Synthesis and Characterization of Ag(I) Complexes Derived from New N-Heterocyclic Carbenes

Abstract

Two new unsymmetrical imidazolium salts viz., [1-(4-ethylphenyl)-3-propyl-1H-imidazole-3-ium bromide] (3) and [1-(2,6-dimethylphenyl)-3-propyl-1H-imidazole-3-ium bromide] (4) have been synthesized via the reaction of propyl bromide with imidazole derivatives, [1-(4-ethylphenyl)-1Himidazole] (1) and [1-(2,6-dimethylphenyl)-1H-imidazole] (2) in absence of solvent. Then two new N-heterocyclic carbene silver complexes (5 and 6) were prepared through the reaction of imidazoluim salts (3 and 4) as a source of N-heterocyclic carbene with Ag2O by in situ method. These complexes can be used in the future as a transfer agent for preparing other transitional metal carbine complexes (NHCs) via transmetallation method. The formation of these compounds was confirmed by spectral analysis.