Synthesis, Characterization and Antioxidant Activity of Nickel(II) Schiff Base Complexes Derived from 4-(Dimethylamino)benzaldehyde

Nickel(II) complexes of the following Schiff base ligands derived from 4-(dimethylamino)benzaldehyde were synthesised: (Z)-1-(4-(dimethylamino)benzylideneamino)-propan-1-ol through condensation with 1-amino-propan-1-ol, ((NE)-E-1,(NE)-E-2)-N-1,N-2-bis(4-dimethylamino)benzylidene)benzene-1,2-diamine through condensation with benzene-1,2-diamine and 2-((4-dimethylamino)benzylidene)amino)phenol through condensation with 2-aminophenol. The synthesised Schiff bases and the resultant Ni(II) complexes were all isolated as crystals and characterized by melting point, elemental analysis, infrared spectroscopy, NMR spectroscopy, mass spectrometry and by conductance measurements. Antioxidant activity of the Ni(II) complexes was tested by assay with the free radical compound 2,2-diphenyl-1-picrylhydrazyl (DPPH).