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  • Publication
    Accès libre
    Hydrogen-bonded systems between monocarboxylic acids and the trinuclear cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ : cold-spray ionisation mass spectroscopic and X-ray crystallographic studies
    (2004-09-01) ;
    Vieille-Petit, Ludovic
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    ;
    Sei, Yoshihisa
    ;
    Yamaguchi, Kentaro
    The hydrogen-bonded systems formed between monocarboxylic acid derivatives and the trinuclear arene-ruthenium cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) have been studied in solution by cold-spray ionisation mass spectroscopy (CSI-MS) and in the solid state by single-crystal X-ray structure analysis of the tetrafluoroborate salts. The presence of 1:1 (acid:cluster) adducts in acetone solution has been clearly demonstrated by CSI-MS. Single-crystal X-ray structure analyses of selected acid-cluster complexes show that in every case the hydroxyl of the acid function interacts strongly with the μ3-oxo ligand of cation 1, the O O distance ranging from 2.499(9) to 2.595(11) Å.
  • Publication
    Accès libre
    Ruthenium(II) complexes with ferrocene-modified arene ligands: synthesis and electrochemistry
    (2004) ;
    Vieille-Petit, Ludovic
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    Jeanneret-Gris, Julie
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    Štěpnička, Petr
    ;
    A series of arene–ruthenium complexes of the general formula [RuCl26-C6H5 (CH2)2R}L] with R=OH, CH2OH, OC(O)Fc, CH2OC(O)Fc (Fc=ferrocenyl) and L=PPh3, (diphenylphosphino)ferrocene, or bridging 1,1′-bis(diphenylphosphino)ferrocene, have been synthesized. Two synthetic pathways have been used for these ferrocene-modified arene–ruthenium complexes: (a) esterification of ferrocene carboxylic acid with 2-(cyclohexa-1,4-dienyl)ethanol, followed by condensation with RuCl3nH2O to afford [RuCl26-C6H5 (CH2)2OC(O)Fc}]2, and (b) esterification between ferrocene carboxylic acid and [RuCl26-C6H5 (CH2)3OH}L] to give [RuCl26-C6H5 (CH2)3OC(O)Fc}L]. All new compounds have been characterized by NMR and IR spectroscopy as well as by mass spectrometry. The single-crystal X-ray structure analysis of [RuCl26-C6H5 (CH2)3OH}(PPh3)] shows that the presence of a CH2CH2CH2OH side-arm allows [RuCl26-C6H5 (CH2)3OH}(PPh3)] to form an intramolecular hydrogen bond with a chlorine atom. The electrochemical behavior of selected representative compounds has been studied. Complexes with ferrocenylated side arms display the expected cyclic voltammograms, two independent reversible one-electron waves of the Ru(II)/Ru(III) and Fe(II)/Fe(III) redox couples. Introduction of a ferrocenylphosphine onto the ruthenium is reflected by an additonal reversible, one-electron wave due to ferrocene/ferrocenium system which is, however, coupled with the Ru(II)/Ru(III) redox system.
  • Publication
    Accès libre
    An asymmetric trihydrido-bridged arene ruthenium complex
    (2004)
    Vieille-Petit, Ludovic
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    ;
    Reaction of [Ru(η6-indane)(H2O)3]2+ and [Ru(η6-C6Me6)(H2O)3]2+ with NaBH4 in water gives a mixture of three triple hydrido-bridged arene ruthenium cations [(η6-arene)Ru(μ-H)3Ru(η6-arene′)]+ (arene=indane and hexamethylbenzene; arene′=indane and hexamethylbenzene). After treatment with NaBF4, the three complexes are separated by column chromatography and the asymmetrical [(η6-indane)Ru(μ-H)3Ru(η6-C6Me6)][BF4] (cation 1a) can be isolated in moderate yield. 1a decomposes in solution to give the corresponding hydroxo-bridged complex [(η6-indane)Ru(μ-OH)3Ru(η6-C6Me6)]+ (2) with retention of the asymmetrical geometry as shown by single-crystal X-ray structure analysis. The indane ligand adopts an envelope conformation toward the ruthenium atom.
  • Publication
    Accès libre
    Supramolecular cluster catalysis : facts and problems
    (2004) ; ;
    Vieille-Petit, Ludovic
    ;
    Tschan, Mathieu J.-L.
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    Romakh, Vladimir B.
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    Ward, Thomas R.
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    Dadras, Massoud
    ;
    Laurenczy, Gabor
    By checking the chemistry underlying the concept of "supramolecular cluster catalysis" we identified two major errors in our 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 we had ascribed to a reaction with water in the presence of ethylbenzene is simply an oxidation reaction which occurs in the presence of air. (2) The higher catalytic activity observed with ethylbenzene, which we had erroneously attributed to the "open" cluster cation [H2Ru3(C6H6)(C6Me6)2(O)(OH)]+ (2), was due to the formation of RuO2nH2O, caused by a hydroperoxide contamination present in ethylbenzene.
  • Publication
    Accès libre
    Synthesis and molecular structure of the trinuclear ruthenium cluster cations [H3Ru3{C6H5(CH2)2OC(O)C6H5}(C6Me6)2(O)]+ and [H3Ru3{C6H5(CH2)2OC(O)(CH2)3C6H5}(C6Me6)2(O)]+
    (2004)
    Vieille-Petit, Ludovic
    ;
    ;
    Benzoic acid 2-cyclohexa-1,4-dienyl ethyl ester (1), and 4-phenylbutyric acid 2-cyclohexa-1,4-dienyl ethyl ester (2) are prepared by reacting, respectively, benzoic acid and 4-phenylbutyric acid with 2-cyclohexa-1,4-dienyl ethanol. These dienyl ester derivatives react with RuCl3n H2O in refluxing ethanol to afford in good yield [Ru{C6H5(CH2)2OC(O)C6H5}Cl2] 2 (3), and [Ru{C6H5(CH2)2OC(O)(CH2)3C6H5}Cl2]2 (4). The trinuclear arene–ruthenium cluster cations [H3Ru3{C6H5 (CH2)2OC(O)C6H5}(C6Me6)2(O)]+ (5), and [H3Ru3{C6H5(CH2)2OC(O)(CH2)3C6H5}(C6Me6)2(O)]+ (6) are synthesised from the dinuclear precursor [H3Ru2(C6Me6)2]+, and the mononuclear complexes [Ru{C6H5(CH2)2OC(O)C6H5}(H2O)3]2+ and [Ru{C6H5(CH2)2OC(O)(CH2)3C6H5}(H2O)3]2+, accessible, respectively, from 3 and 4 in aqueous solution. The water-soluble trinuclear cluster cations 5, and 6 possess a phenyl substituent attach to their side-arm which can act as a substrate for hydrogenation. The single-crystal X-ray structure analyses of [5][PF6], and [6][PF6] have been determined.
  • Publication
    Accès libre
    Chiral Arene Ruthenium Complexes : Synthesis and Molecular Structure of the Enantiopure Cluster Cation (S)-[H3Ru3{C6H5[CH(CH3)CH2OH]}(C6Me6)2(O)]+
    (2003)
    Vieille-Petit, Ludovic
    ;
    ;
    The reaction of enantiopure (R)-(2-cyclohexa-1,4-dienyl)propan-1-ol with ruthenium chloride hydrate yields, without racemisation of the chiral ligand, the chloro-bridged dinuclear complex (S,S)-[RuCl2{C6H5[CH(CH3)CH2OH]}]2 (1). The dimer 1 reacts with triphenylphosphane to give the mononuclear complex (S)-[RuCl2{C6H5[CH(CH3)CH2OH]}(PPh3)] (2). A single-crystal X-ray structure analysis of 2 reveals the absolute configuration of the asymmetric carbon atom to have remained, the change from (R) to (S) being due to the priority change caused by coordination; in the solid state, onedimensional hydrogen-bonded chains are formed between the hydroxy functions and chloro ligands of neighbouring molecules. The mononuclear cationic complex (S)-[Ru{C6H5[CH(CH3)CH2OH]}(H2O)3]2+, formed in situ from 1 in aqueous solution, reacts with the dinuclear complex [H3Ru2(C6Me6)2]+ to give a chiral trinuclear arene-ruthenium cluster, the cation (S)-[H3Ru3{C6H5[CH(CH3)CH2OH]} (C6Me6)2(O)]+ (3). This enantiopure cation has been isolated and characterised as its tetrafluoroborate salt. The single-crystal X-ray structure analysis of (S)-[3][BF4] shows a strong intramolecular hydrogen bond between the μ3-oxo cap and the hydroxy function, which also persists in acetone solvent, as demonstrated by NMR spectroscopy.