Benzothiazole‐Based Sensors for Protons and Chromium(III) ions

Abstract

Two benzothiazole based Schiff bases 5-(diethylamino)-2- (((6methoxybenzo[d]thiazol-2-yl)imino)methyl)phenol (probe 1) and N-(4-(dimethylamino)benzylidene)-6-methoxybenzo[d]thiazol-2-amine (probe 2) were efficiently synthesized and structurally characterized. Molecular structure of probe 1 is obtained by single crystal X-ray analysis. The presence of hydroxyl substituent on phenyl moiety makes probe 1 as ESIPT (Excited State Intramolecular Proton Transfer) probe and the absence of hydroxyl on phenyl moiety differs probe 2 as PET (Photo Induced Electron Transfer) probe towards sensing of H + ions. Probe 1 selectively detects H + ions colorimetrically with reversible changes on adding a base like TEA. Besides H + ions, probe 2 detects Cr(III) ions with a colorimetric response. The addition of TEA leads to reversible changes with primary protonation and these changes were irreversible with second protonation.

Intermolecular hydrogen bonding-assisted aggregation induced emission in quinolone–quinazoline conjugates and their potential use in acidochromism

“…S13, ESI †), the downward curve between emission intensity and orientation polarizability (Df) suggested vulnerability of the excited state toward decay via non-radiative processes in polar solvents, leading to emission quenching. Furthermore, plot of the Stokes shift vs. Df and E T (30) showed linear dependence of the Stokes shift with a positive slope indicating positive solvatochromism (Fig. S13, ESI †).…”

“…Numerous reversible ''ON-OFF-ON'' type sensors offering high sensitivity toward advanced optical applications have been reported in the literature. [27][28][29][30][31][32][33] It is well documented that ratiometric fluorescent sensors have an edge over intensity based probes. In this regard, the efficacy of several heterocycles containing nitrogen has been investigated in terms of their acidochromic behavior, revealing a significant red shift in their absorption maxima upon the addition of trifluoroacetic acid (TFA).…”

Zinc ion detection using a benzothiazole-based highly selective fluorescence “turn-on” chemosensor and its real-time application

“…Benzothiazole [43][44][45][46][47][48][49][50][51] and imidazole [52][53][54][55][56][57][58] derivatives have been intensively implemented in the development of optical chemosensors due to their easy functionalization and photostability. They are particularly effective in chelating metal ions because of sulfur, oxygen, and nitrogen atoms with lone-pair of electrons.…”

New Oxoquinoline‐Imidazole Based Fluorescence Signaling Switches for the Determination of Zn2+/F− (OFF‐ON), and Fe3+/Picric Acid (ON‐OFF): Applications in Anticancer Activity

“…There has been a significant development in the area of sensing the metal cations, anions and organic nitro compounds like 2,4,6-trinitrophenol (TNP) over the past few years because they pose a negative influence on the biosphere. [1][2][3][4][5] Designing the highly specific and selective sensors for metal ions, anions, and TNP is of great interest due to the environmental point of view. So far most of the fluorescence probes have been developed for a single target.…”