Aggregation-Induced Emission-Active Iridium(III) Complexes for Sensing Picric Acid in Water

Herein, two new iridium(III) complexes, namely Ir2 and Ir3, with a phenyl or triphenylamine (TPA) moiety at the 4-position of ring 2-phenylbenzothiazole, have been synthesized, their emission properties studied systematically compared non-substituted complex Ir1. These three complexes exhibit aggregation-induced (AIE) in H2O/CH3CN. The TPA-substituted Ir3 shows highest AIE activity. All can be used as sensors to detect picric acid (PA) water. Stern–Volmer constant (KSV) for detection PA was determined 1.96 × 106 M−1, low limit 2.52 nM. Proton nuclear magnetic resonance spectra, high-resolution mass spectrometry analysis, density function theory calculations confirm that quenching mechanism is caused by photo-induced electron transfer. Furthermore, efficient natural water proves Ir1–Ir3 promising environment. results suggest AIE-active under environment-friendly conditions.