Cationic palladium and platinum complexes with diolefin ligands

Abstract

Chlorine-bridged complexes [M₂(diolefin)₂Cl₂][BF₄]₂ have been prepared from [M(diolefin) Cl₂][M = Pd or Pt; diolefin = cyclo-octa-1,5-diene (cod) or norborna-2,5-diene (nbd)] and [Et₃O][BF₄]. The complex [Pd(cod)₂Cl₂][BF₄]₂ rapidly forms 5,6-η-cyclo-oct-5-enyl complexes [Pd₂(2-Rcot)₂Cl₂](R = MeO, MeCO₂, or HO) with MeOH, MeCO₂H, or H₂O; PPh₃ displaces the cod to form [Pd₂Cl₂(PPh₃)₄][BF₄]₂, but the plantinum analogue forms [Pt(cod)Cl(PPh₃)][BF₄]. Complexes [M(diolefin)Cl(PR₃)]X (X = SFO₃, BF₄, or ClO₄) have been obtained from sym,trans-[M₂Cl₄(PR₃)₂] and the diolefin with SFO₂(OMe)–C₆H₆, [Et₃O][BF₄]–CH₂Cl₂, or Na[ClO₄]–Me₂CO.