Synthesis, characterization, crystal structure, and antimicrobial studies of 2-morpholinoethyl-substituted benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes

Abstract

This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and their Ag(I) N-heterocyclic carbene (NHC) complexes (3a–c). All compounds were characterized by 1H and 13C Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), and elemental analysis, and their antimicrobial effects examined. The molecular structure of the NHC precursor 2a 1 was established by single-crystal X-ray diffraction analysis. Minimum Inhibition Concentration (MIC) values were determined to evaluate their antimicrobial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacterial strains and Candida albicans fungal species. All tested samples were compared with silver nitrate. All the compounds exhibited strong antimicrobial activity.