Hydrogen-bonded Oligo(p-phenylene ethynylene) Liquid-Crystalline J-aggregates

Abstract

We designed and synthesized a new family of liquid-crystalline (LC) oligo(p-phenylene ethynylene) (OPE) based on the 1,4-bis(phenylethynyl)benzene core functionalized with wedge-shape groups, inducing LC behavior, and carboxylic acid (OPE-1) or pyridine (OPE-2) to induce hydrogen bonding capabilities. This design was expected to promote the self-assembly of the OPEs scaffolds into non-conventional columnar liquid crystals, where the OPE cores are aligned parallel to the fiber axis, by hydrogen bonds, acid-base and/or slipped π-π interactions. OPE-1 by itself organize in the desired disposition forming a non-conventional columnar J-aggregate liquid crystal, while the combination of the two OPEs leads to multicomponent LC assemblies.