Straightforward synthesis of [Cu(NHC)(alkynyl)] and [Cu(NHC)(thiolato)] complexes (NHC = N-Heterocyclic Carbene)

The synthetic access to monomeric copper-alkynyl and copper-thiolato complexes of the type [(NHC)Cu(R)] (R = alkynyl or thiolato) using a weak base approach is reported. All reported reactions proceed under mild conditions in air and in environmentally acceptable solvents. The novel complexes are fully characterized and single crystal X-ray analyses unambiguously establish the atom connectivity in these mononuclear complexes. The importance of the supporting NHC ligand steric properties in stabilizing mononuclear complexes is discussed.