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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
    Accès libre
    Regioselective alkane oxygenation with H2O2 catalyzed by titanosilicalite TS-1
    (2006)
    Shul’pin, Georgiy B.
    ;
    Sooknoi, Tawan
    ;
    Romakh, Vladimir B.
    ;
    Süss-Fink, Georg 
    ;
    Shul’pina, Lidia S.
    Titanosilicalite TS-1 catalyses oxidation of light (methane, ethane, propane and n-butane) and normal higher (hexane, heptane, octane and nonane) alkanes to give the corresponding isomeric alcohols and ketones. The oxidation of higher alkanes proceeds in many cases with a unique regioselectivity. Thus, in the reaction with n-heptane the CH2 groups in position 3 exhibited a reactivity 2.5 times higher than those of the other methylene groups. This selectivity can be enhanced if hexan-3-ol is added to the reaction mixture, the 3-CH2/2-CH2 ratio becoming 10. It is assumed that the unusual selectivity in the oxidation of n-heptane (and other higher alkanes) is due to steric hindrance in the catalyst cavity. As a result, the catalytically active species situated on the catalyst walls can only easily react with certain methylenes of the alkane, which is adsorbed in the cavity taking U-shape (hairpin) conformations.
  • Publication
    Accès libre
    Dinuclear iron, ruthenium and cobalt complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo or hydroxo bridges
    (2006)
    Romakh, Vladimir B.
    ;
    Therrien, Bruno 
    ;
    Labat, Gael
    ;
    Stoeckli-Evans, Helen 
    ;
    Shul’pin, Georgiy B.
    ;
    Süss-Fink, Georg 
    The reaction of 1,4-dimethyl-1,4,7-triazacyclononane (L–Me2) with FeSO4 • 7H2O in aqueous ethanol gives, in the presence of sodium carboxylates, hydrogen peroxide, sodium hydroxide and KPF6, the dinuclear Fe(III)–Fe(III) complex cations [(L–Me2)2Fe2(O)(OOCR) 2]2+ (R = H: 1, R = CH3: 2, R = C6H5: 3), which crystallise as the hexafluorophosphate salts. The corresponding reaction with RuCl3 • nH2O does not work, however, the analogous Ru(III)–Ru(III) complex [(L–Me2)2Ru2 (O)(OOCCH3)2]2+ (5) can be synthesised by reacting Ru(dmso)4Cl2 with L–Me2, HCl and air in refluxing ethanol, followed by addition of sodium acetate, the mononuclear intermediate (L–Me2)RuCl3 • H2O (4) being also isolated and characterised. The reaction of L–Me2, sodium acetate, hydrogen peroxide and triethylamine with CoCl2 • 6H2O in acetonitrile yields, however, the hydroxo-bridged Co(III)–Co(III) complex [(L–Me2)2Co2 (OH)(OOCCH3)2]3+ (6). The molecular structures of 2, 5 and 6, solved by single-crystal X-ray structure analyses of the hexafluorophosphate salts, reveal for the orange crystals of [2][PF6]2 a Fe–Fe distance of 3.104(1) Å, for the purple crystals of [5][PF6]2 a Ru–Ru distance of 3.230(1) Å, and for the violet crystals of [6][PF6]3 • (CH3)2CO a Co–Co distance of 3.358(1) Å. All six complexes show catalytic activity for the oxidation of isopropanol with hydrogen peroxide in water to give acetone in the presence of ascorbic acid as co-catalyst.