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

Reaction of the 2-chloro-derivatives of 5-methyl-1,3-thiazole, benzthiazole, and benzoxazole with IrCl(CO)(PMe2Ph)2 affords IrIII 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 PtII, PdII, and NiII. 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.