Cationic cyclic carbene complexes of iridium(III), nickel(II), palladium(II), and platinum(II)

Abstract

Reaction of the 2-chloro-derivatives of 5-methyl-1,3-thiazole, benzthiazole, and benzoxazole with IrCl(CO)(PMe₂Ph)₂ affords Ir^III complexes which on protonation yield cationic carbene complexes [IrCl₂(CO)(PMe₂Ph)₂(L)]⁺(L = [graphic omitted], [graphic omitted], [graphic omitted]). Treatment of IrCl(CO)(PMe₂Ph)₂ with the N-methyl salt of 2-chloro-5-methyl-1,3-thiazole, [Cl[graphic omitted]][BF₄], affords the carbene complex [IrCl₂(CO)(PMe₂Ph)₂{[graphic omitted]}][BF₄]. Similar oxidative-addition of [Cl[graphic omitted]][BF₄] to Pt(PEt₃)₂(stilbene), Pt(PMePh₂)₄, PdL₄(L = PPh₃, PMePh₂) or Ni(PPh₃)₄ gives cationic carbene complexes of Pt^II, Pd^II, and Ni^II. The complex [PtCl{[graphic omitted]}(PEt₃)₂][BF₄] was obtained by treating PtCl([graphic omitted])(PEt₃)₂ with fluoroboric acid. Some chemical and spectroscopic properties of the new complexes are discussed.