EDT as a Metal-Chelating Ligand

EDT chelates a single metal centre through both sulfur atoms, forming a five-membered ring that confers a pronounced thermodynamic stability relative to monodentate thiols. The soft donor character of sulfur favours late transition metals in low oxidation states (Housecroft & Sharpe, 2018).

Nickel, palladium and platinum form square-planar complexes in which the dithiolate occupies two adjacent coordination sites. The ligand field exerted by the two sulfur donors strongly influences the electronic structure of these complexes, and the resulting compounds serve as models for the active sites of hydrogenase enzymes (Housecroft & Sharpe, 2018).

Dithiols react with α-keto aldehydes to form cyclic adducts, effectively reversing their inhibitory action on enzymes that depend on accessible thiol or amine residues. This scavenging behaviour is used analytically and in the study of metabolic pathways where reactive carbonyl species interfere with assay results.

Metal–EDT complexes have been examined as catalysts and catalyst precursors for hydrodesulfurisation models, cross-coupling and oxidation reactions. The robust metal–sulfur framework stabilises the active centre while leaving coordination sites available for substrate binding (Housecroft & Sharpe, 2018).