A simple competition assay to probe pentacopper(I)-thiolato cluster ligand exchange

Two pentanuclear copper(I) thiolato clusters of the formula [Cu5(L)3]− (L = pyridine-2,6-dimethanethiolate (L1), (1); 4-methylpyridine-2,6-dimethanethiolate (L2), (2)) were synthesized utilizing a single-step procedure, and their structures were characterized by X-ray crystallography. The aforementioned pentanuclear complexes possess an interesting propeller-like Cu5S6 core where all Cu centers are three-coordinate. Electrospray ionization mass spectrometry (ESI-MS) investigation of the pentanuclear copper(I) thiolato clusters with added hetero-ligands demonstrated interesting ligand exchange behavior. The product distribution resulting from ligand exchange not only depended on the quantity of added ligand, but also was sensitive to the coordination ability of the ligand. The ESI-MS method used in this study can serve as a useful tool for probing exchange behavior in coordination metal complexes that cannot otherwise be determined by NMR.

ESI-MS assay of the dithiolato ligand exchange on the pentacopper(I)-thiolato clusters may provide some insight to the copper trafficking mechanisms in biological systems.Figure optionsDownload as PowerPoint slideHighlights
► Insight to the copper trafficking mechanisms in biological systems.
► Single-step synthesis of pentanuclear copper(I)-thiolato clusters
► ESI-MS assay of the dithiolato ligand exchange on the pentanuclear copper(I)-thiolato clusters
► The dithiolato ligand will influence the product distributions in ligand exchange assay.