Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Organometallics 9 (1990), S. 1395-1399 
    ISSN: 1520-6041
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Properties of Tellurium-Tellurium Bonds, VI.  -  Structure and Barrier of Interconversion of Enantiomeric Conformations of Bis(2,4,6-tri-tert-butylphenyl)ditellaneOxidation of lithium (2,4,6-tri-tert-butylphenyl)telluride provides red and strong refractive needles of bis(2,4,6-tri-tert-butylphenyl)-ditellane (1) which crystallize monoclinically in the space group C2/c. The bond distance d(Te-Te), the bond angle at the Te atoms, and the torsion angle at the Te-Te bond were found to be 271.3 pm, 100.6°, and 92.1°, respectively. The C2 symmetry of the molecule gives rise to different chemical surroundings for both tert-butyl groups in ortho position belonging to the aryl groups. This effect can also be observed in solution at low temperatures. For the first time, dynamic NMR spectroscopy succeeded in determination of the barrier of rotation about a Te-Te bond. This barrier was found to be 40.9 kJ · mol-1 and is 20% less than that in the corresponding diselane.
    Notes: Bis(2,4,6-tri-tert-butylphenyl)ditellan (1) wird durch Oxidation von Lithium-(2,4,6-tri-tert-butylphenyl)tellurid in Form roter, stark lichtbrechender Kristalle erhalten. 1 kristallisiert monoklin in der Raumgruppe C2/c. Der Bindungsabstand d(Te-Te) beträgt 271.3 pm, der Bindungswinkel an den Te-Atomen 100.6° und der Torsionswinkel an der Te-Te-Bindung 92.1°. Durch die C2-Symmetrie besitzen die beiden ortho-ständigen tert-Butylgruppen der Substituenten unterschiedliche chemische Umgebung, die auch in Lösung bei tiefen Temperaturen erkennbar wird. Aus NMR-spektroskopischen Daten gelang erstmals die Bestimmung der Rotationsbarriere um eine Te-Te-Bindung; sie beträgt 40.9 kJ · mol-1. Dieser Wert ist um 20% kleiner als für das entsprechende Diselan.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0009-2940
    Keywords: Chalcogen-chalcogen bonds ; Selenium ; Selenide (2,4,6-tri-tert-butylphenyl)- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Properties of Chalcogen-Chalcogen Bonds, XV1). - Lithium 2,4,6-Tri-tert-butylphenylselenide: Synthesis, Structure, and Reactions with Formation of Se - P, Se - C, Se - Si, Se - Sn, and Se - Au BondsBis(2,4,6-tri-tert-butylphenyl)diselenide (1) is reduced by lithium triethylhydridoborate to give lithium 2,4,6-tri-tert-butyl-phenylselenide (2) in high yield. 2 crystallizes with three molecules of tetrahydrofuran coordinated to lithium ([2(THF)3] ≡ 2a, space group P&1macr; Z =4). The monomeric compound 2a contains four-coordinate lithium bonded to two-coordinate selenium. 2 (LiSeR) reacts with the nonmetal and metal halides tBu2PCl, CH2Cl2, Me3SiCl, Me3SnCl, and Ph3PAuCl to give tBu2PSeR (3), RSeCH2Cl (4), (RSe)2CH2 (5), Me3SiSeR (6), Me3SnSeR (7), and the novel gold(I) selenophenolate derivative Ph3PAuSeR (8)(R = 2,4,6-tri-tert-butylphenyl).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...