A photo-switchable supramolecular hyperbranched polymer with aggregation-induced emission based on host-guest interaction

In this work, we report a simple strategy by mixing a coumarin appended tetraphenylethylene derivative (TPEC) and gamma-cydodextrin(gamma-CD) in aqueous solution, based on the host-guest interaction between TPEC and gamma-CD to construct a dual-modality supramolecular hyperbranched polymer. The host-guest interaction between gamma-CD and TPEC efficiently restricted the intramolecular rotation and the non-radiative relaxation channel, minimizing energy loss, thereby resulting in the strong emission of TPEC in dilute solution. Moreover, we achieved the conversion between non-covalent supramolecular hyperbranched polymers and its corresponding covalent supramolecular hyperbranched polymers under the irradiation of UV light, which can be reversibly controlled through the irradiation at the wavelengths of 254 nm and 365 nm. Furthermore, both non-covalent supramolecular hyperbranched polymers and covalent supramolecular hyperbranched polymers can self-assemble into spherical structures. This methodology provides a new idea for exploring a new type of supramolecular hyperbranched polymers with aggregation-induced emission.