An efficient ICT based fluorescent turn-on dyad for selective detection of fluoride and carbon dioxide. (28th October 2015)

• Record Type: Journal Article
• Authors: Ali, Rashid; Razi, Syed S.; Gupta, Ramesh C.; Dwivedi, Sushil K.; Misra, Arvind
• Is Part Of: New journal of chemistry. Volume 40:Number 1(2016:Jan.)
• Page Start: 162
• Page End: 170
• Publication Date: 2015-10-28
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c5nj01920f
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : A new intramolecular charge transfer based fluorescent turn-on ratiometric probe exhibiting high sensitivity for F − and CO2 . Abstract : A new intramolecular charge transfer (ICT) based fluorescent turn-on ratiometric probe2 (D–π–A type) has been designed and synthesized by bridging imidazole (donor, D) and benzothiazole (acceptor, A) moieties through a phenyl ring. The photophysical behavior of probe2 in solvents of different polarities and at different pH values has been investigated. Upon interaction with different types of anions probe2 showed selective high affinity for fluoride anions (F − ) in aqueous DMSO (20%) solution. The ratiometric fluorescence turn-on behavior displayed by2 with F − is attributed to changes in the ICT process. Job's plot analysis revealed a 1 : 1 binding stoichiometry for2 + F − interactions with a high binding constant and detection sensitivity (30 ppb). Moreover, a solution of2 + F − enabled the detection of CO2 (∼100 ppb; 2.29 μM) through enhanced emission. The mode of interaction has been confirmed by 1 H NMR titration studies which suggested the deprotonation of the –NH fragment of an imidazolyl unit in the presence of F − .