A Schiff‐Base Molecular Keypad LockandTurn‐On Sensor for Selective Detection of Fe³⁺ with INHIBIT Logic Behaviour

Abstract

A novel emissive Schiff-base (3)has been synthesized through single-step condensation of sulfanilamide and fluorogenic 3formylchromone. Compound (3) senses Fe 3 + ion in semiaqueous media. Both fluorogenic and colorimetrical changes were observed in the presence of Fe 3 + ions. Interestingly, on introduction of EDTA into the putative complex, [(3) + Fe 3 + ], the spectroscopic changes were reversed. The ligand detects Fe 3 + ions sensitively as the limit of detection for Fe 3 + ion was 9.3 × 10 À 7 M. The probe performs molecular logic operation (INHIBIT) as well as function of a three-input keypad lock. Further, the ligand (3)was successfully incorporated into Whatman filter paper as the test strips and aluminium coated silica gel plates, which showed a great selectivity for Fe 3 + ions.

Bifunctional Receptor Based on Calix[4]arene with Chromone Groups as An Efficient Colorimetric Sensor for Co2+, Cu2+, CN− and F−

“…Chromones are naturally occurring compounds which are widely known to have anticancer, antioxidant and other biological properties [1] . Chromone derivatives with Schiff base groups have been studied due to properties to form complexes with metal ions such as copper (II), platinum (II), nickel (II) and other transition metals, [1–6] including chromone‐based sensors for the detection of anions [7] . The development of colorimetric sensors for the detection of environmentally and biologically important ionic species is currently of great interest [8–11] .…”

Computational Studies and Fluorescent Turn‐off Sensing of Biologically Important Cu2+ Ion in Irrigation Water by Schiff Base

“…To this homogenous solution 50.00 μl of glacial AcOH was added drop‐wise and the reaction mixture was allowed to stir along with constant heating at 50 °C until the reaction completion (TLC, 5 h) (Scheme 1). [34] The precipitates obtained after overnight stirring were collected and washed with ether (2×25.00 ml) and recrystallized from methanol to obtain final product, 4‐((3‐nitrobenzylidene)amino)benzene sulfonamide (3) .…”