3-(Pyridine-4-thione)BODIPY as a chemodosimeter for detection of Hg(II) ions

• DOI: 10.1016/j.dyepig.2012.03.015
• Publication Date: 2012-03-23T23:17:24Z
• Authors: Tamanna K. Khan; M. Ravikanth
• Keywords: Chemodosimeter; Aqueous-Solution; Fluorescent Sensor; Pyridine-4-One; Fluorescence Sensor; Chemosensor; Bodipy Dyes; 540; 01 natural sciences; Boron-Dipyrromethene; 0104 chemical sciences; Sensitivity; Hg2+-Selective Chemodosimeter; Hg2+; Dipyrromethene; Mercuric Ion; Desulfurization; Pyridine-4-Thione; 8-Hydroxyquinoline

Abstract A new chemodosimeter for detection of Hg(II) ions based on boron-dipyrromethene (BODIPY) is developed. The 3-(pyridine-4-thione)BODIPY was synthesized in high yield by treating 3-(pyridine-4-one)BODIPY with Lawesson's reagent. The 3-(pyridine-4-thione) BODIPY was confirmed by HR-MS mass, 1 H, 1 H– 1 H COSY, 19 F and 11 B NMR techniques. In 1 H NMR, the protons which are adjacent to sulfur in 3-(pyridine-4-thione)BODIPY showed ∼1 ppm downfield shift compared to equivalent protons in 3-(pyridine-4-one)BODIPY. The absorption and electrochemical properties experienced slight changes in 3-(pyridine-4-thione)BODIPY compared to 3-(pyridine-4-one)BODIPY. The compound 3-(pyridine-4-thione)BODIPY is very weakly fluorescent compared to 3-(pyridine-4-one)BODIPY. Furthermore, 3-(pyridine-4-thione)BODIPY can be used as an exclusive chemodosimeter for Hg 2+ ion as it shows significant enhancement in the fluorescence intensity and a dramatic visible color change from pink to fluorescent green in the presence of Hg(II) ions.