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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
    Mesomorphic Metallo-Dendrimers Based on the Metal-Metal Bonded Ru2(CO)4 Sawhorse Unit
    (2008)
    Frein, Stephane
    ;
    Auzias, Mathieu
    ;
    Sondenecker, Aline
    ;
    Vieille-Petit, Ludovic
    ;
    Guintchin, Boris
    ;
    Maringa, Natacha
    ;
    Süss-Fink, Georg 
    ;
    Barbera, Joaquin
    ;
    Deschenaux, Robert 
    Dinuclear Ru complexes contg. the stable metal-metal bonded Ru2(CO)4 sawhorse unit with two dendritic carboxylato bridges were synthesized and characterized. All complexes Ru2(CO)4(O2CR)2L2 (R = R1, R2, R3) contg. cyanobiphenyl-based poly(arylester) dendrons of 1st (R1), 2nd (R2), and 3rd (R3) generation and PPh3, pyridine, or 4-picoline ligands L proved to be mesomorphic, giving rise to smectic A or smectic A and nematic phases. The supramol. organization within the smectic A phase is governed by the nature and structure of the mesogenic units and dendritic core. Such materials are of interest for the design of catalytically active anisotropic fluids. [on SciFinder(R)]
  • Publication
    Accès libre
    Mesomorphic Metallo-Dendrimers Based on the Metal−Metal Bonded Ru2(CO)4 Sawhorse Unit
    (2008)
    Frein, Stéphane
    ;
    Auzias, Mathieu
    ;
    Sondenecker, Aline
    ;
    Vieille-Petit, Ludovic
    ;
    Guintchin, Boris
    ;
    Maringa, Natacha
    ;
    Süss-Fink, Georg 
    ;
    Barberá, Joaquín
    ;
    Deschenaux, Robert 
    Dinuclear ruthenium complexes containing the stable metal−metal bonded Ru2(CO)4 sawhorse unit with two dendritic carboxylato bridges have been synthesized and characterized. All complexes Ru2(CO)4(O2CR)2L2 (R = R1, R2, R3) containing cyanobiphenyl-based poly(arylester) dendrons of first (R1), second (R2), and third (R3) generation and triphenylphosphine, pyridine, or 4-picoline ligands L proved to be mesomorphic, giving rise to smectic A or smectic A and nematic phases. The supramolecular organization within the smectic A phase is governed by the nature and structure of the mesogenic units and dendritic core. Such materials are of interest for the design of catalytically active anisotropic fluids.
  • Publication
    Accès libre
    Remarkable Anticancer Activity of Triruthenium-Arene Clusters Compared to Tetraruthenium-Arene Clusters
    (2007)
    Therrien, Bruno 
    ;
    Ang, Wee Han
    ;
    Chérioux, Frédéric
    ;
    Vieille-Petit, Ludovic
    ;
    Juillerat-Jeanneret, Lucienne
    ;
    Süss-Fink, Georg 
    ;
    Dyson, Paul J.
    The in vitro activity of a series of ruthenium clusters, [(η6-C6H6)(η6-C6Me6)2Ru3 (μ-H)3 (μ3-O)][BF4], [(η6-C6H6)(η6-1,4-iPrC6H4Me)(η6-C6Me6)Ru3 (μ-H)3 (μ3-O)][BF4], [(η6-C6H6)4Ru4 (μ-H)4][BF4]2, [(η6-C6H5Me)4Ru4 (μ-H)4][BF4]2 and [(η6-C6H6)4Ru4 (μ-H)3 (μ-OH)][Cl]2, has been evaluated against A2780 and A2780cisR ovarian carcinoma cell lines. Both triruthenium clusters are very active compared to ruthenium compounds in general, whereas the tetraruthenium clusters do not display significant cytotoxicities. Since the triruthenium clusters are known to form supramolecular interactions with arenes and other functions, it is possible that such interactions are also important with respect to their mode of biological activity. The X-ray structure analysis of [(η6-C6H5Me)4Ru4 (μ-H)4][PF6]2 is also reported.
  • Publication
    Métadonnées seulement
    Synthesis and characterization of tetrahedral Ru3O clusters with intrinsic framework chirality: a chiral probe of the intact cluster catalysis concept. [Erratum to document cited in CA144:088385]
    (2006)
    Vieille-Petit, Ludovic
    ;
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    ;
    Ward, Thomas R.
    ;
    Stoeckli-Evans, Helen 
    ;
    Labat, Gaeel
    ;
    Karmazin-Brelot, Lydia
    ;
    Neels, Antonia
    ;
    Buergi, Thomas
    ;
    Finke, Richard G.
    ;
    Hagen, Collin M.
    On page 6112, Figure 9 was missing and Figure 11 appeared twice. The correct Figure 9 is given. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Synthesis and Characterization of Tetrahedral Ru3O Clusters with Intrinsic Framework Chirality: A Chiral Probe of the Intact Cluster Catalysis Concept
    (2005)
    Vieille-Petit, Ludovic
    ;
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    ;
    Ward, Thomas R.
    ;
    Stoeckli-Evans, Helen 
    ;
    Labat, Gaeel
    ;
    Karmazin-Brelot, Lydia
    ;
    Neels, Antonia
    ;
    Buergi, Thomas
    ;
    Finke, Richard G.
    ;
    Hagen, Collin M.
    Triruthenium mixed-ligand tetrahedral oxo-capped clusters with framework chirality were prepd. by redn. of areneruthenium triaqua dications followed by capping with areneruthenium dimer as racemic mixts.; diastereomeric mixts. were prepd. using chiral ligand; the prepd. complexes hydrogenate 2-acetamidoacrylate with no ee. Reaction of ArRuCl(?-Cl)2ClRuAr and Ar1RuCl(?-Cl)2ClRuAr1 with Ag2SO4 in aq. soln. gave mixt. of [ArRu(OH2)3]2+ and [Ar1Ru(OH2)3]2+, which upon NaBH4 redn. afforded mixed-ligand binuclear complex Ar1Ru(?-H)3RuAr (4, Ar = ?6-C6Me6, Ar1 = ?6-cymene). Reaction of 4 with Ar2RuCl(?-Cl)2ClRuAr2 and H2O gave the trinuclear cluster [(ArRu)(Ar1Ru)(Ar2Ru)(?3-O)(?-H)3]+ (rac-5, Ar2 = ?6-C6H6). Diastereomeric complexes [(ArRu)(Ar1Ru)(Ar*Ru)(?3-O)(?-H)3]+ [(S,R)-7, (R,R)-7; Ar* = (R)-1-phenylethanol] were prepd. by reaction of 4 with [Ar*RuCl(?-Cl)2ClRuAr*] (6). Analogous complex [(ArRu)(Ar1Ru)(Ar3Ru)(?3-O)(?-H)3]+ (8) was prepd. as a racemic mixt. from known (S,S)-Ar3RuCl(?-Cl)2ClRuAr3 [Ar3 = Et (R)-N-acetyl-?-aminobenzeneacetate]; the complex 8 was sepd. into diastereomers by chromatog., the racemization being caused by epimerization of the chiral ?-carbon. The enantiopure diastereomeric triruthenium clusters [(ArRu)(Ar1Ru)(Ar4Ru)(?3-O)(?-H)3]+ [(S,S)-17, (R,S)-17; Ar4 = (R)-N-acetyl-?-aminobenzeneethanol isobutyrate] were finally prepd. from (S,S)-Ar4RuCl(?-Cl)2ClRuAr4 and 4. The chiral Ru3O framework was evidenced by x-ray crystallog., by CD in the UV and IR regions, and by chiral shift reagents in the NMR spectra. To bring evidence for or against the hypothesis of catalytic hydrogenation by intact trinuclear arene ruthenium clusters contg. an oxo cap, catalytic hydrogenation of Me 2-acetamidoacrylate catalyzed by complexes 13 was performed; the complexes showed low catalytic activity and no asym. induction. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Supramolecular triruthenium cluster-based benzene hydrogenation catalysis: Fact or fiction?
    (2005)
    Hagen, Collin M
    ;
    Vieille-Petit, Ludovic
    ;
    Laurenczy, Gábor
    ;
    Süss-Fink, Georg 
    ;
    Finke, Richard G
    The question is addressed of whether the triruthenium cluster cation [Ru-3(mu(2)-H)(3)(eta(6)C(6)H(6))(eta(6)-C6Me6)(2)(mu(3)-O)](+), 1, is a supramolecular, outer-sphere benzene hydrogenation catalyst or is 1 a precatalyst to well-known Ru(0)(n) catalysis of benzene hydrogenation. This question of "is it homogeneous or heterogeneous catalysis?" is especially important in the present case since if 1 is a supramolecular, homogeneous catalyst as postulated in the literature that is, if 1 can in fact accomplish catalysis of reactions as difficult as benzene reduction with no inner-sphere, d-orbital-mediated ligand dissociation, oxidative addition, migratory insertion, or reductive elimination-then that finding holds promise of rewriting the rules of organometallic-based catalysis. The identity of the true catalyst derived from 1 is, therefore, addressed by a collaborative effort between research groups at the Universite de Neuchatel and Colorado State University. The methodology employed is that worked out previously for addressing the historically vexing question of "is it homogeneous or heterogeneous catalysis?" (Lin, Y.; Finke, R. G. Inorg. Chem. 1994, 33, 489 1). A combination of the following classes of experiments have been employed: (i) Ru metal product studies; (ii) kinetic studies; (iii) Hg(0) and quantitative poisoning experiments, (iv) NMR studies of H/D exchange rates; (v) other data, plus (vi) the principle that the correct mechanism will explain all of the data. The results provide a compelling case that 1 is not the true benzene hydrogenation catalyst as previously believed; instead, all our evidence is consistent with, and supportive of, trace Ru(0) derived from 1 under the reaction conditions as the true, active catalyst. Nine additional conclusions are also presented as part of the summary and take-home messages, as well as a citation of "Halpern's rules" for catalysis.
  • Publication
    Accès libre
    The water-soluble cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+: Improved synthesis, aerobic oxidation, electrochemical properties and ligand exchange studies
    (2005)
    Vieille-Petit, Ludovic
    ;
    Tschan, Mathieu J.-L.
    ;
    Süss-Fink, Georg 
    ;
    Laurenczy, Gabor
    ;
    Hagen, Collin M.
    ;
    Finke, Richard G.
    ;
    Geneste, Florence
    ;
    Moinet, Claude
    The synthesis of the trinuclear cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) has been considerably improved by changes in the NaBH4 addition step and by introducing chromatographic methods; in addition, the redox and ligand exchange properties of 1 have been studied. Although exposure of an aqueous solution of 1 to air yields the oxidised cluster [H3Ru3(C6H6)(C6Me6)2(O) (OH)]+ (2), cyclic voltammetry of [1][BF4] in acetonitrile reveals a first reversible oxidation step that does not involve 2. Bulk electrolysis of 1 and 2 in the same medium affords only decomposition products. Ligand exchange in 1 takes place only at higher temperatures: by heating a mixture of toluene with an aqueous solution of [1][BF4] (1000:1) to 110 °C for 2 h, the formation of the toluene derivative [H3Ru3(C6H5Me)(C6Me6)2 (O)]+ (3) is observed in small quantities. H/D exchange of 1 with D2O does not occur up to 90 °C; however, in the presence of D2, H/D exchange with 1 is observed to give the deuterated derivative [D3Ru3 (C6H6)(C6Me6)2 (O)]+ (1a). The results provide an improved synthesis of 1, as well as information about its redox and ligand-exchange reactions, results necessary to understand and develop the chemistry of 1.
  • Publication
    Accès libre
    X-ray crystallographic study of hydrogen-bonded systems formed between di- and tricarboxylic acids and the trinuclear cluster cation [H3Ru3(C6H6)(C6Me6)2 (O)]+
    (2005)
    Therrien, Bruno 
    ;
    Vieille-Petit, Ludovic
    ;
    Süss-Fink, Georg 
    The hydrogen-bonded systems formed between 5-bromo-isophthalic and trimesic acid derivatives and the trinuclear arene-ruthenium cluster cation [H3Ru3(C6H6)(C6Me6)2 (O)]+ (1) have been studied in the solid state by single-crystal X-ray structure analysis of the tetrafluoroborate salts. The structure analysis of 5-bromo-isophthalic acid with [1][BF4] shows a 1:1 (acid:cluster) supramolecular system, only one hydroxyl of the acid functions interacting with the μ3-oxo ligand of a cation of 1, the hydroxyl group of the second acid function interacting with a tetrafluoroborate anion. With trimesic acid, a 1:2 (acid:cluster) supramolecular system is formed. Two hydroxyl groups interact with the μ3-oxo ligand of two independent cations of 1, while the remaining hydroxyl group of the third acid function interacts with a tetrafluoroborate anion.
  • Publication
    Accès libre
    X-ray crystallographic study of two dinuclear triply-bridged p-cymene osmium complexes
    (2005)
    Therrien, Bruno 
    ;
    Vieille-Petit, Ludovic
    ;
    Süss-Fink, Georg 
    The single crystal X-ray structure analyses of [Os2(p-cymene)2(μ-H)3]PF6 ([1]PF6) and [Os2 (p-cymene)2 (μ-Cl)3]PF6 ([2]PF6) are presented. The two triple bridged arene osmium complexes show the metal to be in an octahedral geometry, where the p-cymene ligand is facially coordinated and where the bridging ligands (Cl or H) occupy the remaining three coordination sites. In the dinuclear trihydrido complex a strong metal–metal interaction is observed. This is not the case for the trichloro complex where a large metal–metal distance indicates no metal–metal bonding.
  • Publication
    Accès libre
    Agrégats trinucléaires arène-ruthénium en tant que catalyseurs d’hydrogénation: Catalyseurs moléculaires intacts ou précurseurs de nanoparticules métalliques catalytiquement actives ?
    (2005)
    Vieille-Petit, Ludovic
    ;
    Süss-Fink, Georg 
    La présente thèse est consacrée à une étude mécanistique de l’hydrogénation des substrats insaturés en solution aqueuse en présence d’agrégats trinucléaires arèneruthénium, utilisés comme catalyseurs hydrosolubles. Dans le domaine de la catalyse, il est primordial de pouvoir discerner un phénomène catalytique moléculaire homogène (manifesté par des complexes organométalliques) d’un phénomène catalytique métallique hétérogène (manifesté par des nanoparticules, issues d’une dégradation partielle du complexe de départ). Cela permet de mieux comprendre les systèmes catalytiques, leurs modes d’action et d’en améliorer les performances ou la sélectivité. En ce qui concerne les agrégats trinucléaires arèneruthénium du type [H3Ru3(arene)3(O)]+, il avait été préalablement conclu qu’ils agissaient en tant que catalyseurs moléculaires intacts pour les réactions d’hydrogénation en milieu aqueux. Cependant, au travers de cette thèse, après différentes démarches différentes mais complémentaires, il a été montré que ces complexes tétraédriques à coeur « Ru3O » n’agissaient pas en tant que catalyseurs moléculaires pour les réactions d’hydrogénation catalytique : sous pression réductrice d’hydrogène, ces agrégats se décomposent partiellement (environ 5%) pour donner naissance à des nanoagrégats « solubles » hautement actifs, représentant la véritable espèce catalytiquement active.