Self-Assembly and Disassembly of Vesicles as Controlled by Anion-π Interactions

Anion-pi interactions have been widely studied as new noncovalent driving forces in supramolecular chemistry. However, self-assembly induced by anion-pi interactions is still largely unexplored. Herein we report the formation of supramolecular amphiphiles through anion-pi interactions, and the subsequent formation of self-assembled vesicles in water. With the pi receptor 1 as the host and anionic amphiphiles, such as sodium dodecylsulfate (SDS), sodium laurate (SLA), and sodium methyl dodecylphosphonate (SDP), as guests, the sequential formation of host-guest supramolecular amphiphiles and self-assembled vesicles was demonstrated by SEM, TEM, DLS, and XRD techniques. The intrinsic anion-pi interactions between 1 and the anionic amphiphiles were confirmed by crystal diffraction, HRMS analysis, and DFT calculations. Furthermore, the controlled disassembly of the vesicles was promoted by competing anions, such as NO3-, Cl-, and Br-, or by changing the pH value of the medium.