Model compounds have been widely utilized in understanding the structure and function of the unusual Cu-4(mu(4)-S) active site (Cu-z) of nitrous oxide reductase (N2OR). However, only a limited number of model compounds that mimic both structural and functional features of Cu-z are available, limiting insights about Cu-z that can be gained from model studies. Our aim has been to construct Cu-4(mu(4)-S) dusters with tailored redox activity and chemical reactivity via modulating the ligand environment. Our synthetic approach uses dicopper(I) precursor complexes (Cu2L2) that assemble into a Cu-4(mu(4)-S)L-4 cluster with the addition of an appropriate sulfur source. Here, we summarize the features of the ligands L that stabilize precursor and Cu-4(mu(4)-S) clusters, along with the alternative products that form with inappropriate ligands. The precursors are more likely to rearrange to Cu-4(mu(4)-S) clusters when the Cu(I) ions are supported by bidentate ligands with 3-atom bridges, but steric and electronic features of the ligand also play crucial roles. Neutral phosphine donors have been found to stabilize Cu-4(mu(4)-S) dusters in the 4Cu(I) oxidation state, while neutral nitrogen donors could not stabilize Cu-4(mu(4)-S) clusters. Anionic formamidinate ligands have been found to stabilize Cu-4(mu(4)-S) dusters in the 2Cu(I):2Cu(II) and 3Cu(I):1Cu(II) states, with both the formation of the dicopper(I) precursors and subsequent assembly of dusters being governed by the steric factor at the ortho positions of the N-aryl substituents. Phosphaamidinates, which combine a neutral phosphine donor and an anionic nitrogen donor in the same ligand, form multinuclear Cu(I) dusters unless the negative charge is valence-trapped on nitrogen, in which case the resulting dicopper precursor is unable to rearrange to a multinuclear duster. Taken together, the results presented in this study provide design criteria for successful assembly of synthetic model dusters for the Cu-z active site of N2OR, which should enable future insights into the chemical behavior of Cu-z.