Structural Diversity in Copper−Sulfur Chemistry: Synthesis of Novel Cu/S Clusters through Metathesis Reactions

With the ultimate goal of understanding the Cu4S cluster in nitrous oxide reductase, studies of the fundamental chemistry of nitrogen-donor ligand-supported copper−sulfur species have been pursued. Reactions of CuIIX2 (X = Cl- or CF3SO3-), N,N,N‘,N‘-tetramethyl-trans-(1R,2R)-diaminocyclohexane, and Li2S or Na2S2 yielded clusters that contain [Cu2(μ-S2)2]2+, [Cu3(μ-S)2]3+, [Cu4(μ-S2)2]4+, and/or [Cu6(μ-S2)4]4+ cores, depending on the specific reaction conditions, notably the nature of X and the sulfur source used. Copper(II) and/or Copper(III) and variable sulfur oxidation levels, including S2-, S22-, and S2-•, were identified by X-ray crystallography and spectroscopy.