Supramolecular Switching between Flat Sheets and Helical Tubules Triggered by Coordination Interaction

Abstract

Here we report the spontaneous formation of switchable sheets in aqueous solution, which is based on bent-shaped aromatic amphiphiles containing <i>m</i>-pyridine units at the terminals and a hydrophilic dendron at the apex. The aromatic segments self-assemble into flat sheets consisting of a zigzag conformation through π–π stacking interactions. Notably, the sheets reversibly transform into helical tubules at higher concentration and into discrete dimeric macrocycles at a lower concentration in response to Ag­(I) ions through reversible coordination interactions between the pyridine units of the aromatic segments and the Ag­(I) ions. While maintaining the coordination bonding interactions, the helical tubules reversibly transform into the dimeric macrocycles in response to the variation in concentration