Synthesis of Nickel(II) Complexes of Novel Naphthalimide Based Heterodipodal Schiff Base Ligands, Structure, Characterization and Application for Degradation of Pesticides

Abstract

To degrade the highly toxic pesticide into less harmful components, we have synthesized four nickel complexes of naphthalimide based organic ligands. These complexes catalyze the hydrolysis of phosphorothioate bonds of organophosphates in an aqueous medium. The metal complexes {[Ni(L1)2]–[Ni(L4)2]} were synthesized by the electrochemical method and characterized using single-crystal X-ray crystallography and mass spectrometry. Analytical techniques revealed that complexes are mononuclear and possess octahedral geometry. The rate of degradation of chlorpyriphos and parathion methyl was evaluated using 31P NMR and LC-MS chromatogram. The by-product of chlorpyriphos upon catalytic degradation with complex was confirmed from mass spectrometry. It was found that chlorpyriphos degrade into 3,5,6-trichloropyridin-2-ol after 50 minutes of incubation with catalyst. However, parathion methyl took only 20 minutes to hydrolyze into its by-product. Moreover, the inhibition assay of acetylcholinesterase was performed for pesticides in the presence of metal complex and the interesting outcome was recorded.