• Citer

Self-organization of polybases neutralized with mesogenic wedge-shaped sulfonic acid molecules: An approach toward supramolecular cylinders

par Zhu, Xiaomin;Beginn, Uwe;Möller, Martin;Gearba, Raluca Raluca R.I.;Anokhin, Denis ;Ivanov, Dimitri
Référence Journal of the American Chemical Society, 128, 51, page (16928-16937)
Publication Publié, 2006-12

Article révisé par les pairs

• Détails
• Contenu

Résumé :

Complexes consisting of poly(4-vinylpyridine) and mesogenic wedge-shaped ligands 4′-[3″,4″,5″-tris(dodecyloxy)benzoyloxy] azobenzene-4-sulfonic acid and 4′-[3″,4″,5″- tris(octyloxy)benzoyloxy]azobenzene-4-sulfonic acid have been prepared with different monomer/ligand ratios. Upon protonation of the poly(4-vinylpyridine) chains by the wedge-shaped sulfonic acid molecules a hypsochromic and hyperchromic effect was observed with the π-π* transition of the azo-chromophor, allowing us to monitor the neutralization process by means of UV-vis spectroscopy in solution. The changes of the absorption characteristics implied a conformational change of the polymer backbone. In the bulk the interaction between pyridine and sulfonic acid moieties was proved by FT-IR spectroscopy. Polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction measurements were used to study the bulk structure of the complexes. The complexes formed a liquid crystalline lamellar phase at low degrees of substitution, while a hexagonal columnar mesophase was observed at degrees of neutralization of 80% and higher. © 2006 American Chemical Society.