Theoretical studies and antibacterial activity for Schiff base complexes

New ligand 4-((2-Hydroxy1-naphthyl) methylene amino)-1.5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (HL) was synthesized from the reaction of 2-hydroxy-1-naphthaldehyde and 4-aminophenaz one. A complexes of this ligand [VO(II)(HL)(SO4)], [Pt(IV)(L)Cl-3], [Re(V)(L)Cl-3]Cl, and [M(II)(L)Cl] (MPd(II), Ni(II), Cu(II)) were synthesized. The resulted compounds were characterized by IR, NMR (H-1 and C-13), mass spectrometry, element analysis, and UV-Vis spectroscopy. Additionally, the spectroscopic studies revealed octahedral geometries for the Re(V), Pt(IV) complexes, and square pyramidal for VO(II), square planar for Pd(II) complex, and tetrahedral for the Ni(II) and Cu(II) complexes. Thermodynamic parameters (E-*, H-*, S-*, G(*), and K) were calculated using from the TGA curve Coats-Red fern method. Therefore, hyper Chem-8 program has been used to predict structural geometries of compounds in the gas phase. Finally, the synthesized Schiff base and its metal complexes were screened for their biological activity against bacterial species, 2 Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and 2 Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa).