Chemistry of bis(cyclo-octa-1,5-diene)platinum: reactions with electrophiles

Abstract

Bis(cyclo-octa-1,5-diene)platinum, [Pt(cod)₂], reacts with the β-diketones acetyl-, hexafluoroacetyl-, and trifluoroacetyl-acetone to give (cyclo-oct-4-en-1-yl)platinum complexes [Pt(1-σ,4–5-η-C₈H₁₃)(L₂)](L₂= acac, hfacac, or tfacac). Protonation [HBF₄ or HPF₆–(CF₃CO)₂O] of [Pt(cod)₂] yields salts [Pt(1-σ,4–5-η-C₈H₁₃)(cod)][X](X = BF₄^– or PF₆^–) : the same cationic species is formed from CF₃CO₂H. The electrophilic reagents [C₇H₆R][BF₄](R = H or Ph) react with [Pt(cod)₂] to give fluxional complexes [Pt(C₇H₆R)(cod)][BF₄]. Treatment of [MCl₂(cod)](M = Pt or Pd) with Ag[BF₄] in the presence of cod yields [Pt(1-σ,4–5-η-C₈H₁₃)(cod)][BF₄] and [Pd(1–3-η-C₈H₁₃)(cod)][BF₄], respectively. The former product reacts with (PhO)₃P to give [PtH{(PhO)₃P}₃][BF₄], and with (MeO)₃P or (EtO)₃P to form [PtH{(RO)₃P}₄][BF₄]. The five-co-ordinate hydridophosphite complexes undergo dynamic behaviour in solution.