimensional Network ◽  
Solid Liquid

The title compound, [SnCl4(H2O)2]·6H2O, was crystallized according to the solid–liquid phase diagram at lower temperatures. It is built-up of SnCl4(H2O)2octahedral units (point group symmetry 2) and lattice water molecules. An intricate three-dimensional network of O—H...O and O—H...Cl hydrogen bonds between the complex molecules and the lattice water molecules is formed in the crystal structure.

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 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).

scholarly journals (μ-Methylenediphosphonato-κ4 O,O′:O′′,O′′′)bis[(ethylenediamine-κ2 N,N′)palladium(II)] tetrahydrate

2018 ◽  
Vol 74 (12) ◽  
pp. 1838-1841
Author(s):  
Viktoriya V. Dyakonenko ◽  
Alexandra N. Kozachkova ◽  
Natalia V. Tsaryk ◽  
Vasily I. Pekhnyo ◽  
Ruslan V. Lavryk
Keyword(s):  
Hydrogen Bonds ◽  
Rotation Axis ◽  
Point Group ◽  
Three Dimensional ◽  
Water Layer ◽  
Group Symmetry ◽  
Water Molecules ◽  
Dimensional Network ◽  
Binuclear Molecule ◽  
Square Planar

The title compound, [Pd2(C2H8N2)2(CH2O6P2)]·4H2O, comprises of a binuclear molecule (point group symmetry 2), with a twofold rotation axis running through the central C atom of the methylenediphosphonate (MDP) anion. The PdII atom has a square-planar coordination environment defined by the N atoms of a bidentate ethylenediamine (en) ligand and two O atoms of the bridging MDP anion. In the crystal structure, metal complexes are arranged in layers parallel (001) and are sandwiched between layers containing disordered water molecules of crystallization. Extensive intralayer hydrogen bonds of the type N—H...O in the metal complex layer and O—H...O in the water layer, as well as O—H...O hydrogen bonds between the two types of layers, lead to the formation a three-dimensional network structure. The two lattice water molecules are each equally disordered over two positions.

scholarly journals Crystal structure of tris(ethylenediammonium) hexasulfatopraseodymium(III) hexahydrate

2014 ◽  
Vol 70 (10) ◽  
pp. 235-237 ◽  
Author(s):  
Peter Held
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Point Group ◽  
Three Dimensional ◽  
Group Symmetry ◽  
Water Molecules ◽  
Point Group Symmetry ◽  
Framework Structure ◽  
Crystal Water ◽  
Medium Strength

In the title salt, (C2H10N2)3[Pr2(SO4)6]·6H2O, the PrIIIcation is surrounded ninefold by five sulfate groups (two monodentate and three chelating) and by one water molecule [range of Pr—O bond lengths 2.383 (3) to 2.582 (3) Å]. The [Pr(SO4)5(H2O)] groups are arranged in sheets parallel to (010). Two crystal water molecules and two ethylenediammonium cations (one with point group symmetry -1) connect the sheetsviaO—H...O and N—H...O hydrogen bonds from weak up to medium strength into a three-dimensional framework structure.

scholarly journals Crystal structures of ZnCl2·2.5H2O, ZnCl2·3H2O and ZnCl2·4.5H2O

2014 ◽  
Vol 70 (12) ◽  
pp. 515-518 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt
Keyword(s):  
Phase Diagram ◽  
Room Temperature ◽  
Three Dimensional ◽  
Water Molecules ◽  
Tetrahedral Coordination ◽  
Lattice Water ◽  
Octahedral Environment ◽  
Dimensional Network ◽  
Different Types ◽  
Solid Liquid

The formation of different complexes in aqueous solutions is an important step in understanding the behavior of zinc chloride in water. The structure of concentrated ZnCl2solutions is governed by coordination competition of Cl−and H2O around Zn2+. According to the solid–liquid phase diagram, the title compounds were crystallized below room temperature. The structure of ZnCl2·2.5H2O contains Zn2+both in a tetrahedral coordination with Cl−and in an octahedral environment defined by five water molecules and one Cl−shared with the [ZnCl4]2−unit. Thus, these two different types of Zn2+cations form isolated units with composition [Zn2Cl4(H2O)5] (pentaaqua-μ-chlorido-trichloridodizinc). The trihydrate {hexaaquazinc tetrachloridozinc, [Zn(H2O)6][ZnCl4]}, consists of three different Zn2+cations, one of which is tetrahedrally coordinated by four Cl−anions. The two other Zn2+cations are each located on an inversion centre and are octahedrally surrounded by water molecules. The [ZnCl4] tetrahedra and [Zn(H2O)6] octahedra are arranged in alternating rows parallel to [001]. The structure of the 4.5-hydrate {hexaaquazinc tetrachloridozinc trihydrate, [Zn(H2O)6][ZnCl4]·3H2O}, consists of isolated octahedral [Zn(H2O)6] and tetrahedral [ZnCl4] units, as well as additional lattice water molecules. O—H...O hydrogen bonds between the water molecules as donor and ZnCl4tetrahedra and water molecules as acceptor groups leads to the formation of a three-dimensional network in each of the three structures.

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 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 Sc1.91In1.39Mo15Se19, containing Mo6and Mo9clusters

2015 ◽  
Vol 71 (7) ◽  
pp. 760-762 ◽  
Author(s):  
Patrick Gougeon ◽  
Philippe Gall ◽  
Diala Salloum
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Point Group ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Acta Cryst ◽  
Rotation Axes ◽  
Set Up

The structure of scandium indium pentadecamolybdenum nonadecaselenide, Sc1.91In1.39Mo15Se19, is isotypic with In2.9Mo15Se19[Grüttneret al.(1979).Acta Cryst.B35, 285–292]. It is characterized by two cluster units Mo6Sei8Sea6and Mo9Sei11Sea6(whereirepresents inner andaapical atoms) that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2band 2cand have point-group symmetry -3 and -6, respectively. The clusters are interconnected through additional Mo—Se bonds. Sc—Se and In—Se bonds complete the structural set-up. In the title compound, the Sc3+cations replace the trivalent indium atoms present in In2.9Mo15Se19, and a deficiency is observed at the monovalent indium site. One Mo, one Se and the Sc atom are situated on mirror planes, whereas two other Se atoms and the In atom are situated on threefold rotation axes.

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.

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