Coumarin-based urea-amide scaffold in ratiometric fluorescence sensing of CN−. Issue 21 (24th May 2017)

• Record Type: Journal Article
• Authors: Tarafdar, Debojyoti; Saha, Indrajit; Ghosh, Kumaresh
• Is Part Of: Tetrahedron letters. Volume 58:Issue 21(2017)
• Page Start: 2038
• Page End: 2043
• Publication Date: 2017-05-24
• Subjects: Urea-amide conjugate -- Fluorescence sensing -- Ratiometric emission -- Coumarin -- Cyanide; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2017.04.033
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Based on structural modulation coumarin-based urea–amide scaffold3 has been established as selective ratiometric fluorescent sensor of cyanide ion. Upon interaction with CN −, the color of the solution of3 in CH3 CN under UV exposure becomes bright yellow, which is beneficial for its naked eye detection. Addition of CN − of ∼10 −4 M brings nice color change from colourless to yellow. Highlights: Coumarin-based urea-amide scaffold3 has been designed and synthesized. Ratiometric fluorescence change is observed selectively in the presence of CN − . CN − addition to3 in CH3 CN brings bright yellow color under UV exposure. Addition of CN − to coumarin encourages intramolecular charge transfer mechanism. Abstract: Coumarin-based urea and urea–amide scaffolds1 –3 have been designed and synthesized for the selective and naked eye detection of cyanide ion. Of the three, compound3 exhibits ratiometric fluorescence change selectively in the presence of CN − and validates the rationality in designing anion receptor. Upon interaction with CN −, the color of the solution of3 in CH3 CN under UV exposure becomes bright yellow, which is beneficial for its naked eye detection. Addition of CN − of ∼10 −4 M brings nice color change from colourless to yellow in ordinary light. The sensing event is supposed to be due to nucleophilic addition of CN − to the coumarin unit enabling intramolecular charge transfer (ICT) mechanism.