Phosphine Control of the Oxidative Addition Chemistry of Tetrathiocins to Palladium(0): Characterization of Mono‑, Di‑, and Hexanuclear Palladium(II) Dithiolate Complexes

The outcome of the oxidative addition reactions of bis­(4′,5′-dimethoxybenzo)-1,2,5,6-tetrathiocin to Pd2dba3 under microwave conditions is sensitive to the nature of the phosphine coreagent; the bidentate phosphines dppm, dppe, and dppf afford the mononuclear dithiolates (dmobdt)­Pd­(dppm) (4), (dmobdt)­Pd­(dppe) (2), and (dmobdt)­Pd­(dppf) (5), whereas more labile monodentate phosphines lead to aggregation; Ph3P afforded the dinuclear dithiolate (dmobdt)2Pd2(PPh3)2 (6), whereas tBu3P generated the phosphine-free hexanuclear edge-capped octahedral complex Pd6(dmobdt)6 (7) [dmobdt = 4,5-dimethoxybenzenedithiolate, (MeO)2C6H2S22–].