Synthesis, characterization and X-ray crystal structure of copper(I) complexes of the 2-(2-quinolyl)benzothiazole ligand. Electrochemical and antibacterial studies

Two new copper(I) complexes of the general formula [Cu(qbtz)(PPh3)(X)] {qbtz = 2-(2-quinolyl)benzothiazole and X = Br (1), I (2)} have been synthesized and characterized by elemental analyses, IR, UV–Vis and 1H NMR spectroscopy. The crystal and molecular structures of these complexes have been determined by single-crystal X-ray diffraction. The coordination geometry around the central metal ion is a distorted tetrahedron. The electrochemical behavior of the ligand and its copper(I) complexes has been investigated by cyclic voltammetry in DMF solution. The redox potential of the copper center is influenced by the nature (the σ-donor ability) of the coordinated halide X−, and it shifts to more anodic potentials for complex 2 as compared to that of 1. The in vitro antibacterial activities of the ligand and its copper complexes were tested against Staphylococcus aureus, Bacillus cereus and Salmonella typhi.

Graphical abstractTwo new copper(I) complexes, [Cu(qbtz)(PPh3)(X)] {qbtz = 2-(quinolinyl)benzothiazole and X = Br, I}, have been synthesized and fully characterized. The X-ray crystal structures of these complexes have been determined. Cyclic voltammetric behavior and preliminary antibacterial activity of the ligand and both complexes against Gram-positive and Gram-negative bacteria are reported.Figure optionsDownload full-size imageDownload as PowerPoint slide