Photocontrolled Reversible Conversion of Nanotube and Nanoparticle Mediated by β-Cyclodextrin Dimers

A photochemically interconvertible supramolecular nanotube-nanoparticle system was constructed through secondary assembling of self-aggregates of amphiphilic porphyrin derivatives mediated by trans- and cis-azobenzene-bridged bis(permethyl-β-cyclodextrin). Significantly, these nanotubes and nanoparticles were able to interconvert upon irradiation at different wavelengths, and this photocontrolled morphological conversion is reversible and recyclable for tens of times, which will provide a feasible and convenient way to construct the ordered nanostructure with various morphologies that can be smartly controlled by the environmentally benign external stimulus.