scholarly journals Tetra-n-butylammoniumdicyanoaurat(I), (n-C4H9)4NAu(CN)2 / Tetra-n-butylammonium Dicyanoaurate(I), (n-C4H9)4NAu(CN)2

1990 ◽  
Vol 45 (8) ◽  
pp. 1118-1122 ◽  
Author(s):  
R. J. Schubert ◽  
K.-J. Range
Keyword(s):  
Least Squares ◽  
Single Crystals ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Calculated Density ◽  
Space Group ◽  
Computer Controlled ◽  
R Factors ◽  
Measured Density

Single crystals of (n-C4H9)4NAu(CN)2 were obtained by crystallization using the temperature decreasing method in a newly developed computer-controlled apparatus. The colourless crystals are monoclinic, space group A2/n, with a = 20.216(2) Å, b = 13.130(1) Å, c = 9.328(1) Å, and β = 109.69(1)°. The measured density is 1.45 g/cm3, which agrees with the calculated density of 1.40 g/cm3 for Ζ = 4. The structure was solved by Direct Methods using 674 independent reflections and refined by least-squares procedures to conventional and weighted R factors of 0.068 and 0.058, respectively. The nearly linear [Au(CN)2]--anions form pseudohexagonal layers, in which they are arranged parallel to each other. The shortest Au—Au distance is 8.05 A. The stacking of the layers produces pseudo-trigonal channels, occupied by the cations. The tetra-n-butylammonium cation has four ordered trans chains with idealized D2d symmetry (4̄2 m).

scholarly journals Synthesis and Molecular Structure of cis-Tetracarbonyl[N-(diphenylphosphino-kP)-naphthalen-1-yl-P,P-diphenylphosphinous amide-kP]chromium(0)

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Harbi Tomah Al-Masri
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Molar Ratio ◽  
Planar Geometry ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
Distorted Octahedral ◽  
Least Squares Techniques

The reaction of N,N-bis(diphenylphosphanyl)naphthylamine C10H7-1-N(PPh2)2 with (C5H10NH)2Cr(CO)4 (1 : 1 molar ratio) in dichloromethane afforded cis-[Cr(CO)4{C10H7-1-N(PPh2)2}] (1). This complex was crystallized in the monoclinic space group P21/n. The structure was solved by direct methods and refined by full-matrix least squares techniques to an R factor of 0.0313 for 6488 observed reflections. The Cr-metal is coordinated by four terminal CO molecules and a P,P′-bidentate N,N-bis(diphenylphosphanyl)naphthylamine ligand in a distorted octahedral array. The N-atom adopts a planar geometry with the two P-atoms and C-atom attached to it. The four-membered metallacycle ring P2CrN is nearly planar.

Hodrushite—a new sulphosalt

1970 ◽  
Vol 37 (290) ◽  
pp. 641-648 ◽  
Author(s):  
M. Koděra ◽  
V. Kupčík ◽  
E. Makovický
Keyword(s):  
Chemical Composition ◽  
Electron Microprobe ◽  
Monoclinic Space Group ◽  
Calculated Density ◽  
Space Group ◽  
Lattice Constants ◽  
Maximum Reflectivity ◽  
Measured Density

SummaryHodrushite, a new sulphosalt of copper and bismuth, was found in the Rosalia ore vein at Banská Hodrušá near Banská Štiavnica, Czechoslovakia. It has chemical composition Cu8·12Bi11·54Fe0·29S22 (as determined by electron-microprobe method) close to Cu8Bi12S22. Symmetry is monoclinic, space group A2/m, lattice constants a 27·21, b 3·93, c 17·58 Å, β 92° 9′, measured density 6·35, calculated density 6·45 g/cm3. Microhardness 200 kg/mm2, anisotropic, weak bireflectance, creamy with pinkish tint, maximum reflectivity about 6000 Å. Crystals needle-shaped and striated along [010], colour steel-grey, quickly tarnishing to bronze. Associated with quartz, hematite, and chalcopyrite. Closely related to cuprobismutite.

Crystal structures of two lactones of the bicyclo[2,2,2]octane series

1982 ◽  
Vol 35 (2) ◽  
pp. 457 ◽  
Author(s):  
RM Carman ◽  
SS Smith ◽  
CHL Kennard ◽  
G Smith ◽  
AH White ◽  
...  
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
A Cell

The crystal structures of two γ-lactones of the bicyclo[2,2,2]octane series, endo-3-carboxy-exo-5- iodobicyclo[2,2,2]octane-2,6-carbolactone (2; R = CO2H) and exo-3-methoxycarbonyl-endo-5-acetoxybicyclo[2,2,2] octane-2,6-carbolactone (7b), have been determined by direct methods from three-dimensional X-ray data and refined by least-squares to final residuals of 0.033 (2; R = CO2H) and 0.036 (7b) for 1918 and 630 'observed' reflections respectively. Crystals for (2; R = CO2H) are monoclinic, space group P21/c with Z 8 in a cell of dimensions a 7.192(2), b 23.785(8), c 13.199(5) �, β 105.35(2)�, while (7b) crystallizes in the orthorhombic space group P212121 with Z 4 in a cell of dimensions a 13.347(7), b 11.839(7), c 8.227(11) �.

Approaches to the synthesis of triterpenes. V. An unusual acid-catalysed rearrangement of a β,γ-unsaturated ketone

1978 ◽  
Vol 56 (16) ◽  
pp. 2150-2155 ◽  
Author(s):  
John W. ApSimon ◽  
Satyanand Badripersaud ◽  
Michael L. Post ◽  
Eric J. Gabe
Keyword(s):  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
Unsaturated Ketone ◽  
Geometric Features ◽  
Space Group ◽  
Positional Disorder ◽  
Block Diagonal

The reaction of 2-keto-1β,4aβ-dimethyl-1α-[2-(3-keto-1,4,4-trimethylcyclohexyl)ethyl]-7-methoxy-1,2,3,4,4a,9-hexahydrophenanthrene 1a and b with p-toluenesulphonic acid in boiling xylene yields the rearranged product, 1,10-dimethyl-2-[2-(3-keto-1,4,4-trimethylcyclohexyl)-ethyl]-7-methoxy-3,4-dihydroanthracene (3). Crystals of 3 are monoclinic, space group P21/c, Z = 4, with a = 7.2684(3), b = 30.942(2), c = 10.5544(7) Å, β = 98.24(1)°. The structure was determined by direct methods from diffractometer data and refined by block-diagonal least-squares to an R of 0.043 for 1810 observed reflections. The molecule exhibits no unusual geometric features, although positional disorder is apparent in the cyclohexanone moiety.A possible route for the formation of 3 from 1a and b is presented.

The reaction of tetrasulphur dinitride with norbornadiene; the crystal and molecular structure of S4N2•C7H8, an eight-membered C2S4N2 heterocycle

1983 ◽  
Vol 61 (6) ◽  
pp. 1185-1188 ◽  
Author(s):  
Hans Koenig ◽  
Richard T. Oakley ◽  
A. Wallace Cordes ◽  
Mark C. Noble
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Dihedral Angle ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The reaction of tetrasulphur dinitride with norbornadiene produces the 1:1 adduct S4N2•C7H8; X-ray crystallographic analysis of this compound reveals that olefin addition cleaves one of the sulphur–sulphur bonds of S4N2, yielding a novel eight-membered C2S4N2 ring. Crystals of S4N2•C7H8 are monoclinic, space group P21/c, a = 6.127(1), b = 17.369(1), c = 9.580(1) Å, β = 106.74(1)°, V = 1003.8(5) Å3Z = 4. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039. The S—S—N—S—N—S fragment of the C2S4N2 ring is planar to within 0.15 Å. The S—C—C—S unit is folded out of this plane to produce a dihedral angle of 74.5°.

Relative humidity as a driver of structural change in three new ferric-sulfate-tellurite hydrates: New minerals tamboite and metatamboite, and a lower-hydrate derivative, possibly involving direct uptake of atmospheric {H2O}4 clusters

2019 ◽  
Vol 57 (5) ◽  
pp. 605-635
Author(s):  
Mark A. Cooper ◽  
Frank C. Hawthorne ◽  
Yassir A. Abdu ◽  
Phillip C. Walford ◽  
Malcolm E. Back
Keyword(s):  
Hydrogen Bonds ◽  
Room Temperature ◽  
Direct Methods ◽  
Structural Formula ◽  
Ferric Sulfate ◽  
Index Of Refraction ◽  
Monoclinic Space Group ◽  
Calculated Density ◽  
Space Group ◽  
Cell Parameters

Abstract Tamboite (x = 3; y = 2) and metatamboite (x = 3; y = 0), Fe3+3(SO4)(Te4+O3)3(Te4+O(OH)2)(OH)(H2O)x{H2O}y, are new tellurite minerals from the Tambo mine, Coquimbo Province, Chile. The two minerals transform to each other reversibly with changes in ambient humidity. They occur as pale-yellow clusters of radiating fiber bundles on the surface of a compact aggregate of silicified tuff. Tamboite and metatamboite are optically biaxial, and their calculated mean index of refraction is greater than 1.80. The calculated densities are 3.648 g/cm3 for tamboite and 4.053 g/cm3 for metatamboite. Tamboite and metatamboite are monoclinic, space group P21/c, Z = 4. Unit-cell parameters for tamboite are a 16.879(10), b 7.310(4), c 16.666(9) Å, β 108.857(11)°, V 1958(3) Å3; for metatamboite they are a 14.395(5), b 7.296(4), c 16.411(6) Å, β 98.909(10)°, V 1703(2) Å3. Chemical analysis by electron microprobe gave the empirical cations [calculated on the basis of 22 anions pfu with OH = 3 and H2O = 5 pfu (tamboite) or H2O = 3 pfu (metatamboite)] as (Fe3+3.10Al0.15)Σ3.25(S6+0.75Se6+0.05)Σ0.80Te4+4.11. The seven strongest lines in the X-ray powder diffraction patterns [listed as d (Å), I, (hkl)] are as follows: metatamboite: 14.221, 100, (100); 2.874, 13, ; 3.140, 12, (221); 3.423, 11, ; 3.400, 11, (312); 3.012, 11, ; 4.054, 9, ; tamboite: 16.068, 100, (100); 3.425, 9, ; 2.999, 8, ; 3.171, 6, (221); 2.853, 5, ; 4.153, 4, ; 3.943, 4, (004). The crystal structures were solved by direct methods and refined to R1 indices of 4.3 and 3.0%. The structures consist of virtually identical ferric-sulfate-tellurite-hydrate slabs that are constructed from strands of ferric-sulfate-hydrate polyhedra linked by Te4+ cations. In metatamboite, the slabs are linked directly by hydrogen bonds whereas in tamboite, interslab linkage occurs by hydrogen bonds through interstitial {H2O}4 clusters known as Ci cyclic tetramers. Exposure of a crystal to a desiccant at room temperature resulted in a third variant (x = 2; y = 0) with the structural formula Fe3+2Fe2+(SO3(OH))(Te4+O3)3(Te4+O(OH)2)(OH)(H2O)x, space group P21/c, Z = 4, a 16.879(10), b 7.310(4), c 16.666(9) Å, β 108.857(11)°, V 1958(3) Å3, calculated density 4.176 g/cm3. This lower-hydrate variant has less cation-bonded (H2O) than metatamboite and tamboite, and the ferric-sulfate-tellurite-hydrate slabs are polymerized to form a framework structure. Attempts to transform the lower hydrate back to tamboite or metatamboite at room temperature and elevated humidity were unsuccessful.

Zur Kenntnis von EuBeGd2O5 mit einem Beitrag über Phasen der Zusammensetzung M1-xM′xBeLn2O5: Ca0,4Sr0,6BeSm2O5, Ba0,25Ca0,75BeNd2O5 und Ba0,36Sr0,64BeNd2O5 / On EuBeGd2O5 and on Phases of the Composition M1-xM′xBeLn2O5: Ca0,4Sr0,6BeSm2O5, Ba0,25Ca0,75BeNd2O5 and Ba0,36Sr0,64BeNd2O5

1994 ◽  
Vol 49 (7) ◽  
pp. 919-922 ◽  
Author(s):  
Hk. Müller-Buschbaum ◽  
S. Frenzen
Keyword(s):  
Single Crystals ◽  
Plasma Torch ◽  
Monoclinic Space Group ◽  
Orthorhombic Symmetry ◽  
Laser Technique ◽  
Space Group

Abstract Single crystals of (I): EuBeGd2O5, (II): Ca0,4Sr0,6BeSm2O5, (III): Ba0,25Ca0,75BeNd2O5 and (IV): Ba0.36Sr0.64BeNd2O5 were prepared by (I): plasma torch and (II)-(IV ): CO2-LASER technique. X-Rayo investigations lead to (I) monoclinic (space group C52h-P21/c, a = 7.126, b = 6.457, c = 9.394 Å , β = 90.40°) and (II)-(IV) orthorhombic symmetry (D162h-Pnma). (II: a = 9.454, b = 7.142, c = 6.490 Å; III: a = 9.508, b = 7.188, c = 6.531 Å; IV: a = 9.642, b = 7.295, c = 6.614 Å). In contrary to the phases M1-xM′xBeLn2O5, EuBeGd2O5 is characterized by an ordered distribution of Eu2+ and Gd3+ inside of the Kagomé network.

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

Studies in aryltin chemistry. Part 6. Crystal and molecular structures of tetra(p-methylsulphonylphenyl)tin(IV) and tetra(p-methylsulphinylphenyl)tin(IV) monohydrate

1990 ◽  
Vol 68 (8) ◽  
pp. 1277-1282 ◽  
Author(s):  
Ivor Wharf ◽  
Michel G. Simard ◽  
Henry Lamparski
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Direct Method ◽  
Molecular Structures ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Molecular Symmetry ◽  
Asymmetric Unit ◽  
Full Matrix ◽  
Space Group

Tetrakis(p-methylsulphonylphenyl)tin(IV) and tetrakis(p-methylsulphinylphenyl)tin(IV) n-hydrate have been prepared and their spectra (ir 1350–400 cm−1; nmr, 1H, 13C, 119Sn) and X-ray crystal structures are reported. The first compound is monoclinic, space group C2/c, Z = 4, with a = 21.589(6), b = 6.207(3), c = 22.861(11) Å, β = 93.80(3)° (22 °C); the structure was solved by the direct method and refined by full-matrix least squares calculations to R = 0.043 for 2755 observed reflections. It has 2 molecular symmetry with the methyl group and one oxygen atom completely disordered in both CH3S(O2) groups in the asymmetric unit. The second compound is tetragonal, space group P42/n, Z = 2, with a = b = 15.408(6), c = 6.379(2) Å (−100 °C); the structure was solved by the Patterson method and refined by full-matrix least squares calculations to R = 0.060 for 1209 observed reflections. It has [Formula: see text] molecular symmetry with the whole asymmetric unit disordered. Water molecules occupy positions on parallel 42 axes but molecular packing requirements prevent all sites having 100% occupancy giving n ~ 1 for the hydrate. Keywords: Tetra-aryltins, crystal structures, sulphone, sulphoxide, hydrogen-bonding.

The crystal structure of arsenic telluroxide AsTe0.5O2

1993 ◽  
Vol 205 (1) ◽  
Author(s):  
A. C. Stergiou
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Single Crystals ◽  
Direct Methods ◽  
Anomalous Dispersion ◽  
Thermal Parameters ◽  
Trigonal Prism ◽  
Population Parameter ◽  
Full Matrix

AbstractSingle crystals of AsTeSolution of the structure was essentialy effected by direct methods combined with successive Fourier syntheses. The positional and anisotropic thermal parameters were refined by full-matrix least-squares calculations. Absorption and anomalous dispersion corrections were applied to all atoms. The finalThe As atom is coordinated by six O atoms forming a right trigonal prism. The Te atom site is partially occupied by Te atoms with a population parameter 0.5 and surrounded by six O atoms also forming a right trigonal prism. The structure looks like that of NiAs. Each of the AsO

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