Acetylene Dithiolate Linking up the [Tp′W(CO)(CN)] Moiety with RuII or PdII

A series of heterodinuclear complexes with acetylene dithiolate (acdt^2?) as the bridging moiety were synthesised by a facile one‐pot procedure that avoided use of the highly elusive acetylene dithiol. Generation of the W–Ru complex Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] (Tp’=hydrotris(3,5‐dimethylpyrazolyl)borate) and the W–Pd complexes Tp′W(CN)(CO)(C₂S₂)Pd(dppe)] and Tp′W(CO)₂(C₂S₂)Pd(dppe)]PF₆] (dppe=1,2‐bis(diphenylphoshino)ethane), which exhibit a W(η²‐κ²‐C₂S₂)M] core (M=Ru, Pd), was accomplished by using a transition‐metal‐assisted solvolytical removal of the Me₃Si‐ethyl thiol protecting groups. All intermediate species of the reaction have been fully characterised. The highly coloured W–Ru complex Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] shows reversible redox chemistry, as does the prototype complex Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)]PF₆]. Single crystal X‐ray diffraction and IR, EPR and UV/Vis spectroscopic studies in conjunction with DFT calculations prove the high electronic delocalisation of states over the acdt^2? linker. Comparative studies revealed a higher donor strength and more pronounced dithiolate character of acdt^2? in Tp′W(CN)(CO)(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)] relative to Tp′W(CO)₂(C₂S₂)Ru(η⁵‐C₅H₅)(PPh₃)]⁺. In addition, the influence of the overall complex charge on the metric parameters was investigated by single‐crystal X‐ray diffraction studies with the W–Pd complexes Tp′WL₂(C₂S₂)Pd(dppe)] (L=(CN^?)(CO) or (CO)₂). The central W(C₂S₂)Pd] units exhibit high structural similarity, which indicates the extensive delocalisation of charge over both metals.