Vignette d'image

Deschenaux, Robert

Nom
Deschenaux, Robert
Affiliation principale
Fonction
Professeur ordinaire
Email
Robert.Deschenaux@unine.ch

Résultat de la recherche

Filtres

1314
1229
1238
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 10 sur 131
  • Publication
    Accès libre
    Ferrocene-containing liquid-crystalline dendrimers: a novel family of mesomorphic macromolecules
    (1997)
    Deschenaux, Robert 
    ;
    Serrano, Elisabeth
    ;
    Levelut, Anne-Marie
    The synthesis and liquid-crystalline properties of a first-generation dendritic core substituted with six mesomorphic ferrocene units are reported; the investigated compound exhibited a broad enantiotropic smectic A phase (polarized optical microscopy, DSC, and XRD studies) and good thermal stability (thermogravimetry).
  • Publication
    Métadonnées seulement
    Liquid-crystalline fullerene-oligophenylenevinylene conjugates
    (2002)
    Campidelli, Stephane
    ;
    Deschenaux, Robert 
    ;
    Eckert, Jean-Francois
    ;
    Guillon, Daniel
    ;
    Nierengarten, Jean-Francois
    Functionalization of C60-oligophenylenevinylene derivs. with a cyanobiphenyl-terminated dendromesogen leads to new donor-acceptor systems with liq.-cryst. properties. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Fullerene-containing liquid-crystalline dendrimers
    (2001)
    Dardel, Blaise
    ;
    Guillon, Daniel
    ;
    Heinrich, Benoit
    ;
    Deschenaux, Robert 
    Addn. reaction of mesomorphic malonate-based dendrimers (up to the fourth generation) with C60 gave liq.-cryst. fullerene derivs. The cyanobiphenyl unit was used as liq.-cryst. promoter. The malonates presented nematic and/or smectic A phases. The fullerenes showed only smectic A phases, with the exception of the second generation dendrimer for which smectic A and nematic phases were obsd. The supramol. organization of the fullerene-based mol. units within the smectic A layers was investigated by X-ray diffraction. Two structural regimes were detd. For the low generation dendrimers, the supramol. organization is detd. by steric factors. For the high generation dendrimers, the mesogenic groups impose a microphase organization: due to lateral extension of the branching part of the mol., the cyanobiphenyl groups arrange in a parallel fashion as in classical smectic A phases, the rest of the macromol. being located between the mesogenic sublayers. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Ferrocene-containing thermotropic liquid crystals
    (: John Wiley & Sons Ltd., 2008)
    Deschenaux, Robert 
    A review. Liq.-cryst. ferrocenes with planar chirality are discussed, along with ferrocene-contg. side-chain liq.-cryst. polymers, redox-active liq.-cryst. ferrocenes, ferrocene-contg. liq.-cryst. dendrimers, and liq.-cryst. ferrocene-fullerene dyads. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Liquid-Crystalline Fullerodendrimers which Display Columnar Phases
    (2006)
    Lenoble, Julie
    ;
    Maringa, Natacha
    ;
    Campidelli, Stephane
    ;
    Donnio, Bertrand
    ;
    Guillon, Daniel
    ;
    Deschenaux, Robert 
    The title compds. were synthesized by applying the 1,3-dipolar cycloaddn. reaction of aldehyde-based poly(benzyl ether) dendrimers and sarcosine (N-methylglycine) to [60]fullerene (C60). The dendritic building blocks used to functionalize C60 displayed cubic and hexagonal columnar phases. The fullerene derivs. showed rectangular columnar phases of c 2. mm symmetry. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    1,3-Disubstituted ferrocene-containing thermotropic liquid crystals: synthesis, mesomorphic properties and the crystal and molecular structure
    (1993)
    Deschenaux, Robert 
    ;
    Kosztics, Isabelle
    ;
    Marendaz, Jean Luc
    ;
    Stoeckli-Evans, Helen 
    Two families of 1,3-disubstituted ferrocene derivs. were synthesized and their liq.-crystal behavior investigated. Compds. of series I, (?5-C5H5)Fe[(?5-C5H3)-1,3-(COOC6H4OOCC6H4OCnH2n+1)2] (n = 1-14, 16, 18), exhibited remarkable mesomorphic properties. Indeed, nematic and/or smectic C phases, assocd. with large anisotropic domains, were obsd. Derivs. of series II, (?5-C5H5)Fe[?5-C5H3)-1,3-(COOC6H4OCnH2n+1)2] (n = 1-9), were nonmesogenic. The crystal and mol. structure of Ih (n = 8) was detd. by x-ray anal. The compd. is orthorhombic, space group Pnma, with a 7.602(1), b 57.538(3), and c 10.760(1) Å; Z = 4, dc = 1.302; R = 0.102, Rw = 0.132 for 1401 reflections. The crystallog. data confirmed both a highly anisometric structure for Ih and a compact arrangement of the mols. in the crystal. The present results show that a crit. length/depth ratio of approx. 5-7 must be passed for obtaining liq.-crystal properties. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Ferrocene- and fullerene[60]-containing liquid-crystalline materials
    (1998)
    Chuard, Thierry
    ;
    Deschenaux, Robert 
    A review with 22 refs. showing the versatility of ferrocene and fullerene for the design of thermotropic liq.-cryst. materials: (i) the electrochem. properties of the ferrocene-ferrocenium system were exploited to design redox-active metallomesogens; (ii) ferrocene-contg. side-chain liq.-cryst. polysiloxane and polymethacrylates were synthesized by grafting a mesomorphic vinyl-ferrocene monomer onto com. available polysiloxane and by free-radical polymn. of mesomorphic methacrylate-ferrocene monomers, resp.; (iii) a 1st-generation ferrocene-contg. liq.-cryst. dendrimer was synthesized; and (iv) liq.-cryst. fullerene (10) and mixed fullerene-ferrocene (11) derivs. were obtained by functionalizing the C60 core with a twin cholesterol moiety. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Crystal structures of the lanthanum(III), europium(III), and terbium(III) cryptates of tris(bipyridine) macrobicyclic ligands
    (1991)
    Bkouche-Waksman, Itka
    ;
    Guilhem, Jean
    ;
    Pascard, Claudine
    ;
    Alpha, Beatrice
    ;
    Deschenaux, Robert 
    ;
    Lehn, Jean Marie
    The crystal structures of I.LaCl3.2H2O and I.TbCl3.4H2O (X = H) and I.EuCl3.4H2O (X = COOCH3) were detd. I.LaCl3.2H2O is triclinic, space group P?1, with a 18.602(5), b 17.342(5), c 14.130(5) Å, ? 99.98(2), ? 106.26(4), and ? 103.2(3)°; R = 5.8% (Rw = 5.6%). I.TbCl3.4H2O is orthorhombic, space group Cmca, with a 25.510(8), b 10.279(4), and c 31.021(9) Å; R = 5.0% (Rw = 7.3%). I.EuCl3.4H2O is monoclinic, space group C2/c, with a 30.715(8), b 14.121(5), c 23.813(8) Å, and ? 118.62(4)°; R = 5.9% (Rw = 6.2%). The structures confirm the cryptate nature of these species, the cations being bound to the 8 N sites of the ligand. The macrobicycle presents 2 open faces, thus allowing addnl. coordination of 2 species, Cl- ions or H2O mols., to the bound cations. These data provide structural support for the photophys. studies of the luminescent properties of the EuIII and TbIII cryptates, which indicated residual coordination of H2O mols. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Synthesis, characterization, and electrochemical and photophysical properties of rhenium(I) and ruthenium(II) complexes of 2,2'-bipyridine ligand functionalized ?-cyclodextrins
    (1995)
    Deschenaux, Robert 
    ;
    Ruch, Thomas
    ;
    Deschenaux, Pierre-Francois
    ;
    Juris, Alberto
    ;
    Ziessel, Raymond
    The synthesis, characterization, and electrochem. and photophys. properties of the ReI ad RuII complexes of permethylated ?-cyclodextrins, functionalized on the primary face by a 2,2'-bipyridine ligand, are reported. For comparison, model compds., in which the cyclodextrin was replaced by a Me group, were also prepd. and their properties studied. [on SciFinder(R)]
  • Publication
    Métadonnées seulement
    Ferrocene-containing thermotropic side-chain liquid-crystalline polymethacrylate from a mesomorphic trisubstituted ferrocene monomer
    (1997)
    Deschenaux, Robert 
    ;
    Turpin, Francois
    ;
    Guillon, Daniel
    The synthesis and mesomorphic properties of a methacrylate-contg. ferrocene monomer bearing two flexible chains at the 1,1'-positions and a corresponding side-chain homopolymer are described. Both polymer and monomer showed enantiotropic smectic C and smectic A phases. The liq.-cryst. phases were fully characterized by means of X-ray diffraction expts. Dilatometric measurements pointed to a head-to-tail mol. arrangement of the monomeric units within the smectic A phase. The results described in this report confirm that ferrocene-contg. thermotropic side-chain liq.-cryst. polymethacrylates represent a valuable family of metallomesogenic polymers. [on SciFinder(R)]