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Deschenaux, Robert

Nom
Deschenaux, Robert
Affiliation principale
Fonction
Professeur ordinaire
Email
Robert.Deschenaux@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/384

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  • Publication
    Accès libre
    Liquid-Crystalline Mixed [5 : 1]Hexa-adducts of [60]Fullerene. Preliminary Communication
    (2007)
    Gottis, Sébastien
    ;
    Kopp, Cyril
    ;
    Allard, Emmanuel
    ;
    Deschenaux, Robert 
    A liquid-crystalline mixed [5 : 1]hexa-adduct of [60]fullerene was synthesized by addition of two different malonate derivatives onto C60. The hexa-adduct derivative 2 was prepared by a stepwise synthetic procedure (fullerene -> mono-adduct of C60 -> hexa-adduct of C60). Cyanobiphenyl and octyloxybiphenyl derivatives were selected as mesogens. The malonate derivatives showed either a monotropic nematic phase or a monotropic smectic A phase, and the hexa-adduct derivative gave rise to an enantiotropic smectic A phase.
  • Publication
    Accès libre
    A Mixed Fullerene-Ferrocene Thermotropic Liquid Crystal: Synthesis, Liquid-Crystalline Properties, Supramolecular Organization and Photoinduced Electron Transfer
    (2001)
    Even, Michaël
    ;
    Heinrich, Benoît
    ;
    Guillon, Daniel
    ;
    Guldi, Dirk M.
    ;
    Prato, Maurizio
    ;
    Deschenaux, Robert 
    Grafting of a ferrocene-containing liquid-crystalline malonate derivative to C60 led to the mixed fullerene-ferrocene material 1 which gave rise to a smectic A phase. Cholesterol was used as liquid-crystalline promoter. X-ray diffraction experiments and volumetric measurements indicated that 1 is organized in double layered structures. The corresponding supramolecular organization within the mesomorphic lamellar phase is characterized by a microsegregation of the different units (ferrocene, fullerene, and cholesterol) in distinct sublayers. In such a smectic A phase, C60 imposes the arrangement of the other molecular moieties. Photophysical studies revealed that electron transfer occurs from the donor ferrocene to the electron accepting fullerene. The formation of a long-lived radical pair, with lifetimes of the order of several hundred nanoseconds, was confirmed by time-resolved spectrometry, especially in the near infrared region, in which the radical anion of the fullerene moiety displays its characteristic fingerprint absorption.
  • Publication
    Accès libre
    Designing liquid-crystalline gold nanoparticles via the olefin cross-metathesis reaction
    Nguyen, Thanh Tung
    ;
    Nguyen, Thi Le Anh
    ;
    Deschenaux, Robert 
    Liquid-crystalline gold nanoparticles were prepared by grafting mesomorphic α,β- unsaturated carbonyl olefins onto the organic shell of gold nanoparticles containing terminal olefin ligands by applying the olefin cross-metathesis. The latter reaction was performed under standard conditions using second-generation Grubbs catalyst. The title materials were found to be stable up to 200 °C and gave rise to the formation of smectic A phases in agreement with the structure and nature of the liquid-crystalline promoters. The olefin cross-metathesis proved to be a reaction of choice for the design of liquid-crystalline nanoparticles.