Synthesis, and study biological activity of CuI complexes involving imidazole-2-selones as ligands

Abstract

A series of imidazole-2-selone (IMSe) ligands were synthesized by reacting of bis-imidazolium salts with selenium in the presence of mild base. These lignads were treated with Cu2Cl2 to form IMSe-CuI complexes. All ligands and their complexes were characterized by FTIR, NMR spectroscopy and mass spectrometry. 1H NMR spectra suggested that the structures of the IMSe-CuI complexes are dinuclear complexes in form [Cu2(diIMSe)2]2+ existed in equilibrium. The complexes had limited stability, with the complexes exhibiting slow decomposition in the solid state and solution. All imidazol-2-selones and their Cu(I) complexes were investigated against E. coli as a Gram-negative bacteria and S. aureus as a Gram-positive bacteria. The ligands and their complexes had promising results against these types of bacterial activity, for example the Cu(I) complexes (C2 and C5) exhibited significantly low MIC values against E. coli (12.5 and 6.25 respectively) as well as S. aureus (6.25 and 3.12 respectively).