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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.

The aim of this thesis work is to combine self-organizing liquid-crystalline dendrimers with isotropic components, such as C60 and rotaxane to create complexes supramolecular architectures of interests for optoelectronic applications. This work is intended to rationalize the relation between molecular design and liquid-crystalline properties, with emphasis on the influence of isotropic...

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

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...

Université de Neuchâtel

Liquid-Crystalline Bisadducts of [60]Fullerene

Campidelli, Stéphane ; Vázquez, Ester ; Milic, Dragana ; Lenoble, Julie ; Atienza Castellanos, Carmen ; Sarova, Ginka ; Guldi, Dirk M. ; Deschenaux, Robert ; Prato, Maurizio

In: The Journal of Organic Chemistry (JOC), 2006, vol. 71, no. 20, p. 7603–7610

A second-generation cyanobiphenyl-based dendrimer was used as a liquid-crystalline promoter to synthesize mesomorphic bisadducts of [60]fullerene. Liquid-crystalline trans-2, trans-3, and equatorial bisadducts were obtained by condensation of the liquid-crystalline promoter, which carries a carboxylic acid function, with the corresponding bisaminofullerene derivatives. A monoadduct...

Université de Neuchâtel

Liquid−Crystalline Janus-Type Fullerodendrimers Displaying Tunable Smectic−Columnar Mesomorphism

Lenoble, Julie ; Campidelli, Stéphane ; Maringa, Natacha ; Donnio, Bertrand ; Guillon, Daniel ; Yevlampieva, Natalia ; Deschenaux, Robert

In: Journal of the American Chemical Society (JACS), 2007, vol. 129, no. 32, p. 9941–9952

Janus-type liquid−crystalline fullerodendrimers were synthesized via the 1,3-dipolar cycloaddtition of two mesomorphic dendrons and C60. By assembling poly(aryl ester) dendrons functionalized with cyanobiphenyl groups, displaying lamellar mesomorphism, with poly(benzyl ether) dendrons carrying alkyl chains, which display columnar mesomorphism, we could tailor by design the...

Université de Neuchâtel

Liquid-Crystalline Fullerodendrimers which Display Columnar Phases

Lenoble, Julie ; Maringa, Natacha ; Campidelli, Stéphane ; Donnio, Bertrand ; Guillon, Daniel ; Deschenaux, Robert

In: Organic Letters, 2006, vol. 8, no. 9, p. 1851–1854

The title compounds were synthesized by applying the 1,3-dipolar cycloaddition 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 derivatives showed rectangular columnar phases of c2mm...

Université de Neuchâtel

Liquid-Crystalline [60]Fullerene-TTF Dyads

Allard, Emmanuel ; Oswald, Frédéric ; Donnio, Bertrand ; Guillon, Daniel ; Delgado, Juan Luis ; Langa, Fernando ; Deschenaux, Robert

In: Organic Letters, 2005, vol. 7, no. 3, p. 383-386

[60]Fullerene was functionalized with a TTF derivative and a bis-mesogenic fragment. The synthetic methodology was based on the addition of a malonate derivative to C60 (Bingel-type reaction). Both the malonate and dyad showed smectic B and A phases. The supramolecular organization within the smectic layers was of the monolayer type for the malonate and of the bilayer type for the...