scholarly journals Kristallstruktur des „supramolekularen“ Silber(I)thiocyanat-Cyclam-Komplexes [Ag(SCN)·(C10H24N4)1/2] / Crystal Structure of the “Supramolecular” Silver(I)thiocyanate Cyclam Complex [Ag(SCN)·(C10H24N4)1/2]

1994 ◽  
Vol 49 (2) ◽  
pp. 211-214 ◽  
Author(s):  
Joachim Pickardt ◽  
Jing Shen

Colourless crystals of the 1,4,8,11-tetraazacyclotetradecane (cyclam) silver(I) thiocyanate complex [Ag(SCN) · (C10H24N4)1/2] were obtained by diffusion of a solution of cyclam in ethanol into an aqueous solution of K[Ag(SCN)2], The crystals are tetragonal, space group P42/n, Z = 8, a = b - 1256.0(4), c = 1185.5(9) pm. The SCN groups act as μ3 ligands, the S atoms of two SCN groups bridge two neighbouring Ag ions, which are only 297.5 pm apart, forming butterfly-like Ag2S2 moieties, the N atoms of the SCN groups form bonds to Ag atoms of adjacent Ag2S2 moieties. Two Ag2S2 units are again connected by cyclam molecules which act as two-dentate bridging ligands. Thus a complicated three-dimensional “supramolecular” structure results.

1994 ◽  
Vol 49 (3) ◽  
pp. 321-324 ◽  
Author(s):  
Joachim Pickardt ◽  
Gill-Taik Gong ◽  
Dietmar Röleke

Abstract Crystals of the adduct Hg(SCN)2 · 2HgCl2·2C6H12N4 were obtained from an aqueous solution containing 0.1 mol/l hexamethylenetetramine and 0.05 mol/l potassium thiocyanate and mercury(II) chloride. The compound crystallizes monoclinically; space group P21/n, a = 767.3(4), b = 1854.7(7), c = 872.5(7) pm, and β = 101.48(5)°. The structure consists of a net­ work of chains -Cl-Hg-Cl-Hg- and -(Cl-Hg-)2NCS-Hg-SCN-(Hg-Cl)2-which share common Hg atoms and form distorted hexagonal and trigonal channels. The hexamethylenetetramine molecules lie in the hexagonal channels. They act as μ3 bridging ligands, forming bonds to two Hg atoms in a given layer, and an additional bond to a Hg atom a neighbouring layer.


2007 ◽  
Vol 63 (11) ◽  
pp. m2826-m2827
Author(s):  
Wen-Dong Song ◽  
De-Yun Ma ◽  
Chao-Hua Zhang

The title erbium coordination polymer, {[Er2(C8H4O4)3(H2O)2]·H2O} n , was obtained by the hydrothermal reaction of ErCl3 with benzene-1,3-dicarboxylic acid (1,3-BDC) in alkaline aqueous solution. Each of the two crystallographically independent ErIII ions is seven-coordinate and has a distorted pentagonal–bipyramidal geometry. One Er centre is coordinated by seven O atoms from six 1,3-BDC ligands and the other Er centre is surrounded by five O atoms from five 1,3-BDC ligands and two water molecules. The bridging ligands, which have two different coordination modes, link the metal centres to form a three-dimensional network with channels parallel to the b axis in which solvent water molecules are located. The crystal structure is stabilized by intra- and intermolecular O—H...O hydrogen-bonding interactions. One benzene ring and the solvent water molecule are independently disordered over two positions each, with occupancy ratios of 0.595 (2):0.405 (2) and 0.661 (1):0.339 (1), respectively.


2014 ◽  
Vol 70 (11) ◽  
pp. 1054-1056 ◽  
Author(s):  
Qiang Li ◽  
Hui-Ting Wang

A new cadmium dicyanamide complex, poly[tetramethylphosphonium [μ-chlorido-di-μ-dicyanamido-κ4N1:N5-cadmium(II)]], [(CH3)4P][Cd(NCNCN)2Cl], was synthesized by the reaction of tetramethylphosphonium chloride, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each CdIIatom is octahedrally coordinated by four terminal N atoms from four anionic dicyanamide (dca) ligands and by two chloride ligands. The dicyanamide ligands play two different roles in the building up of the structure; one role results in the formation of [Cd(dca)Cl]2building blocks, while the other links the building blocks into a three-dimensional structure. The anionic framework exhibits a solvent-accessible void of 673.8 Å3, amounting to 47.44% of the total unit-cell volume. The cavities in the network are occupied by pairs of tetramethylphosphonium cations.


Author(s):  
Joseph R. Smyth

AbstractTechniques allowing single-crystal investigations on the precession camera up to the melting point of platinum have been developed. The crystal structure of protoenstatite has been refined from three-dimensional intensity data obtained at 1100°C using a crystal of enstatite from the Norton County, Kansas meteorite. The space group is


2015 ◽  
Vol 71 (10) ◽  
pp. o719-o720 ◽  
Author(s):  
Tomohiko Ishii ◽  
Tatsuya Senoo ◽  
Akihide Yoshihara ◽  
Kazuhiro Fukada ◽  
Genta Sakane

The title compound, C6H12O6, was crystallized from an aqueous solution of equimolar mixture of D- and L-fructose (1,3,4,5,6-pentahydroxyhexan-2-one,arabino-hexulose or levulose), and it was confirmed that D-fructose (or L-fructose) formed β-pyranose with a2C5(or5C2) conformation. In the crystal, two O—H...O hydrogen bonds between the hydroxy groups at the C-1 and C-3 positions, and at the C-4 and C-5 positions connect homochiral molecules into a column along theaaxis. The columns are linked by other O—H...O hydrogen bonds between D- and L-fructose molecules, forming a three-dimensional network.


2008 ◽  
Vol 41 (6) ◽  
pp. 1182-1186 ◽  
Author(s):  
Ivan Orlov ◽  
Lukas Palatinus ◽  
Gervais Chapuis

The symmetry of a commensurately modulated crystal structure can be described in two different ways: in terms of a conventional three-dimensional space group or using the superspace concept in (3 +d) dimensions. The three-dimensional space group is obtained as a real-space section of the (3 +d) superspace group. A complete network was constructed linking (3 + 1) superspace groups and the corresponding three-dimensional space groups derived from rational sections. A database has been established and is available at http://superspace.epfl.ch/finder/. It is particularly useful for finding common superspace groups for various series of modular (`composition-flexible') structures and phase transitions. The use of the database is illustrated with examples from various fields of crystal chemistry.


Author(s):  
P. Bayliss ◽  
N. C. Stephenson

SummaryThe crystal structure of gersdorffite (III) has been examined with three-dimensional Weissenberg X-ray diffraction data. The unit cell is isometric with a 5·6849 ± 0·0003 Å, space group PI, and four formula units per cell. This structure has the sulphur and arsenic atoms equally distributed over the non-metal atom sites of pyrite. All atoms show significant random displacements from the ideal pyrite positions to produce triclinic symmetry, which serves to distinguish this mineral from a disordered cubic gersdorffite (II) and a partially ordered cubic gersdorffite (I). Factors responsible for the atomic distortions are discussed.


1993 ◽  
Vol 48 (4) ◽  
pp. 452-456 ◽  
Author(s):  
Matthias Asbrand ◽  
Brigitte Eisenmann

The metallic grey compound Na2[SnAs2] was prepared from a molten mixture of the elements. Na2[SnAs2] crystallizes in the tetragonal space group I41/acd, Z = 32, with the lattice constants: a = 1416.6(3) pm, c = 2119.1(4) pm, c/a = 1.4959.In the crystal structure four [SnAs4] tetrahedra are connected by common corners forming adamantan analogous [Sn4As10] units. The further connection of these tetrameric moieties by the terminal As atoms results in a three-dimensional framework ∞3[SnAs22-], in which the Na atoms occupy distorted tetrahedral and octahedral holes.


1995 ◽  
Vol 50 (4) ◽  
pp. 577-580 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum

Single crystals of (Cu0.22Mg0.78)BaNd2Mo4O16 have been prepared by crystallization from melts and investigated by X-ray methods. The compound crystallizes monoclinically, space group C62h - C12/c1, Z = 4, a = 5.351(1), b = 12.891(2), c = 19.391(4) Å,β = 90.899(14)° and is isotypic to CuKHo2Mo4O16. The crystal structure is dominated by BaO10 and NdO8 polyhedra forming a three-dimensional polyhedra network, which is filled by axially distorted (Cu,Mg)O6 octahedra and MoO4 tetrahedra.


1991 ◽  
Vol 46 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Klaus Brodersen ◽  
Jörg Zimmerhackl

1,13-Bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane-dimercury(I)-diperchlorate is formed by the reaction of 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane in ethanol with an aqueous solution of dimercury(I)-diperchlorate.It crystallizes in the triclinic space group P Ī with a = 1020.6(2), b = 1200.6(8), c = 1441.1(6) pm , α = 69.60(5)°, β = 83.04(13)°, y = 66.53(4)° and Z = 2. The crystal structure was determined by X -ray diffraction and refined to an R-value o f 0.079. The Hg22+ -ion is coordinated to both nitrogen atoms and four oxygen atoms of one molecule of the ligand. By changing four C - O torsional angles from trans to gauche, the ligand adopts a helical, chiral configuration around the Hg22+-ion. The CIO4--ions are not coordinated to the Hg22+-ion.


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