Twisted helical microfibers by hierarchical self-assembly of an aromatic oligoamide foldamer

Abstract

A series of aromatic oligoamide foldamers based on 8-fluoro amino-quinoline carboxyl acid have been synthesized and characterized. Studies show that these foldamers self-assemble to form well-defined twisted helical microfibers in chloroform-methanol (1:1, V/V) binary solvent due to the intermolecular π-π stacking and van der Waals forces of aliphatic chains, which are supported by SEM, TEM and XRD. It is also revealed that the assembly morphologies show strong dependence on the length of alkyl chains. A non-natural aromatic foldamer with unique 'S'-styled helical supersecondary structures does self-assemble to well-defined twisted helical microfibers in binary solvent. Copyright © 2013 SIOC, CAS, Shanghai & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.