Preparation, Characterization, ESR study and Antibacterial Studies of Cu(II) Chelates of Schiff bases

Volume : IV, Issue : IV, April - 2015

V. Prakash

Copper metal complexes find applications in medicine as drugs. The copper metal complexes are a special variety

of complexes having nine electrons in the outermost level. They are widely available in the nature and are used in the

manufacture of batteries, drugs, enzymatic reactions, insecticides etc. In continuation of our work, in this paper we have tried to study the

synthesis, characterization and the antibacterial property of the Schiff bases and their copper complexes. A new series of transition metal

complexes of Cu(II) with two bidentate and two tetradentate Schiff base ligands were prepared. The characterization of the Schiff bases and

the complexes were done by elemental analysis, molar conductance, infrared, electronic (UV-Vis), electron spin resonance (esr) spectroscopic

techniques and thermogravimetric analysis was used to investigate the chemical structure of the prepared ligands and Cu(II) complexes. The

infrared spectral studies reveal the involvement of azomethine nitrogen (-C=N) coordination/ carbonyl (-C=O) coordination / carboxylate

(-COO-) coordination with the copper (II) ion in the four complexes. Electron Spin Resonance spectroscopy was recorded at 300K (room

temperature) and 77K (liquid nitrogen temperature). Quantum mechanical treatment of the esr spectrum was done to evaluate the nature of

bonding in the copper (II) complexes. The thermal decomposition of the copper (II) complexes were studied using thermogravimetric analysis

in static air with a heating rate of 20�C per minute. Antibacterial screening against bacteria such as staphylococcus aureus, Escherichia coli,

bacillus subtilis and pseudomonas aeruginosa were performed using disc diffusion technique. The comparative study of MIC (minimum

inhibitory concentration) values of the Schiff base its metal complexes indicate that the copper (II) complexes exhibit greater antibacterial

activity than the free ligands. The copper (II) complexes were powdery in texture and hence the XRD was not recorded.