Chiral Assemblies from an Achiral Pyridinium-Tailored Anthracene

Chiral helical structures have attracted increasing attention in the field of supramolecular assembly because of their critical roles in life and material sciences. In this research, the achiral amphiphile 1-[11-(2-anthracenylmethoxy)-11-oxoundecyl] pyridinium bromide (2-APB), in which the hydrophobic anthracene and the hydrophilic pyridinium units are linked by alkyl chains, was found to form chiral supramolecular assemblies in a cooperative manner in the presence of iodide anion. Moreover, these assemblies show left (L)-or right (R)-handedness randomly, independent of the assembly conditions. By using the same method, 2-APB could assemble together with other pseudo-halogen anions (OCN-, SCN-, SeCN-) that have similar anionic radius as iodide to form chiral structures. This work illustrates a simple and rational design that can be used to fabricate supramolecular chiral structures from achiral molecules.