Synthesis, Structural Characterization and Antimicrobial Studies of Novel Schiff Base Copper(ii) Complexes

Abstract

Five novel copper(II) complexes have been synthesized using Schiff base ligands, synthesized by the condensation reaction of anthranilic acid and Knoevenagel b-ketoanilide condensates (obtained by the condensation of acetoacetanilide and substituted benzaldehydes). The ligands and copper(II) complexes have been characterized on the basis of Microanalytical, Mass, UV-Vis., IR, 1 H NMR, ESR, XRD and CV spectral studies, as well as magnetic susceptibility and conductivity data. On the basis of spectral studies, a square-planar geometry has been proposed for the copper(II) complexes. From the XRD data, the CuL 1 complex has the crystallite size of 50 nm respectively. The in vitro antimicrobial activity of the compounds is tested against the bacteria Escherichia coli, Salmonella typhi, Staphylococcus aureus, Klebsiella pneumoniae and Pseudonomas aeruginosa and fungi Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by well diffusion method. The complexes show stronger antimicrobial activity than the free ligands. They represent a novel class of metal-based antimicrobial agents which provide opportunities for a large number of synthetic variations for modulation of the activities.

Synthesis, Characterization, Antimicrobial and Anticancer Activities of 14-Membered Macrocyclic Schiff Base Metal Complexes

“…It also increases the interaction of metal chelates with cell wall of microbes which disturbs the respiratory process of the cell and blocks the production of proteins that retards the growth of organisms [44][45][46][47]. …”

Synthesis, Characterization, Electrochemical Behaviour, DNA Binding and Cleavage Studies of Substituted β-DiketimineCopper(II) and Zinc(II) Complexes

“…The spectra of free ligands show a band in the region 1630-1610 cm -1 characteristics of the (C=N) stretching mode [7] indicating the formation of the Schiff base products. This band is shifted towards lower frequency by ca.20 cm −1 on complexation compared to free ligands indicating the involvement of the azomethine nitrogen in chelation with the metal ion, the coordination of the nitrogen to the metal ion would be expected to reduce the electron density of the azomethine link and thus causes a shift in the (C=N) group [8].…”

Biological Screening Studies of DNA Relate Metal Complexes from Benzylidene-4-imino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one and 2-aminothiazole

“…Besides, the mode of action of the compounds could involve the formation of a hydrogen bond through the azomethine group with the active centre of cell constituents, ensuing in interferences with the normal cell process. Moreover, it disturbs the respiration process of the cell and accordingly blocks the synthesis of the proteins that restricts further growth of the organisms [44,45].…”