Synthesis, characterization and antimicrobial activity of new silver complexes with N-heterocyclic carbene ligands

Synthesis, structure, and antimicrobial studies of silver complexes of N-heterocyclic carbene (NHC) are reported. All the silver-NHC complexes (1a-f) were prepared from the benzimidazolium salts by the reactions with Ag2O in dichloromethane as a solvent at room temperature. The new compounds characterized by H-1 NMR, C-13 NMR, IR and elemental analysis techniques which support the proposed structures. Chloro[1-(2,4,6-trimethylbenzyl)-3-(methoxyethyl) benzimidazol-2-ylidene] silver(I) complex was structurally characterized by single-crystal X-ray diffraction. A series of new Ag-NHC complexes were screened for their in vitro antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria as well as for their antifungal activity against a Candida albicans and Candida tropicalis. (c) 2010 Elsevier B. V. All rights reserved.