Benzimidazole Metal Complexes (Zn/Cu/Co): Ligand Protonation, Stability Constants, and Antimicrobial Performance
DOI:
https://doi.org/10.64354/6fsxr420Keywords:
Benzimidazole, Metal complexes, Stability constants, Protonation, Antimicrobial activity , Coordination chemistryAbstract
Coordination chemistry has concentrated on benzimidazole derivatives due to their various binding and biological characteristics. Benzimidazole-based ligands are coordinated with zinc(II), copper(II), and cobalt(II) metal ions in this work. We study thermodynamic stability constants, ligand protonation equilibria, and antibacterial activity. The imidazole ring's nitrogen atoms are donor sites, allowing stable metal complexes to form in many coordination geometries. Protonation experiments have indicated that substituent effects and the electronic nature of attached functional groups affect the basicity of benzimidazole nitrogen atoms. According to the Irving-Williams series, copper(II) complexes are the most stable, followed by zinc(II) and cobalt(II) derivatives. Potentiometric titration methods were used to estimate stability constants. The antibacterial properties of these metal complexes have been extensively tested against Gram-positive and Gram-negative bacteria and numerous fungus species. It appears that metal coordination improves the biological activity of benzimidazole ligands, with copper(II) complexes generally outperforming others. This review synthesises the results of many studies from the last decade to help researchers comprehend the structure-activity correlations in this important class of bioactive metal complexes.
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