Synthesis and antimicrobial activity of novel gold(I) N-heterocyclic carbene complexes

Benzimidazolium salts and six anionic gold-NHC complexes (NHC = N,N'-dialkylbenzimidazol-2-ylidene) were prepared and characterized. Novel [Au(NHC)(2)]AuCl2-type complexes were prepared in good yields from silver-NHC complexes by treatment with [AuCl(PPh3)], following the commonly used silver carbene transfer route. All compounds were characterized using H-1 and C-13 NMR spectroscopy, elemental analysis, and IR. The gold complexes showed antimicrobial activity against Gram-positive/negative and fungal strains.