Reactions of Palladium Germylene Complexes: Formation of Sulfide Bridges

Reactivity of three novel Pd germylene species is presented. (Et3P)2PdGe[N(SiMe3)2]2 (1) and (dppe)PdGe[N(SiMe3)2]2 (6) react with COS to give the sulfide bridged species (Et3P)2Pd((mu)S)Ge[N(SiMe3)2]2 (2) and (dppe)Pd((mu)S)Ge[N(SiMe3)2]2 (7) (dppe = (diphenylphosphino)ethane). (Ph3P)2PdGe[N(SiMe3)2]2 (4) reacts with COS to give the disulfide bridged complex (Ph3P)2Pd( S)2Ge[N (SiMe3)2]2 (5) resulting in Pd-Ge bond cleavage. This phosphine dependent reactivity is explored. Crystal structures of 2, 5, 7, and the dimeric form of complex 2, {(Et3P)Pd((mu)S)Ge[N(SiMe3)2]2}2 (8), are reported. In the presence of excess germylene, complexes 2 and 5 are shown to partially regenerate their parent palladium germylene complexes, 1 and 4, respectively, via photolysis or heating.