Aggregation-induced phosphorescence emission and pH recognition properties of an Iridium (III) complex

A novel Iridium (III) complex [Ir(ppy)2(Hppip)]PF6 (1) has been synthesized and characterized. The complex exhibits strong phosphorescence emission in high viscosity solvent glycerol and aggregation-induced phosphorescence emission in hexane solution. The high viscosity of glycerol and aggregation may restrict intramolecular rotation so that the compound exhibits stronger phosphorescence emission in glycerol and aggregated state. Compound 1 can also be a pH chemosensor to monitor pH changes in PBS buffer solution because of two successive protonation processes of pyridyl and imidazole moieties in acidic condition.