N-heterocyclic carbene stabilized copper- and silver-phenylchalcogenolate ring complexes.

The ligation of a N-heterocyclic carbene (NHC) to group 11 metal salts (Cu, Ag) was explored as an alternative to PR3 ligands for the formation of copper- and silver-chalcogenolate cluster complexes. AgOAc and CuCl salts ligate with the NHC 1,3-di-isopropylbenzimidazole-2-ylidene (iPr2-bimy) forming [Ag(OAc)(iPr2-bimy)] 1, [Ag(OAc)(iPr2-bimy)2] 2, [CuCl(iPr2-bimy)]23 and [CuCl(iPr2-bimy)2] 4 depending on the ratio of ligand to metal used. These have been characterized via spectroscopic and crystallographic methods. Complexes 1 and 3 were reacted with S(Ph)SiMe3 and Se(Ph)SiMe3 to form the polynuclear metal–chalcogenolates [Ag4(μ-EPh)4(iPr2-bimy)4] (5, E = S; 6, E = Se) and [Cu3(μ-EPh)3(iPr2-bimy)3] (7, E = S; 8, E = Se) in good yields. The structures of 5–8, as determined by single crystal X-ray crystallography, are described.