Unique Trinuclear Ag(I)-N-Heterocyclic Carbene (NHC) Complex having Three Silver Centers: Synthesis and characterization

The employment of carbene salts to facilitate metal-metal interactions is becoming a more pronounced zone of interest due to their efficient sigma electron donor features, facile synthesis protocols and their ability to develop strong ligand-metal interactions which may further be attributed to their flat steric factors. The research work discussed in this article was conducted to achieve this goal. Herein we report the synthesis of a novel trinuclear silver complex by a new approach. An imidazolium salt 2 was synthesized by in situ deprotonation and its trinuclear silver(I) complex 3 was synthesized by using initially controlled excess of precursor in order to understand the effect of excess of the selected reactant on complex formation. Both the ligand and complex were characterized by physico-chemical techniques. The results revealed the final product obtained was a trinuclear complex 3 having a core of three silver centres in a row, with the two distal silver ions bound to two carbene ligands and central one was bound by nitrogen of N-methyl imidazole. ESI-MS spectrum of compound 3 indicated that the complex chooses trinuclear structure in a solid and liquid state while in gas phase it appears as a mononuclear unit.