Switchable supramolecular crosslinking of cyclodextrin-modified hyperbranched polyethylenimine via anthraquinone dyes

摘要

Two anthraquinone dyes, 5,8-di-N-adamantylamino-1,4-dihydroxyanthraquinone (AQ-OH) and 1,4-di-N-adamantylaminoanthraquinone (AQ-H), are synthesized. The combination of AQ-OH and AQ-H with hyperbranched polyethylenimine (PEI) bearing covalently attached β-cyclodextrin spontaneously formed host-guest complexes with hydrodynamic diameters of about 260 nm. Even enlarged structures of the trifunctional AQ-H were observed via DLS. Repeated measurements show that their assembly and disassembly is reversible with a critical point at 26 °C and therefore switchable via temperature. Also superstructures up to 100 μm were detected via TEM, cryo-TEM-, and SEM. Hence, a smart colored network of switchable size consisting of a supramolecular approach involving an organic dye is described. The possibility to control the size of supramolecular complexes is investigated using β-CD-PEI as a host molecule. In combination with multifunctional guests based on new anthraquinone dyes enlarged, colorful spheres of switchable size are described.