A Twisted Cucurbit[14]Uril-Based Fluorescent Supramolecular Polymer Mediated by Metal Ion

Twisted cucubit[14]uril, tQ [14], forms a fluorescent supramolecular polymer with the water-soluble fluorescent tetrapyridinium pyrene compound TPYP via host-guest interactions. Binding is via the alkyl chains and pyridines of TPYP at a molar ratio of 2:1 (tQ [14]:TPYP), and the structure forms a loose and porous supramolecular polymer TPYP-tQ [14]. Upon addition of different metals to a solution of TPYP-tQ [14], it was found that Ni2+ significantly reduced the emission of TPYP-tQ [14] and impacted the morphology of the TPYP-tQ [14], changing it from a loose porous structure to a chain. Due to the special structure of tQ [14], the mechanism of regulation is considered to be a coordination interaction between Ni2+ and the third portal of tQ [14]. This research makes full use of the structural advantages associated with twisted cucurbit[n]urils and provides a new method for controlling the structure of a polymer through coordination-type interactions.