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Süss-Fink, Georg
Nom
Süss-Fink, Georg
Affiliation principale
Fonction
Professeur ordinaire
Email
georg.suess-fink@unine.ch
Identifiants
Résultat de la recherche
Voici les éléments 1 - 10 sur 448
- PublicationAccès libreMetallic Ruthenium nanoparticles intercalated in hectorite for highly selective catalytic hydrogenations(2015)
By intercalating organometallic benzene ruthenium complexes or Werner-type ruthenium(III) ions from RuCl3 ∙ xH2O as precursor, ruthenium nano¬particles intercalated in hectorite are successfully obtained via a reduction process with molecular hydrogen approach or sodium borohydride. Depending on the properties of solvents and the reduction conditions, a variety of ruthenium nanoparticles with different morphology are formed.
In the catalytic hydrogenation of quinoline, hectorite-intercalated ruthenium nanoparticles show excellent reactivity and selectivity to the specific product. By using water or cyclohexane as reaction medium under a certain pressure of molecular H2, 1,2,3,4-tetrahydroquinoline and decahydroquinoline were exclusively obtained, respectively. Furthermore, by using sodium borohydride as reducing agent, the catalytic hydrogenation of quinoline proceeds in water under atmospheric pressure with the conversion and selectivity superior to 99%. Isotope labeling experiments combined with semi-empirical calculations reveal that both the sodium borohydride and water participate in the hydrogenation process by means of hydride transfer and proton transfer, respectively.
Furthermore, hectorite-intercalated ruthenium nanoparticles can also be used for the hydrogenation of aromatic amino acids in aqueous media. By screening of the influencing factors, the pH of the solution was found to be critical for the complete conversion of aromatic amino acids. Critically, during the hydrogenation process, the chirality of the substrates remains unchanged. - PublicationAccès libreThiolato-bridged arene ruthenium complexes as anticancer agents(2015)
The goal of the presented thesis was to investigate the properties of dinuclear arene ruthenium thiolato-bridged complexes and to establish their potential as anticancer drugs. In the first part of the thesis, several monothiolato, dithiolato and trithiolato complexes were synthesized and evaluated for their stability and reactivity with biological substrates. The results were correlated with the in vitro anticancer activity of the three types of complexes and showed the most stable trithiolato complexes to be the most active against ovarian cancer cell lines. Subsequently, the most active trithiolato derivative, diruthenium-1, was thoroughly investigated in vitro and in vivo to establish the mode of action of this complex, showing its promising ability to influence the tumor growth and to prolong the survival of tumor-bearing mice.
In the second part of this thesis, three series of conjugates of the mixed trithiolato complexes were synthesized to demonstrate the potential of the coupling of dinuclear arene ruthenium complexes with biologically active organic molecules. Thus, the thiolato-bridged complexes were coupled with propargyl bromide, the resulting conjugates being available for the 1,3-Huisgen addition with tumor targeting compounds. Conjugates with ibuprofen were synthesized to investigate the effect of the antiinflamatory agent on the activity and selectivity of the resulting complexes towards cancer cells. Finally, conjugates of dinuclear trithiolato arene ruthenium complexes with alkylating agent chlorambucil were synthesized to show the effect of the two different modes of action of the conjugates on their activity in vitro and in vivo.
These results demonstrate the potential of the dinuclear thiolato-bridged arene ruthenium complexes as a versatile platform for the synthesis of anticancer agents with variable biological properties and modes of action. - PublicationMétadonnées seulementArene ruthenium and pentamethylcyclopentadienyl rhodium and iridium complexes containing N,O-chelating ligands derived from piroxicam: Synthesis, molecular structure and cytotoxicity(2014)
; ; ; - PublicationMétadonnées seulementHighly cytotoxic diruthenium trithiolato complexes of the type [(?6-p-MeC6H4Pri)2Ru2(?2-SR)3]+: synthesis, characterization, molecular structure and in vitro anticancer activity(2013)
; Cationic dinuclear p-cymene Ru complexes bridged by three thiophenolato ligands contg. various substituents mainly in meta and ortho positions, [(?6-p-MeC6H4Pri)2Ru2(?2-SR)3]+ (R = 3-C6H4Me: 1; R = 3-C6H4OMe: 2; R = 3-C6H4OEt: 3; R = 3-C6H4CF3: 4; R = 3-C6H4NH2: 5; R = 3-C6H4Cl: 6; R = 2-C6H4Me: 7; R = 2-C6H4OMe: 8; R = 2-C6H4Pri: 9; R = 2-C6H4CF3: 10; R = npt: 11 (npt = 2-naphthyl); R = mco: 12 (mco = 4-methylcoumarinyl); R = 3,5-C6H3Me2: 13; R = 3,5-C6H3(CF3)2: 14; R = 3,5-C6H3Cl2: 15; R = 3,4-C6H3(OMe)2: 16), were prepd. from the reaction of the neutral p-cymene diruthenium dichloride dimer, [(?6-p-MeC6H4Pri)2Ru2Cl4], with the corresponding thiophenol RSH. All cationic complexes were isolated as their chloride salts and fully characterized by spectroscopic and anal. methods. The mol. structures of 10 and 15 were solved by a single-crystal x-ray structure anal. of [10]Cl and [15]Cl, which show that the two Ru atoms adopt a pseudo-octahedral geometry without a metal-metal bond in accordance with the noble gas rule. All complexes are highly cytotoxic towards human ovarian cancer cells, the IC50 values being mostly in the nanomolar range. Complex 9 shows the highest cytotoxicity with an IC50 value of 0.03 ?M towards the A2780 cell line and the cisplatin-resistant mutant A2780cisR. The cytotoxicity of these complexes, which belong to the most active Ru anticancer compds. reported so far, can be correlated with the lipophilicity of the corresponding thiols. In comparison with the previous series, the positions of the substituents in the thiophenolato bridges are not as important as the nature of the substituents, alkyl substituents being the best ones in line with their lipophilic character. [on SciFinder(R)] - PublicationMétadonnées seulementSynthesis, characterisation and in vitro anticancer activity of hexanuclear thiolato-bridged arene ruthenium metalla-prisms(2013)
; ; Hexanuclear hexacationic thiolato-bridged arene ruthenium metalla-prisms of the general formula [[(?6-p-cymene)Ru]6(?-SR)6(?3-tpt)2][OTf]6 (R = CH2Ph, CH2C6H4-p-tBu, CH2CH2Ph; tpt = 2,4,6-tri-4-pyridyl-1,3,5-triazine), obtained from the self-assembly of dinuclear precursors [(p-cymene)2Ru2(?-SR)2Cl2] with tpt and AgCF3SO3, have been isolated and fully characterized as triflate salts. The metalla-prisms are highly cytotoxic against human ovarian cancer cells, esp. towards the cisplatin-resistant cell line A2780cisR (IC50 - PublicationMétadonnées seulementSynthesis, molecular structure, computational study and in vitro anticancer activity of dinuclear thiolato-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes(2013)
; ; Neutral dinuclear dithiolato-bridged pentamethylcyclopentadienyl Rh(III) complexes (C5Me5)2Rh2(?-SR)2Cl2 (R = CH2Ph, 1; R = CH2CH2Ph, 2) and cationic dinuclear trithiolato-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes [(C5Me5)2M2(?-SR)3]+ (M = Rh, R = CH2Ph, 3; M = Rh, R = CH2CH2Ph, 5; M = Rh, R = CH2C6H4-p-tBu, 7: M = Ir, R = CH2Ph, 4; M = Ir, R = CH2CH2Ph, 6; M = Ir, R = CH2C6H4-p-tBu, 8) were synthesized from the chloro-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) dimers (C5Me5)2M2(?-Cl)2Cl2 by reaction with the corresponding thiol deriv. (RSH). Complexes 3-8 were isolated as chloride salts. All complexes were obtained in good yield and were fully characterized by spectroscopic methods. The mol. structures of the neutral complexes (1 and 2) show interesting features: the two Rh atoms are bridged by two thiolato ligands with no metal-metal bonds and the pentamethylcyclopentadienyl and chlorido ligands are oriented syn to each other, an uncommon conformation for such dinuclear complexes. These structural features were rationalized using DFT calcns. Addnl., the antiproliferative activity of the complexes was evaluated against the cancerous A2780 (cisplatin sensitive) and A2780cisR (cisplatin resistant) human ovarian cell lines and on the noncancerous HEK293 human embryonic kidney cells. All complexes are active and the cationic Ir complexes 4, 6 and 8 are particularly cytotoxic, with IC50 values in the nanomolar range (IC50 < 0.1 ?M). The catalytic activity of the complexes for the oxidn. of glutathione (GSH) to GSSG was evaluated by NMR spectroscopy. [on SciFinder(R)] - PublicationMétadonnées seulementArene ruthenium dichloro complexes containing isonicotinic ester ligands: Synthesis, molecular structure and cytotoxicity(2013)
; ; - PublicationMétadonnées seulementArene Ruthenium Complexes with Phosphinoferrocene Amino Acid Conjugates: Synthesis, Characterizeation and Cytotoxicity(2013)
; ; - PublicationMétadonnées seulementSynthesis, Characterization and(2013)
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