Cleavage of Bis(thiophosphinyl)disulfanes, R2P(S)SSP(S)R2 (R = Et, Ph),by a Low-Valent Palladium Dimer

Article abstract of DOI:10.1021/ic00128a027

The reaction of Pd2(μ-dcpe)2 (dcpe = 1,2-bis(dicyclohexylphosphino)ethane) with the bis(thiophosphinyl)disulfanes, R2P(S)SSP(S)PR2 (R = Et, Ph), give the ionic complexes [(dcpe)Pd(SPR2S)](1+)[SPR2S](1-) in 60% (1; R = Et) and 72% (2: R = Ph) yields. An unusual dimer, {(Et2PS2)Pd}2(μ-Et2PS2)2, is also isolated in low yield for R = Et. The X-ray structure of a benzene solvate of 1 (C50H68P4S4Pd.1.5C6H6; monoclinic, a = 14.628(1) ?, b = 16.662(3) ?, c = 21.612(4) ?, β = 107.66(1), P21/n, Z = 4, R = 0.047(Fo), Rw = 0.056(Fo)) shows a nearly planar spirocyclic palladium atom in the cation and a free SPR2S(1-) anion. Variable-temperature (31)P NMR spectra of 1 indicate rapid interchange of thecoordinated and free SPR2S(1-) counterion in solution at room temperature.