Supramolecular phosphorescent assemblies based on cucurbit[8]uril and bromophenylpyridine derivatives for dazomet recognition

A bromophenylpyridine derivative (N1) was designed, synthesized, and the molecule was incorporated into the cavity of the cucurbit[8]uril (Q[8]) as a guest to form a 2:1 host-guest complex. This complex demonstrates good room temperature phosphorescence (RTP) properties in aqueous solution. The host-guest interaction and optical properties of N1@Q[8] in aqueous solution were studied by means of ¹H NMR, ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, phosphorescence spectroscopy, scanning electron microscopy and inverted fluorescence microscopy. The results show that the bromophenyl part of the guest molecule enters the cavity of Q[8], while the other part of N1 remains outside the cavity, resulting in a 2:1 supramolecular structure. This assembly exhibits specific recognition of dazomet on the phosphorescence spectrum with a detection limit of 8.8329 × 10^-7 mol·L^-1. Collectively, this finding opens up a new possibility for the potential application of room temperature phosphorescent materials in analytical detection.