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  • 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
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    Gras, Michaël
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    ; ;
    Zava, Olivier
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    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
    Study of complexes of platinum group metals containing nitrogen bases derived from pyridine aldehydes: Interesting molecular structures with unpredicted bonding modes of the ligands
    (2011)
    Gupta, Gajendra
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    Gloria, Sairem
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    Nongbri, Saphidabha. L.
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    Rao, Kollipara Mohan
    A series of mono-cationic dinuclear half sandwich ruthenium, rhodium and iridium metal complexes have been synthesized using ((pyridin-2-yl)methylimino)nicotinamide (L1) and ((picolinamido)phenyl)picolinamide (L2) ligands: [(η6-arene)2Ru2 (μ-L1)Cl3]+ (arene = C6H6, 1; p-iPrC6H4Me, 2; C6Me6, 3), [(η5-C5Me5)2M2(μ-L1)Cl3] + (M = Rh, 4; Ir, 5), and [(η6-arene)2Ru2(μ-L2)(μ-Cl)]+ (arene = C6H6, 6; p-iPrC6H4Me, 7; C6Me6, 8), [(η5-C5Me5)2M2(μ-L2)Cl2]+ (M = Rh, 9; Ir, 10). All the complexes have been isolated as their hexafluorophosphate salts and fully characterized by use of a combination of NMR and IR spectroscopy. The solid state structure of three representatives 4, 6 and 9 has been determined by X-ray crystallographic studies. Interestingly, in the molecular structure of 4, the first metal is bonded to two nitrogen atoms whereas the second metal center is coordinated to only one nitrogen atom with two terminal chloride ligands. Fascinatingly in the case of the complexes with the symmetrical ligand L2, both ruthenium centers having η6-arene groups are bonded to nitrogen atoms with a bridging chloride atom between the two metal centers, whereas the metals with η5-Cp∗ groups are bonded to the ligand N,O and N,N fashion.
  • 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
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    ; ;
    Angela Casini
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    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
    Designing the Host-Guest Properties of Tetranuclear Arene Ruthenium Metalla-Rectangles to Accommodate a Pyrene Molecule
    (2010)
    Barry, Nicolas P. E.
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    Furrer, Julien
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    ; ;
    Cationic tetranuclear arene ruthenium complexes of the general formula [Ru4(p-cymene)4(NN)2(dhnq)2]4+ comprising rectangular structures are obtained in methanol from the reaction of the dinuclear arene ruthenium precursor [Ru2(p-cymene)2(dhnq)2Cl2] (dhnq = 5,8-dihydroxy-1,4-naphthoquinonato) with pyrazine or bipyridine linkers [NN = pyrazine, 1; 4,4-bipyridine, 2; 1,2-bis(4-pyridyl)ethylene, 3] in the presence of AgCF3SO3. All complexes 1-3, isolated in good yield as triflate salts, have been characterised by NMR and IR spectroscopy. The interaction of these rectangular complexes with pyrene as a guest molecule has been studied in solution by various NMR techniques (1D, DOSY, ROESY). In [D3]acetonitrile, the pyrazine-containing metalla-rectangle 1 shows no meaningful interactions with pyrene. On the other hand, the 4,4-bipyridine- and 1,2-bis(4-pyridyl)ethylene-containing metalla-rectangles 2 and 3 clearly interact with pyrene in [D3]acetonitrile. DOSY measurements suggest that, in the case of [Ru4p-cymene)4(4,4-bipyridine)2(dhnq)2]4+ (2), the interactions occur on the outside of the rectangular assembly, while in the case of [Ru4(p-cymene)4{1,2-bis(4-pyridyl)ethylene}2 (dhnq)2]4+ (3), the pyrene molecule is found inside the hydrophobic cavity of the metalla-rectangle, thus giving rise to a host-guest system.
  • Publication
    Accès libre
    Bimetallic ruthenium–tin chemistry: Synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands
    (2010) ;
    Thai, Trieu-Tien
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    ; ;
    Shapovalov, Sergey S.
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    Pasynskii, Alexandr A.
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    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
    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
    Arene Ruthenium Cages: Boxes Full of Surprises
    Self-assembly of polypyridyl ligands with dinuclear arene ruthenium building blocks bridged by chlorido, oxalato or benzoquinonato ligands has allowed the construction of a wide range of cationic metalla complexes possessing different architectures and functionalities: (i) metalla-rectangles showing host-guest possibilities and allowing intramolecular template-controlled photochemical [2 + 2] dimerisation reactions; (ii) metalla-prisms allowing encapsulation of molecules and giving rise to potential drug delivery systems; (iii) metalla-boxes that can be used to stabilise the formation of G-quadruplex DNA. This microreview covers the synthetic and structural aspects of these metalla complexes, as well as their most promising applications, with a particular focus on their potential biological applications.
  • 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
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    Gueniat, Joël
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    ; ;
    Renfrew, Anna K.
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    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
    Photochemical [2+2] cycloaddition of the olefinic double bonds in the supramolecular rectangle [Ru46-p-cymene)4(μ-oxalato)2(μ-4,4′-bipyridylethylene)2]4+
    (2009)
    Barry, Nicolas P.E.
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    Self-assembly of 4,4′-bipyridylethylene (bpe) bidentate connector with the dinuclear arene ruthenium clip [Ru26-p-cymene)2(μ-oxalato)Cl2] in the presence of silver triflate affords the cationic organometallic rectangle [Ru46-p-cymene)4(μ-oxalato)2(μ-bpe)2]4+ ([1][CF3SO3]4). Upon UV irradiation of a methanol solution of [1]4+, dimerisation of the olefinic double bonds of the two parallel bpe ligands occurs, thus giving rise to the [2+2] cycloaddition derivative [Ru46-p-cymene)4(μ-oxalato)2(μ-tpcb)]4+ ([2][CF3SO3]4) (tpcb = tetrakis(4-pyridyl)cyclobutane). The [2+2] photodimerisation reaction was followed by 1H NMR spectroscopy. Moreover, the molecular structure of these two systems was deduced by one-dimensional and two-dimensional NMR experiments (1H, 13C, ROESY, COSY, HSQC). These data suggest the formation of only the rctt-tetrakis(4-pyridyl)cyclobutane isomer.
  • Publication
    Accès libre
    Cationic half-sandwich complexes (Rh, Ir, Ru) containing 2-substituted-1,8-naphthyridine chelating ligands: Syntheses, X-ray structure analyses and spectroscopic studies
    (2008)
    Prasad, Kota Thirumala
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    ;
    Mohan Rao Kollipara
    Reactions of the dinuclear complexes [(η6-arene)Ru(μ-Cl)Cl]2 (arene = C6H6, p-iPrC6H4Me) and [(η5-C5Me5)M(μ-Cl)Cl]2 (M = Rh, Ir) with 2-substituted-1,8-naphthyridine ligands, 2-(2-pyridyl)-1,8-naphthyridine (pyNp), 2-(2-thiazolyl)-1,8-naphthyridine (tzNp) and 2-(2-furyl)-1,8-naphthyridine (fuNp), lead to the formation of the mononuclear cationic complexes [(η6-C6H6)Ru(L)Cl]+ {L = pyNp (1); tzNp (2); fuNp (3)}, [(η6-p-iPrC6H4Me)Ru(L)Cl]+ {L = pyNp (4); tzNp (5); fuNp (6)}, [(η5-C5Me5)Rh(L)Cl]+ {L = pyNp (7); tzNp (8); fuNp (9)} and [(η5-C5Me5)Ir(L)Cl]+ {L = pyNp (10); tzNp (11); fuNp (12)}. All these complexes are isolated as chloro or hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV/Vis spectroscopy. The molecular structures of [1]Cl, [2]PF6, [4]PF6, [5]PF6 and [10]PF6 have been established by single crystal X-ray structure analysis.