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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
    endo and exo Coordination of Indanol: Synthesis, Isolation and Structural Characterisation of [H3Ru3 (endo-Indanol)(C6Me6)2(O)]+ and [H3Ru3 (exo-Indanol)(C6Me6)2 (O)]+ as Their Tetrafluoroborate Salts
    (2004)
    Vieille-Petit, Ludovic
    ;
    Karmazin-Brelot, Lydia
    ;
    Labat, Gael
    ;
    Süss-Fink, Georg 
    The reaction of 2,3,4,7-tetrahydro-1H-inden-2-ol with ruthenium chloride hydrate in refluxing ethanol yields the chloro-bridged dinuclear complex [RuCl2(indanol)]2 (1). The mononuclear complex [Ru(indanol)(H2O)3]2+ (2), formed in situ from 1 in aqueous solution, reacts with the dinuclear complex [H3Ru2(C6Me6)2]+ to give a trinuclear arene-ruthenium cluster as a mixture of two isomers, the cations [H3Ru3(endo-indanol)(C6Me6)2(O)]+ (3a) and [H3Ru3(exo-indanol)(C6Me6)2(O)]+ (3b), in a 1:1 ratio. The hydroxy function of the indanol ligand is oriented towards the μ3-oxo cap of 3a, whereas the OH group is bent away from the metal skeleton of 3b. These two isomers, which can easily be separated by silica-gel chromatography, were isolated and characterised as their tetrafluoroborate salts. The single-crystal X-ray structure analysis of [3a][BF4] shows a strong intramolecular hydrogen bond between the μ3-oxo ligand and the hydroxyl function, which even persists in acetone solution, as demonstrated by NMR spectroscopy. On the other hand, the hydroxy function of 3b was found to be free in the solid state as well as in solution, as shown by an X-ray crystal structure analysis and by NMR spectroscopy. The catalytic activities of the water-soluble trinuclear cations 3a and 3b for the hydrogenation of benzene to give cyclohexane under biphasic conditions are considerably different, the exo isomer 3b being more active than the endo isomer 3a.
  • Publication
    Accès libre
    Synthesis of a trinuclear cation [H3Ru3(Fc-arene)(C6Me6)2(O)]+ containing a ferrocenyl group tethered to an arene ligand
    (2003-11-20)
    Vieille-Petit, Ludovic
    ;
    Unternährer, Sabine
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    Ferrocene carboxylic acid 2-cyclohexa-1,4-dienyl-ethyl ester (1) is prepared from ferrocene carboxylic acid and 2-cyclohexa-1,4-dienyl-ethanol. This diene reacts with RuCl3•nH2O in refluxing ethanol to afford quantitatively [Ru(Fc-arene)Cl2]2 (2) (Fc-arene=ferrocene carboxylic acid phenethyl ester). The dinuclear complex 2 reacts with triphenylphosphine to give the mononuclear complex [Ru(Fc-arene)(PPh3)Cl2] (3). The trinuclear arene-ruthenium cluster cation [H3Ru3 (Fc-arene)(C6Me6)2(O)]+ (4) is synthesised from the dinuclear precursor [H3Ru2 (C6Me6)2]+ and the mononuclear complex [Ru(Fc-arene)(H2O)3]2+, accessible from 2 in aqueous solution. The water-soluble trinuclear cluster cation 4 catalyses the hydrogenation of benzene to give cyclohexane under biphasic conditions.
  • Publication
    Accès libre
    Synthesis and molecular structure of the trinuclear ruthenium cluster cations [H3Ru3(C6H6)(C6H2Me4)2(O)]+ and [H3Ru3{C6H5(CH2)2OH}(C6H2Me4)2(O)]+
    (2003-11-20)
    Vieille-Petit, Ludovic
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    The trinuclear arene–ruthenium cluster cations [H3Ru3(C6H6)(C6H2Me4)2(O)]+ (2) and [H3Ru3{C6H5(CH2)2OH}(C6H2Me4)2(O)]+ (3) have been synthesised from the dinuclear precursor [H3Ru2(C6H2Me4)2]+ (1) and the mononuclear complexes [Ru(C6H6)(H2O)3]2+ and [Ru{C6H5(CH2)2OH}(H2O)3]2+, isolated and characterised as the tetrafluoroborate salts. Cations 2 and 3 are analogues of the cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ which was found to catalyse the hydrogenation of benzene to give cyclohexane under biphasic conditions (‘supramolecular cluster catalysis’). The single-crystal X-ray structure analyses of 2 and 3 have been determined. Unlike [2][BF4]•3H2O, [3][PF6]•H2O shows a dimeric structure in the solid state, thanks to hydrogen bonds between the hydroxo function of one molecule of 3, a water molecule and the oxo cap of an other molecule of 3.
  • Publication
    Accès libre
    Isolation and single-crystal X-ray structure analysis of the catalyst–substrate host–guest complexes [C6H6⊂H3Ru3{C6H5(CH2) nOH}(C6Me6)2(O)]+ (n = 2, 3)
    (2003-11-01)
    Vieille-Petit, Ludovic
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Ward, Thomas R.
    The trinuclear arene-ruthenium cluster cations [H3Ru3{C6H5 (CH2)nOH}(C6Me6)2 (O)]+ (3: n=2, 4: n=3) have been synthesised from the dinuclear precursor [H3Ru2 (C6Me6)2]+ and the mononuclear complexes [{C6H5(CH2)nOH}Ru(H2O)3]2+ in aqueous solution, isolated and characterised as the hexafluorophosphate or tetrafluoroborate salts. Both 3 and 4 are derivatives of the parent cluster cation [H3Ru3 (C6H6)(C6Me6)2(O)]+ (1) which was found to catalyse the hydrogenation of benzene to give cyclohexane under biphasic conditions. The mechanism postulated for this catalytic reaction (‘supramolecular cluster catalysis’), involving the hydrophobic pocket spanned by the three arene ligands in 1, was based on the assumption that the substrate molecule benzene is hosted inside the hydrophobic pocket of the cluster molecule to form a catalyst–substrate host–guest complex in which the hydrogenation of the substrate takes place. With the analogous cluster cations 3 and 4, containing a (CH2)nOH side-arm (n=2, 3) as substituent at the benzene ligand, it was possible to isolate the cationic host–guest complexes as the hexafluorophosphate or tetrafluoroborate salts. The single-crystal X-ray structure analyses of [C6H6⊂3][PF6] and [C6H6⊂4][BF4], compared to that of [3][PF6] show that the substrate molecule benzene is indeed held inside the hydrophobic pocket of 3 and 4, the angle between the metal (Ru3) plane and the aromatic plane being 67° and 89°, respectively.