Synthesis, spectral, and biological studies of transition metal chelates of N-[1-(3-aminopropyl)imidazole]salicylaldimine

Tridentate chelate complexes M[LX · 2H2O], where M = Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) have been synthesized from the Schiff base L = N-[1-(3-aminopropyl)imidazole]salicylaldimine and X = Cl. Microanalytical data, UV-Vis, magnetic susceptibility, IR, 1H-NMR, mass, and EPR techniques were used to confirm the structures. Electronic absorption spectra and magnetic susceptibility measurements suggest square-planar geometry for copper complex and octahedral for other metal complexes. EPR spectra of copper(II) complex recorded at 300 K confirm the distorted square-planar geometry of the copper(II) complex. Biological activities of the ligand and metal complexes have been studied on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans by the well diffusion method. The activity data show the metal complexes to be more potent than the parent ligand against two bacterial species and one fungus. The electrochemical behavior of the copper complex was studied by cyclic voltammetry.