Colorimetric Probes Based on Anthraimidazolediones for Selective Sensing of Fluoride and Cyanide Ion via Intramolecular Charge Transfer

Abstract

Probes based on anthra[1,2-d]imidazole-6,11-dione were designed and synthesized for selective ion sensing. Each probe acted as strong colorimetric sensors for fluoride and cyanide ions and exhibited intramolecular charge transfer (ICT) band, which showed significant red-shifts after addition of either the F(-) or CN(-) ion. One of the probes (2) showed selective colorimetric sensing for both cyanide and fluoride ions. In organic medium, 2 showed selective color change with fluoride and cyanide, whereas in aqueous organic medium it showed a ratiometric response selectively for cyanide ion.

Chromogenic and fluorogenic chemosensors and reagents for anions. A comprehensive review of the years 2010–2011

“…21), based on anthraimidazoleidone, acted as a colorimetric probe for F -and CN -in CH 3 CN via significant red shifts of 120 nm and 81 nm, respectively, of the absorption band of 60, which resulted in colour changes from light yellow to dark blue (for F -) and to red (for CN -). 40 The 1:1 interaction of F -and CN -with benzimidazole NH (deprotonation of the most labile proton in 60) led to an accumulation of a negative charge density at the donor site, which enhanced the intramolecular charge transfer. Only very slight changes in colour to orange were observed upon the addition of Spectrophotometric experiments in CH 3 CN provided evidence (a blue shift of the bands in the 270-285 nm range) for the encapsulation of F -by trisbenzimidazolium cyclophane receptor 61…”

Design and Synthesis of Some Imidazolyl Derivatives: Photophysical Studies and Application in the Detection of Anions

“…Thus, clearly suggested about the dual mode of interaction wherein, first Michael adduct was formed due to the nucleophile addition of cyanide at the dicyanovinyl fragment. The new entity so formed then further establish an interaction with -NH fragment of phenanthroimidazolyl was established [26,35] through the -N…CN…H type of hydrogen bonding leading to typical deprotonation of the N-H function [19 -29].…”

Chalcone Based Colorimetric Sensor for Anions: Experimental and TD-DFT Study

“…Most of the sensor-anion interactions are based on hydrogen bonding interaction and some of them are followed by sensor deprotonation [4][5][6]. Furthermore, the chemosensor sensing mechanisms have been suggested as intramolecular charge transfer (ICT) [7], photoinduced electron transfer (PET) [8], excited states proton transfer (ESPT) [9], and metal-ligand charge transfer (MLCT) [10]. Chalcone derivative, 3-(4-hydroxy-3-methoxy phenyl)-1-phenyl-2-propen-1-one (1), is promising candidate for anion chemosensor because of its ability for proton donating in hydrogen bonding interaction and its conjugation system through phenol ring and enone group [11][12].…”