Synthesis and characterization of transition metal complexes with a Schiff base derived from cephalexin and 1,2–diaminobenzene. antibacterial activity

Abstract

From the reaction of 1,2-diaminobenzene 1 with cephalexin 2 antibiotic a cephalexin–based Schiff base (HL) 3, was obtained and the transition metal Schiff base complexes were synthesized. The products were characterized by physical and spectral techniques, namely, UV–Vis, FT-IR, 1H-NMR, EPR, MALDI mass spectrometry, magnetic susceptibility, molar conductance, molecular modeling, together with elemental and thermal analysis. The general composition [M(L)(OAc)(H2O)2], M(II) = Mn2+ 4, Co2+ 5, Ni2+ 6, Cu2+ 7, Zn2+ 8, where L represents deprotonated tridentate NNO Schiff base, have been assigned to the adducts. Direct calcinations of the complexes 6 and 8 at 700 °C resulted high-quality metal oxide (MO) nanoparticles. Paper disc diffusion method was used to test the bactericidal activity of the synthesized products.