Selective sensing of 2,4,6-trinitrophenol (TNP) in aqueous media with aggregation-induced emission enhancement'' (AIEE)-active iridium(III) complexes

A series of new phosphorescent cyclometalated iridium(III) complexes which possess aggregation-induced emission enhancement (AIEE) detect 2,4,6-trinitrophenol (TNP) selectively with high quenching constants in aqueous media. The sensing mechanism was systematically investigated by mass spectrometry, H-1 and F-19 NMR spectroscopy. X-ray crystal structure analysis reveals an O-H center dot center dot center dot O interaction between TNP and the ancillary ligand which explains the high selectivity for TNP compared to other nitro-aromatics.