Synthesis, Structures, and Antimicrobial Activity of Schiff Base Cobalt Complexes [Co(HL¹)₂(N₃)₂]·H₂O and [CoL²₂]·ClO₄

Abstract

The new Schiff bases 4-bromo-2-[(3-diethylaminopropylimino) methyl]phenol (HL¹) and 2-methoxy-6-[(2-phenylaminoethy limino) methyl]phenol (HL²) derived from 5-bromosalicylaldehyde with N,N- diethylpropane -1,3- diamine and 3- methoxysalicylaldehyde with N-phenylethane-1,2-diamine, respectively, and their cobalt complexes, [Co(HL¹)₂(N₃)₂]·H₂O and [CoL² ₂]·ClO₄, have been prepared and characterized by elemental analyses, infrared, and single crystal X-ray crystallographic determination. The HL¹ coordinates to the Co atom through the phenolic O and imino N atoms with a zwitterionic form, while the HL² coordinates to the Co atom through the phenolic O, imino N, and amino N atoms with a deprotonated form. Each Co atom in the complexes adopts an octahedral coordination. The effect of the Schiff bases and the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans were studied.

Keywords:

• antimicrobial
• cobalt complex
• crystal structure
• Schiff base
• synthesis

Acknowledgments

This research was supported by the National Sciences Foundation of China (No. 20676057 and 20877036) and Top-class foundation of Pingdingshan University (No. 2008010).