Synthesis, Characterization, Biological Activity and Antioxidant Studies of New Metal Ion Complexes Based on (E)-4-((benzo[d]thiazol-2-ylimino)methyl)-1,5-dimethyl-2-phenylpyrazolidin-3-one

The study involved synthesis of four new complexes involving bidentate ligand [(E)-4-((benzo[d]thiazol-2-ylimino) methyl)-1,5-dimethyl-2-phenylpyrazolidin-3-one] with the general formula [M(L)2Cl2].xH2O or [MLCl2]. xH2O, where M represents Mn2+, Co2+, Ni2+ and Cu2+. The ligand was synthesized by treating the 4-Antipyrinecarboxaldehyde and 2-aminobenzothiazoles in an alcoholic solution. The structural characteristics of ligand and complexes were characterized quantitatively and qualitatively by using various techniques including elemental analyses, magnetic susceptibility measurement, molar conductivity, infrared, ultraviolet absorption, Gc-Mass, and 1H-NMR spectroscopy studies. The physical measurements indicated that the prepared complexes are non-electrolyte and showed that the ligand is bidentate when coordinated with metal ions through the nitrogen of azomethine (-C=N-) and oxygen atom of carbonyl (-C=O) for antipyrine, octahedral geometry for Mn2+ and Ni2+ complexes but tetrahedral geometry of Co2+ and Cu2+ complexes with good yield. This study emphasized the importance of using a metal complexation method to stabilize ligands and increase their bioactivity. The biological screening of the complexes demonstrates that the Schiff base metal complexes exhibit remarkable efficacy in combating microorganisms, by utilizing Psedomonas ,E. coli, strepto and staph as bacterial strains using doxycycline, tetracyclin, clindamycin, rifampin, clarithromycin, levofloxacin, amikacin, ceftriaxone, vancomycin, ampicillin as reference to determine Pharmacological resistance to negative and positive bacteria . Hence, their results were good in inhibition. Then, the potential of these prepared compounds as antioxidants was determined by inhibiting free radicals using DPPH as a free radical.