Fluorene Based Ferric Complex as Colorimetric and Fluorometric Probe for Highly Selective Detection of CN- and S2- Anions.

A series of new chemosensor molecules bearing benzothiazole-, quinoline- and phthalazine-functionalized fluorene derivatives were synthesized and their complexation behaviors with Fe3+ and Sn2+ ions were investigated. The sensing abilities of their complexes towards both cyanide and sulfide anions were investigated by colorimetric and fluorometric techniques in detail. The sensing mechanism was investigated by Job's and Scatchard plots evaluations, and also absorption/fluorescence titration experiments. Among the studied dye/metal binary systems, F-BT sensor to Fe3+ giving the detection limits of 3.1 µg has also displayed high selectivity and sensitivity towards CN- and S2- anions, lead to a significant color change of the solution observable by the naked eye.