Palladium(II) phosphine thiocarboxylates. Structures of cis-Pd(κS-SOCMe)2(dppf) [dppf=1,1′-bis(diphenylphosphino)ferrocene] and trans-Pd(κS-SOCMe)2(PPh3)2

Abstract

Although palladium phosphine acetates are generally unstable and served as catalytic precursors, their monothioacetate analogues can be isolated and structurally characterized. Spectroscopic and X-ray single-crystal crystallographic analyses suggested that Pd(κS-S{O}CMe)2(P2) [P2=dppf, I; P=PPh3, II] are mononuclear with thioacetate coordinates in a unidentate manner through sulfur. Dppf imposes a cis configuration on I whereas PPh3 promotes a trans-structure for II. The compounds are obtained in isomerically pure form - there is no evidence for chelating or bridging thioacetate or bridging diphosphine. The Me group of thioacetate is significantly more shielded in II than I by the Ph rings of the neighboring phosphine. © 2001 Elsevier Science B.V.