Synthesis of Bis(N,N´-di(5 -bromosalicylidene)-4,5-dimethyl -1,2 -phenylenediaminato) Zirconium(IV) Complexe And Study of Antibacterial Activity

Schiff bases and their complexes are flexible compounds synthesized from the condensation of an amino compound with carbonyl compounds and extensively used for a broad range of biological activities including antibacterial, antifungal, antiviral, antimalarial, ant proliferative, anti-inflammatory, anticancer, anti-HIV properties [1]. The biological activity is usually increased by complexation therefore to understand the properties of both ligand and metal can lead to the synthesis of highly active compounds [2]. In this study the title complex zirconium (IV) has been successfully prepared by heating a 1:2 mole ratio of [Zr(acac)4] and the free ligand in absolute in methanol. It is mononuclear and eight-coordinate in the solid state. The new complexe have been characterized using FT-IR, lH NMR, 13C{1H} NMR spectroscopic techniques and elemental analyses (CHN). Then, the synthesized Schiff base complexe and free ligand were screened for their biological activity against bacterial species, A Gram‐positive bacteria (Staphylococcus aureus) and a Gram‐negative bacteria (Escherichia coli ) by the disk diffusion method. The antibacterial tests used 64 μg/mL concentrations of the test compounds dissolved in DMSO. Bacteria culture Petri dishes treated with the test compounds were incubated for 24 h at 37ᵒ C. The antibacterial activity were determined by evaluating the inhibition zone (mm), MIC and MBC. MIC is the lowest concentration of an antimicrobial compound that inhibits the noticeable growth of microorganisms at 37ᵒ C after overnight incubation. The MIC of the test compounds were assayed against bacterial strains through a broth dilution method, using test compound concentrations from 0.128 to 0.0005 mg/ml in DMSO. The in vitro biological screening experiments showed higher activities for the complexe compared to the free Schiff base.