Schiff base (methyl 6-(2- (4-hydroxyphenyl) -2- (1-phenyl ethyl ideneamino) acetamido) -3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylate)Co(II), Ni(II), Cu (II), Zn (II), and Hg(II)] ions were employed to make certain complexes. Metal analysis M percent, elemental chemical analysis (C.H.N.S), and other standard physico-chemical methods were used. Magnetic susceptibility, conductometric measurements, FT-IR and UV-visible Spectra were used to identified. Theoretical treatment of the generated complexes in the gas phase was performed using the (hyperchem-8.07) program for molecular mechanics and semi-empirical computations. The (PM3) approach was used to determine the heat of formation (ΔH˚f), binding energy (ΔEb), and total energy (ET) for ligands and metal complexes at 298 ᴼK. To explore the reactive sites of the compounds, the electrostatic potential of the ligand (L) was computed. PM3 was used to calculate the vibrational frequencies of the ligand (L) and its metal complexes, which were then compared to experimental data. The antibacterial activity of (L) and its metal complexes against three harmful microorganisms were examined: Staphylococcus aureus (gram positive), Echerchia coli (gram negative), and Candida albicans.
