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Süss-Fink, Georg

Nom
Süss-Fink, Georg
Affiliation principale
Fonction
Professeur ordinaire
Email
georg.suess-fink@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/385

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  • Publication
    Métadonnées seulement
    The kinetics and mechanism of cyclohexane oxygenation by hydrogen peroxide catalyzed by a binuclear iron complex
    (2003)
    Kozlov, Yuriy N
    ;
    Gonzalez-Cuervo, Laura
    ;
    Süss-Fink, Georg 
    ;
    Shul'pin, Georgiy B
    The binuclear iron complex containing 1,3,7-triazacyclononane and acetate bridges as ligands was found to catalyze effective oxidation of alkanes by hydrogen peroxide in acetonitrile at room temperature in the presence of pyrazine-2-carboxylic acid (P) as a cocatalyst. The primary reaction products were alkylhydroperoxides, which gradually decomposed to produce the corresponding ketones (aldehydes) and alcohols. Alkane activation was caused by the attack of hydroxyl radicals on a C-H alkane bond, which resulted in the formation of alkyl radicals. Hydroxyl radicals were generated in the rate-determining step of monomolecular decomposition of the iron diperoxo adduct with one P molecule. A kinetic model of the process that satisfactorily described the whole set of experimental data was suggested. The constants of supposed equilibria and the rate constant for the decomposition of the diperoxo complex of iron with P were estimated.
  • Publication
    Métadonnées seulement
    Alkane oxidation with hydrogen peroxide catalyzed homogeneously by vanadium-containing polyphosphomolybdates
    (2001)
    Süss-Fink, Georg 
    ;
    Gonzalez-Cuervo, Laura
    ;
    Shul'pin, Georgiy B
    Alkanes (cyclooctane, n-octane, adamantane, ethane) can be efficiently oxidized by hydrogen peroxide in acetonitrile using tetra-n-butylammonium salts of the vanadium-containing polyphosphomolybdates [PMo11 VO40](4-) and [PMo6V5O39](12-) as catalysts. The oxidation of alkanes gives rise to the corresponding alkyl hydroperoxides as the main products, which slowly decompose in the course of the reaction to produce the corresponding ketones (aldehydes) and alcohols. The reaction in acetic acid and water is much less efficient. The oxidation of cyclooctane at 60 degreesC in acetonitrile gives within 9 h oxygenates with turnover numbers > 1000 and yields > 30% based on the alkane. Pyrazine-2-carboxylic acid added as co-catalyst accelerates the reaction but does not enhance the product yield. The oxidation of the cis- and trans-isomers of decalin proceeds without retention of configuration. The mechanism assumed involves the reduction of V(V) to V(IV) by a first molecule of hydrogen peroxide, followed by the reaction of V(IV) with a second H2O2 Molecule to generate hydroxyl radicals. The latter abstract a hydrogen atom from the alkane, RH, leading to alkyl radicals, R-., which rapidly react with aerobic oxygen. The alkyl peroxy radicals thus formed are then converted into alkyl hydroperoxides. (C) 2001 Elsevier Science B.V. All rights reserved.