The crystal structure of dundasite

1972 ◽  
Vol 38 (297) ◽  
pp. 564-569 ◽  
Author(s):  
G. Cocco ◽  
L Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Three Dimensional ◽  
Water Molecules ◽  
Intensity Data ◽  
Chemical Formula ◽  
Orthorhombic Space Group ◽  
Coordination Polyhedra ◽  
Patterson Function ◽  
Pb Ions

SummaryThe crystal structure of dundasite from Gonnesa (Italy) was solved by a three-dimensional Patterson function computed using intensity data collected photographically by the Weissenberg method, and refined by successive Fourier maps and least-squares cycles to an R index 0·.066 for 505 independent observed reflections.The chemical formula resulting from the structural analysis is PbAl2(CO3)2(OH)4·H2O. The mineral is orthorhombic, space group Pbnm, with a 9·08 Å, b 16·37 Å, c 5·62 Å. The dundasite structure consists of a three-dimensional framework of coordination polyhedra around Pb and Al. Pb ions are coordinated by nine oxygen atoms with distances ranging from 2·53 to 2·91 Å. Al ions show the usual octahedral coordination with average Al-O distance 1.90 Å. C-O mean distances are 1·28 and 1·27 Å for the two non-equivalent CO3 groups. The water molecules are not coordinated by the cations.

The crystal structure of buttgenbachite

1973 ◽  
Vol 39 (303) ◽  
pp. 264-270 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi ◽  
A. R. Zanzari
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Least Squares ◽  
Three Dimensional ◽  
Intensity Data ◽  
Cell Content ◽  
Space Group ◽  
Patterson Function

SummaryThe crystal structure of buttgenbachite from Likasi (Congo) was solved by a three- dimensional Patterson function, computed using intensity data collected photographically by the Weissenberg method, and refined by successive Fourier maps and least-squares refinement to an R index 0·055 for 328 independent observed reflections. The cell content resulting from the structural analysis is Cu36·6Cl6·7(NO3)2·6(OH)63·9.2·1 H2O. The space group is P63/mmc with a = 15·750 Å and c = 9·161Å. The buttgenbachite structure is not completely ordered. It consists of a rigid three-dimensional skeleton formed by Cu co-ordination polyhedra sharing edges and corners. The large channels in the framework show a zeolite-like nature; inside the channels the disorder is caused by the different orientations of nitrate groups and by the occurrence of the substitution . The crystal structure of buttgenbachite is closely related to that of connellite. The mechanism of forming an isomorphous series is discussed: the present study shows that the replacement is more complicated than was supposed in the literature.

scholarly journals Crystal structure of poly[tetra-μ-chlorido-tetrachloridobis(μ3-4,4′-bi-1,2,4-triazole-κ3 N 1:N 2:N 1′)(μ-4,4′-bi-1,2,4-triazole-κ3 N 1:N 1′)tetracopper(II)]

2019 ◽  
Vol 75 (6) ◽  
pp. 800-803
Author(s):  
Kostiantyn V. Domasevitch ◽  
Andrey B. Lysenko
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Orthorhombic Space Group ◽  
Coordination Polyhedra ◽  
Space Group ◽  
Axis Direction ◽  
Metal Atoms ◽  
Triazole Ligand ◽  
Left And Right

The title Cu2+–chloride coordination polymer with the 4,4′-bi-1,2,4-triazole ligand (btr), [Cu4Cl8(C4H6N6)3] n , crystallizes in the non-centrosymmetric orthorhombic space group Fdd2. The two independent Cu2+ cations adopt distorted square-pyramidal geometries with {Cl2N2+Cl} coordination polyhedra. The metal atoms are bridged by μ-Cl anions forming left- and right-handed helical chains of sequence [–(μ-Cl)CuCl–] n along the c-axis direction. In the perpendicular directions, the btr ligands act in μ- and μ 3– coordination modes in a 2:3 ratio. The μ-btr bridges connect neighboring helices of the same handedness, whereas the μ 3-btr ligands link the helices of opposite handedness, leading to a racemic three-dimensional framework. The structure is consolidated by weak C—H...Cl and C—H...N interactions.

Electron crystallography of the polymethylene chain. 3. Three-dimensional crystal structure of a refined paraffin wax1

1999 ◽  
Vol 214 (6) ◽  
Author(s):  
D. L. Dorset
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Three Dimensional ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Diffraction Intensity ◽  
Orthorhombic Space Group ◽  
Oriented Samples ◽  
Commercial Paraffin Wax ◽  
Dimensional Crystal

AbstractThe three-dimensional crystal structure of a commercial paraffin wax has been determined from electron diffraction intensity data collected from epitaxially oriented samples. The orthorhombic space group is

scholarly journals Three salts from the reactions of cysteamine and cystamine withL-(+)-tartaric acid

2013 ◽  
Vol 69 (6) ◽  
pp. 658-664 ◽  
Author(s):  
Amina Benylles ◽  
Donald Cairns ◽  
Philip J. Cox ◽  
Graeme Kay
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Tartaric Acid ◽  
Three Dimensional ◽  
Water Molecules ◽  
Amino Groups ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Hydrogen Bonding Networks

Reaction between cysteamine (systematic name: 2-aminoethanethiol, C2H7NS) and L-(+)-tartaric acid [systematic name: (2R,3R)-2,3-dihydroxybutanedioic acid, C4H6O6] results in a mixture of cysteamine tartrate(1−) monohydrate, C2H8NS+·C4H5O6−·H2O, (I), and cystamine bis[tartrate(1−)] dihydrate, C4H14N2S22+·2C4H5O6−·2H2O, (III). Cystamine [systematic name: 2,2′-dithiobis(ethylamine), C4H12N2S2], reacts with L-(+)-tartaric acid to produce a mixture of cystamine tartrate(2−), C4H14N2S22+·C4H4O62−, (II), and (III). In each crystal structure, the anions are linked by O—H...O hydrogen bonds that run parallel to theaaxis. In addition, hydrogen bonding involving protonated amino groups in all three salts, and water molecules in (I) and (III), leads to extensive three-dimensional hydrogen-bonding networks. All three salts crystallize in the orthorhombic space groupP212121.

Structure and twinning in spencerite

1972 ◽  
Vol 38 (298) ◽  
pp. 687-692 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
British Columbia ◽  
Three Dimensional ◽  
Frequent Occurrence ◽  
Water Molecules ◽  
Intensity Data ◽  
Atomic Arrangement ◽  
Twin Crystal

SummaryA refinement of the crystal structure of spencerite, Zn4(PO4)2(OH)2·3H2O, was performed on a twin crystal from Salmo, British Columbia. Three-dimensional intensity data were collected by a Weissenberg apparatus. The R index was 0·098 for 335 independent observed reflections. The crystal structure previously determined is essentially confirmed. Co-ordination around Zn is both octahedral and tetrahedral. The atomic arrangement consists of complex sheets of co-ordination octahedra and tetrahedra around Zn and P atoms connected by layers of water molecules. The frequent occurrence of twinning in spencerite is explained from structural considerations.

scholarly journals Crystal structure of the deuterated heptahydrate of potassium phosphate, K3PO4·7D2O

2020 ◽  
Vol 76 (2) ◽  
pp. 177-179
Author(s):  
Matthias Weil ◽  
Berthold Stöger
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Three Dimensional ◽  
Potassium Phosphate ◽  
Water Molecules ◽  
Coordination Polyhedra ◽  
Dimensional Network ◽  
Potassium Orthophosphate ◽  
Medium Strength ◽  
Absolute Structure

Deuterated potassium orthophosphate heptahydrate, K3PO4·7D2O, crystallizes in the Sohnke space group P21, and its absolute structure was determined from 2017 Friedel pairs [Flack parameter 0.004 (16)]. Each of the three crystallographically unique K+ cations is surrounded by six water molecules and one oxygen atom from the orthophosphate group, using a threshold for K—O bonds of 3.10 Å. The highly irregular coordination polyhedra are linked by corner- and edge-sharing into a three-dimensional network that is consolidated by an intricate network of O—D...O hydrogen bonds of medium strength.

scholarly journals Synthesis, Crystal Structure, Hydrogen Bonding and Thermal Behaviour of a Three-Dimensional Cu(II)-benzene-1,2,4,5-tetracarboxylate Templated by 1,9-Diaminononane

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Three Dimensional ◽  
Water Molecules ◽  
Excess Charge ◽  
Gauche Conformation ◽  
Coordination Polyhedra ◽  
Thermoanalytical Measurements

Triclinic single crystals of Cu4(H3N–(CH2)9–NH3)(OH)2[C6H2(COO)4]2·5H2O were preparedin aqueous solution at 80 °C in the presence of 1,9-diaminononane. Space group P-1 (no. 2)with a = 1057.5(2), b = 1166.0(2), c = 1576.7(2) pm, alpha = 106.080(10)°, beta = 90.73(2)° and gamma =94.050(10)°. The four crystallographic independent Cu2+ ions are surrounded by five oxygenatoms each with Cu–O distances between 191.4(3) and 231.7(4) pm. The connection betweenthe Cu2+ coordination polyhedra and the [C6H2(COO)4]4–anions yields three-dimensionalframework with negative excess charge and wide centrosymmetric channel-like voids. Thesevoids extend parallel to [001] with the diagonal of the nearly rectangular cross-section ofapproximately 900 pm. The channels of the framework accommodate [H3N–(CH2)9–NH3]2+cations and water molecules, which are not connected to Cu2+. The nonane-1,9-diammoniumcations adopt a partial gauche conformation. Thermoanalytical measurements in air show aloss of water of crystallization starting at 90 °C and finishing at approx. 170 °C. Thedehydrated compound is

Crystal structures of tricalcium citrates

2018 ◽  
Vol 33 (2) ◽  
pp. 98-107 ◽  
Author(s):  
James A. Kaduk
Keyword(s):  
Crystal Structures ◽  
Density Functional ◽  
Three Dimensional ◽  
Water Molecules ◽  
Calcium Citrate ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Calcium Supplements ◽  
Dimensional Network

The crystal structures of calcium citrate hexahydrate, calcium citrate tetrahydrate, and anhydrous calcium citrate have been solved using laboratory and synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Both the hexahydrate and tetrahydrate structures are characterized by layers of edge-sharing Ca coordination polyhedra, including triply chelated Ca. An additional isolated Ca is coordinated by water molecules, and two uncoordinated water molecules occur in the hexahydrate structure. The previously reported polymorph of the tetrahydrate contains the same layers, but only two H2O coordinated to the isolated Ca and two uncoordinated water molecules. Anhydrous calcium citrate has a three-dimensional network structure of Ca coordination polyhedra. The new polymorph of calcium citrate tetrahydrate is the major crystalline phase in several commercial calcium supplements.

Protoenstatite: a crystal-structure refinement at 1100°C

1971 ◽  
Vol 134 (3-4) ◽  
Author(s):  
Joseph R. Smyth
Keyword(s):  
Crystal Structure ◽  
Melting Point ◽  
Single Crystal ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Intensity Data ◽  
Crystal Structure Refinement ◽  
Space Group

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

scholarly journals Crystal structure of poly[diaquabis(μ5-benzene-1,3-dicarboxylato)(N,N-dimethylformamide)cadmium(II)disodium(I)]

2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Carboxylate Groups ◽  
Benzene Rings ◽  
Coordinated Water ◽  
Coordinate Geometry

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.

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