Université de Neuchâtel

Ferrocene-Containing Thermotropic Side-Chain Liquid-Crystalline Polysiloxanes

Deschenaux, Robert ; Jauslin, Isabelle ; Scholten, Ulrich ; Turpin, François ; Guillon, Daniel ; Heinrich, Benoît

In: Macromolecules, 1998, vol. 31, no. 17, p. 5647–5654

The synthesis, purification, characterization, and liquid-crystalline properties of side-chain polysiloxanes bearing mesomorphic 1,1‘- or 1,3-disubstituted ferrocene units are reported. The polymers were prepared by grafting the appropriate vinyl-containing ferrocene monomer onto commercially available poly(hydrosiloxane)s following a standard procedure. The monomers gave smectic A or smectic A...

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

Bent Tridentate Receptors in Calamitic Mesophases with Predetermined Photophysical Properties: New Luminescent Lanthanide-Containing Materials

Nozary, Homayoun ; Piguet, Claude ; Tissot, Paul ; Bernardinelli, Gérald ; Bünzli, Jean-Claude G. ; Deschenaux, Robert ; Guillon, Daniel

In: Journal of the American Chemical Society (JACS), 1998, vol. 120, no. 47, p. 12274–12288

A new synthetic strategy has been developed to introduce bent and rigid tridentate 2,6-bis(benzimidazol-2‘-yl)pyridine cores into rodlike ligands L11-17. The crystal structure of the nonmesogenic ligand L13 (C39H37N5O4, triclinic, P1̄, Z = 2) shows the expected trans−trans conformation of the tridentate...

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

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

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...