Synthesis, Spectral Identification, Thermal Studies, Antioxidant Properties, and Biological Effects for Some Metal Ion Complexes with New Schiff Base Ligand

The tetradentate N2O2 Schiff base ligand, which is produced via the condensation reaction of 2-hydroxynaphthaldehyde with phthalohydrazide, is prepared in this work with a fair yield. The prepared ligand was characterized using a microanalysis technique (C.H.N), UV-vis, FTIR, 1H-,13C-NMR, mass spectrometry, and thermal gravimetric analysis (TGA). New complexes were synthesized by a reaction between ligand (N'1E,N'2Z)-N'1,N'2-bis((1-hydroxynaphthalen-2yl)methylene)phthalohydrazide and metal chloride of Co+2, Ni+2, and Zn+2 ions in absolute ethanol. The present complexes are also characterized by techniques such as C.H.N, UV-vis, FTIR, TGA, molar conductivity, atomic absorption, and magnetic moment measurements. The in vitro antimicrobial activity of the prepared compounds was tested against two Gram-positive bacteria (Staphylococcus aureus and Bacillus) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), as well as Candida albicans as a fungal species, by diffusion technique in addition to antioxidant properties. The spectroscopy measurement showed that the ligand coordinated with the metal ion as a tetradentate ligand via oxygen and nitrogen in addition to the chloride ion to form octahedral shapes. All compounds under study had a positive effect against antibacterial, antifungal, and antioxidant activities.