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, 1H and 19F NMR spectroscopy. X-ray crystal structure analysis reveals an O-HO interaction between TNP and the ancillary ligand which explains the high selectivity for TNP compared to other nitro-aromatics.