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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
    Dinuclear Manganese Complexes Containing Chiral 1,4,7-Triazacyclononane-Derived Ligands and Their Catalytic Potential for the Oxidation of Olefins, Alkanes, and Alcohols
    (2007)
    Romakh, Vladimir B.
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Shul'pin, Georgiy B.
    Five new 1,4,7-triazacyclononane-derived compds., sodium 3-(4,7-dimethyl-1,4,7-triazacyclononan-1-yl)propionate (Na[LMe2R']) as well as enantiopure (S)-1-(2-methylbutyl)-4,7-dimethyl-1,4,7-triazacyclononane (S-LMe2R''), (S,S)-trans-2,5,8-trimethyl-2,5,8-triazabicyclo[7.4.01,9]tridecane ((S,S)-LBMe3), (S)-1-(2-hydroxypropyl)-4,7-dimethyl-1,4,7-triazacyclononane (S-LMe2R), and (R)-1-(2-hydroxypropyl)-4,7-dimethyl-1,4,7-triazacyclononane (R-LMe2R), were synthesized. Reaction of MnCl2 with the chiral macrocycles S-LMe2R and R-LMe2R in aq. EtOH gives, upon oxidn. with H2O2, the brown dinuclear Mn(III)-Mn(IV) complexes which are enantiomers, [Mn2(S-LMe2R)2(?-O)2]3+ (S,S-1) and [Mn2(R-LMe2R)2(?-O)2]3+ (R,R-1). The single-crystal x-ray structure analyses of [S,S-1][PF6]3·0.5Me2CO and [R,R-1][PF6]3·0.5Me2CO show both enantiomers to contain Mn(III) and Mn(IV) centers, each of which being coordinated to three N atoms of a triazacyclononane ligand and each of which being bridged by two oxo and by two chiral hydroxypropyl pendent arms of the macrocycle. The enantiomeric complexes S,S-1 and R,R-1 catalyze the oxidn. of olefins, alkanes, and alcs. with H2O2. In the epoxidn. of indene the enantiomeric excess values attain 13%. The bond selectivities of the oxidn. of linear and branched alkanes suggest the crucial step in this process to be the attack of a sterically hindered high-valent Mn-oxo species on the C-H bond. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Synthesis, Molecular Structure, and Catalytic Potential of the Tetrairon Complex [Fe4(N3O2-L)4(?-O)2]4+ (L = 1-Carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane)
    (2007)
    Romakh, Vladimir B.
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Shul'pin, Georgiy B.
    The reaction of Fe sulfate with 1-carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane (L) and H2O2 in aq. EtOH gives a brown dinuclear complex considered to be [Fe2(N3O-L)2(?-O)(?-OOCCH3)]+ (1), which converts upon standing in MeCN soln. into the green tetranuclear complex [Fe4(N3O2-L)4(?-O)2]4+ (2). A single-crystal x-ray structure anal. of [2][PF6]4·5MeCN reveals 2 to contain four Fe(III) centers, each of which is coordinated to three N atoms of a triazacyclononane ligand and is bridged by one oxo and two carboxylato bridges, a structural feature known from the active center of methane monooxygenase. Accordingly, 2 was found to catalyze the oxidative functionalization of methane with H2O2 in aq. soln. to give MeOH, Me hydroperoxide, and formic acid; the total turnover nos. attain 24 catalytic cycles within 4 h. To gain more insight into the catalytic process, the catalytic potential of 2 was also studied for the oxidn. of higher alkanes, cycloalkanes, and iso-PrOH in MeCN, as well as in aq. soln. The bond selectivities of the oxidn. of linear and branched alkanes suggest a ferroxy radical pathway. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Supramolecular cluster catalysis: facts and problems
    (2004)
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    ;
    Vieille-Petit, Ludovic
    ;
    Tschan, Mathieu
    ;
    Romakh, Vladimir B.
    ;
    Ward, Thomas R.
    ;
    Dadras, Massoud
    ;
    Laurenczy, Gabor
    By checking the chem. underlying the concept of supramol. cluster catalysis the authors identified two major errors in their publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the closed cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the open cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), which the authors had ascribed to a reaction with H2O in the presence of ethylbenzene is simply an oxidn. reaction which occurs in the presence of air. (2) The higher catalytic activity obsd. with ethylbenzene, which the authors had erroneously attributed to the open cluster cation 2, was due to the formation of RuO2·nH2O, caused by a hydroperoxide contamination present in ethylbenzene. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Supramolecular cluster catalysis: Facts and problems
    (: American Chemical Society, 2003)
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    ;
    Vieille-Petit, Ludovic
    ;
    Tschan, Mathieu
    ;
    Romakh, Vladimir B.
    ;
    Ward, Thomas R.
    Organometallic catalysis is generally thought to proceed through a catalytic cycle which involves coordination of the substrate to the metal center and decoordination of the product after the transformation. The water-sol. trinuclear cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) and derivs. thereof seem to catalyze the hydrogenation of benzene under biphasic conditions without prior coordination of the substrate, the interactions between catalyst and substrate relying on supramol. host-guest contacts thanks to the hydrophobic pocket spanned by the three arene ligands in the catalyst mol. The concept of supramol. cluster catalysis, the isolation and characterization of the catalyst-substrate host-guest complexes postulated, as well as errors and problems with this chem. will be discussed. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Supramolecular cluster catalysis: A case study of benzene hydrogenation
    (2003)
    Therrien, Bruno 
    ;
    Vieille-Petit, Ludovic
    ;
    Tschan, Mathieu
    ;
    Romakh, Vladimir B.
    ;
    Süss-Fink, Georg 
    A review. The hydrogenation of benzene to give cyclohexane, catalyzed under biphasic conditions by the water-sol. trinuclear arene ruthenium cluster cations [H3Ru3(C6H6)(C6Me6)2(O)]+ (1), [H3Ru3(C6H5Me)(C6Me6)2(O)]+ (2), [H3Ru3(1,4-MeC6H4Pri)(C6Me6 )2(O)]+ (3), [H3Ru3(1,2,4,5-C6H2Me4)3(O)] + (4), [H3Ru3{C6H5(CH2)2OH}(C6Me6)2(O)]+ (5), and [H3Ru3{C6H5(CH2)3OH}(C6Me6)2(O)]+ (6), is believed to occur within the hydrophobic pocket spanned by the three arene ligands of the trinuclear cluster, thus forming a supramol. catalyst-substrate host-guest complex. This paper is a short overview of our research efforts directed to a new catalytic concept for which we coined the term "supramol. cluster catalysis". [on SciFinder(R)]