Electrochemical, Kinetic, Antimicrobial (MIC) Studies of Acyclic Schiff-Base Nickel(II) Complexes

Abstract

A series of acyclic mononuclear nickel(II) complexes have been prepared by Schiff base condensation derived from 5-bromosalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, nickel perchlorate. Electronic spectra of nickel(II) complexes show d-d transition in the range of 780-920 nm. Electrochemical studies of the nickel(II) complexes show irreversible one electron reduction, oxidation process. The reduction potential of the mononuclear nickel(II) complexes shifts towards anodic direction and oxidation potential shift towards to more cathodic direction upon increasing the chain length of the imine compartment. Electrochemical and catalytic studies of the complexes were compared on the basis of increasing the chain length of the imine compartment. All the complexes were screened for antifungal and antibacterial activity. Nickel is recognized as an essential trace element for bacteria, plants and animals. The active sites of enzymes such as urease, carbon monoxide dehydrogenase, [NiFe]-hydrogenase and methylS -coenzyme-M methylreductase are known to contain nickel centres, which are intimately involved in the catalytic cycles.