ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Chemistry  (2)
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 3581-3588 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Autoxidation of Trialkylboranes, II: 1H NMR Spectroscopic Investigations on the Mechanism of the Redox Reaction between Trialkylboranes und Dialkyl(alkylperoxy)boranesThe intermolecular redox reaction between dimethyl(methylperoxy)borane and [D9]trimethylborane, triethylborane, tri-n-propylborane, triisopropylborane, and tri-n-butylborane, as well as between [D9]dimethyl(methylperoxy)borane and trimethylborane was investigated directly in an NMR spectrometer. From the CIDNP effects a mechanism of this redox reaction was deduced, which can be considered as generally valid for any reaction between (alkylperoxy)boranes and alkylboranes. According to this mechanism, the alkoxy group of the peroxide is transferred to the boron atom of the alkylborane after homolysis of the O—O bond. The four-coordinate boron compound eliminates instantly an alkyl radical, which forms a radical pair in the singlet state with the boroxyle radical left after the homolysis of the peroxide.
    Notes: Die intermolekularen Redoxreaktionen Zwischen Dimethyl(methylperoxy)boran und [D9]Trimethylboran, Triethylboran, Tri-n-propylboran, Triisopropylboran und Tri-n-butylboran sowie zwischen [D9]Dimethyl(methylperoxy)boran und Trimethylboran wurden in Lösung im 1H-NMR-Spektrometer untersucht. Aus den CIDNP-Effekten wird ein allgemeingültiger Mechanismus der Redoxreaktion zwischen (Alkylperoxy)boranen und Alkylboranen abgeleitet. Danach wird in einem Stoßkomplex zwischen (Alkylperoxy)boranen und Alkylboran durch Homolyse der O—O-Bindung gezielt die Alkoxygruppe des Peroxids auf das Boratom des Alkylborans übertragen. Das vierfach koordinierte Alkoxyalkylboran stößt sofort ein Alkyl-Radikal ab, welches mit dem Boroxylradikal aus der Spaltung des Peroxids zu einem Radikalpaar mit Singulett-Konfiguration der Radikalelektronen zusammenfindet.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2189-2199 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Autoxidation of Trialkylboranes. 1H NMR Spectroscopic Investigations on the Mechanism of the Oxidation of TrimethylboraneThe oxidation by air of a solution of trimethylborane leads to methoxydimethylborane and hydroxydimethylborane as main products, as well as methane, ethane, and 1,1,1-trichloroethane as by-products. The peroxide CH3OOB(CH3)2 appears as an intermediate. All final products have been confirmed by 1H NMR spectra; they result from the reaction of the peroxide with trimethylborane. The presence of CIDNP signals in the NMR spectra taken during the reaction shows clearly that this redox reaction involves radicals. The interpretation of the CIDNP spectra and the quantitative product analysis lead to a suggestion for the reaction mechanism, as well as an explanation for the violent, often explosive, course of reaction of the autoxidation.
    Notes: Die Oxidation von Trimethylboran mit Luft in Lösung führt zu den Hauptprodukten Methoxy-dimethylboran und Hydroxydimethylboran, sowie zu Methan, Ethan und 1,1,1-Trichlorethan als Nebenprodukten. Als Zwischenprodukt tritt das Peroxid CH3OOB(CH3)2 auf. Alle 1H-NMR-spektroskopisch nachgewiesenen Endprodukte entstehen durch Umsetzung dieses Peroxids mit Trimethylboran. Diese Redoxreaktion verläuft radikalisch, was durch CIDNP-Effekte in den während des Reaktionsverlaufs aufgenommenen NMR-Spektren bewiesen werden konnte. Die Interpretation der CIDNP-Spektren und die quantitative Produktanalyse führen zu einem Vorschlag für den Mechanismus der Redoxreaktion sowie zu einer Erklärung für den so heftigen, bis zur Explosion führenden Reaktionsverlauf der Autoxidation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...