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

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.

1975 ◽  
Vol 30 (1-2) ◽  
pp. 22-25 ◽  
Author(s):  
M. L. Ziegler ◽  
H.-E. Sasse ◽  
B. Nuber

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.


1975 ◽  
Vol 30 (9-10) ◽  
pp. 699-709 ◽  
Author(s):  
Peter O. Tremmel ◽  
Klaus Weidenhammer ◽  
Henning Wienand ◽  
Manfred L. Ziegler

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.


Detailed interpretations of the X -ray diffraction patterns of fibres and sheets of 66 and 6.10 polyamides (polyhexam ethylene adipamide and sebacamide respectively) are proposed. The crystal structures of the two substances are completely analogous. Fibres of these two polyam ides usually contain two different crystalline forms, α and β, which are different packings of geometrically similar molecules; most fibres consist chiefly of the α form. In the case of the 66 polymer, fibres have been obtained in which there is no detectable proportion of the β form. Unit cell dimensions and the indices of reflexions for the α form were determined by trial, using normal fibre photographs, and were checked by using doubly oriented sheets set at different angles to the X -ray beam. The unit cell of the a form is triclinic, with a — 4·9 A, b = 5·4 A, c (fibre axis) = 17·2A, α = 48 1/2º, β = 77º, γ = 63 1/2º for the 66 polymer; a = 4·95A, b = 5·4A, c (fibre axes) = 22·4A, α = 49º, β = 76 1/2º, γ = 63 1/2º for the 6.10 polymer. One chain molecule passes through the cell in both cases. Atomic coordinates in occrystals were determined by interpretation of the relative intensities of the reflexions. The chains are planar or very nearly so; the oxygen atoms appear to lie a little off the plane of the chain. The molecules are linked by hydrogen bonds between C = 0 and NH groups, to form sheets. A simple packing of these sheets of molecules gives the α arrangement.


1976 ◽  
Vol 31 (4) ◽  
pp. 455-462 ◽  
Author(s):  
Peter Feldhaus ◽  
Richard Ratka ◽  
Hermann Schmid ◽  
Manfred L. Ziegler

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%.


2006 ◽  
Vol 21 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Mohamed Chakir ◽  
Abdelaziz El Jazouli ◽  
Jean-Pierre Chaminade

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.


1977 ◽  
Vol 55 (1) ◽  
pp. 111-114 ◽  
Author(s):  
Lillian Y. Y. Chan ◽  
E. E. Isaacs ◽  
W. A. G. Graham

Reaction of [n-Bu4N]2[Re4(CO)16] with AgBF4 in acetonitrile affords the compound [(CH3CN)3Re(CO)3][BF4]. The latter crystallizes in monoclinic space group P21/c with unit cell dimensions a = 11.021(5) Å, b = 11.136(5) Å, c = 12.980(6) Å, β = 96.906(25)°, and four molecules per unit cell. Data were collected by counter methods and the structure was refined using least-squares procedures to give R = 0.041. The rhenium cation is approximately octahedrally coordinated by six facially arranged ligands. The mean rhenium–nitrogen distance is 2.13 Å, and the mean rhenium–nitrogen–carbon angle in the coordinated acetonitrile is 174.7°.


1984 ◽  
Vol 62 (3) ◽  
pp. 570-573 ◽  
Author(s):  
J. Zukerman-Schpector ◽  
E. E. Castellano ◽  
G. Oliva ◽  
Timothy John Brocksom ◽  
Elisabete Terezinha Canevarolo

The crystal structures of the title compounds have been determined from diffractometric X-ray data and refined by full-matrix least-squares to final R factors of 0.047 and 0.060 from 830 and 620 independent reflections above background, respectively. The space group and the number of molecules per unit cell are the same in both cases: P212121 and Z = 4. Cell dimensions are: a = 7.982(2), b = 9.538(3), c = 18.785(3) Å for the S form and a = 10.339(3), b = 11.510(3), and c = 11.886(6) Å for the R form. The molecules, produced simultaneously in the same chemical reaction, have essentially identical configuration except for the location of the chlorine atoms at C-11 (in the S case) and at C-10 (in the R case). This difference gives rise to a completely different molecular packing of the structures. In each compound the two cyclopropane rings present a cis relationship to one another, with an identical dihedral angle of 77.0°.


1971 ◽  
Vol 49 (2) ◽  
pp. 167-172 ◽  
Author(s):  
F. Leung ◽  
S. C. Nyburg

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.


1991 ◽  
Vol 6 (1) ◽  
pp. 48-49 ◽  
Author(s):  
C. J. Rawn ◽  
R. S. Roth ◽  
H. F. McMurdie

AbstractThe compound AlNbO4 has been studied by single crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated using a least squares analysis that refined to a Δ2θ° of no more than 0.03°. A monoclinic cell was found with space group C2/m, a = 12.1558(5)Å, b = 3.7345(2)Å, c = 6.4886(3)Å, and β = 107.613(4)°.


1988 ◽  
Vol 41 (4) ◽  
pp. 597 ◽  
Author(s):  
MI Bruce ◽  
MP Cifuentes ◽  
KR Grundy ◽  
MJ Liddell ◽  
MR Snow ◽  
...  

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).


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