Synthesis, Antibacterial Assessment, Molecular Docking, and Computational study of 2-Hydroxy-1-naphthaldehyde-Derived Schiff Bases and Their Cu(II), Co(II), Ni(II), Fe(II), and Mn(II) Complexes

Abstract

In this study, two novel tetradentate Schiff base ligands, naphthalideneamino-4,4'-dimethyl-1,1'-biphenyl (L1) and its dibromo analog (L2), were synthesized from 2-hydroxy-1-naphthaldehyde and structurally characterized using FT-IR, UV-Vis, CHN elemental analysis, and NMR spectroscopy. Their corresponding Cu(II), Co(II), Ni(II), Fe(II), and Mn(II) complexes were prepared and analyzed. The antimicrobial activities of both ligands and complexes were assessed against Gram-positive and Gram-negative bacterial strains. Density Functional Theory (DFT) calculations were employed to optimize the molecular geometries of selected Cu(II) complexes. Furthermore, molecular docking studies were carried out to evaluate their potential as α-glucosidase inhibitors, revealing strong binding affinities driven mainly by hydrophobic interactions and π–π stacking. The findings indicate promising antibacterial and enzymatic inhibitory potential of these Schiff base metal complexes and provide a framework for future drug design.