Metal complexes of sulphur ligands. Part 11. Reactions of platinum(II) and palladium(II) dithiocarbonates with dithiocarbonate ions

Abstract

Reaction of the complexes [Pt(S₂COR)₂] with K[S₂COR](R = Et or Prⁱ) followed by addition of [AsPh₄]Cl generates [AsPh₄][Pt(S₂COR)₃]. Variable-temperature ¹H n.m.r. studies indicate rapid unidentate–bidentate exchange at ambient temperature. Attempted recrystallisation from CH₂Cl₂ or CDCl₃, results in an intramolecular rearrangement to give [AsPh₄][Pt(S₂CO)(S₂COR)]. Reaction of [Pd(S₂COEt)₂] with K[S₂COEt] and [AsPh₄]Cl gives [AsPh₄4][Pd(S₂CO)(S₂COEt)] as the main product. Reaction of [Pt(S₂COR)₂] with K[S₂COR](R = Me, or CH₂Ph) and [AsPh₄]Cl generates [AsPh₄][Pt(S₂CO)(S₂COMe)] or [AsPh₄]₂[Pt(S₂CO)₂], both of which give [PtL₂(S₂CO)] on addition of various Lewis bases L (L = PPh₃, PMe₂Ph, or ½Ph₂PC₂H₄PPh₂). The salt [AsPh₄]-[Pt(S₂COEt)₃] is shown by X-ray diffraction analysis to have square-planar stereochemistry with one bi- and two uni-dentate [S₂COEt]^– groups. The crystals are monoclinic, space group P2₁/c with a= 9.95, b= 14.26, _c= 25.82 Å, β= 99.3°.