Dual sites fluorescence probe for H2S and Hg2+ with 'AIE transformers' function

Dual sites fluorescence compound 1 based on 5-bromosalicylaldehyde and 2-benzothiazoleacetonitrile was synthesized. 1 exhibited different aggregation-induced emission (AIE) state in different solution boosting different emission. Different aggregated states gave different chance for H2S and Hg2+ to respond with the formation of new aggregated states. Especially, 1 responded to H2S selectively with an ultrafast rate within 20 s. Intramolecular and intermolecular hydrogen bonding play an important role on the aggregated state conversion. Herein, the notion of “AIE Transformers” was put forward for the first time. It permits us to study their aggregation state with their photophysical and functional changes.