Abstract
A series of aliphatic nitrile functionalized benzimidazolium salts and their respective mononuclear
N
-heterocyclic carbene Ag(I)-NHC complexes are reported. The benzimidazolium salts were synthesized by
N
-alkylation of 1
H
-benzimidazole with an appropriate alkyl bromide, followed by reaction with either 5-bromovaleronitrile or 6-bromohexanenitrile. The respective mononuclear Ag(I)-NHC complexes were prepared by the reaction of the benzimidazolium salts with Ag
2
O. All the synthesized compounds were characterized by physico-chemical and spectroscopic techniques. The molecular structures of the two complexes were elucidated through single-crystal X-ray diffraction analyses. Density functional theory was used to model the structures of the other complexes. The benzimidazolium salts and their complexes were screened for cytotoxicity against a breast cancer cell line (MCF-7), using the MTT assay. All the Ag(I)-NHC complexes gave IC
50
values ranging from 7.0 ± 1.06 to 12.9 ± 1.55 µM which are comparable to the standard drug, tamoxifen (IC
50
= 11.2 ± 1.84 µM), while all of the benzimidazolium salts proved to be inactive.