Voici les éléments 1 - 10 sur 36
  • Publication
    Accès libre
    Thiolato-Bridged Arene–Ruthenium Complexes: Synthesis, Molecular Structure, Reactivity, and Anticancer Activity of the Dinuclear Complexes [(arene)2Ru2 (SR)2Cl2]
    (2012)
    Ibao, Anne-Flore
    ;
    Gras, Michaël
    ;
    ; ;
    Zava, Olivier
    ;
    Dyson, Paul J.
    Treatment of an arene–ruthenium dichloride dimer with thiols RSH to lead to cationic trithiolato complexes of the type [(arene) 2Ru2(SR)3]+ was shown to proceed through the neutral thiolato complexes [(arene)2Ru2(SR)2Cl2], which have been isolated and characterized for arene = p-MeC6H4iPr and R = CH2Ph (1), CH2CH2Ph (2), CH2C6H4-p-tBu (3), and C6H11 (4). The single-crystal X-ray structure analysis of the p-tert-butylbenzyl derivative 3 reveals that the two ruthenium atoms are bridged by the two thiolato ligands without a metal–metal bond. The neutral dithiolato complexes[(arene)2Ru2(SR)2Cl2] (1–3) are intermediates in the formation of the cationic trithiolato complexes [(arene)2Ru2(SR)3]+ (5–7). Of the new [(arene)2Ru2(SR)2Cl2] complexes, derivative 2 is highly cytotoxic against human ovarian cancer cells, with IC50 values of 0.20 μM for the A2780 cell line and 0.31 for the cisplatin-resistant cell line A2780cisR.
  • Publication
    Accès libre
    Superparamagnetic Core-Shell-Type Fe3O4/Ru Nanoparticles as Catalysts for the Selective Hydrogenation of an Unconstrained α,β-Unsaturated Ketone
    (2012)
    Khan, Farooq-Ahmad
    ;
    Superparamagnetic core-shell-type Fe3O4/Ru nanoparticles (particle size ca. 15 nm) synthesized by co-precipitation, adsorption and reduction methods were found to selectively hydrogenate the carbon-oxygen double bond in trans-4-phenyl-3-penten-2-one (conversion 100 %, selectivity > 90 %) with a catalytic turnover of 900 under mild reaction conditions (30 °C, 15 bar H2). The finely dispersed catalyst can be separated from the reaction mixture by using an external magnet, recycled, and reused without significant loss of activity and selectivity.
  • Publication
    Accès libre
    Ru2(CO)4(OOCR)2L2 sawhorse-type complexes containing axial 5-(4-pyridyl)-10,15,20-triphenylporphyrin ligands
    (2011)
    Gras, Michaël
    ;
    Barry, Nicolas P.E.
    ;
    ;
    The thermal reaction of Ru3(CO)12 with various carboxylic acids (benzoic, 4-hydroxyphenylacetic, ferrocenic, stearic, oleic, 4-(octadecyloxy)benzoic) in refluxing tetrahydrofuran, followed by addition of 5-(4-pyridyl)-10,15,20-triphenylporphyrin (L), gives the dinuclear complexes Ru2(CO)4(OOCR)2L2 (1: R = –C6H5, 2: R = –CH2-p-C6H4OH, 3: R = –C5H4FeC5H5, 4: R = –(CH2)16CH3, 5: R = –(CH2)7CHdouble bond; length as m-dashCH(CH2)7CH3, 6: R = –p-C6H4O(CH2)17CH3). Complexes 1–6 were characterised by IR, NMR, and ESI-MS as well as by elemental analysis. The UV–Vis spectra show the Soret band centred at 417 nm and the Q bands at 515, 550, 590 and 645 nm, respectively.
  • Publication
    Accès libre
    Arene ruthenium bis-saccharinato complexes: Synthesis, molecular structure and catalytic oxidation properties in aqueous solution
    (Elsevier, 2011)
    Thai, Trieu-Tien
    ;
    ;
    Arene ruthenium complexes [(η6-arene)Ru(sacc)2(OH2)] (arene = para-cymeme, benzene) containing an aqua and two saccharinato ligands have been synthesized from [(η6-arene)RuCl2]2 and sodium saccharinate in a water-ethanol mixture (1:1). The aqua complex [(η6-MeC6H4Pri)Ru(sacc)2(OH2)] reacts with acetonitrile to give the acetonitrile complex [(η6-MeC6H4Pri)Ru(sacc)2(NCMe)]. The corresponding benzene derivative [(η6-C6H6)Ru(sacc)2(NCMe)] was obtained from [(η6-C6H6)RuCl2]2 and saccNa in an acetonitrile-methanol mixture (1:1). All new complexes show a piano-stool geometry with two mono-hapto nitrogen-bonded saccharinato ligands in addition to a H2O or MeCN ligand. All complexes of the type [(η6-arene)Ru(sacc)2(OH2)] and [(η6-arene)Ru(sacc)2(NCMe)] were found to catalyze the oxidation of secondary alcohols with tert-butyl hydroperoxide (ButOOH) to give the corresponding ketones in aqueous solution.
  • Publication
    Accès libre
    Anticancer activity of new organo-ruthenium, rhodium and iridium complexes containing the 2-(pyridine-2-yl)thiazole N,N-chelating ligand
    (Elsevier, 2010)
    Gras, Michaël
    ;
    ; ;
    Angela Casini
    ;
    Edafe, Fabio
    ;
    Paul Dyson
    The dinuclear dichloro complexes [(η6-arene)2Ru2(μ-Cl)2Cl2] and [(η5-C5Me5)2M2 (μ-Cl)2Cl2] react with 2-(pyridine-2-yl)thiazole (pyTz) to afford the cationic complexes [(η6-arene)Ru(pyTz)Cl]+ (arene = C6H61, p-iPrC6H4Me 2 or C6Me63) and [(η5-C5Me5)M(pyTz)Cl]+ (M = Rh 4 or Ir 5), isolated as the chloride salts. The reaction of 2 and 3 with SnCl2 leads to the dinuclear heterometallic trichlorostannyl derivatives [(η6-p-iPrC6H4Me)Ru(pyTz)(SnCl3)]+ (6) and [(η6-C6Me6)Ru(pyTz)(SnCl3)]+ (7), respectively, also isolated as the chloride salts. The molecular structures of 4, 5 and 7 have been established by single-crystal X-ray structure analyses of the corresponding hexafluorophosphate salts. The in vitro anticancer activities of the metal complexes on human ovarian cancer cell lines A2780 and A2780cisR (cisplatin-resistant), as well as their interactions with plasmid DNA and the model protein ubiquitin, have been investigated.
  • Publication
    Accès libre
    Permanent Encapsulation or Host–Guest Behavior of Aromatic Molecules in Hexanuclear Arene Ruthenium Prisms
    Cationic arene ruthenium metallaprisms of the general formula [Ru6(p-cymene)6(tpt)2(OOOO)3]6+ {tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine; OOOO = 9,10-dioxo-9,10-dihydroanthracene-1,4-diolato [1]6+, 6,11-dioxo-6,11-dihydronaphthacene-5,12-diolato [2]6+} have been obtained from the corresponding dinuclear arene ruthenium complexes [Ru2(p-cymene)2(OOOO)Cl2] by reaction with tpt and silver trifluoromethanesulfonate. Aromatic molecules (phenanthrene, pyrene, triphenylene, coronene) present during the synthesis of these metallaprisms are permanently encapsulated to give carceplex systems. All empty cages ([1]6+ and [2]6+) and carceplex systems ([guest⊂1]6+ and [guest⊂2]6+) were isolated in good yield as trifluoromethanesulfonate salts and characterized by NMR, UV, and IR spectroscopy. The host–guest properties of [1]6+ and [2]6+ were studied in solution in the presence of small aromatic molecules (phenanthrene andpyrene). The stability constant of association (Ka) wasestimated by NMR spectroscopy for the following host–guest systems: [phenanthrene⊂1]6+, [pyrene⊂1]6+ and [phenanthrene⊂2]6+, [pyrene⊂2]6+. All Ka values were found to be larger than 2.0 × 104M–1 for these host–guest systems ([D3]acetonitrile, 21 °C).
  • Publication
    Accès libre
    Bimetallic ruthenium–tin chemistry: Synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands
    (2010) ;
    Thai, Trieu-Tien
    ;
    ; ;
    Shapovalov, Sergey S.
    ;
    Pasynskii, Alexandr A.
    ;
    Plasseraud, Laurent
    A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl2 and the corresponding arene ruthenium dichloride dimers [(η6-arene)Ru(μ2-Cl)Cl]2 (arene = C6H6, PriC6H4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η6-C6H6)Ru(PPh3)(SnCl3)Cl] (1) and [(η6-PriC6H4Me)Ru(PPh3)(SnCl3)Cl] (2), the neutral di(trichlorostannyl) complex [(η6-PriC6H4Me)Ru(NCPh)(SnCl3)2] (3) could be obtained for the para-cymene derivative with benzonitrile as additional ligand. By contrast, the analogous reaction with the benzene derivative leads to a salt composed of the cationic mono(trichlorostannyl) complex [(η6-C6H6)Ru(NCPh)2(SnCl3)]+ (5) and of the anionic tris(trichlorostannyl) complex [(η6-C6H6)Ru(SnCl3)3] (6). On the other hand, [(η6-PriC6H4Me)Ru(μ2-Cl)Cl]2 reacts with SnCl2 and hexamethylenetetramine hydrochloride or 18-crown-6 to give the anionic di(trichlorostannyl) complex [(η6-PriC6H4Me)Ru(SnCl3)2Cl] (4), isolated as the hexamethylenetetrammonium salt or the chloro-tin 18-crown-6 salt. The single-crystal X-ray structure analyses of 1, 2, [(CH2)6N4H][4], [(18-crown-6)SnCl][4] and [5][6] reveal for all complexes a pseudo-tetrahedral piano-stool geometry with ruthenium–tin bonds ranging from 2.56 (anionic complexes) to 2.60 Å (cationic complex).
  • Publication
    Accès libre
    Combined arene ruthenium porphyrins as chemotherapeutics and photosensitizers for cancer therapy
    (2009)
    Schmitt, Frédéric
    ;
    Govindaswamy, Padavattan
    ;
    Zava, Olivier
    ;
    ;
    Juillerat-Jeanneret, Lucienne
    ;
    Mononuclear 5-(4-pyridyl)-10,15,20-triphenylporphyrin and 5-(3-pyridyl)-10,15,20-triphenylporphyrin as well as tetranuclear 5,10,15,20-tetra(4-pyridyl)porphyrin (tetra-4-pp) and 5,10,15,20-tetra(3-pyridyl)porphyrin) (tetra-3-pp) arene ruthenium(II) derivatives (arene is C6H5Me or p-PriC6H4Me) were prepared and evaluated as potential dual photosensitizers and chemotherapeutics in human Me300 melanoma cells. In the absence of light, all tetranuclear complexes were cytotoxic (IC50 ≤ 20 μM), while the mononuclear derivatives were not (IC50 ≥ 100 μM). Kinetic studies of tritiated thymidine and tritiated leucine incorporations in cells exposed to a low concentration (5 μM) of tetranuclear p-cymene derivatives demonstrated a rapid inhibition of DNA synthesis, while protein synthesis was inhibited only later, suggesting arene ruthenium–DNA interactions as the initial cytotoxic process. All complexes exhibited phototoxicities toward melanoma cells when exposed to laser light of 652 nm. At low concentration (5 μM), LD50 of the mononuclear derivatives was between 5 and 10 J/cm2, while for the tetranuclear derivatives LD50 was approximately 2.5 J/cm2 for the [Ru46-arene)4 (tetra-4-pp)Cl8] complexes and less than 0.5 J/cm2 for the [Ru46-arene)4 (tetra-3-pp)Cl8] complexes. Examination of cells under a fluorescence microscope revealed the [Ru46-arene)4 (tetra-4-pp)Cl8] complexes as cytoplasmic aggregates, whereas the [Ru4(η6-arene)4(tetra-3-pp)Cl8] complexes were homogenously dispersed in the cytoplasm. Thus, these complexes present a dual synergistic effect with good properties of both the arene ruthenium chemotherapeutics and the porphyrin photosensitizer.
  • Publication
    Accès libre
    Arene–ruthenium complexes with ferrocene-derived ligands: Synthesis and characterization of complexes of the type [Ru(η6-arene)(NC5H4CH2NHOC-C5H4FeC5H5)Cl2] and [Ru(η6-arene)(NC3H3N(CH2)2O2C–C5H4FeC5H5)Cl2]
    (2009)
    Auzias, Mathieu
    ;
    Gueniat, Joël
    ;
    ; ;
    Renfrew, Anna K.
    ;
    Dyson, Paul J.
    Arene–ruthenium complexes of general formula [Ru(η6-arene)(L)Cl2] where L = NC5H4CH2NHOC-C5H4FeC5H5, arene = p-iPrC6H4Me (1) or C6Me6 (2); L = NC3H3N(CH2) 2O2C–C5H4FeC5H5, arene = p-iPrC6H4Me (3) or C6Me6 (4), and diruthenium–arene complexes of general formula [Ru(η6-arene)Cl2] 2 (L) where L = 1,1′-(NC5H4CH2NHOC)2-C5H4FeC5H4, arene = p-iPrC6H4Me (5) or C6Me6 (6); L = 1,1′-(NC3H3N(CH2)2O2C)2–C5H4FeC5H4, arene = p-iPrC6H4Me (7) or C6Me6 (8) have been synthesized and characterized. The molecular structures of 1 and 3 were confirmed by single-crystal X-ray diffraction. The in vitro anticancer activities of complexes 1–8 have been studied comparatively to the uncoordinated ligands. The complexes exhibit fairly low cytotoxicities in comparison to related ferrocene-derived arene–ruthenium complexes.
  • Publication
    Accès libre
    Sawhorse-type diruthenium tetracarbonyl complexes
    The review covers dinuclear ruthenium complexes that contain a Ru2(CO)4 backbone arranged in a typical sawhorse geometry as well as two three-electron bridges and two terminal two-electron ligands. Synthetic and structural aspects of these complexes are presented, and their catalytic and biological properties as well as their potential applications for nano-materials are reviewed.