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

The structural, spectroscopic, and electrochemical properties of [Co{(naph)(2)dien}(N-3)] and [Co{(naph)(2)dpt}(N-3)], where (naph)(2)dien=bis-(2-hydroxy-1-naphthaldimine)-N-diethylenetriaminedianion and (naph)(2)dpt=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. -0.8V, accompanied by dissociation of the axial Co-II-N-3 bond. The in vitro antibacterial activities of these complexes were tested against Staphylococcus aureus and Bacillus licheniformis.