A Carboethoxy Quinoline-Derived Schiff Base Chemosensor: Crystal Structure, Selective Hg 2+ Ion Detection and its Computational Study

• Published in: Environmental research 2024-04, p.118983
• Main Authors: Ebenazer, Franklin, Ramasamy, Selva Kumar, N, Sampathkumar, Venkatesan, Geetha, Awad Alahmadi, Tahani, Rohini, Ponnusamy, A, Anderson
• Format: Article
• Language: English
• ISSN: 1096-0953
• DOI: 10.1016/j.envres.2024.118983

Environmental monitoring of mercury (Hg ) ions has become increasingly important as a result of their detrimental effects on biological organisms at all levels. To recognize toxic metal ions, utmost effort has been devoted to developing new materials that are highly selective, ultra-sensitive, and provide rapid response. In this context, a new chemosensor, 2-imino [N - (N-amido phenyl)]-6-methoxy-3-carbethoxy quinoline (L), has been synthesized by combining 2-formyl-6-methoxy-3-carbethoxy quinoline and benzhydrazide and it has been extensively characterized by NMR, FTIR, ESI-Mass and SXRD analysis. Probe L has excellent specificity and sensitivity toward Hg ions in semi-aqueous solutions, with a detection limit of 0.185 μM, regardless of the presence of other interfering cations. Chromogenic behavior was demonstrated by the L when it changed the color of the solution from colorless to light yellow, a change that can be observed visually. The probe L forms a 1:1 stochiometric complex with an estimated association constant (K ) of 6.74 ×10 M . The H NMR change and density functional theory calculations were analyzed to improve our understanding of the sensing mechanism. Also, an inexpensive and simple paper-based test kit has been developed for the on-site detection of mercury ions in water samples.