Synthesis, characterization, antibacterial, and thermal studies of unsymmetrical Schiff-base complexes of cobalt(II)
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Date
2010-09-23
Authors
Nejo, A.A.
Nejo, A.O.
Kolawole, G.A.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Coordination Chemistry
Abstract
Cobalt(II) complexes of a new series of unsymmetrical Schiff bases have been synthesized and
characterized by their elemental analyses, melting points, magnetic susceptibility, thermogravimetric
analysis, differential scanning calorimetry, infrared (IR), and electronic spectral
measurements. The purity of the ligands and the metal complexes are confirmed by
microanalysis, while the unsymmetrical nature of the ligands was further corroborated by
1H-NMR. Comparison of the IR spectra of the Schiff bases and their metal complexes confirm
that the Schiff bases are tetradentate and coordinated via N2O2 chromophore. The magnetic
moments and electronic spectral data support square-planar geometry for the cobalt(II)
complexes. The complexes were thermally stable to 372.3 C and their thermal decomposition
was generally via the partial loss of the organic moiety. The Schiff bases and their complexes
were screened for in vitro antibacterial activities against 10 human pathogenic bacteria and their
minimum inhibitory concentrations were determined. Both the free ligands and cobalt(II)
complexes exhibit antibacterial activities against some strains of the microorganisms, which in
a number of cases were comparable with, or higher than, that of chloramphenicol.
Description
Keywords
Cobalt(II), Unsymmetrical Schiff base, Antibacterial activities, MIC
Citation
Adeola A. Nejo , Gabriel A. Kolawole & Ayorinde O. Nejo (2010) Synthesis, characterization, antibacterial, and thermal studies of unsymmetrical Schiffbase complexes of cobalt(II), Journal of Coordination Chemistry, 63:24, 4398-4410