scholarly journals Molekül- und Kristallstruktur von C7H7Mo(CO)2-SnCl3 / The Crystal Structure of C7H7Mo(CO)2-SnCl3

1975 ◽  
Vol 30 (1-2) ◽  
pp. 22-25 ◽  
Author(s):  
M. L. Ziegler ◽  
H.-E. Sasse ◽  
B. Nuber
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Three Dimensional ◽  
Unit Cell ◽  
Fourier Methods ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Group D

The structure of the title compound has been determined from three dimensional X-ray data by Patterson and Fourier methods. The crystals are orthorombic, with unit cell dimensions a = 1181,50 pm, b = 943,68 pm, c = 1181,50 pm, space group D2h16 and Z = 4. Least squares refinement, by use of 1540 independent reflections measured on a diffractometer has reached R = 5,9%.There are discrete C7H7Mo(CO)2 SnCl3 molecules, the molybdenum-tin bond has been dicussed together with the corresponding bonds in other C7H7Mo(CO)2 SnR3 compounds.

Darstellung und Röntgenstrukturanalyse von (CH3)3C-C7H7Mo(CO)3 (1-6- η-7-tert-Butyl-cycloheptatrien)(tricarbonyl)molybdän(0) / Synthesis and Crystal Structure of (CH3)3C-C7H7Mo(CO)3 (1-6-η-7-tert-Butyl-cycloheptatriene)(tricarbonyl)molybdenum(0)

1975 ◽  
Vol 30 (9-10) ◽  
pp. 699-709 ◽  
Author(s):  
Peter O. Tremmel ◽  
Klaus Weidenhammer ◽  
Henning Wienand ◽  
Manfred L. Ziegler
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Three Dimensional ◽  
Synthesis And Crystal Structure ◽  
Fourier Methods ◽  
X Ray ◽  
Tert Butyl ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The title compound has been synthesized by three different methods and its structure determined from three dimensional X-ray data by Patterson and Fourier methods. The crystals are triclinic with unit cell dimensions a = 1022.60 ± 0.07 pm, b = 638.69 ± 0.27 pm, c = 1478.00 ± 0.19 pm, α = 78.48 ±0.02°, β = 131.049 ± 0.008°, γ = 87.16 ± 0.03 °, space group Ci1—PT and Z = 2. Least squares refinement by use of 2160 independent reflections measured on a diffractometer has reached R = 5.4%.There are discrete (CH3)3C—C7H7Mo(CO)3 molecules, the central molybdenum atom is octahedrally coordinated.

Die Kristall- und Molekülstrukturen von π-C7Η7Μο(CO)2Cl und π-C7H7Mo(CO)2Br / The Crystal Structures of π-C7Η7Μο(CO)2Cl and π-C7H7Mo(CO)2Br

1975 ◽  
Vol 30 (1-2) ◽  
pp. 26-29 ◽  
Author(s):  
M. L. Ziegler ◽  
H. E. Sasse ◽  
B. Nuber
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Unit Cell ◽  
Fourier Methods ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Group D ◽  
Chlorine Bond

The structures of the title compounds have been determined from three dimensional X-ray data by Patterson and Fourier methods. The crystals of both are orthorombic with the space group D42-P 212121. The chloride (2) and the bromide (3) are isomorphous, they have unit cell dimensions a = 642,76 pm, b =1187,27 pm, c =1311,14 pm (2) and 644,59 pm, 1183,78 pm, c = 1321,83 pm (3) and Z = 4. Least squares refinement by use of 1179 (2) and 1037 (3) independent reflections measured on a diffractometer has reached R = 12,5% and R = 7,4% respectively. The molybdenum-bromine bond in 3 is relatively shorter than the molybdenum-chlorine bond in 2, due to greater dπ-dπ interaction.

Synthesis and crystal structure of Na3.5Cr1.5Co0.5(PO4)3 phosphate

2006 ◽  
Vol 21 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Mohamed Chakir ◽  
Abdelaziz El Jazouli ◽  
Jean-Pierre Chaminade
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Hexagonal Unit Cell ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

A new Nasicon phosphates series [Na3+xCr2−xCox(PO4)3(0⩽x⩽1)] was synthesized by a coprecipitation method and structurally characterized by powder X-ray diffraction. The selected compound Na3.5Cr1.5Co0.5(PO4)3 (x=0.5) crystallizes in the R3c space group with the following hexagonal unit-cell dimensions: ah=8.7285(3) Å, ch=21.580(2) Å, V=1423.8(1) Å3, and Z=6. This three-dimensional framework is built of PO4 tetrahedra and Cr∕CoO6 octahedra sharing corners. Na atoms occupy totally M(1) sites and partially M(2) sites.

The Crystal Structure of a Thiathiophthen Nitrogen Isostere, 3,5-Epidithio-2,5-diphenyl-2,4-pentadienylidene-3-aminoquinoline

1971 ◽  
Vol 49 (2) ◽  
pp. 167-172 ◽  
Author(s):  
F. Leung ◽  
S. C. Nyburg
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Unit Cell ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths ◽  
Triclinic System ◽  
R Factor ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal structure of a thiathiophthen nitrogen isostere (7) has been solved by X-ray analysis. The crystal belongs to the triclinic system with unit cell dimensions: a = 11.275(11), b = 9.558(10), c = 10.797(10) Å, α = 92.50(10), β = 116.98(10), γ = 92.61(10)°. There are two molecules per unit cell, space group [Formula: see text]. The data were collected by diffractometer with CuKα radiation. The structure was solved by symbolic addition procedures, and fully refined anisotropically using full-matrix least squares to an R factor of 6.3%.The S—S and S—N bond lengths were found to be 2.364 and 1.887 Å, respectively. This reveals the partial bonding character between S … S … N atoms.

Kristallstruktur von Bis(N.N′-bis(8-chinoyl)äthylendiaminato)nickel(II) / Crystal Structure of Bis(N,N′-bis(8-chinoyl)ethylenediaminato)nickel(II)

1977 ◽  
Vol 32 (2) ◽  
pp. 131-133 ◽  
Author(s):  
H. Endres ◽  
H. J. Keller ◽  
A. Poveda
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Least Squares ◽  
Title Compound ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Cell Dimensions ◽  
Planar Molecules ◽  
Unit Cell Dimensions

The title compound NiC20H16N4 crystallizes in the monoclinic space group Ρ21/a with unit cell dimensions a = 12.07(2) Å, b= 10.712(4) Å, c = 13.50(3) Å, β= 113.1(1)°. The structure was refined by a blockmatrix least squares procedure to R = 0.126, based on 1258 observed intensities. The planar molecules form centro-symmetric dimers in the solid state with interplane distances of 3.3 A.

Cyclopentadienyl-Ruthenium and -Osmium Chemistry. XXX. Synthesis and X-Ray Structure of [Ru(dppm-P)(dppm-P,P')(η-C5H5)][PF6]0.5[PO2F2]0.5

1988 ◽  
Vol 41 (4) ◽  
pp. 597 ◽  
Author(s):  
MI Bruce ◽  
MP Cifuentes ◽  
KR Grundy ◽  
MJ Liddell ◽  
MR Snow ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Phenyl Group ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
One Pot ◽  
Full Matrix ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

An improved, one-pot synthesis is reported for the [Ru (dppm -P)(dppm -P, P′)(η-C5H5)]+ cation as its BF4- salt. The crystal structure of [Ru ( dppm - P)( dppm -P,P′)(η-C5H5)]+, obtained as the mixed PF6-/PO2F2- salt, has also been determined. There are few differences in dimensions between the mono- and bi-dentate dppm ligands; chelation sharply reduces the P-CH2-P angle, and one phenyl group on each phosphorus is bent away from the metal. Crystals are monoclinic, space group C2/c with unit cell dimensions a 21.743(3), b 23.594(3), c 21.352(3)Ǻ, β 110.17(1) and Z 8. The structure was refined by a full-matrix least-squares procedure to final R 0.078 and Rw 0.087 for 4490 reflections with I > 2.5σ(I).

scholarly journals The reaction of 3,5-diphenyl-1,2-dithiolium-4-olate with aniline: the crystal structure of 1-phenylimino-2-phenylamino-3-phenylindene

1987 ◽  
Vol 65 (12) ◽  
pp. 2830-2833 ◽  
Author(s):  
David M. McKinnon ◽  
Peter D. Clark ◽  
Robert O. Martin ◽  
Louis T. J. Delbaere ◽  
J. Wilson Quail
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

3,5-Diphenyl-1,2-dithiolium-4-olate (1) reacts with aniline to form 1-phenylimino-2-phenylamino-3-phenylindene (3a). Under suitable conditions, 6-phenylbenzo[b]indeno[1,2-e]-1,2-thiazine is also formed. These structures are confirmed by alternative syntheses. The molecular structure of 3a has been determined by single crystal X-ray diffraction. Compound 3a crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 20.777(3) Å, b = 6.130(3) Å, c = 31.327(3) Å, 3 = 99.59(1)°, and Z = 8. The structure was solved by direct methods and refined by least squares to a final R = 0.055. The molecular structure of 3a shows the three phenyl containing substituents to have the planes of their ring systems tilted between 40° and 60° from the plane of the indene system due to steric repulsions.

Refinement of the structure of Mg2As2O7

1970 ◽  
Vol 48 (6) ◽  
pp. 890-894 ◽  
Author(s):  
C. Calvo ◽  
K. Neelakantan
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Unit Cell ◽  
Full Matrix ◽  
Space Group ◽  
Cell Dimensions ◽  
Central Oxygen ◽  
R Value ◽  
Unit Cell Dimensions

The crystal structure of Mg2As2O7 has been refined by full matrix least squares procedures using 587 observed reflections. The structure of Mg2As2O7 is of the thortveitite type, as reported by Łukaszewicz, with space group C2/m and unit cell dimensions a = 6.567(2) Å, b = 8.524(4) Å, c = 4.739(1) Å, β = 103.8(1)°, and Z = 2. The As—O—As group in the anion appears to be linear but the central oxygen atom undergoes considerable disorder in the plane perpendicular to this group. The AsO bond distances uncorrected for thermal motion are 1.67 Å for the As—O(—As) bond and 1.66 and 1.65 Å for the terminal As—O bonds. The final R value obtained is 0.088.

Reaktion von 1.4-Dienen mit Metallkomplexen, I Darstellung und Röntgenstrukturanalyse eines π-enyl-Komplexes der Zusammensetzung (C8H13PdCl)2/ Reaction of 1,4-Dienes with Metal Complexes, I Synthesis and X-ray Structure Determination of a π-enyl Complex of Composition (C8H18PdCl)2

1976 ◽  
Vol 31 (4) ◽  
pp. 455-462 ◽  
Author(s):  
Peter Feldhaus ◽  
Richard Ratka ◽  
Hermann Schmid ◽  
Manfred L. Ziegler
Keyword(s):  
Metal Complexes ◽  
Structure Determination ◽  
Three Dimensional ◽  
Fourier Methods ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Reaction of (C6H5CN)2PdCl2 and 1,3-dimethylenecyclohexane led to an exocyclic π-enyl complex of formula (C8H13PdCl)2-bis(η3-2-methylene-6-methylcyclohexyl)(di-µ-chloro)-dipalladium. IR and 1H NMR data are in agreement with this formulation.The compound is monoclinic, with unit cell dimensions α = 499.97 ± 0.08, b =1342.26 ± 0.19, c =1379.60 ± 0.20 pm, β = 99.43 ± 0.02°, space group C5h2-P21/C, Ζ = 2, dX-ray = 1.83 g/cm3.The structure was determined from three-dimensional X-ray data by Patterson and Fourier methods. Least squares refinement by use of 1045 independent reflections has reached R1 = 5.6%.

scholarly journals Computer Programs for Standardless Quantitative Analysis of Minerals Using the Full Powder Diffraction Profile

1991 ◽  
Vol 6 (1) ◽  
pp. 2-9 ◽  
Author(s):  
J. C. Taylor
Keyword(s):  
Crystal Structure ◽  
Quantitative Analysis ◽  
Least Squares ◽  
Powder Diffraction ◽  
Profile Analysis ◽  
Unit Cell ◽  
Diffraction Profile ◽  
Pattern Processing ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractA Fortran 77 computer program has been developed for the quantitative analysis of minerals by multiphase profile analysis of the complete powder diffraction pattern. Featured are full-matrix least-squares refinement of 14 Rietveld “instrumental parameters” (phase scales, asymmetry, preferred orientations (March model), linewidths, instrument zero, lineshapes and unit cell dimensions), Brindley particle absorption contrast factors and amorphicity corrections. The program uses a crystal structure Databank, which contains information on absorption coefficients, unit cell data and crystal structures for some 90 common minerals. New minerals can be easily added. Structure parameters are also refinable by a profile decomposition method using a program called STRUCT. The sum of the calculated patterns, derived from the crystal structure data, is fitted to the observed pattern by a program called TRACSCAL which runs in singlepass multiphase mode and, after the above corrections have been applied, the weight percentages of the component phases are calculated from the Rietveld scaling factors.The program runs on an IBM-compatible AT computer with 640K of RAM, on an extended memory AT, or a mainframe system. Examples of its use are given with standard mixtures and naturally occurring specimens. On an AT computer with 20MHz clock speed a scaling run, including data input, reading of the pattern, processing of (hkl) files, calculation of the profile and one cycle of least squares fitting takes about 30 seconds for binary standard mixtures and about 2.5 minutes for a 7-phase natural bauxite pattern containing 320 independent (hkl) reflections.

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