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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

Designing liquid-crystalline gold nanoparticles via the olefin cross-metathesis reaction

Nguyen, Thanh Tung ; Nguyen, Thi Le Anh ; Deschenaux, Robert

In: Journal of Porphyrins and Phthalocyanines, 2016, vol. 20, no. 08n11, p. 1060-1064

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...

Université de Neuchâtel

Conception de bisfullérodendrimères liquides-cristallins par la réaction de métathèse croisée d'oléfines

Russo, Virginie ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2016.

In this thesis, the topic was the design of liquid-crystalline bisfullerodendrimers. Indeed, the field of liquid-crystalline fullerodendrimers is being extensively investigated. Combining [60]fullerene (C60) with liquid crystal organization give numerous applications in the field of self-assembled supramolecular materials. Currently, the mesomorphic fullerodendrimers are made of only...

Université de Neuchâtel

Propriétés mésomorphes ou biologiques d'assemblages dendritiques et métallodendritiques

Pitto-Barry, Anaïs ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2012 ; 2256.

The aim of this thesis is to combine metals and dendrimers to obtain mesomorphic or biological properties. The design of metamaterials from gold nanoparticles is still a challenge as the spatial organisation is difficult to control. Thus, the combination of gold nanoparticles with liquid-crystalline dendrimers is a way to explore the organisation of such systems in mesophases. We...

Université de Neuchâtel

La chimie click pour la conception de nanoparticules d'or liquides-cristallines

Mischler, Sylvain ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2012 ; 2254.

Ce travail de thèse présente une nouvelle voie de synthèse efficace à l’obtention de nanoparticules d’or liquides-cristallines. La stratégie adoptée est fondée sur l’utilisation de la chimie click et consiste au greffage par cycloaddition 1,3-dipolaire catalysée par du cuivre(I) de dendrons liquides-cristallins à la surface de nanoparticules d’or. L’influence de différents...

Université de Neuchâtel

Conception de matériaux dendritiques chiraux mésomorphes pour l’élaboration de commutateurs électroactifs basés sur le couple ferrocène/ferrocenium

Kopp, Cyril ; Deschenaux, Robert (Dir.) ; Süss-Find, Georg (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2010.

This thesis focuses on the design of new mesomorphic materials. Two chiral dendrimers were synthesized with the aim to transfer their liquid-crystalline properties to ferrocene derivatives. An evolution towards peralkylated ferrocene gave stable ferrocenium derivatives showing a switch between liquid-crystalline phases. The role of the dendritic structure and oxidation could be explained. Then,...

Université de Neuchâtel

Conception de dendrimères liquides-cristallins pour la fonctionnalisation de nanoparticules d'or et de composés inorganiques et organiques

Frein, Stéphane ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2009 ; Th. 2118.

The main objective of the thesis is the design of liquid-crystalline dendrimers for the functionalization of various organic and organometallic moieties including gold nanoparticles, fullerene, diruthenium clusters, fluorescent dyes and carbon nanotubes. Three different families of dendrimers were prepared: poly(aryl ester) dendrimers functionalized with cyanobiphenyl mesogenic units (smectic and...

Université de Neuchâtel

A Mixed Fullerene-Ferrocene Thermotropic Liquid Crystal: Synthesis, Liquid-Crystalline Properties, Supramolecular Organization and Photoinduced Electron Transfer

Even, Michaël ; Heinrich, Benoît ; Guillon, Daniel ; Guldi, Dirk M. ; Prato, Maurizio ; Deschenaux, Robert

In: Chemistry - A European Journal, 2001, vol. 7, no. 12, p. 2595-2604

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...

Université de Fribourg

Functional columnar liquid crystalline phases from ionic complexes of dendronized polymers and sulfate alkyl tails

Canilho, Nadia ; Kasëmi, Edis ; Schlüter, Dieter A. ; Ruokolainen, Janne ; Mezzenga, Raffaele

In: Macromolecular Symposia, 2008, vol. 270, no. 1, p. 58 - 64

We describe how cationic dendronized polymers of generations 1, and 2 and anionic monoalkyl tails can be combined by supramolecular ionic complexation into comb-like liquid crystalline polymers. The final structures in bulk of these supramolecular complexes were studied by differential scanning calorimetry (DSC), cross-polarized optical microscopy (CPOM), small angle x-rays scattering (SAXS) and...

Université de Neuchâtel

Synthèse, caratérisation et étude de composés liquides-cristallins du fullerène : poly-adduits et bis-méthanofullerènes chiraux

Gottis, Sébastien ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2008 ; Th.2032.

Liquid crystals play a crucial role in new technologies. Indeed, in a society in which audio and video media are increasingly used by more and more people, organic liquid crystals have a bright future. On the other hand, chemicals like fullerenes, which display unique physical and chemical properties, are appealing compounds for the design of multifunctional liquid-crystalline materials. In this...