A multi-stimuli-responsive metallosupramolecular gel based on pillararene hierarchical assembly

A metallosupramolecular polymer network (DSPy subset of SHP5@Zn) is constructed by the hierarchical self-assembly of a double-armed pillar[5]arene host (SHP5), a ditopic guest (DSPy), and Zn2+ ions, in which host-guest recognition and metal-ligand coordination interactions play a crucial role. Owing to the reversible feature of both dynamic covalent and noncovalent interactions, the DSPy subset of SHP5@Zn assembly can form metallosupramolecular gels, which show good sol-gel transition properties in response to various external stimuli, including thermal, redox, and pH changes, and competitive guests. Interestingly, the DSPy subset of SHP5@Zn assembly can serve as an excellent sensor for highly selective dual-channel recognition of OH, and therefore a convenient and feasible test kit for sensing OH anions based on DSPy subset of SHP5@Zn is fabricated. The present work provides a facile and efficient method to construct multi-stimuli-responsive smart gels, which may further enrich and expand the scope and application of smart supramolecular materials.