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  • Cobalt  (1)
  • Multicentered metal-metal multiple bond  (1)
  • Osmium  (1)
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  • 1
    ISSN: 1572-8862
    Keywords: Osmium ; tungsten ; thiolato ; methylene ; carbide ; heterometallic clusters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Condensation of be triosmium acetonitrile complex Os3(CO)10(NCMe)2 with the sulfido complex CpW(CO)3(CH2SMe) in refluxing THF solution produced three sulfur-containing compounds Os3(C0)10)(µ-H)(µ-SMe) (1), Os3(CO)11 [S(Me)CH2W(CO)3Cp] (2) and CpWOs3(CO)12(µ-CH2)(µ-SMe) (3). Clusters 2 and 3 were products involving a 1:1 combination of starting materials and were characterized by X-ray diffraction studies. Crystals of 2 belongs to monoclinic space group P 21 /c witha=8.418(2),b = 11.912(2),c = 28.288 Å,β=97.64(2)°,Z=4;R F=0.044,R W,=0.044. Crystal dara far 3: space group P 21/e,a 18.156(4).b=9.255(6),c = 15.347(4) Å.β = 103.49(2)°,Z = 4;R F -=0.047,R W = 0.045. Upon thermolysis in toluene, the methylene cluster 3 released CO and induced C-H bond activation to afford two tetrametallic carbido clusters with formula CPWOS3(CO)9(µ4-C)(µ-H)2(µ-SMe) (4) and CPWOs3(CO)11(µ4-C)(µ-SMe) (5) as the principle products. The first complex possesses a butterfly framework encapsulating a µ4-C ligmd and a µ-SMe ligand linking a W-Os edge, whereas the second product adopts a puckered, cyclic arrangement of WOs3 metal atoms with µ-SMe ligand located on a nonbonding Os-Os vector. Complex4 crystallizes in monoclinic space group P 21 /c witha=15.633(4) Å,b = 8.699 (3) Å,c=15.422(4) Å,β=93.12(2)=°, Z=4,R=0.036,R W =0.034 for 2780 observed reflections. Crystal data for5: space groupP nma,a=14.542(3),b=13.710(6),c=11.758(3) Å.Z=4,R F =0.038,R W = 0.037 for 1826 observed reflections. A variable temperature1H NMR study was also presented to demonstrate the solution fluxionality of5.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-1948
    Keywords: Metal string complexes ; Multicentered metal-metal multiple bond ; Quadruple bonds ; Metal-metal interactions ; Chromium ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The linear pentanuclear chromium complexes [CrII5(μ5-tpda)4Cl2] (1), [CrII5(μ5-tpda)4(NCS)2] (2), [CrIIICrII4(μ5-tpda)4F2](BF4) (3), and [CrIIICrII4(μ5-tpda)4F(OTf)](OTf) (4), with four all-syn tri(α-pyridyl)diamido dianion (tpda2-) ligands, have been prepared and structurally characterized. Compounds 1 and 2 possess a delocalized Cr(II)-Cr(II)-Cr(II)-Cr(II)-Cr(II) five-centred metal-metal bond of order 1.5. In both 1 and 2 two values for CrII-CrII bond lengths are found both; the outer ones connected with axial ligands are 2.284(1) and 2.285(2) Å, and the inner ones are 2.2405(8) and 2.246(1) Å, for 1 and 2, respectively. When compound 1 reacts with 2 equiv. of AgBF4 or Ag(OTf), a oxidation reaction takes place and one of the terminal chromium(II) ions is oxidized to produce [CrIIICrII4(μ5-tpda)4F2]BF4 (3) or [CrIIICrII4(μ5-tpda)4F(OTf)](OTf) (4). Two short Cr-Cr distances [1.969(2) and 2.138(2) Å for 3, 1.846(1) and 1.922(1) Å for 4] are found, with the presence of two quadruple bonds among four adjacent CrII ions. The fifth CrIII ion, which is separated from the neighboring CrII ion by 2.487(2) Å for 3 and 2.610(1) Å for 4, is simply a square pyramidal unit with no metal-metal bonding interaction.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0044-8249
    Keywords: Cobalt ; Helicale Strukturen ; Magnetische Eigenschaften ; Nickel ; N-Liganden ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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