Cucurbit[8]uril-Assisted Nucleophilic Reaction: A Unique Supramolecular Approach for Cyanide Detection and Removal from Aqueous Solution

A unique supramolecular approach
of preparing and using a cucurbit[8]­uril
(Q[8])-based dynamic host–guest assembly for cyanide sensing
in and removal from water has been successfully developed. The dicyanovinyl-attached
cationic guest (1) was designed as the fluorescent response
moiety for the detection of the cyanide anion via a nucleophilic addition
reaction in the assist of the Q[8]-based 2:2 quaternary complexes.
Furthermore, the reaction of cyanide with 1 further switched
the Q[8]-based host–guest assemblies from the 2:2 complexes
to the 1:1 supramolecular polymers that precipitate in water. Thus,
the macrocyclic-based dynamic host–guest assembly has potential
use in applications for solving the problem of toxic anion pollutants
present in aqueous environments.