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  • Titanium  (2)
  • Azaboratantalacyclobutanes  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Weitere Reaktionen der Iminoborane RB≡NR′ mit Neopentylidentantal-Komplexen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1571-1577 
    Details
    ISSN: 0009-2940
    Keywords: Iminoboranes ; Tantalum complexes, cyclic carbene- ; Azaboratantalacyclobutanes ; Azaboratantalacyclobutenes ; Diazoniadiboratatantalacyclohexadienes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Further Reactions of Iminoboranes RB≡NR' with Neopentylidenetantalum ComplexesThe azaboratantalacyclobutanes [-NR≡-BR-CH(tBu)-Ta-CpCl2-] (3b, d, f, h-1; R/R′=Pr/tBu, iPr/tBu, iPr/iPr, tBuCH2/tBuCH2, Me3SiCH2/Me3SiCH2, tBu/Me, tBu/iPr, tBu/SiMe3) are formed from the corresponding iminoboranes RB≡NR′ and the neopentylidenetantalum complex [tBuHC=TaCpCl2] (2a) by [2 + 2] cycloaddition. The elimination of HCl from 3b, d, f, h and from the four known azaboratantalacyclobutanes 3a, c, e, g [R/R'equals;Et/tBu, Bu/tBu, Ph/tBu, iBu/iBu] gives the azaboratantalacyclobutenes [-NR′-BR-C(tBu)=TaCpCl-] (4a-h). X-Ray structural analyses of 4e, f show these cyclic carbenetantalum complexes to contain short Ta-C and Ta-N bonds and perhaps some transannular Ta-B interaction. The complex [tBuHC=TaCl3(THF)2] (2b) adds iminoboranes RB≡NtBu with unbranched alkyl groups (R=Et, Pr, Bu) in a 1:2 molar ratio to yield the diazoniadiboratatantalacyclohexadienes 5a-c; the product 5a adopts a non-planar ring structure in the crystal. The 1:2 reaction of 2b with tBuB≡NMes, instead, results in the cyclobutane [-N(Mes)-B(tBu)-N(Mes)-TaCl3(THF)-] (7m).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260711
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  • 2
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of [1]Borametallocenophanes of Titanium, Zirconium, and Hafnium (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1899-1904 
    Details
    ISSN: 1434-1948
    Keywords: Boron ; Titanium ; Zirconium ; Hafnium ; Metallocenophanes ; Metallocenophanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various [1]borametallocenophane complexes of all the group IV metals were obtained in high yield by a very efficient multistep, one-pot synthesis. By this method not only the biscyclopentadienyl and diindenyl complexes [{R2NB(η5-C5H4)2}MCl2] (M = Zr, R = Me, SiMe3, 4a, b; M = Hf, R = SiMe3, 5) and [{(Me3Si2)NB(η5-C9H6)2}MCl2] (M = Ti, 6; M = Zr, 7) were obtained, but also complexes with two different η5-coordinated ligands such as [{iPr2NB(η5-C5H4)(η5-C9H6)}MCl2] (M = Zr, 8; M = Hf, 9). Some of compounds 4-9 were chosen to investigate their catalytic properties with respect to Ziegler-Natta-type polymerisation of olefins, and proved to be highly efficient for the preparation of polyethylene.
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of the First [1]Boratitanocenophanes (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 69-73 
    Details
    ISSN: 1434-1948
    Keywords: Boron ; Titanium ; Metallocenophanes ; [1]Boratitanocenophanes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper presents two methods for the synthesis of the first [1]boratitanocenophanes. The novel biscyclopentadienylborane [(Me3Si)2NB(C5H5)2], the dilithio salt Li2[(Me3Si)2NB(C5H4)2] (1) of which was characterized by multinuclear NMR methods, was prepared in situ, and served as starting material for several [1]boratitanocenophanes. [Cl2Ti{(C5H4)2BN(SiMe3)2}] (2) was obtained in high yield by a convenient one-pot synthesis starting from 1 and [TiCl3(thf)3], followed by oxidation with PbCl2. The highly reactive [(Me2N)2Ti{(C5H4)2BN(SiMe3)2}] (3) was obtained by the reaction of [(Me3Si)2NB(C5H5)2], prepared in situ, with Ti(NMe2)4and converted into the chloro derivatives [(Me2N)ClTi{(C5H4)2BN(SiMe3)2}] (4) and [Cl2Ti{(C5H4)2BN(SiMe3)2}] (2) by treatment with one or two equivalents of a suitable diaminochloroborane. All [1]boratitanocenophanes were characterized in solution by multinuclear NMR spectroscopy, and in addition the structure of 2 in the crystalline state was determined by a single-crystal X-ray study.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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