Single-crystal X-ray characterization of an Aminoquinoline Schiff Base as a selective Chemosensor for Sn(II) with antioxidant and anticancer activities.

Abstract

A Schiff base EVQ is synthesized and evaluated as a selective chemosensor for Sn(II). The ligand is characterized using X-ray diffraction with R value 0.0958, NMR spectroscopy (13C and 1H), Mass spectrometry, and IR spectroscopy, confirming its structure. Ultraviolet-visible and fluorescence studies showed high selectivity and sensitivity toward Sn(II), with the limit of detection (LOD) determined to be 0.948 μM which indicates significant sensing capability. Benesi-Hildebrand (BH) analysis provides the binding constant to be 2.15 × 103 M-1 further confirming strong metal-ligand interaction. In addition to its sensing performance, the Schiff base exhibits significant antioxidant activity with IC50 value of 9.6 μM and anticancer activities with a reduction of cell viability to 49.82%, which are corroborated through molecular docking studies, suggesting potential biological relevance. Density functional theory calculations support the formation and stability of the Sn(II)-Schiff base complex, offering insights into its electronic structure and metal coordination behaviour. Overall, this work highlights the multifunctional nature of the synthesized Schiff base, combining efficient metal ion detection with promising bioactivity, and underscores its potential applications in environmental monitoring and medicinal chemistry.