Self-Assembly of a Mesogenic Polyamide: Induction and Significant Stabilization of a Liquid-Crystalline Phase through Complexation of a Phenylbenzoic Acid with a Polymer Backbone Derived from 2,6-Bis(amino)pyridine Units

摘要

The use of specific interactions for the design and preparation of molecular materials such as liquid crystals has attracted attention because of their potential as dynamically functional molecular systems. For liquid-crystalline polymers, specific intermolecular forces such as hydrogen bonding, ionic, and charge transfer interactions have been used for several years for the formation of mesogenic structures. Thus, for instance, the first hydrogen-bonded supramolecular mesogenic polymer, which consists of different and independent molecular components, was prepared from a stilbazole and a polyacrylate containing a benzoic acid group in the side chain. Two bifunctional complementary components were used for the formation of the first main-chain supramolecular mesogenic polymer. Since then, a wide variety of hydrogen-bonded supramolecular polymers that exhibit mesomorphic behavior have been prepared by self-assembly processes. Recently we have shown that 2,6-bis(acylamino)pyridine can be used as a molecular component for supramolecular liquid-crystalline materials through the formation of double hydrogen bonds. These complexes exhibit only monotropic mesophases with relatively narrow temperature ranges. Aminopyridines have been used frequently as versatile molecular units for the control of molecular aggregation.