Copper–sulfur complexes supported by N-donor ligands: Towards models of the CuZ site in nitrous oxide reductase

The distinctive structure of the [(his)7Cu4(μ-S)]n+ cluster in the “CuZ” active site of nitrous oxide reductase and the intriguing mechanistic hypotheses for its catalytic reactivity provide inspiration for synthetic model studies aimed at characterizing relevant copper–sulfur compounds and obtaining fundamental insights into structure and bonding. In this brief review, we summarize such studies that have focused on the synthesis and characterization of a range of copper–sulfur complexes supported by N-donor ligands. Compounds with variable nuclearities and sulfur redox levels have been isolated, with the nature of the species obtained being dependent on the supporting ligand, sulfur source, and the reaction conditions. Spectroscopic data and theoretical calculations, often performed with a view toward drawing comparisons to oxygen analogs, have provided insight into the nature of the copper–sulfur bonding interactions in the complexes.

Graphical abstractThe unusual structure of the [(his)7Cu4(μ-S)]n+ cluster in the “CuZ” active site of nitrous oxide reductase and the intriguing mechanistic hypotheses for its catalytic reactivity provide motivation for synthetic model studies aimed at characterizing relevant copper–sulfur compounds and obtaining fundamental insights into structure and bonding. In this brief review, recent work aimed at synthesizing and characterizing copper–sulfur complexes relevant to the CuZ site is described. A wide range of compounds with variable copper nuclearities and sulfur oxidation states have been prepared, opening new vistas into the inorganic chemistry of copper and sulfur.Figure optionsDownload full-size imageDownload as PowerPoint slide