Université de Neuchâtel

Self-organisation of dodeca-dendronized fullerene into supramolecular discs and helical columns containing a nanowire-like core

Guerra, Sebastiano ; Iehl, Julien ; Holler, Michel ; Peterca, Mihai ; Wilson, Daniela A ; Partridge, Benjamin E ; Zhang, Shaodong ; Deschenaux, Robert ; Nierengarten, Jean-Francois ; Percec, Virgil

In: Chemical Science, 2015, vol. 6, no. 6, p. 3393-3401

Twelve chiral and achiral self-assembling dendrons have been grafted onto a [60]fullerene hexa-adduct core by copper-catalyzed alkyne azide "click" cycloaddition. The structure adopted by these compounds was determined by the self-assembling peripheral dendrons. These twelve dendrons mediate the self-organisation of the dendronized [60]fullerene into a disc-shaped structure containing the...

Université de Neuchâtel

Design of liquid-crystalline gold nanoparticles by click chemistry

Mischler, Sylvain ; Guerra, Sebastiano ; Deschenaux, Robert

In: Chemical Communications, 2012, vol. 48, no. 16, p. 2183-2185

Mesomorphic alkyne-based first- and second-generation dendrons were grafted onto gold nanoparticles carrying azide groups under click reaction conditions. The nanoparticles decorated with the dendrons displayed liquid-crystalline properties and good thermal stability.

Université de Neuchâtel

Piling Up Pillar[5]arenes To Self-Assemble Nanotubes

Nierengarten, Iwona ; Guerra, Sebastiano ; Ben Aziza, Haifa ; Holler, Michel ; Abidi, Rym ; Barberá, Joaquín ; Deschenaux, Robert ; Nierengarten, Jean-François

In: Chemistry – A European Journal, 2016, vol. 22, no. 18, p. 6185-6189

New liquid-crystalline pillar[5]arene derivatives have been prepared by grafting first- generation Percec-type poly(benzylether) dendrons onto the macrocyclic scaffold. The molecules adopt a disc-shaped structure perfectly suited for self-organization into a columnar liquid-crystalline phase. In this way, the pillar[5]arene cores are piled up, thus forming a nanotubular wire encased within a...

Université de Neuchâtel

Macrocyclic Effects in the Mesomorphic Properties of Liquid-Crystalline Pillar[5]- and Pillar[6]arenes

Nierengarten, Iwona ; Guerra, Sebastiano ; Holler, Michel ; Karmazin-Brelot, Lydia ; Barberá, Joaquín ; Deschenaux, Robert ; Nierengarten, Jean-François

In: European Journal of Organic Chemistry, 2013, vol. 2013, no. 18, p. 3675-3684

Whereas the reaction of 1,4-bis(2-bromoethyloxy)benzene (4) with paraformaldehyde in the presence of BF3·Et2O afforded exclusively the cyclopentameric pillar[5]arene derivative (5), both cyclopenta- and cyclohexameric macrocycles 5 and 6 were obtained when the reaction of 4 with paraformaldehyde was performed at 45 °C in CHCl3 with FeCl3 as the...

Université de Neuchâtel

Building liquid crystals from the 5-fold symmetrical pillar[5]arene core

Nierengarten, Iwona ; Guerra, Sebastiano ; Holler, Michel ; Nierengarten, Jean-Francois ; Deschenaux, Robert

In: Chemical Communications, 2012, vol. 48, no. 65, p. 8072-8074

Comparison of the liquid-crystalline properties of a pillar[5]arene core functionalized with 10 mesogenic cyanobiphenyl units with those of a corresponding model compound revealed the strong influence of the macrocyclic pillar[5]arene core on the mesomorphic properties.

Université de Neuchâtel

Liquid-Crystalline Dendrimers Designed by Click Chemistry

Guerra, Sebastiano ; Nguyen, Thi Le Anh ; Furrer, Julien ; Nierengarten, Jean-François ; Barberá, Joaquín ; Deschenaux, Robert

In: Macromolecules, 2016, vol. 49, no. 9, p. 3222-3231

Liquid-crystalline dendrimers have been prepared from second-generation Percec- type poly(benzyl ether) dendrons or second-generation poly(aryl ester) dendrons carrying cyanobiphenyl mesogens. The Janus dendrimer, which combines the two types of dendromesogens, has also been synthesized. Those compounds have been prepared under copper-catalyzed azide–alkyne cycloaddition conditions. The ...

Université de Neuchâtel

La chimie click au service des cristaux liquides : du concept à l'application

Guerra, Sebastiano ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2012 ; 2249.

Ce travail de thèse traite de la mise en place ainsi que de l’application d’une nouvelle méthodologie de synthèse basée sur la cycloaddition 1,3-dipolaire de Huisgen connue sous le nom de chimie click. Tout au long de ce travail, cette méthode sera appliquée dans la synthèse de nouveaux composés mésomorphes dont la complexité structurale augmentera au fur et à mesure des...

Université de Neuchâtel

Accordion-optimized DEPT experiments

Furrer, Julien ; Guerra, Sebastiano ; Deschenaux, Robert

In: Magnetic Resonance in Chemistry, 2011, vol. 49, no. 1, p. 16-22

In this contribution, a pulse sequence is described for recording accordion-optimized DEPT experiments. The proposed ACCORDEPT experiment detects a wide range of one-bond coupling constants using accordion optimization. As a proof of concept, this strategy has been applied to a mesogen containing a large range of one-bond 1JCH coupling constants associated with the various...