The antimicrobial resistance is a global human threat which has led to the withdrawal of antibiotics from the market. Therefore, it is a need to develop new and effective antimicrobial agents to overcome this problem. In this paper, new Dioxovanadium(V) complexes (1–8) with ligands viz. (2-(5-phenyl-1,3,4-oxadiazole-2-yl)phenol; L1) and 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole (L2) were synthesized and assessed for antimicrobial-activity. Both a bidentate and tetradentate oxadiazole ligands coordinate with vanadium ions through the nitrogen and oxygen atoms giving octahedral geometries. Thermal analysis and IR data confirmed the presence of hydrated water in the metal-complexes. The investigated compounds were assessed for antimicrobial viz four strains of bacterial and one a fungal strain. The antibacterial data showed that, the complexes (1–8) are lower potency against bacterial strain than the free ligands except (5) and (7) complexes. These complexness showed the highest antibacterial potency via the Staphylococcus aureus. All investigated compounds were inactive against C. albicans except complexes 2 and 5 which showed high activity. The performance of DFT was conducted to examine an interaction mode of the target compounds with biological system. The QSPR was calculated as: optimization geometries, (FMOs), and chemical-reactivities for the synthesized compounds. The (MEPs) were figured to predict the interaction behavior of the ligand and its complexes against the receptor. The molecular docking was performed against DNA gyrase to study the interaction mode with biological system.

New Vanadium(V) complexes with new ligand 2-(4-((2-(carboxy) phenoxy) methyl)-1H-1,2,3triazol-1-yl)benzoic acid (L 1 ) has been synthesized and characterized by different analytical techniques such as elemental analyzer, 1 H NMR, UV-Vis, IR, Mass spectrometry and thermal gravimetric analysis (TGA). The analytical data showed the stoichiometry of the Vanadium(V) to ligand was 1:1, and also indicated that the ligand (L 1 ) coordinate to the vanadium ions through oxygen and nitrogen atoms giving octahedral geometry. The ligands and their complexes have been examined for antimicrobial activity against four types of bacterial strains and one fungal strain. All the tested ligands and their complexes showed moderate to significant activity against Staphylococcus aureus, where the complex N(Pr) 4 [VO(L 1 )] (4) showed highest activity comparable to the standard drug, Amoxicillin. The other tested bacterial strains were resistant against the ligands and their complexes. The result of antifungal activity against the pathogenic fungi C. albicans indicated that the tested strain was resistant towards the ligand and its vanadium (V) complexes.