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Université de Neuchâtel

Conception, synthèse et étude de "tris"-fullérodendrimères et rotaxanes liquides-cristallins

Pieper, Pauline ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

Ce travail de thèse est basé sur l’utilisation de l’auto-assemblage de dendrimères liquides-cristallins pour créer des architectures supramoléculaires complexes contenant des éléments isotropes tels que les [60]fullerène (C60) ou des rotaxanes. Le but a été d’étudier l’influence de l’incorporation de ces éléments isotropes sur la formation et la stabilité des...

Université de Neuchâtel

Switchable Mesomorphic Materials Based on the Ferrocene−Ferrocenium Redox System: Electron-Transfer-Generated Columnar Liquid-Crystalline Phases

Deschenaux, Robert ; Vilches, Maria-Teresa ; Schweissguth, Martin ; Levelut, Anne-Marie ; Long, Gary J. ; Hautot, Dimitri ; Luneau, Dominique

In: Organometallics, 1999, vol. 18, no. 26, p. 5553–5559

Oxidation of the non-mesomorphic ferrocene derivative 1 with silver toluene-4-sulfonate gave the ferrocenium derivative 2, which showed a monotropic columnar phase. The latter two-dimensional phase is composed of ribbons, in which derivative 2 is organized into bilayers, and has a centered rectangular symmetry with a = 318.3 Å and c = 94.9 Å. The Mössbauer...

Université de Neuchâtel

A Ferrocene-Containing Carbohydrate Surfactant: Thermotropic and Lyotropic Phase Behavior

Donnio, Bertrand ; Seddon, John M. ; Deschenaux, Robert

In: Organometallics, 2000, vol. 19, no. 16, p. 3077–3081

A ferrocene-containing carbohydrate surfactant has been synthesized and shown by polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction to exhibit both thermotropic and lyotropic liquid-crystalline phase behavior. This new class of materials should prove useful for the design of redox-active lyotropic liquid crystals, allowing fine electrochemical control of the...

Université de Neuchâtel

Organized Molecular Films from New Ferrocene-Containing Molecular Units

Deschenaux, Robert ; Megert, Sonia ; Zumbrunn, Cornélia ; Ketterer, Jurgen ; Steiger, Rolf

In: Langmuir, 1997, vol. 13, no. 8, p. 2363–2372

The design and synthesis of new amphiphilic ferrocene derivatives and their capability for forming Langmuir and Langmuir−Blodgett films are reported. The film formation at the air−water interface was followed by surface pressure−molecular area isotherm, surface potential−molecular area isotherm, and Brewster angle microscopy. The stability and structure of the transferred films were...

Université de Neuchâtel

Ferrocene-Containing Thermotropic Side-Chain Liquid-Crystalline Polysiloxanes

Deschenaux, Robert ; Jauslin, Isabelle ; Scholten, Ulrich ; Turpin, François ; Guillon, Daniel ; Heinrich, Benoît

In: Macromolecules, 1998, vol. 31, no. 17, p. 5647–5654

The synthesis, purification, characterization, and liquid-crystalline properties of side-chain polysiloxanes bearing mesomorphic 1,1‘- or 1,3-disubstituted ferrocene units are reported. The polymers were prepared by grafting the appropriate vinyl-containing ferrocene monomer onto commercially available poly(hydrosiloxane)s following a standard procedure. The monomers gave smectic A or smectic A...

Université de Neuchâtel

Ferrocene-Containing Thermotropic Side-Chain Liquid-Crystalline Polymethacrylate from a Mesomorphic Trisubstituted Ferrocene Monomer

Deschenaux, Robert ; Guillon, Daniel

In: Macromolecules, 1997, vol. 30, no. 13, p. 3759–3765

The synthesis and mesomorphic properties of a methacrylate-containing ferrocene monomer bearing two flexible chains at the 1,1‘-positions and the corresponding side-chain homopolymer are described. Both polymer and monomer showed enantiotropic smectic C and smectic A phases. The liquid-crystalline phases were fully characterized by means of X-ray diffraction experiments. Dilatometric...

Université de Neuchâtel

Synthesis, Characterization, and Mesomorphic Properties of a Mixed [60]Fullerene−Ferrocene Liquid-Crystalline Dendrimer

Dardel, Blaise ; Deschenaux, Robert ; Even, Michael ; Serrano, Elisabeth

In: Macromolecules, 1999, vol. 32, no. 16, p. 5193-5198

Addition reaction of the malonate-based second-generation ferrocene-containing liquid-crystalline dendrimer 16 to [60]fullerene led to the title compound 1. Molecule 1 showed good solubility in common organic solvents and good thermal stability. Examination of its mesomorphic properties revealed the presence of an enantiotropic smectic A phase, which was identified by...

Université de Neuchâtel

Supramolecular Fullerene Materials: Dendritic Liquid-Crystalline Fulleropyrrolidines

Campidelli, Stéphane ; Lenoble, Julie ; Barberá, Joaquín ; Paolucci, Francesco ; Marcaccio, Massimo ; Paolucci, Demis ; Deschenaux, Robert

In: Macromolecules, 2005, vol. 38, no. 19, p. 7915–7925

[60]Fullerene-containing liquid-crystalline dendrimers were synthesized from the first to the fourth generation by applying the 1,3-dipolar cycloaddition reaction from a mesomorphic dendritic-type aldehyde derivative, sarcosine (N-methylglycine) or glycine and C60. The cyanobiphenyl unit was used as a liquid-crystalline promoter. With the exception of the first-generation...

Université de Neuchâtel

Polar and Electrooptical Properties of [60]Fullerene-Containing Poly(benzyl ether) Dendrimers in Solution

Scanu, David ; Yevlampieva, Natalia P. ; Deschenaux, Robert

In: Macromolecules, 2007, vol. 40, no. 4, p. 1133–1139

[60]Fulleropyrrolidine-containing poly(benzyl ether) dendrimers 1−4 were synthesized via 1,3-dipolar cycloaddition of amino acid and aldehyde derivatives and [60]fullerene. Their dielectric and electrooptical (Kerr effect) solution properties were studied and compared with poly(propyleneimine) dendrimers, namely DAB-dendr-(alkyl chain)n and...