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 φF values of P3 in the aqueous mixtures with different water fractions further confirm the AIE characteristics of the polymers.