Synthesis of novel 2-((2-(benzothiazol-2-yl)hydrazono)methyl)naphthalen-1-ol (NBS) and its selective sensing of fluoride ions

• DOI: 10.1016/j.cplett.2019.136891
• Publication Date: 2019-10-22T15:25:41Z
• Authors: V. Vijayakumar; A. Karuppusamy; P. Kannan; P. Nagaraaj
• Keywords: Proton NMR; Trifluoroacetic acid; Naked eye

Abstract Naphthalene based chemosensor 2-((2-(benzothiazol-2-yl)hydrazono)methyl)naphthalen-1-ol (NBS) was synthesized and characterized utilizing analytical techniques namely FT-IR, NMR, Mass spectrometry, UV–Visible spectroscopy and elemental analysis. NBS was utilized as colorimetric chemosensor for naked eye detection of fluoride ions. Fluoride ion sensing mechanism has been studied by UV–visible and 1H NMR titration investigations. The 1H NMR titration experiment was confirmed the deprotonation of OH and NH protons by F− as a strong evidence for fluoride ion sensing mechanism. Furthermore, anionic state of NBS was protonated using trifluoroacetic acid as protonating agent. Moreover, NBS coated XAD-7 beads were subjected to the fluoride ion sensing.