Conception, caractérisation et application des complexes à base de ligands hétérocycliques

Abstract

This work has been devoted to the design and characterization of some new heterocyclic nitrogen and sulfur donor ligands derived from quinoline, benz-imidazole and benzothiazole, as well as their coordination complexes. The evaluation of their antibacterial and antioxidant activity was also discussed. The 2-(1H-benzo[d]imidazol-2-yl) quinoline (BQ), 2-(((1-methyl-1H-imidazol-2- ylmethyl)sulfanyl)methyl)-1H-benzo[d]ligands imidazole (MIMTMB), 2-(((1-methyl-1Himidazol- 2-yl)methyl)sulfanyl)benzo[d]thiazole (MIMTBT), as well as two other ligands previously prepared in the laboratory: The bis((1H-benzo[d]imidazol-2-yl)methyl) sulfane (BBMS) and 2-((1H-benzo[d]imidazol-2-yl)methylthio)-1H-benzo[d]imidazole (BTMB) react with the chlorides of cobalt (II), zinc (II), manganese (II), mercury (II), lead (II), copper (II), and cadmium (II) to lead to coordination complexes. The structures of the ligands and their complexes have been elucidated by IR spectroscopy, 1H NMR, 13C NMR, UV-visible, elemental analysis and single-crystal X-ray diffraction. The structural characterization by RX revealed the complex environment and the stability of the crystal structure by hydrogen bonds and π-π interactions. Theoretical calculations for some complexes were made to understand the geometry and the electronic structure of some compounds. As well as thermogravimetric analyzes that have been performed on some compounds to better understand their behavior and thermal stability. The antibacterial activity of certain ligands and complexes was evaluated against three strains: Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. As well as an evaluation of their antioxidant activity (DPPH test).