Synthesis, Characterization, and Bioactivity Evaluation of (E)-N'-(2-Fluoro-6-hydroxybenzylidene)-4-methoxybenzohydrazide and Its Ni(II), Co(II), Cu(II), Pd(II), Mn(II), and Fe(II) Complexes1Vishal Kumar,

This study reports the successful synthesis and comprehensive characterization of a novel hydrazone ligand, (E)-N'-(2-fluoro-6-hydroxybenzylidene)-4-methoxybenzohydrazide, along with its coordination complexes with nickel(II), cobalt(II), copper(II), palladium(II), manganese(II), and iron(II) ions. Structural elucidation was achieved through spectroscopic techniques including FT-IR, 1H and 13C NMR, and mass spectrometry, confirming ligand coordination and complex formation. The antibacterial and antifungal activities of the free ligand and its metal complexes were evaluated against a range of pathogenic strains. The complexes exhibited enhanced antimicrobial efficacy relative to the parent ligand, with significant inhibitory zones observed against Gram-positive and Gram-negative bacteria, as well as fungal species. These findings suggest that metal complexation improves bioactivity, indicative of potential applications in therapeutic agent development. This work contributes to the growing field of bioinorganic chemistry by providing insight into structure-activity relationships of hydrazone-metal complexes as promising antimicrobial candidates.