Synthesis, structural characterization, and antibacterial activity of mononuclear cobalt(III) azido complexes of two pentadentate Schiff bases derived from 2-hydroxynaphthaldehyde

Abstract

The structural, spectroscopic, and electrochemical properties of [Co{(naph)₂dien}(N₃)] and [Co{(naph)₂dpt}(N₃)], where (naph)₂dien = bis-(2-hydroxy-1-naphthaldimine)-N-diethylenetriaminedianion and (naph)₂dpt = bis-(2-hydroxy-1-naphthaldimine)-N-dipropylenetriaminedianion have been investigated. These complexes are characterized by elemental analyses, IR, and UV–Vis spectroscopy. The crystal structures of these complexes have been determined by X-ray diffraction. The geometry around cobalt is distorted octahedral. The electrochemical behavior of these complexes in acetonitrile solution was also investigated. Both complexes show an irreversible Co^III–Co^II reduction at ca. −0.8 V, accompanied by dissociation of the axial Co^II–N₃ bond. The in vitro antibacterial activities of these complexes were tested against Staphylococcus aureus and Bacillus licheniformis.

Keywords:

• Cobalt(III) azido complexes
• Pentadentate Schiff base ligand
• Electrochemistry
• Crystal structure
• Antibacterial activity

Acknowledgement

Partial support of this work by the Isfahan University of Technology Research Council is gratefully acknowledged.