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  • Publication
    Accès libre
    Encapsulation of Pyrene-Functionalized Poly(benzyl ether) Dendrons into a Water-Soluble Organometallic Cage
    (2011)
    Pitto-Barry, Anaïs
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    Barry, Nicolas P. E.
    ;
    Zava, Olivier
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    ;
    Two generations of lipophilic pyrenyl functionalized poly(benzyl ether) dendrimers (P1 and P2) have been synthesized. The thermal properties of the two functionalized dendrimers have been investigated, and the pyrenyl group of the dendritic molecules encapsulated in the arene–ruthenium metalla-cage, [Ru6(p-cymene)6(tpt)2(donq)3]6+ ([1]6+) (tpt=2,4,6-tri(pyridin-4-yl)-1,3,5-triazine; donq=5,8-dioxydo-1,4-naphthoquinonato). The host–guest properties of [P1⊂1]6+ and [P2⊂1]6+ were studied in solution by NMR and UV/Vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water-soluble host–guest systems was evaluated on human ovarian cancer cells.
  • Publication
    Accès libre
    Double Targeting of Tumors with Pyrenyl-Modified Dendrimers Encapsulated in an Arene-Ruthenium Metallaprism
    (2011)
    Pitto-Barry, Anais
    ;
    Barry, Nicolas P. E.
    ;
    Zava, Olivier
    ;
    ;
    Dyson, Paul J.
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    The self-assembly of 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine (tpt) triangular panels with p-cymene-ruthenium building blocks and 5,8-dioxido-1,4-naphthoquinonato (donq) bridges, in the presence of pyrenyl-contg. dendrimers of different generations (P0, P1 and P2), affords the triangular prismatic host-guest compds. [Pn?Ru6(p-cymene)6(tpt)2(donq)3]6+ ([Pn?1]6+). The host-guest nature of these systems, with the pyrenyl moiety being encapsulated in the hydrophobic cavity of the cage and the dendritic functional group pointing outwards, was confirmed by NMR spectroscopy (1H, 2D and DOSY). The host-guest properties of these systems were studied in soln. by NMR and UV/Vis spectroscopic methods, allowing the detn. of their affinity consts. (Ka). Moreover, the ability of these water-sol. host-guest systems to carry the pyrenyl-contg. dendrimers into cancer cells was evaluated on human ovarian cancer cells. The host-guest systems are all more cytotoxic than the empty cage [1][CF3SO3]6 (IC50?4 ?M), with the most active compd., [P0?1][CF3SO3]6, being an order of magnitude more cytotoxic. [on SciFinder(R)]
  • Publication
    Accès libre
    Double Targeting of Tumours with Pyrenyl-Modified Dendrimers Encapsulated in an Arene–Ruthenium Metallaprism
    (2011)
    Pitto-Barry, Anaïs
    ;
    Barry, Nicolas P. E.
    ;
    Zava, Olivier
    ;
    ;
    Dyson, Paul J.
    ;
    The self-assembly of 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine (tpt) triangular panels with p-cymene–ruthenium building blocks and 5,8-dioxido-1,4-naphthoquinonato (donq) bridges, in the presence of pyrenyl-containing dendrimers of different generations (P0, P1 and P2), affords the triangular prismatic host–guest compounds [Pn⊂Ru6(p-cymene)6(tpt)2(donq)3]6+ ([Pn⊂1]6+). The host–guest nature of these systems, with the pyrenyl moiety being encapsulated in the hydrophobic cavity of the cage and the dendritic functional group pointing outwards, was confirmed by NMR spectroscopy (1H, 2D and DOSY). The host–guest properties of these systems were studied in solution by NMR and UV/Vis spectroscopic methods, allowing the determination of their affinity constants (Ka). Moreover, the ability of these water-soluble host–guest systems to carry the pyrenyl-containing dendrimers into cancer cells was evaluated on human ovarian cancer cells. The host–guest systems are all more cytotoxic than the empty cage [1][CF3SO3]6 (IC50≈4 μM), with the most active compound, [P0⊂1][CF3SO3]6, being an order of magnitude more cytotoxic.
  • Publication
    Accès libre
    Synthesis and characterization of fullerene-pyridyl arene ruthenium complexes
    Association of [60]fullerene with arene ruthenium moieties has been achieved for the first time. Two fullerenopyrrolidine derivatives (Npyr-C60) were synthesized via a 1,3-dipolar cycloaddition, and coordinated to arene ruthenium complexes to form two half-sandwich complexes of the general formula (p-cymene)RuCl2(Npyr-C60). The coordination of the fullerenopyrrolidines to the arene ruthenium unit was evidenced by NMR spectroscopy and mass spectrometry, thus confirming the formation of these novel arene ruthenium complexes.
  • Publication
    Accès libre
    Combining coordination and hydrogen-bonds to form arene ruthenium metalla-assemblies
    Appavoo, Divembal
    ;
    Carnevale, Diego
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    ;
    Three ureido-pyrimidone derivatives (N-LH) were used to generate in combination with four dinuclear arene ruthenium clips, (p-cymene) 2Ru2(OO boolean AND OO)Cl2 (OO boolean AND OO = oxalato, 2,5-dioxido-1,4-benzoquinonato, 2,5-dichloro-1,4-benzoquinonato, 5,8-dioxido-1,4-naphtoquinonato), twelve cationic arene ruthenium metalla-cycles of the general formula [(p-cymene)2Ru2(OO boolean AND OO)(N-LH)2]2 (CF3SO3)4. The ureidopyrimidone moieties are able to form strong hydrogen-bonds by self-pairing, thus giving rise to dimeric structures in solution. In addition, to better understand the behavior of the tetranuclear metallacycles in solution, the neutral dinuclear arene ruthenium ureido-pyrimidone complexes of the general formula ((p-cymene)RuCl2(N-LH)} 2 were also prepared and characterized. All metalla-assemblies were studied in solution by NMR spectroscopy, confirming the high stability of the metalla- cycles and the usefulness of hydrogen-bonds in constructing supramolecular assemblies
  • Publication
    Accès libre
    Enhancement of Cytotoxicity by Combining Pyrenyl-Dendrimers and Arene Ruthenium Metallacages
    Pitto-Barry, Anaïs
    ;
    Zava, Olivier
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    Dyson, Paul J
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    ;
    Three generations of pyrenyl bis-MPA dendrimers with two different end-groups, acetonide (pyrGn) or alcohol (pyrGn-OH) (n = 1–3), were synthesized, and the pyrenyl group of the dendritic molecules was encapsulated in the arene ruthenium metallacages, [Ru6(p-cymene) 6 (OO∩OO)3(tpt)2]6+ (OO∩OO = 5,8-dioxydo- 1,4-naphtaquinonato (donq) [1]6+ and 6,11-dioxydo-5,12- naphtacenedionato (dotq) [2]6+; tpt =2,4,6-tri(pyridin-4-yl)-1,3,5-triazine). The host–guest properties of [guestC1]6+ and [guestC2]6+ were studied in solution by NMR and UV–vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water- soluble host–guest systems and the pyrenyl-dendrimers was evaluated on human ovarian cancer cells.
  • Publication
    Accès libre
    NMR spectroscopy and DFT calculations of a self-assembled arene ruthenium rectangle obtained from a combination of coordination and hydrogen bonds
    Appavoo, Divambal
    ;
    Raja, Nandhagopal
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    ; ;
    Carnevale, Diego
    The hydrogen-bonded arene ruthenium metalla-rectangle, [(p-cymene) 2Ru2(OOnOO)(UPy)2]24+ , obtained from 1-(4-oxo-6-undecyl-1,4-dihydropyrimidin-2-yl)-3-(pyridin-4- ylmethyl)urea (UPy) and the dinuclear arene ruthenium clip (p-cymene) 2Ru2(OOnOO)Cl2 (OOnOO = 2,5-dioxido-1,4- benzoquinonato), is investigated by means of solution-phase NMR spectroscopy. Rotating frame nuclear Overhauser effect measurements are used to probe the H- bond network that drives the UPy self-assembly as well as the full rectangular supramolecular system. An effective distance that takes into account both intra-and intermolecular polarization-transfer pathways is utilised for data analysis. The experimental findings are corroborated by DFT calculations of NMR parameters and internuclear distances, thus confirming the formation of a very stable tetranuclear metalla-assembly.
  • Publication
    Accès libre
    Designing Supramolecular Liquid-Crystalline Hybrids from Pyrenyl-Containing Dendrimers and Arene Ruthenium Metallacycles
    Pitto-Barry, Anaïs
    ;
    Barry, Nicolas P. E
    ;
    Russo, Virginie
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    Heinrich, Benoît
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    Donnio, Bertrand
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    ;
    The association of the arene ruthenium metallacycle [Ru4(p- cymene)4(bpe)2(donq)2][DOS]4 (bpe = 1,2- bis(4-pyridyl)ethylene, donq = 5,8-dioxydo-1,4-naphtoquinonato, DOS = dodecyl sulfate) with pyrenyl-functionalized poly(arylester) dendrimers bearing cyanobiphenyl end- groups is reported. The supramolecular dendritic systems display mesomorphic properties as revealed by polarized optical microscopy, differential scanning calorimetry and small- angle X-ray scattering measurements. The multicomponent nature of the dendrimers and of the corresponding host–guest supramolecules (i.e., end-group mesogens, dendritic core, pyrene unit, aliphatic spacers, and metallacycle) leads to the formation of highly segregated mesophases with a complex multilayered structure due to the tendency of the various constitutive building-blocks to separate in different organized zones. The pyrenyl dendrimers exhibit a multilayered smectic A-like phase, thereafter referred to as LamSmA phase to emphasize this unaccustomed morphology. As for the corresponding Ru4–metallacycle adducts, they self-organize into a multicontinuous thermotropic cubic phase with the Im3¯m space group symmetry. This represents a unique example of liquid- crystalline behavior observed for such large and complex supramolecular host–guest assemblies. Models of their supramolecular organizations within both mesophases are proposed.