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

Preparation of Pillar[5]arene-Based [2]Rotaxanes from Acyl Chlorides and Amines

Milev, Radian ; Lopez-Pacheco, Alberto ; Nierengarten, Iwona ; Trinh, Thi Minh Nguyet ; Holler, Michel ; Deschenaux, Robert ; Nierengarten, Jean-François

In: European Journal of Organic Chemistry, 2015, vol. 2015, no. 3, p. 479-485

Pillar[5]arene-based [2]rotaxanes have been prepared from the reactions of diacyl chloride reagents with various amine stoppers. The yields of the [2]rotaxanes are sensitive to the reaction conditions (solvent and stoichiometry) as well as to structural and electronic factors. In particular, the nature of the starting amine reagent has a dramatic influence on the yields of [2]rotaxanes; thus,...

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

Amphiphilic Fullerene-Cholesterol Derivatives: Synthesis and Preparation of Langmuir and Langmuir-Blodgett Films

Felder, Delphine ; Carreón, Maria del Pilar ; Gallani, Jean-Louis ; Guillon, Daniel ; Nierengarten, Jean-François ; Chuard, Thierry ; Deschenaux, Robert

In: Helvetica Chimica Acta, 2001, vol. 84, no. 5, p. 1119-1132

Amphiphilic fullerene bis-adducts 11 and 14 containing two and four cholesterol moieties, respectively, were prepared starting from the corresponding bis-malonate derivatives. In a systematic study, their spreading behavior at the air-water interface was compared to that of bis-adduct 6 with no polar head-group. Compared to 6, for which some three-dimensional...

Université de Neuchâtel

Liquid-crystalline fullerene–oligophenylenevinylene conjugates

Campidelli, Stéphane ; Deschenaux, Robert ; Eckert, Jean-François ; Guillon, Daniel ; Nierengarten, Jean-François

In: Chemical Communications, 2002, p. 656 - 657

Functionalization of C60–oligophenylenevinylene derivatives with a cyanobiphenyl-terminated dendromesogen leads to new donor–acceptor systems with liquid-crystalline properties.