Synthesis, characterization, and DFT study of a Pd(II) Schiff base complex: Exploration of its catalytic efficacy in the Suzuki cross-coupling reaction and its antibacterial activity

A Schiff base ligand (H2L) was synthesized by condensation of 3,3′-methylenedianiline with 2-hydroxy-1-naphthaldehyde under reflux conditions. Subsequently, the corresponding palladium(II) complex was prepared by reacting the ligand with palladium(II) acetate in a 1:1 molar ratio. The structures of both the ligand and its Pd(II) complex were characterized by elemental analysis, NMR, mass spectrometry, UV-vis spectroscopy, and FT-IR spectroscopy. Density functional theory calculations were performed to optimize the molecular structure and evaluate its electronic properties, providing further insight into the stability of the complex. The catalytic performance of the Pd(II) complex was investigated in the Suzuki cross-coupling reaction conducted in an aqueous medium. In addition, the in vitro antibacterial activities of the free ligand and the Pd(II) complex were evaluated against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae. Molecular docking was used to explore possible protein-complex interaction modes; these calculations were not treated as independent confirmation of the antibacterial results.