Über die Reduktion von Alkinkomplexen des Molybdäns und Wolframs in hohen Oxidationsstufen. Die Kristallstruktur von MoCl3(THF)3 / On the Reduction of Alkyne Complexes of Molybdenum and Tungsten in High Oxidation States. The Crystal Structure of MoCl3(THF)3

1989 ◽  
Vol 44 (10) ◽  
pp. 1161-1166 ◽  
Author(s):  
Peter Hofacker ◽  
Claus Friebel ◽  
Kurt Dehnicke ◽  
Petra Bäuml ◽  
Wolfgang Hiller ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Oxidation States ◽  
Epr Spectra ◽  
Space Group ◽  
X Ray ◽  
High Oxidation ◽  
Oxygen Sensitive ◽  
Alkyne Complexes ◽  
Ray Methods

The reduction of the tungsten alkyne complexes [WCl4(RC≡CR)]2 (R = Ph, SiMe3) with cobaltocen in THF solutions leads to the complexes [CoCp2]2[WCl4(RC≡CR)]2 (R = Ph (1); R = SiMe3 (2)), as green, oxygen sensitive crystalline powders. Reduction of [WCl4(Me3SiC=CSiMe3)]2 and of [MoCl4(PhC=CPh)]2 with sodium naphthalide in THF solutions in the presence of 15-crown-5 gives [Na-15-crown-5]3[W2Cl9], and MoCl3(THF)3, respectively. All compounds have been characterized by IR spectroscopy, and 1 and 2, in addition, by their EPR spectra. The crystal structure of MoCl3(THF)3 was determined by X-ray methods. Space group P21/c, Z = 4, 2642 observed unique reflexions, R = 0.050. Lattice dimensions at 20 °C: a = 888.4(2), b = 1281.5(3), c = 1535.2(3) pm, β = 92.17(2)°. The compound forms monomeric octahedral molecules with a meridional arrangement of the ligands.

Acetylenkomplexe von Rhenium(+ VI). Die Kristallstrukturen von [ReCl4(n-C3H7 – C= C – n-C3H7)(POCl3)] und ReCl4(THF)2 / Alkyne Complexes of Rhenium(+VI). The Crystal Structures of [ReCl4(n-C3H7 – C= C – n-C3H7)(POCl3)] and ReCl4(THF)2

1990 ◽  
Vol 45 (9) ◽  
pp. 1227-1234 ◽  
Author(s):  
Hans-Walter Swidersky ◽  
Jürgen Pebler ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
Space Group ◽  
Bond Lengths ◽  
In Trans ◽  
Alkyne Complexes ◽  
In Cis ◽  
Ray Methods

The results of the magnetic susceptibility measurements of the previously reported rhenium alkyne complexes [ReCl4(PhC≡CPh)]2.2 CH2Cl2 and [ReCl4(PhC=CPh)(CH3CN)] in the temperature range of 4.2-293 K suggest d1-configurations, corresponding with oxidation state +VI for the rhenium atoms. The new alkyne complex [ReCl4(n-C3H7–C=C–n-C3H7)(POCl3)] has been prepared by the reaction of ReCl5·OPCl3 with n-C3H7-C≡C–n-C3H7 in CCl4 solution, forming dark red single crystals, which were characterized by IR spectroscopy as well as by a crystal structure determination with X-ray methods (space group P2,/c, Z = 4, 3235 observed unique reflexions, R = 0.026; lattice dimensions at –70 °C: a = 805.6(2), b = 1000.6(4), c = 2188.8(6) pm, β = 79.59(2)°). [ReCl4(n-C3H7-C=C–n-C3H7)(POCl3)] has a molecular structure with the alkyne ligand bonded side-on (bond lengths Re-C 198.4 and 198.2(5) pm). The oxygen atom of the solvating POCl3 molecule is coordinated in trans position to the ReC2 unit of the alkyne ligand (bond length Re—O = 223.7(3) pm).In THF solutions the alkyne complexes of this type undergo a slow reaction forming ReCl4(THF)2, which was also characterized by IR spectroscopy and a crystal structure determination (space group P212121, Z = 4, 2243 observed unique reflexions, R = 0.053; lattice dimensions at –70 °C: a = 773.0(14), b = 1267.1(6), c = 1398.6(7) pm). In ReCl4(THF)2 the THF molecules coordinate in cis-position (bond lengths Re–O 208 and 212(1) pm).

Über die Kristallstruktur von KSc2 F7 / The Crystal Structure of KSc2 F7

1985 ◽  
Vol 40 (6) ◽  
pp. 726-729 ◽  
Author(s):  
Klaus Güde ◽  
Christoph Hebecker
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
Monoclinic Unit Cell ◽  
R Value ◽  
Ray Methods

Abstract Single crystals of KSc2F7 have been prepared from a mixture of KF and ScF3 . The samples were investigated by X-ray methods. KSc2F7 crystallizes orthorhombically with a = 10.643(2), b = 6.540(1), c = 4.030(1) Å. These data indicate a close crystallographic connection to the monoclinic unit cell of KIn2F7 [1], But in contrast to KIn2F7 , KSc2 F7 crystallizes in space group No. 65. Cmmm - D192h. The R-value for 341 observed independent reflections is 0.060.

Notizen: Die Kristallstruktur von Rb2Ca(N3)4 · 4 H2O / The Crystal Structure of RB2Ca(N3)4 · 4 H2O

1988 ◽  
Vol 43 (4) ◽  
pp. 497-498
Author(s):  
Franz A. Mautner ◽  
Harald Krischner ◽  
Christoph Kratky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

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.

Die Kristallstruktur von SrHg(SeCN)4 · 4 Pyridin / The Crystal Structure of SrHg(SeCN)4 · 4 Pyridine

1984 ◽  
Vol 39 (5) ◽  
pp. 582-585 ◽  
Author(s):  
Klaus Brodersen ◽  
Manfred Cygan ◽  
Hans-Ulrich Hummel
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Experimental Error ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

Single crystals of SrHg(SeCN)4 · 4 pyridine are prepared by reaction of K2Hg(SeCN)4 with SrCl2 in CH3OH/C2H5OH in the presence of pyridine.The crystal structure was solved with X-ray methods (Mr = 1024.1, space group P4̄n2, Z = 2, a = 9.552(2) Å, c = 17.610(7) Å, V = 1606.7 Å3, λ(AgKα) = 0.5583 Å, dc = 2.12 g cm-3, μ(AgKα) = 57.40 cm-1, F(000) = 943.7, T = 298 K. Final R = 0.043 for 1050 independent reflections).The structure consists of nearly tetrahedral Hg(SeCN)4-units. The SeCN-group is linear within the experimental error. The N-atoms of SeCN and pyridine contribute to the Archimedean antiprismatic coordination of strontium

Alkin-Komplexe des Rheniums in hohen Oxidationsstufen / Alkyne Complexes of Rhenium in High Oxidation States

1990 ◽  
Vol 45 (6) ◽  
pp. 876-886 ◽  
Author(s):  
Wolfgang A. Herrmann ◽  
Josef K. Felixberger ◽  
Josef G. Kuchler ◽  
Eberhardt Herdtweck
Keyword(s):  
Diffraction Study ◽  
Scale Up ◽  
Oxidation States ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reducing Conditions ◽  
Molar Amount ◽  
High Oxidation ◽  
Alkyne Complexes ◽  
Type 3

The class of π-alkyne complexes of metals in medium and high oxidation states has been extended by the type CH3ReO2(RC≡CR′) (3a—i). Exchange of alkyne for oxo ligands under reducing conditions has been employed as a new general synthesis. Compounds 3 are thus obtained by reaction of methyltrioxorhenium(VII) (1) with the alkynes 2a—i in the presence of a ca. 1.1-fold molar amount of polymer-bound triphenylphosphane as reducing agent (desoxygenation). The structural characterization was carried out for the example of the tolan complex 3 e by virtue of a single-crystal X-ray diffraction study at —80 °C, according to which the description of compounds 3 as “rhenacyclopropenes” seems justified. Evidence from NMR investigations of 3 a and 3 c shows that no fast rotation of the respective alkyne ligand around the axis to the metal atom occurs on the NMR time scale up to at least 105 °C. A minimal rotation barrier of approximately 20 kcal/mol is thus to be estimated. Reaction of type 3 compounds (R = R′ = CH3, b; R = R′ = C2H5, c) with polymer-bound triphenylphosphane under more drastic conditions (boiling toluene) for two days effects further reduction, with the dinuclear, diamagnetic rhenium(IV) complexes 4b and 4c, resp., being formed. Sterically demanding alkynes (e.g., R = R′ = Si(CH3)3, C6H5) seem to prevent this type of reaction. According to an X-ray diffraction study, 4b has an equilateral Re2O-triangular core geometry, with the ligands O, CH3, and butyne(2) arranged in such a way that C2-symmetry results. The alkyne complexes reported here are the first ones of tetra- and pentavalent rhenium.

Über das Erdalkalimetall-Lanthanoid-Kupfer-Oxomolybdat (Cu0,22Mg0 ,78)BaNd2Mo4O16/The Alkaline Earth Rare Earth Copper-Oxomolybdate (Cu0.22Mg0.78)BaNd2Mo4O16

1995 ◽  
Vol 50 (4) ◽  
pp. 577-580 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystals ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

Single crystals of (Cu0.22Mg0.78)BaNd2Mo4O16 have been prepared by crystallization from melts and investigated by X-ray methods. The compound crystallizes monoclinically, space group C62h - C12/c1, Z = 4, a = 5.351(1), b = 12.891(2), c = 19.391(4) Å,β = 90.899(14)° and is isotypic to CuKHo2Mo4O16. The crystal structure is dominated by BaO10 and NdO8 polyhedra forming a three-dimensional polyhedra network, which is filled by axially distorted (Cu,Mg)O6 octahedra and MoO4 tetrahedra.

Darstellung und Kristallstruktur von MgNi2,5B3 und Li1,2Ni2,5B2 / Preparation and Crystal Structure of MgNi2,5B2 and Li1,2Ni2,5B2

1977 ◽  
Vol 32 (12) ◽  
pp. 1371-1374 ◽  
Author(s):  
Walter Jung
Keyword(s):  
Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

The ternary borides MgNi2,5B2 and Li1,2Ni2,5B2 have been prepared and investigated by X-ray methods. They are isotypic and crystallize hexagonal in the space group P6222—D46-with the following constants :MgNi2.5B2 α = 4.887 ± 0.002 Å, c = 8.789 ± 0.004 Å;Li1.2Ni2.5B2 a = 4.842 ± 0.002 Å, c = 8.664 ± 0.004 A.The structure contains boron-pairs and can be derived from the CeCo3B2-type of structure.

scholarly journals Ba2ZnGe2S6O: Ein neues Oxidsulfid mit Tetraedergerüststruktur/On Ba2ZnGe2S6O. A New Oxide Sulfide with Tetrahedral Framework Structure

1980 ◽  
Vol 35 (6) ◽  
pp. 672-675 ◽  
Author(s):  
Chr. L. Teske
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Coordination Sphere ◽  
Framework Structure ◽  
Tetrahedral Framework ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
First Time ◽  
Ray Methods

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.

scholarly journals Die Kristallstruktur des Cyano-Elpasoliths [N(CH3)4]2CsFe(CN)6 / The Crystal Structure of the Cyano Elpasolite [N(CH3)4]2CsFe(CN)6

1982 ◽  
Vol 37 (12) ◽  
pp. 1534-1539 ◽  
Author(s):  
D. Babel
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
The Other ◽  
Methyl Groups ◽  
Orientational Disorder ◽  
Space Group ◽  
X Ray ◽  
Ray Methods ◽  
The Ideal

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

Die Kristallstruktur von Di-μ-hydroxo-bis[aquotriamminkobalt(III)]-nitrat-2-Hydrat / The Crystal Structure of Di-μ-hydroxo-bis[aquotriamminecobalt (III)] - nitrate-2-hydrate

1971 ◽  
Vol 26 (10) ◽  
pp. 987-989 ◽  
Author(s):  
Karl Wieghardt
Keyword(s):  
Crystal Structure ◽  
Complex Cation ◽  
Monoclinic Space Group ◽  
Spatial Behaviour ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

The crystal structure of Di-µ-hydroxy-bis [aquo-triamminecobalt (III)] nitrate-2-hydrate has been determined by x-ray diffraction using counter techniques. The compound crystallizes in the monoclinic space group C2h5-P21/n with a=9.444 (2), b=9.684 (3), c=10.736 (3) Å, β=90.1 (2)°, Z= 2. A total of 1765 independent reflections was used in solving the structure, which was refined to a conventional R1-factor of 0.047. It was not possible to distinguish by x-ray methods between the oxygen and nitrogen atoms of the NH3- and H2O molecules in the complex cation, because of their similarity in point of electrostatical and spatial behaviour.

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