Synthesis, Characterization, and Biological Screening of Novel Cobalt(II) Complexes Derived from Coumarin Derivatives

International Journal of Chemistry | Vol. 2, No. 4, April 2011 | pp. 52–59

DOI: 10.46882/2011/IJC/000031

Article Type: Original Research Paper

Title: Synthesis, Characterization, and Biological Screening of Novel Cobalt(II) Complexes Derived from Coumarin Derivatives

Names of Authors: A. O. Balogun¹, R. M. Shittu²*

Authors’ Affiliations:
¹Department of Chemistry, University of Ilorin, Ilorin, Nigeria.
²Department of Chemical Sciences, Fountain University, Osogbo, Nigeria.

Abstract: Coumarin derivatives represent an essential class of oxygen heterocycles with broad pharmacological frameworks, whose medicinal efficacy can be amplified via coordination to transition metal centers. This study details the synthesis and molecular characterization of novel cobalt(II) complexes derived from 3-acetylcoumarin Schiff bases. The synthesized coordination compounds were characterized using elemental analysis, molar conductance, magnetic susceptibility, and Fourier-transform infrared (FT-IR) spectroscopy. Analytical data established a 1:2 metal-to-ligand stoichiometry with an empirical formula of [Co(L)₂] where L represents the deprotonated Schiff base ligand. Molar conductivity metrics in dimethylformamide (DMF) indicated a non-electrolytic nature for the complexes. FT-IR spectra established that the ligand behaves in a bidentate manner, coordinating to the Co(II) center through the azomethine nitrogen and the deprotonated lactone carbonyl oxygen. Electronic absorption data and magnetic moment values suggested a stable octahedral geometry around the metal core. In vitro antibacterial and antifungal screenings were executed using the well diffusion technique against Staphylococcus aureus and Aspergillus flavus. The metal complexes demonstrated a two-fold increase in antimicrobial activity compared to the uncoordinated coumarin ligands, which is explained via Tweedy's chelation theory.

Keywords: Coumarin; Cobalt complexes; Coordination chemistry; FT-IR spectroscopy; Antimicrobial efficacy; Chelation theory

Manuscript Timeline: Received: January 10, 2011; Revised: February 18, 2011; Accepted: March 05, 2011; Published: April 02, 2011.

Citation: Balogun, A. O., & Shittu, R. M. (2011). Synthesis, Characterization, and Biological Screening of Novel Cobalt(II) Complexes Derived from Coumarin Derivatives. International Journal of Chemistry, 2(4), 52–59.

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