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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
    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
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    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 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
    Water-soluble arene ruthenium complexes containing pyridinethiolato ligands: Synthesis, molecular structure, redox properties and anticancer activity of the cations [(η6-arene)Ru(p-SC5H4NH)3]2+
    (2008)
    Gras, Michaël
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    ; ;
    Štěpnička, Petr
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    Renfrew, Anna K.
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    Dyson, Paul J.
    The cationic complexes [(η6-arene)Ru(SC5H4NH)3]2+, arene being C6H6 (1), MeC6H5 (2), p-iPrC6H4Me (3) or C6Me6 (4), have been synthesised from the reaction of 4-pyridinethiol with the corresponding precursor (η6-arene)2Ru22-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 centre through the sulphur atom, with the hydrogen atom transferred from the sulphur to the nitrogen atom. The electrochemical study of 14 shows a clear correlation between the Ru(II)/Ru(III) redox potentials and the number 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 derivative 4 being the most cytotoxic one. The corresponding reaction of the ortho-isomer, 2-pyridinethiol, with (η6-C6Me6)2Ru22-Cl)2Cl2 does not lead to the expected 2-pyridinethiolato analogue, but yields the neutral complex (η6-C6Me6)Ru(η2-SC5H4N)(η1-SC5H4N) (5). The analogous complex (η6-C6Me6)Ru(η2-SC9H6N)-(η1-SC9H6N) (6) is obtained from the similar reaction with 2-quinolinethiol.
  • Publication
    Accès libre
    Mono and dinuclear rhodium, iridium and ruthenium complexes containing chelating 2,2′-bipyrimidine ligands: Synthesis, molecular structure, electrochemistry and catalytic properties
    (2007)
    Govindaswamy, Padavattan
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    Canivet, Jérôme
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    ; ;
    Štěpnička, Petr
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    Ludvík, Jiří
    The mononuclear cations [(η5-C5Me5)RhCl(bpym)]+ (1), [(η5-C5Me5)IrCl(bpym)]+ (2), [(η6-p-PriC6H4Me)RuCl(bpym)]+ (3) and [(η6-C6Me6)RuCl(bpym)]+ (4) as well as the dinuclear dications [{(η5-C5Me5)RhCl}2 (bpym)]2+ (5), [{(η5-C5Me5)IrCl}2 (bpym)]2+ (6), [{(η6-p-PriC6H4Me)RuCl}2 (bpym)]2+ (7) and [{(η6-C6Me6)RuCl}2 (bpym)]2+ (8) have been synthesised from 2,2′-bipyrimidine (bpym) and the corresponding chloro complexes [(η5-C5Me5)RhCl2]2, [(η5-C5Me5)IrCl2]2, [(η6-PriC6H4Me)RuCl2]2 and [(η6-C6Me6)RuCl2]2, respectively. 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 centres; in the dinuclear complexes the chloro ligands attached to the two metal centres are found to be, with respect to each other, cis oriented for 5 and 6 but trans for 7. The electrochemical behaviour of 1–8 has been studied by voltammetric methods. In addition, the catalytic potential of 1–8 for transfer hydrogenation reactions in aqueous solution has been evaluated: All complexes catalyse 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 °C, pH 4) with rhodium complexes, giving turnover frequencies of 10.5 h−1 for 1 and 19 h−1 for 5.
  • Publication
    Accès libre
    Dinuclear hexamethylbenzene ruthenium cations containing η12-2-(ferrocenyl)ethen-1-yl ligands: Synthesis, structure, electrochemistry
    (2006)
    Tschan, Mathieu J.-L.
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    Ludvík, Jiří
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    Štěpnička, Petr
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    The cationic ferrocenyl-containing complexes [(η6-C6Me6)2Ru2 (μ-η12-CH–CHFc)2 (μ-H)]+ (3) and [(η6-C6Me6)2Ru2 (μ-PPh2)(μ-η12-CH–CHFc)(μ-H)]+ (4) have been synthesised in ethanol from ethynylferrocene and the dinuclear precursors [(η6-C6Me6)2Ru2 (μ-H)3]+ (1) and [(η6-C6Me6)2Ru2(μ-PPh2)(μ-H)2]+ (2) respectively, and isolated as tetrafluoroborate salts. The spectroscopic data of 3 and 4 as well as the single-crystal X-ray diffraction analysis of [4][BF4] show that the alkyne function of ethynylferrocene has been converted to a σ/π-ethenyl ligand by transfer of a bridging hydride from the diruthenium backbone onto the α-carbon of the triple bond in ethynylferrocene. The ferrocenyl-containing diruthenium compounds [3][BF4] and [4][BF4] as well as their parent compounds [1][BF4] and [2][BF4] have been studied by voltammetric techniques: Whereas 1 shows only an irreversible Ru(II)/Ru(III) oxidation, the phosphido-bridged derivative 2 displays two well-separated one-electron redox processes. In the case of 3 and 4, the ferrocenyl substituents give rise to additional reversible ferrocene/ferrocenium waves.
  • Publication
    Accès libre
    Sulfur-containing trinuclear arene ruthenium clusters
    (2005)
    Tschan, Mathieu
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    Chérioux, Frédéric
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    The single-crystal X-ray structure analyses of [HRu3(C6H6)(C6Me6)23-SC6H4Me)(μ2-O)][BF4]2 ([1][BF4]2), [HRu3(C6H6)(C6Me6)23-SC6H4Me)(μ2-S)][PF6]2 ([2][PF6]2) and [H2Ru3(1,2,4,5-Me4C6H2)32-S)(Cl)]PF6([3][PF6]) are presented. The structures show the sulfur ligands to act as bridges between ruthenium atoms. In [1][BF4]2 and [2][PF6]2 the metallic core adopts a nido framework. However, in [3][PF6] the absence of a μ3-SR ligand combined with the presence of one terminal chloro unit gives rise to a closo metallic arrangement.