Synthesis, characterization and antibacterial activity of ethylene di-amine and 2-hydroxybenzadehyde Schiff base and its metal complexes

Abstract

A number of modern techniques have been developed for the synthesis of Schiff bases. We reported the synthesis of ethylene di-amine and 2-hydroxybenzadehyde Schiff base (SB) via the condensation method. To remove phenolic hydrogen to form Schiff base it was reacted with sodium hydroxide and then treated with M(II) chloride (M=Fe, Cu, Zn, Ni and Sn) to fabricate their respective metal complexes. The synthesis of SB metal complexes and detailed functional group characterization were validated via Fourier transform infrared (FT-IR) spectroscopy. In the final SB, FT-IR results revealed a vibrational peak at 1614 cm^-1, which was credited to the –C=N part. The absence of a vibration band for –OH vibration on 1613 cm^-1 and the presence of a novel band in the 659 to 586 cm^-1 range were due to the metal-oxygen bond, confirming the synthesis of metal complexes. The Schiff base showed high antibacterial activity against E. coli, Pseudomonas aeruginosa, Salmonella typhi, S.aureus and Bacillus whereas Streptococcus was found resistant. Cu, Fe and Sn coordination improved Schiff base activity while Ni coordination did not affect the activity. Similarly, Fe and Sn complex had no effect on E. coli. In comparison with standard Ciprofloxacin, the activities of respective metal complexes were low.