Self-Organization of Polybases Neutralized with Mesogenic Wedge-Shaped Sulfonic Acid Molecules: An Approach toward Supramolecular Cylinders

摘要

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]azoben-zene-4-sulfonic acid have been prepared with different monomer/ligand ratios.Upon protonation of the poiy(4-vinylpyridine) chains by the wedge-shaped sulfonic acid molecules a hypsochromic and hyperchromic effect was observed with the pi-pi 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.