Silver and ruthenium complexes with anthracene functionalized N-heterocyclic carbene ligands: catalytic and cytotoxicity properties

Abstract

In this study, we have synthesized two Ag (2a and 2b) and two Ru (3a and 3b) complexes with anthracene substituted N-heterocyclic carbene (NHC) ligands. Ag‒NHC complexes have been synthesized by the interaction of corresponding benzimidazolium chloride and Ag₂O. Ru‒NHC complexes have been synthesized by the transmetalation reaction between corresponding Ag‒NHC and [RuCl₂(p-cymene)]₂ dimer. The synthesized complexes have been characterized by elemental analysis, NMR (¹H and ¹³C NMR), and mass (high resolution mass spectroscopy, HRMS) spectroscopic techniques. In order to assess the catalytic potential of the Ru‒NHC complexes, we have conducted experiments involving the hydrosilylation of terminal alkynes. Both complexes have exhibited a moderate level of catalytic activity, achieving conversions ranging from 70 to 90%, along with a substantial β-(Z) selectivity within the range of 80–90%. Furthermore, we have also subjected the benzimidazolium chlorides (1a and 1b), Ag‒NHCs and Ru‒NHCs to cytotoxicity testing using human breast cancer cells (MCF-7) and human colorectal cancer cells (Caco-2). The results of these assays have demonstrated that all compounds strongly inhibit the proliferation of both cell lines.