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

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...

Université de Neuchâtel

Aromatic Bent-Core Liquid Crystals: an Opportunity for Introducing Terdentate Binding Units into Mesophases

Nozary, Homayoun ; Piguet, Claude ; Rivera, Jean-Pierre ; Tissot, Paul ; Morgantini, Pierre-Yves ; Weber, Jacques ; Bernardinelli, Gérald ; Bünzli, Jean-Claude G. ; Deschenaux, Robert ; Donnio, Bertrand ; Guillon, Daniel

In: Chemistry of Materials, 2012, vol. 14, no. 3, p. 1075–1090

Lipophilic linear semirigid side arms containing two or three successive phenyl rings separated by carboxylate spacers have been connected to the 5 or 6 positions of bent aromatic terdentate 2,6-bis(benzimidazol-2-yl)pyridine binding units to give extended V-shaped (L11) and I-shaped receptors (L12, L12b, and L13). The carboxylate spacers limit the flexibility of the...

Université de Neuchâtel

Mesomorphic Hexabenzocoronenes Bearing Perfluorinated Chains

Alameddine, Bassam ; Aebischer, Olivier F. ; Amrein, Walter ; Donnio, Bertrand ; Deschenaux, Robert ; Guillon, Daniel ; Savary, Corinne ; Scanu, David ; Scheidegger, Oliver ; Titus A. , Jenny

In: Chemistry of Materials, 2005, vol. 17, no. 19, p. 4798–4807

Synthesis and characterization of new hexabenzocoronene (HBC) derivatives bearing perfluoroalkylated chains are described. These disc-shaped polycondensed aromatic hydrocarbons are known to self-assemble by π-stacking into columnar architectures. The peripheral decoration with perfluorinated chains, well-known for their low van der Waals forces, leads as expected to reduced intercolumnar...

Université de Neuchâtel

Olefin Cross-Metathesis: a Versatile Synthetic Reaction for the Design of Janus Liquid Crystals

Trinh, Thi Minh Nguyet ; Nguyen, Thanh Tung ; Kopp, Cyril ; Pieper, Pauline ; Russo, Virginie ; Heinrich, Benoît ; Donnio, Bertrand ; Nguyen, Thi Le Anh ; Deschenaux, Robert

In: European Journal of Organic Chemistry, 2015, vol. 2015, no. 27, p. 6005-6010

The olefin cross-metathesis reaction using the second-generation Grubbs catalyst was employed to prepare non-symmetrical thermotropic liquid crystals from various mesomorphic or nonmesomorphic type I and type II olefinic constructs, including linear, chiral, dendritic and ferrocenyl olefins. Smectic C, smectic A and nematic phases, as well as chiral smectic A and chiral nematic phases were...

Université de Neuchâtel

Design, Synthesis, and Self-Assembly Behavior of Liquid-Crystalline Bis-[60]Fullerodendrimers

Russo, Virginie ; Pieper, Pauline ; Heinrich, Benoît ; Donnio, Bertrand ; Deschenaux, Robert

In: Chemistry – A European Journal, 2016, vol. 22, no. 48, p. 17366-17376

Bis-[60]fullerodendrimers were synthesized by assembling [60]fullerene-containing type I (terminal olefin) and type II (a,ß-unsaturated carbonyl olefin) olefins through the olefin cross-metathesis reaction. The synthetic modular approach developed in this study allowed the preparation of mono-[60]fullerodendrimers and their [60]fullerene-free analogues. First- and second-generation poly(aryl...

Université de Neuchâtel

Designing Supramolecular Liquid-Crystalline Hybrids from Pyrenyl-Containing Dendrimers and Arene Ruthenium Metallacycles

Pitto-Barry, Anaïs ; Barry, Nicolas P. E ; Russo, Virginie ; Heinrich, Benoît ; Donnio, Bertrand ; Therrien, Bruno ; Deschenaux, Robert

In: Journal of the American Chemical Society, 2014, vol. 136, no. 50, p. 17616-17625

The association of the arene ruthenium metallacycle [Ru4(p- cymene)4(bpe)2(donq)2][DOS]4 (bpe = 1,2- bis(4-pyridyl)ethylene, donq = 5,8-dioxydo-1,4-naphtoquinonato, DOS = dodecyl sulfate) with pyrenyl-functionalized poly(arylester) dendrimers bearing cyanobiphenyl end- groups is reported. The supramolecular dendritic systems display...

Université de Fribourg

Influence of linear and branched perfluoroalkylated side chains on the π–π stacking behaviour of hexa-peri-hexabenzocoronene and thermotropic properties

Alameddine, Bassam ; Aebischer, Olivier Frédéric ; Heinrich, Benoît ; Guillon, Daniel ; Donnio, Bertrand ; Jenny, Titus A.

In: Supramolecular Chemistry, 2014, vol. 26, no. 2, p. 125–137

The thermotropic properties and self-assembly of two different series of hexa-peri-hexabenzocoronenes (HBC) bearing either linear or branched perfluoroalkylated side chains, each with a wide range of alkyl spacer and perfluorinated tail lengths, have been studied. Correlations between thermogravimetric analysis, differential scanning calorimetry, polarised optical microscopy and small-angle X-ray...