Electrochemical sensing of 4‐nitrophenol through heteroleptic complexes of Ag(I) and Hg(II) based on 2‐thiazoline‐2‐thiol: Synthesis, crystal structures, and Hirshfeld analysis

Abstract

In pursuit of a more effective electro‐sensor for environmentally hazardous nitro phenols detection at the trace level, we have developed two novel complexes [Ag(μ‐S‐thzt)(Hthzt)(PPh3)]2·2CH3CH2OH (1) and [Hg (thzt)2(o‐phen)](2) based on 2‐thiazoline‐2‐thiol (Hthzt). In complexes 1 and 2, triphenylphosphine and o‐phen were used as co‐ligands, respectively. Both the synthesizedcomplexes have been characterized by single crystal X‐ray diffraction data,UV–vis., infrared, and NMR spectrometry. Geometry around both the metal ion complexes is distorted tetrahedral. Noticeably, in complex 1, the Hthzt acts as a bridging as well as terminal ligand. The intermolecular interaction found in complexes 1 and 2 have been further investigated through Hirshfeld surface analysis. On comparing fluorescence intensities of Hthzt, complex 1, and complex 2, the order of fluorescence behavior was found to be Hthzt > complex 1 > complex 2. The electrochemical performance of both complexes 1 and 2 and their ability to sense 4‐nitrophenol (NP) have been evaluated through modified glassy carbon electrodes and were detected by the differential pulse voltammetry (DPV) and cyclic voltammetry (CV) methods. Based on electrochemical responses, complex 1 shows more effective performance as anelectro‐sensor than complex 2. With a relatively low detection limit of 0.19 μM, great selectivity, and acceptable sensitivity, the complex 1/GCE sensor demonstrated an exceptional linear plot between the oxidation peak current and NP concentration in the ranges of 0.5–500 μM.