Vignette d'image

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

Résultat de la recherche

Filtres

9
9
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 9 sur 9
  • Publication
    Métadonnées seulement
    Heterodinuclear Arene Ruthenium Complexes Containing a Glycine-Derived Phosphinoferrocene Carboxamide: Synthesis, Molecular Structure, Electrochemistry, and Catalytic Oxidation Activity in Aqueous Media
    (2012)
    Tauchman, Jiri 
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    Three series of heterodinuclear Ru-Fe complexes were synthesized from (?6-arene)ruthenium dichloride dimers and phosphinoferrocene ligands contg. glycine-based carboxamido substituents. The neutral complexes [(?6-arene)RuCl2(Ph2PfcCONHCH2CO2Me-?P)] (4, arene = benzene (a), p-cymene (b), hexamethylbenzene (c); fc = ferrocene-1,1'-diyl) were obtained by the bridge cleavage reaction of [(?6-arene)RuCl2]2 with Ph2PfcCONHCH2CO2Me (1) in CHCl3 soln. [(?6-P-cymene)RuCl2(Ph2PfcCONHCH2CONH2-?P)] (6b) was synthesized in the same way from Ph2PfcCONHCH2CONH2 (3); the prepn. of [(?6-p-cymene)RuCl2(Ph2PfcCONHCH2CO2H-?P)] (5b), featuring the ferrocene ligand in the free acid form (2), failed due to side reactions and isolation problems. [(?6-Arene)RuCl(MeCN)(1-?P)][PF6] (7a-c) and [(?6-arene)Ru(MeCN)2(1-?P)][PF6]2 (8a-c) were prepd. from 1 and the MeCN precursors [(?6-arene)RuCl(MeCN)2][PF6] and from 4a-c via halide removal with Ag[PF6] in MeCN soln., resp. Alternative synthetic routes to 7b and 8b were also studied. The compds. were fully characterized by elemental anal., multinuclear NMR, IR, and electrospray ionization mass spectra, and their electrochem. properties were studied by cyclic voltammetry at a Pt-disk electrode. The single-crystal x-ray analyses of two representatives (4b and 8b) revealed a pseudotetrahedral coordination geometry at the Ru centers and eclipsed conformations of the ferrocene moieties, with the substituents at the two cyclopentadienyl rings being anti with respect to each other. All complexes showed high activity for the catalytic oxidn. of secondary alcs. with tert-Bu hydroperoxide to give ketones in aq. media. The most active catalyst was obtained from the neutral p-cymene complex 4b, showing a catalytic turnover frequency of 13,200 h-1 at room temp. for the oxidn. of 1-phenylethanol at a substrate/catalyst ratio of 100,000. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Highly cytotoxic trithiophenolatodiruthenium complexes of the type [(?6-p-MeC6H4Pri)2Ru2(SC6H4-p-X)3]+: synthesis, molecular structure, electrochemistry, cytotoxicity, and glutathione oxidation potential
    (2012)
    Giannini, Federico
    ;
    Furrer, Julien
    ;
    Ibao, Anne-Flore
    ;
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    ;
    Zava, Olivier
    ;
    Baquie, Mathurin
    ;
    Dyson, Paul J.
    ;
    Stepnicka, Petr
    A series of cationic binuclear areneruthenium tris(arenethiolato)-bridged complexes [(?6-p-cymene)2Ru2(?-SC6H4-p-X)3]+ (1-11; X = H, Me, Ph, Br, OH, NO2, OMe, CF3, F, iPr, tBu) were prepd. by complexation of the chloride-bridged dimer [(?6-p-cymene)2Ru2(?-Cl)2Cl2] with the corresponding thiols, isolated as the chloride salts, and further studied for their electrochem. properties, cytotoxicity towards human ovarian cancer cells, and catalytic activity for glutathione (GSH) oxidn. Complex 1 was also compared with the benzene and hexamethylbenzene analogs [(?6-C6H6)2Ru2(?-SC6H5)3]+ (12) and [(?6-C6Me6)2Ru2(?-SC6H5)3]+ (13). The most active compd. [11]Cl was structurally studied by single-crystal x-ray diffraction anal. The concns. corresponding to 50% inhibition of cancer cell growth (IC50 values) in the A2780 and A2780cisR cell lines of these complexes except for 6 were in the submicromolar range, complex 11 showing an IC50 value of 0.03 ?M in both cell lines. The high in vitro anticancer activity of these complexes may be at least partially due to their catalytic potential for the oxidn. of GSH, although there is no clear correlation between the IC50 values and the turnover frequencies at about 50% conversion. However, the cytotoxicity is tentatively correlated to the physicochem. properties of the compds. detd. by the electronic influence of the substituents X (Hammett consts. ?p) and the lipophilicity of the thiols p-XC6H4SH (calcd. log P parameters). [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Synthesis, Molecular Structure, and Anticancer Activity of Cationic Arene Ruthenium Metallarectangles
    (2009)
    Mattsson, Johan
    ;
    Govindaswamy, Padavattan
    ;
    Renfrew, Anna K.
    ;
    Dyson, Paul J.
    ;
    Stepnicka, Petr
    ;
    Süss-Fink, Georg 
    ;
    Therrien, Bruno 
    Cationic arene ruthenium-based tetranuclear complexes comprising rectangular structures have been obtained from the dinuclear arene ruthenium complexes [Ru2(arene)2(OO?OO)2Cl2] (arene = p-cymene, hexamethylbenzene; OO?OO = 2,5-dihydroxy-1,4-benzoquinonato, 2,5-dichloro-1,4-benzoquinonato) by reaction with pyrazine or bipyridine linkers (N?N = pyrazine, 4,4'-bipyridine, 1,2-bis(4-pyridyl)ethylene) in methanol in the presence of AgO3SCF3, forming tetranuclear cations of general formula [Ru4(arene)4(N?N)2(OO?OO)2]4+. All complexes were isolated in good yield as triflate salts and were characterized by NMR and IR spectroscopy and studied by cyclic voltammetry. The cytotoxicities of the water-sol. compds. of the 4,4'-bipyridine and 1,2-bis(4-pyridyl)ethylene series have been established using ovarian A2780 cancer cells. The large rectangles incorporating 1,2-bis(4-pyridyl)ethylene linkers are ca. 5 times more cytotoxic (IC50 ? 6 ?M) than the 4,4'-bipyridine-contg. cations (IC50 ? 30 ?M). Structural characterization by x-ray diffraction of two representative compds., i.e., the triflate salts of [Ru4(hexamethylbenzene)4(4,4'-bipyridine)2(2,5-dihydroxy-1,4-benzoquinonato)2]4+and [Ru4(hexamethylbenzene)4(1,2-bis(4-pyridyl)ethylene)2(2,5-dichloro-1,4-benzoquinonato)2]4+, reveals differently sized cavities, different flexibilities, and different packing arrangements, suggesting a correlation between these structural properties and the obsd. cytotoxicities. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Ferrocenoyl Pyridine Arene Ruthenium Complexes with Anticancer Properties: Synthesis, Structure, Electrochemistry, and Cytotoxicity
    (2008)
    Auzias, Mathieu
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    ;
    Ang, Wee Han
    ;
    Dyson, Paul J.
    Reaction of the dimers [Ru(?6-arene)Cl2]2 (arene = C6H6, C6H5Me, p-iPrC6H4Me, C6Me6) with 2 equiv of the ferrocenoyl pyridine (NC5H4(OOCC5H4FeC5H5)-4) affords Ru(II) complexes [Ru(?6-arene)Cl2(NC5H4OOCC5H4FeC5H5)] (arene = C6H6 (1, 85% yield), C6H5Me (2, 81%), p-iPrC6H4Me (3, 91%), C6Me6 (4, 38%)) or with 1 equiv of the dipyridylferrocene deriv. ligand, 1,1'-ferrocene dicarboxylic acid pyridin-4-yl ester (NC5H4OOCC5H4FeC5H4COOC5H4N,) gives [Ru(?6-arene)Cl2]2(NC5H4OOCC5H4FeC5H4COOC5H4N) (arene = p-iPrC6H4Me (5, 74%), C6Me6 (6, 92%)). The mol. structures of these complexes was confirmed by single-crystal x-ray structure anal. of complex 4 as a representative example. The redox properties and in vitro anticancer activities of complexes 1-6 were studied. All the compds. are moderately cytotoxic toward the A2780 and A2780cisR (cisplatin-resistant) human ovarian carcinoma cell lines. The diruthenium arene complexes 5 and 6 are about twice as active as their mononuclear analogs 3 and 4. Cyclic voltammetry revealed a good correlation of the RuII/RuIII redox potentials of 1-4 and the no. of alkyl substituents in the arene ligand. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Water-soluble arene ruthenium complexes containing pyridinethiolato ligands: Synthesis, molecular structure, redox properties and anticancer activity of the cations [(?6-arene)Ru(p-SC5H4NH)3]2+
    (2008)
    Gras, Michael
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    ;
    Renfrew, Anna K.
    ;
    Dyson, Paul J.
    The cationic complexes [(?6-arene)Ru(SC5H4NH)3]2+, arene being C6H6 (1), MeC6H5 (2), p-iPrC6H4Me (3) or C6Me6 (4), have been synthesized from the reaction of 4-pyridinethiol with the corresponding precursor (?6-arene)2Ru2(?2-Cl)2Cl2 and isolated as the chloride salts. The single-crystal x-ray structure of [4](PF6)2 reveals three 4-pyridinethiol moieties coordinated to the ruthenium center through the sulfur atom, with the hydrogen atom transferred from the sulfur to the nitrogen atom. The electrochem. study of 1-4 shows a clear correlation between the Ru(II)/Ru(III) redox potentials and the no. of alkyl substituents at the arene ligand (E°' (RuII/III): 1 > 2 > 3 > 4), whereas the cytotoxicity towards A2780 ovarian cancer cells follows the series 4 > 1 > 3 > 2, the hexamethylbenzene deriv. 4 being the most cytotoxic one. The corresponding reaction of the ortho-isomer, 2-pyridinethiol, with (?6-C6Me6)2Ru2(?2-Cl)2Cl2 does not lead to the expected 2-pyridinethiolato analog, but yields the neutral complex (?6-C6Me6)Ru(?2-SC5H4N)(?1-SC5H4N) (5). The analogous complex (?6-C6Me6)Ru(?2-SC9H6N)-(?1-SC9H6N) (6) is obtained from the similar reaction with 2-quinolinethiol. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Mono and dinuclear rhodium, iridium and ruthenium complexes containing chelating 2,2'-bipyrimidine ligands: Synthesis, molecular structure, electrochemistry and catalytic properties
    (2007)
    Govindaswamy, Padavattan
    ;
    Canivet, Jerome
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    ;
    Ludvik, Jiri
    The mononuclear cations [(?5-C5Me5)RhCl(bpym)]+ (1), [(?5-C5Me5)IrCl(bpym)]+ (2), [(?6-p-PriC6H4Me)RuCl(bpym)]+ (3) and [(?6-C6Me6)RuCl(bpym)]+ (4) as well as the dinuclear dications [{(?5-C5Me5)RhCl}2(bpym)]2+ (5), [{(?5-C5Me5)IrCl}2(bpym)]2+ (6), [{(?6-p-PriC6H4Me)RuCl}2(bpym)]2+ (7) and [{(?6-C6Me6)RuCl}2(bpym)]2+ (8) have been synthesized from 2,2'-bipyrimidine (bpym) and the corresponding chloro complexes [(?5-C5Me5)RhCl2]2, [(?5-C5Me5)IrCl2]2, [(?6-PriC6H4Me)RuCl2]2 and [(?6-C6Me6)RuCl2]2, resp. The x-ray crystal structure analyses of [3][PF6], [5][PF6]2, [6][CF3SO3]2 and [7][PF6]2 reveal a typical piano-stool geometry around the metal centers; in the dinuclear complexes the chloro ligands attached to the two metal centers are , with respect to each other, cis oriented for 5 and 6 but trans for 7. The electrochem. behavior of 1-8 has been studied by voltammetric methods. In addn., the catalytic potential of 1-8 for transfer hydrogenation reactions in aq. soln. has been evaluated: All complexes catalyze the reaction of acetophenone with formic acid to give phenylethanol and carbon dioxide. For both the mononuclear and dinuclear series the best results were obtained (50°, pH 4) with rhodium complexes, giving turnover frequencies of 10.5 h-1 for 1 and 19 h-1 for 5. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Mono and dinuclear iridium, rhodium and ruthenium complexes containing chelating carboxylato pyrazine ligands: Synthesis, molecular structure and electrochemistry
    (2007)
    Govindaswamy, Padavattan
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    ;
    Ludvik, Jiri
    Mononuclear complexes [(?5-C5Me5)IrCl(L1)] (1), [(?5-C5Me5)RhCl(L1)] (2), [(?6-p-PriC6H4Me)RuCl(L1)] (3) and [(?6-C6Me6)RuCl(L1)] (4) have been synthesized from pyrazine-2-carboxylic acid (HL1) and the corresponding complexes [{(?5-C5Me5)IrCl2}2], [{(?5-C5Me5)RhCl2}2], [{(?6-p-PriC6H4Me)RuCl2}2], and [{(?6-C6Me6)RuCl2}2], resp. Related dinuclear complexes [{(?5-C5Me5)IrCl}2(?-L2)] (5), [{(?5-C5Me5)RhCl}2(?-L2)] (6), [{(?6-p-PriC6H4Me)RuCl}2(?-L2)] (7) and [{(?6-C6Me6)RuCl}2(?-L2)] (8) have been obtained in a similar manner from pyrazine-2,5-dicarboxylic acid (H2L2). Compds. isomeric to the latter series, [{(?5-C5Me5)IrCl}2(?-L3)] (9), [{(?5-C5Me5)RhCl}2(?-L3)] (10), [{(p-PriC6H4Me)RuCl}2(?-L3)] (11) and [{(?6-C6Me6)RuCl}2(?-L3)] (12), have been prepd. by using pyrazine-2,3-dicarboxylic acid (H2L3) instead of H2L2. The mol. structures of 2 and 3, detd. by x-ray diffraction anal., show the pyrazine-2-carboxylato moiety to act as an N,O-chelating ligand, while the structure analyses of 5-7, confirm that the pyrazine-2,5-dicarboxylato unit bridges two metal centers. The electrochem. behavior of selected representatives has been studied by voltammetric techniques. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Synthesis, structure and electrochemistry of cationic diruthenium complexes of the type [(N-N)2Ru2(CO)2(?-CO)2(?-OOCFc)]+ containing a ferrocenecarboxylato bridge and two chelating aromatic diimine ligands
    (2007)
    Auzias, Mathieu
    ;
    Therrien, Bruno 
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    ;
    Ludvik, Jiri
    The dinuclear bis(ferrocenecarboxylato) complex Ru2(CO)4(?-OOCFc)2(py)2 (Fc = ferrocenyl, py = pyridine) was found to react with arom. diimines (2,2'-dipyridyl, 4,4'-dimethyl-2,2'-dipyridyl, 1,10-phenanthroline, 5-nitro-1,10-phenanthroline, and 5-amino-1,10-phenanthroline) in methanol to give the cationic diruthenium complexes [(N-N)2Ru2(CO)2(?-CO)2(?-OOCFc)]+ (1: N-N = 2,2'-dipyridyl, 2: N-N = 4,4'-dimethyl-2,2'-dipyridyl, 3: N-N = 1,10-phenanthroline, 4: N-N = 5-nitro-1,10-phenanthroline, 5: N-N = 5-amino-1,10-phenanthroline), which have been isolated as the hexafluorophosphate salts. The mol. structure of 3, solved by single-crystal x-ray anal. of the tetraphenylborate salt [3][BPh4], shows a diruthenium backbone bridged by two carbonyl and by one ferrocenecarboxylato ligand, the two 1,10-phenanthroline ligands being in the axial positions. Cyclic voltammetry in dichloromethane reveals for all compds. two successive oxidns. due to ferrocene/ferrocenium redox couple and oxidn. of the diruthenium core. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Water-soluble phenanthroline complexes of rhodium, iridium and ruthenium for the regeneration of NADH in the enzymatic reduction of ketones
    (2007)
    Canivet, Jerome
    ;
    Süss-Fink, Georg 
    ;
    Stepnicka, Petr
    The nicotinamide coenzyme NADH, consumed in enantioselective reduction of ketones catalysed by alcohol dehydrogenases, needs to be regenerated in order to maintain enzymatic activity. We therefore studied the catalytic potential of the cationic complexes [(eta(5)-(CMe5)-Me-5)Rh(NnN)Cl](+) (1: N boolean AND N = 1,10-phenanthrohne; 2: NnN = 5 -nitro-1, 10-phenanthroline; 3: NnN = 5-amino-1, 1 0-phenanthroline), [(eta(5)-C5Me5) Ir(N boolean AND N)CI](+) (4: N boolean AND N = 5-nitro-1, 10-phenanthroline) and [(eta(6)-C-6,Me-6)Ru(N boolean AND N)Cl](+) (5: NnN = 5-nitro-1,10-phenanthroline), isolated as the water-soluble chloride salts, for transfer hydrogenation of NAD(+) to give NADH in aqueous solution. The best results were obtained with rhodium complex 1, which gave catalytic turnover frequencies up to 2000 h(-1) in aqueous solution at pH 7 and 60 degrees C with sodium formate as the hydrogen source. When this NADH-regenerating catalytic system is combined with NADH-dependent enzymes, it is possible to chemoenzymatically reduce prochiral ketones such as acetophenone or 4-phenylbutan-2-one with high enantioselectivity. Combination of horse liver alcohol dehydrogenase (HLADH) or alcohol dehydrogenase from Rhodococcus sp. (S-ADH) with 1/formate as the NADH-regenerating system resulted in ee values up to 98 %, depending on the nature of the substrate and the enzyme. In order to explain the different catalytic activities, the electrochemical behaviour of complexes 1-5 has been studied. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)