A 4-phenyl thiophene appended 2,4-dinitrophenylhydrazone as a colorimetric chemosensor for selective detection of cyanide ion and its application for real-life samples

Synthesis molecular docking and DFT studies on novel indazole derivatives

The amide bond is an important functional group used in various fields of chemistry, including organic synthesis, drug discovery, polymers, and biology. Although normal amides are planar, and the amide has an N-C(O) bond, herein, the 26 indazole derivatives were reported via amide cross-coupling (8a-8z). Using IR, 1H NMR, 13C NMR, and mass spectrometry, all of the produced compounds were analysed. A DFT computational study was also conducted using GAUSSIAN 09-Gaussian View 6.1, which revealed that 8a, 8c, and 8s had the most substantial HOMO-LUMO energy gap. The effectiveness of indazole moieties with renal cancer-related protein (PDB: 6FEW) was assessed by docking the derivatives using Autodock 4. The analysis showed that derivatives 8v, 8w, and 8y had the highest binding energies.

Functionalized 2-Hydrazinobenzothiazole with Bithiophene as a Colorimetric Sensor for Lethal Cyanide Ions and Its Application in Food Samples

A newly synthesized Schiff's base 2-(2-([2,2'-bithiophen]-5-ylmethylene)hydrazinyl)benzothiazole (BT) was obtained from the condensation reaction between 2-hydrazinobenzothiazole and 2,2-bithiophene-5-carboxaldehyde. The prepared probe BT was subjected to a confirmation of the structural arrangement through NMR, FTIR, ESI-HRMS, and single-crystal XRD spectral analysis. The BT colorimetric sensor showed selectivity and sensitivity toward the cyanide (CN-) ion over other common anions such as ClO4-, Cl-, Br-, F-, I-, NO2-, OH-, HSO4-, and H2PO4- in a partial aqueous system CH3CN/H2O (8:2, v/v). The probe BT detects CN- with the lowest detection range as low as 1.33 × 10-8 M (3.59 ppm); in comparison to that given by WHO guidelines, it is significantly lower. The stoichiometric interaction between the probe BT and analyte CN- was found to be 1:1 (BT/CN-) binding mode using Jobs plot, and further association binding affinity was calculated to be 6.64 × 10-3 M-1. Additionally, these results were further supported by the FTIR and DFT calculations, as well as the 1H NMR titration analysis, which complemented the binding data. The sensor probe BT was successfully employed in a cotton swab test kit approach and also in smartphone-assisted applications for the determination of CN- ions. Finally, the outstanding sensing properties of probe BT aided the quantitative detection of CN- ions, and it could be further applied to a variety of food samples, including apple seeds, sprouting potatoes, and cassava.