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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
    New aryl phosphinite ligands avoiding ortho-metallation: Synthesis and molecular structures of trans-[PdCl2(PPh2OR)(2)] and trans-[Rh(CO)Cl(PPh2OR)(2)] (R=2,4,6-Me3C6H2; 2,6-Ph2C6H3)
    (2005)
    Chahen, Ludovic
    ;
    Karmazin-Brelot, Lydia
    ;
    Süss-Fink, Georg 
    The new aryl phosphinites PPh2OR (R = 2,4,6-Me3C6H2, 1; R = 2,6-Ph2C6H3, 2) have been prepared from chlorodiphenylphosphine and the corresponding phenols. In these ligands, the ortho-positions of the aromatic phosphite function are blocked by methyl and phenyl substituents, which allows coordination to metal centres without ortho-metallation. Thus, reaction with [PdCl2(cod)] leads to the complexes trans-[PdCl2(PPh2OR)(2)] (R = 2,4,6-Me3C6H2, 3; R = 2,6-Ph2C6H3, 4), while the reaction with [Rh-2(CO)(4)Cl-2] gives trans-[Rh(CO)Cl(PPh2OR)(2)] (R = 2,4,6-Me3C6H2, 5; R = 2,6-Ph2C6H3, 6). The single-crystal X-ray structure analyses of 3 and 5 confirm the trans-coordination of the new ligands in these square-planar complexes. (c) 2005 Elsevier B.V. All rights reserved.
  • 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.
  • Publication
    Métadonnées seulement
    Oxidations by the reagent 'O-2-H2O2 vanadate anion pyrazine-2-carboxylic acid'. Part 10 - Oxygenation of methane in acetonitrile and water
    (1998)
    Süss-Fink, Georg 
    ;
    Nizova, Galina V
    ;
    Stanislas, Sandrine
    ;
    Shul'pin, Georgiy B
    The oxidation of methane by a combination of air and hydrogen peroxide is effectively catalyzed in solution by a system composed of vanadate and pyrazine-2-carboxylic acid (PCA). In acetonitrile solution, containing the vanadate anion as tetrabutylammonium salt, the reaction gives, over a temperature range of 25 to 50 degrees C, methanol, carbon monoxide, formaldehyde, formic acid and carbon dioxide, the latter three compounds, however, being partially due to the oxidation of the acetonitrile used as the solvent, especially at higher temperatures. In aqueous solution, containing the vanadate anion in the form of the sodium salt, the reaction affords, over a temperature range of 40 to 70 degrees C, selectively methyl hydroperoxide within 4 h. The yield of CH3OOH attains 24%, based on H2O2, after 24 h at 50 degrees C, the catalytic turnover number being 480. The process seems to involve hydroxyl radicals, generated by the catalyst from H2O2 even at low temperatures. At 120 degrees C, methane is oxidized by O-2 and H2O2 to give formaldehyde and formic acid, even in the absence of the catalyst, presumably due to the formation of HO radicals from H2O2 in the presence of very low concentrations of metal ions from the autoclave under high temperature conditions. (C) 1998 Elsevier Science B.V.