Reactivity of co-ordinated ligands. Part VII. Some cationic cycloocta-1,5-diene complexes of rhodium(I) and pentane-2,4-dionato-complexes of palladium(II)

Abstract

Treatment of (C₈H₁₂)Rh(C₅H₇O₂) with triphenylmethyl tetrafluoroborate in methylene chloride followed by the addition of ligand (L) gives the cationic olefin complexes [C₈H₁₂RhL₂]BF₄(L = Ph₃P, Ph₂EtP, PhEt₂P, or Ph₃As). Other salts [(C₅H₇O₂)PdL₂]BF₄ have been prepared from (C₅H₇O₂)₂Pd by the same general reaction [L = Ph₃P, Ph₂EtP, PhEt₂P, (p-MeC₆H₄)₃P, or Ph₃As]. In contrast, the neutral complexes Pd(Ph₃Sb)_n, Pd(Ph₃P)_n, and Pd(Ph₃As)_n(n= 2–3) are the products from the reaction of (C₅H₇O₂)₂Pd with fluoroboric acid followed by the addition of the appropriate ligand. The ¹H n.m.r. spectra of the rhodium(I) and palladium(II) salts are discussed. Treatment of the platinum(II) salt [C₈H₁₂Pt(C₅H₇O₂)]BF₄ with 2,2′-bipyridyl(bipy) leads to the σ–π complex [(C₈H₁₂·C₅H₇O₂)Pt(bipy)]BF₄.