Synthesis and Characterization of Novel Transition Metal Complexes of Benzo-α-Pyranone Derivatives and their Biological Activities

Some novel transition metal [Mn(II), Co(II), Ni(II), Cu(II), Pd(II)] complexes of multidentate Schiff base ligand obtained from semicarbazide and substituted α-benzopyronone have been prepared and characterized by physical, spectral and analytical data. The synthesized Schiff base act as tridentate ligand for the complexation reaction with Mn(II), Co(II), Ni(II), Cu(II) and Pd(II) ions. The new compounds, possessing the general formula [M(L)₂.H₂O] where [M= Mn(II), Co(II), Ni(II), Cu(II) and Pd(II)] show an octahedral geometry. In order to evaluate the effect of metal ions upon chelation, the Schiff base and their metal complexes have been screened for antimicrobial activity. The transition metal complexes have shown enhanced antimicrobial activities as compared to Schiff base.