Crystal structure of coalingite

1971 ◽  
Vol 38 (295) ◽  
pp. 286-294 ◽  
Author(s):  
J. Pastor-Rodriguez ◽  
H. F. W. Taylor

SummaryThe crystal structure of coalingite (Mg10Fe2(OH)24(CO3)·2H2O) has been determined using single-crystal X-ray methods. The mineral is trigonal, with space group Rm, aH = 3·12, cH = 37·4 Å, Z = ½, and (0001) cleavage. The structure is of a layer type, and is based on a structural element about 12·5 Å thick in the c-direction and consisting of two brucite-like layers and one disordered layer containing carbonate ions and water molecules and resembling those in sjögrenite and pyroaurite. The unit cell comprises three of these structural elements stacked together in the c-direction. The Mg2+ and Fe3+ ions are randomly distributed among all the octahedral sites of the brucite-like layers. The structure closely resembles those of sjögrenite and pyroaurite, but has two brucite-like layers between each CO32−−H2O layer where these have one. There is a tendency to random interstratification, and the crystals appear to contain intergrown regions of brucite and of sjögrenite or pyroaurite. Coalingite-K probably has a similar structure, but with three brucite-like layers between each -H2O layer; its idealized formula is probably Mg16Fe2(OH)36(CO3).2H2O.

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.


1988 ◽  
Vol 43 (4) ◽  
pp. 497-498
Author(s):  
Franz A. Mautner ◽  
Harald Krischner ◽  
Christoph Kratky

Abstract The crystal structure of Rb2Ca(N3)4 · 4H2O has been determined by single crystal X-ray methods. The compound is isotypic with K2Ca(N3)4 · 4 H2O and crystallizes in the orthorhombic space group Ccca, Z = 4, a = 1949.1(12) pm, b = 1099.5(3) pm, c - 622.2(1) pm.


2019 ◽  
Vol 31 (8) ◽  
pp. 1755-1761
Author(s):  
K. Naresh ◽  
B.N. Sivasankar

A new copper complex of pyridine-2,6-dicarboxylate containing hydrazinium cation, formulated as (N2H5)2[Cu(PDC)2]·4H2O (PDC = pyridine-2,6-dicarboxylate) has been synthesized from copper(II) nitrate, hydrazine hydrate and pyridine-2,6-dicarboxylic acid as a single crystal and characterized by elemental analysis and spectroscopic (IR and UV-visible), thermal (TG/DTG), single crystal X-ray diffraction and biological studies. A six-coordinate complex with a distorted octahedral geometry around Cu(II) ion is proposed and confirmed by X-ray single crystal method. The structure reveals that two pyridine-2,6-dicarboxylate species acting as tridentate ligands and hydrazinium cation present as a counter ion along with non-coordinated four water molecules. The structural units of copper(II) is mutually held by the hydrogen bonds and π···π and C–O···π interactions. The copper(II) complex is connected to one another via O–H···O hydrogen bonds, forming water clusters, which plays an important role in the stabilization of the crystal structure. In the water clusters, the water molecules are trapped by the cooperative association of coordination interactions as well as hydrogen bonds. Both cation and anion interactions and crystal from various types of intermolecular contacts and their importance were explored using Hirshfeld surface analysis. This indicates that O···H/H···O interactions are the superior interactions conforming excessive H-bond in the molecular structure. The interaction of copper(II) complex with calf thymus DNA (CT-DNA) was investigated by electronic absorption spectroscopic technique. The electronic evidence strongly shows that the compound interacts with calf thymus through intercalation with a binding constant of Kb = 5.7 × 104 M–1.


1989 ◽  
Vol 44 (8) ◽  
pp. 942-945 ◽  
Author(s):  
Wolfgang Schnick

Phosphorothionic triamide SP(NH2)3 is obtained by slow addition of SPCl3 dissolved in dry CH2Cl2 to a satured solution of NH3 in CH2Cl2 at —50°C. Ammonium chloride is removed from the resulting precipitate by treatment with HNEt2 followed by extraction with CH2Cl2. Coarse crystalline SP(NH2)3 is obtained after recrystallization from dry methanol. The crystal structure of SP(NH2)3 has been determined by single crystal X-ray methods (Pbca; a = 922.3(1), b = 953.8(1), c = 1058.4(2) pm, Z = 8). In the crystals the molecules show non-crystallographic point symmetry C8. The P—S bond (195.4(1) pm) is slightly longer than in SPCl3. From P—N bond lengths of about 166 pm a significant electrostatic strengthening of the P—N single bonds is assumed. Weak intermolecular hydrogen bonding interactions (N —H · · · N ≥ 329.5 pm; N — H · · · S ≥ 348.3 pm) are observed.Investigation of thermal properties shows a melting temperature of 115°C for SP(NH2)3. According to combined DTA/TG and MS investigations above this temperature the compound decomposes by evolution of H2S and NH3 to yield amorphous phosphorus(V)nitride.


Author(s):  
Kurt Sahl ◽  
Niranjan Deb Chatterjee

AbstractThe crystal structure of synthetic bicchulite was determined with single-crystal x-ray methods (


1994 ◽  
Vol 49 (6) ◽  
pp. 721-728 ◽  
Author(s):  
Gerhard Cordier ◽  
Volker Müller

Na17Ga29ln12 (a = 2178.5(5) pm, Fd3m, Z = 8, R = 0.081) and K17In41 (a = 2424.1(5) pm, Fd3m, Z = 8, R = 0.060) have been prepared from the elements and characterized by single crystal X -ray methods. Na17Ga29ln12 is a ternary variant of K17In41. The crystal structure of Na17Ga29ln12 contains Ga12 icosahedra (In 12 icosahedra in K17In41) and truncated In12 tetrahedra which are four-capped and centred by additional Ga atoms (In atoms in K17In41). The packing of icosahedra and truncated tetrahedra leads to interpenetrating Samson polyhedra. The Ga12 icosahedra (In12 icosahedra in K17In41) take the Cu positions of the MgCu2 type, the In12 clusters take the positions of the Mg atoms of this structure type. The alkali atoms in Na17Ga29In12 and K17In41 occupy the deltahedral faces of the icosahedra and form pentagonal dodecahedra


1980 ◽  
Vol 35 (6) ◽  
pp. 672-675 ◽  
Author(s):  
Chr. L. Teske

Abstract Ba2ZnGe2S6O was prepared for the first time and the crystal structure determined by using single crystal X-ray methods. The space group is D32d-P4̄21m, tetragonal (No. 113). Lattice constants: a = 963.59 ± 0.22; c = 645.06 ± 0.25 pm. The tetrahedral framework structure is described and discussed. Zn is linked only to sulfur. The oxygen belongs to the coordination sphere of Ge and Ba.


1967 ◽  
Vol 22 (9) ◽  
pp. 1440-1451 ◽  
Author(s):  
Ingo Berthold ◽  
Alarich Weiss

The crystal structure of Na2S2O6·2 H2O has been refined by means of single crystal X-ray intensity data. The structure of the isotypic Li2S2O6·2 H20 was also determined by single crystal studies. Two dimensional differential FOURIER synthesis revealed the approximate positions of the hydrogen atoms. From 1H-NMR investigations, the crystal structure, and information gained by IR spectroscopy the complete atomic arrangement in these two substances was obtained. The influence of the dynamical behaviour of the water molecules is taken into account in determining the hydrogen positions.


1982 ◽  
Vol 37 (12) ◽  
pp. 1534-1539 ◽  
Author(s):  
D. Babel

The crystal structure of the cubic compound [N(CH3)4]2CsFe(CN)6 was determined by X-ray methods: a = 2527.4(6) pm, space group Fd3c, Z = 32, Rg = 0.028 (260 independent single crystal reflections). The resulting distances within the practically undistorted Fe (CN)63- - octahedron are Fe-C = 193.4(6) and C-N = 115.7(7) pm. Compared to the ideal elpasolite structure of space group Fm3m, Z = 4, the octahedra are rotated by 7.4° through their 3 axis. This is discussed as caused by steric requirements of the tetramethylammonium groups (N-C = 148.4(10) and 149.1(38) pm, resp.). Three quarters of them, of which also the hydrogen positions could be located, are well oriented. The remaining quarter shows orientational disorder to approach similar contact distances as the other N(CH3)4+ ion exhibits between the methyl groups and the nitrogen ends of the anions


1972 ◽  
Vol 27 (3) ◽  
pp. 296-301 ◽  
Author(s):  
Chr. L. Teske ◽  
Hk. Müller-Buschbaum

The preparation and chemical properties of barium-oxocuprat (I) inclusive the results of the crystal structure determination by single crystal X-ray investigations are described. BaCu2O2 crystallizes isotypically with SrCu2O2 . (a = 5.72 and c = 10.06 Å. Spacegroup : D194h - 141/amd.) The influence of the bigger Ba2⨁-ion on the oxigenconfiguration surrounding the cations is discussed. It seems that the stretched O - Cu - O-dumbell is an invariable structural element in the oxocompounds of copper (I), which is shown by comparison of already known oxocuprates (I) . Only the way of interchainment varies evidently with stoichiometry.


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