Synthesis of 1-oxidopyridinium-2-thiolato- and pyridine-2-thiolato-complexes of nickel, palladium, and platinum
Abstract
Quinoline N-oxide reacts with K[PtCl3(CH2CH2)] to give [PtCl2(C2H4)(ONC9H7)] whereas 1-oxidopyridinium-2-thiol (1a) gives [Pt(SONC5H4)2](3a) and an insoluble oligomeric material containing at least four Pt atoms; complex (3a) and the oligomer can also be synthesised from K2[PtCl4]. The oligomeric material can be cleaved by PPh3 and PMe2Ph to give [PtCl(SONC5H4)(PPh3)](5) and [PtCl(SONC5H4)(PMe2Ph)2](6) respectively, and compound (3a) is converted by PPh3into the monophosphine complex [Pt(SONC5H4)2(PPh3)](7a). The complex (7a) and an analogue [Pd(SONC5H4)2(PPh3)](7b) have been prepared from [MCl2(PPh3)2] and the thallium salt of (1a), and related complexes [M(SC5H4N)2(PPh3)2][M = Pt (8a) or Pd (8b)] have been similarly synthesised from the thallium salt of 2-mercaptopyridine. Evidence for intramolecular scrambling in (7) and (8) has been adduced from variable temperature 1H n.m.r. spectra.