Polytriazoles with Aggregation-Induced Emission Characteristics: Synthesis by Click Polymerization and Application as Explosive Chemosensors

Tetraphenylethene (TPE)-containing polytriazoles (P3) with high molecular weights in high yields was synthesized by the Cu(I)-catalyzed click polymerization of diyne with diazides. The diyne and diazide monomers, namely 1,4-bis(propargyloxy) benzene (1), 1,2-bis[4-(azidohexyloxy)phenyl]-1,2- diphenylethene (2a), and 1,2-bis[(4-azidomethyl)phenyl]-1,2-diphenylethene (2b), were synthesized. The monomer structures were confirmed by spectroscopic analyses. The click polymerization in organic media using an organosoluble catalyst of Cu(PPh₃)₃Br. Utilizing the novel AIE effect, the polytriazoles are used as chemosensors for the detection of explosives in the aggregate and solid states. The emission quenching is observed at a concentration as low as 0.1 μg/mL or 0.1 ppm. The changes in the φ_F values of P3 in the aqueous mixtures with different water fractions further confirm the AIE characteristics of the polymers.