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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
    Double HCl elimination and configuration change in the square-planar palladium complex trans-[{(Ph2PC6H4CONH) 2C6H4}PdCl2] under Suzuki conditions: Isolation and molecular structure of cis-[{(Ph2PC6H4CON)2C6H4}Pd]
    (2006)
    Chahen, Ludovic
    ;
    Karmazin-Brelot, Lydia
    ;
    Süss-Fink, Georg 
    The trans-configurated square-planar palladium complex trans-[{(Ph2PC6H4CONH) 2C6H4}PdCl2] (1), which catalyzes the Suzuki cross coupling of 4-bromotoluene with phenylboronic acid, was found to react with potassium carbonate in toluene at 90 °C (Suzuki conditions) to give cis-[{(Ph2PC6H4CON)2C6H4}Pd] (2). The single-crystal X-ray structure analysis of 2 reveals the square-planar palladium center to be in a cis configuration. The trans–cis configuration change at palladium is possible because of the elimination of two HCl equivalents in the conversion of 1 into 2. Both complexes 1 and 2 show approximately the same catalytic performance for Suzuki reactions, suggesting 2 to be the catalytically active species.
  • Publication
    Accès libre
    (μ-Diphenylphosphido-κP:P)-μ-hydrido-(μ-4-hydroxybenzenethiolato-κ2S:S)bis[(η6-hexamethylbenzene)ruthenium(II)] tetrafluoroborate
    (2006)
    Tschan, Mathieu J.-L.
    ;
    Chérioux, Frédéric
    ;
    Therrien, Bruno 
    ;
    Karmazin-Brelot, Lydia
    ;
    Süss-Fink, Georg 
    The new triple-bridged dinuclear cation [(η6-C6Me6)2Ru2(μ2-p-S-C6H4-OH)(μ2-PPh2)(μ2-H)]+, isolated and characterized as the tetrafluoroborate salt, was prepared by reacting the precursor [(η6-C6Me6)2Ru2(μ2-H)2(μ2-PPh2)](BF4) and p-hydroxythiophenol in refluxing ethanol. The single-crystal X-ray structure analysis of [(η6-C12H18)2Ru2(μ2-S-C6H4-OH)(μ2-H){μ2-P(C6H5)2}](BF4) shows the formation of the meso form; despite the two stereogenic centres the complex is not chiral.
  • Publication
    Accès libre
    Dinuclear manganese complexes containing 1,4-dimethyl-1,4,7-triazacyclononane ligands as well as carboxylato and oxo bridges
    (2006)
    Romakh, Vladimir B.
    ;
    Therrien, Bruno 
    ;
    Karmazin-Brelot, Lydia
    ;
    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 MnCl2 • 4H2O in acetonitrile gives, in the presence of sodium formate, hydrogen peroxide, triethylamine and KPF6, the dinuclear Mn(III)–Mn(IV) complex cation [(L-Me2)2Mn2 (O) 2 (OOCH)]2+ (1) which crystallises as the hexafluorophosphate salt.The analogous reaction with sodium benzoate, however, yields the dinuclear Mn(III)–Mn(III) complex cation [(L-Me2)2Mn2 (O)(OOCC6H5)2]2+ (2), isolated also as the hexafluorophosphate salt.In the case of sodium acetate, both cations, the Mn(III)–Mn(IV) complex [(L-Me2)2Mn2 (O) 2 (OOCCH3)]2+ (3) and the known Mn(III)–Mn(III) complex [(L-Me2)2Mn2 (O)(OOCCH3)2]2+ (4) are available, depending upon the molar ratio.The single-crystal X-ray structure analyses show for the green crystals of [1][PF6]1.5 [Cl]0.5 • 1.5 H2O and [3][PF6]2 • (CH3)2CO, a Mn–Mn distance of 2.620(2) and 2.628(4) Å, respectively, while for the red-violet crystal of [4][PF6]2, a Mn–Mn distance of 3.1416(8) Å is observed.All four compounds show catalytic activity for the oxidation of isopropanol with hydrogen peroxide in water and in acetonitrile to give acetone in the presence of oxalic or ascorbic acid as co-catalysts.
  • Publication
    Accès libre
    New aryl phosphinite ligands avoiding ortho-metallation: Synthesis and molecular structures of trans-[PdCl2(PPh2OR)2] and trans-[Rh(CO)Cl(PPh2OR) 2] (R = 2,4,6-Me3C6H2; 2,6-Ph2C6H3)
    (2005)
    Chahen, Ludovic
    ;
    Karmazin-Brelot, Lydia
    ;
    Süss-Fink, Georg 
    The new aryl phosphinites PPh2OR (R = 2,4,6-Me3C6H2, 1; R = 2,6-Ph2C6H3, 2) have been prepared from chlorodiphenylphosphine and the corresponding phenols. In these ligands, the ortho-positions of the aromatic phosphite function are blocked by methyl and phenyl substituents, which allows coordination to metal centres without ortho-metallation. Thus, reaction with [PdCl2 (cod)] leads to the complexes trans-[PdCl2 (PPh2OR)2] (R = 2,4,6-Me3C6H2, 3; R = 2,6-Ph2C6H3, 4), while the reaction with [Rh2 (CO)4Cl2] gives trans-[Rh(CO)Cl(PPh2OR)2] (R = 2,4,6-Me3C6H2, 5; R = 2,6-Ph2C6H3, 6). The single-crystal X-ray structure analyses of 3 and 5 confirm the trans-coordination of the new ligands in these square-planar complexes.
  • 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.