Ordered nanoassemblies from self-assembly of amphiphilic molecule containing pillar[5]arene and azobenzene groups

The derivatization of pillar[n]arenes is a prerequisite for endowing them with functions, as well as enriching the application of pillar[n]arene materials in advanced material science. Herein, we report the self-assembly of amphiphilic rim-differentiated pillar[5]arene (H1). One side of the pillar[5]arene is composed of hydrophilic poly(ethylene oxide) chains, benzene and azobenzene groups connected with ether bonds, and the other side is composed of ethoxy groups. In CHCl3 solvent, the amphiphile H1 self-assembled into spherical micelles, while in H2O/THF mixed solvent H1 self-assembled into nanorod-like assemblies. Interestingly, addition of a guest molecule composed of tetraphenylethene and hexanenitrile groups (G1) to the CHCl3 solution of H1 produces large sheet aggregates via the strong pi-pi stacking of rod segments. The reversible transformation between the nanosheet assemblies of host-guest complexes and nanoparticles is achieved by addition of the guest molecule 1,4-butylamine (G2) and pillar[5]arene with ethoxy groups as competitive molecules. Notably, worm-like and nanorod micelles of H1 were constructed in H2O/THF solution triggered by light irradiation, which assemblies can be used as photosensitive erasable writing materials. (c) 2023 Society of Industrial Chemistry. The reversible conversion of various nanostructures is achieved by light irradiation or host-guest interaction of amphiphilic rod-coil molecule containing pillar[5]arene and azobenzene groups in selective solvent.dagger image