Mechanistic Insights in the Exchange of Arylthiolate Groups in Aryl(arylthiolato)palladium Complexes Supported by a Dippe Ligand

Carbon sulfur activation of phenyl p-tolyl sulfide by a mixture of [Pd(dippe)(mu-H)](2) (1a) and dinudear Pd(0), [(mu-dippe)Pd](2) (1b) (dippe = 1,2-bis(diisopropylphosphino)-ethane), to yield four carbon sulfur activation products, (dippe)Pd(p-tolyl)(SPh) (3a), (dippe)Pd(Ph)(S-p-tolyl) (3b), (dippe)Pd(SPh)(Ph)(3c), and (dippe)Pd(p-toly1)(S-p-tolyl) (3d), was investigated. The carbon sulfur complexes 3a-3d were completely characterized by H-1, P-31, and C-13 NMR spectroscopy, elemental analysis, and X-ray diffraction. Exchange interactions between arylthiolate groups in (dippe)Pd(Ar)-(SAr') (3a-3d) were investigated, leading to understanding the mechanism of interconversions among the complexes.