Formation of iridium fluoroacyl complexes by reaction of iridium carbonyls with XeF2 and reactions of these to generate unusual acyl complexes

Abstract

Fluoroacyl complexes of iridium have been prepared by reaction of XeF₂ with iridium carbonyl complexes [Ir(CO)₃L₂]⁺(L = PMe₃, PMe₂Ph, PEt₂Ph or PEtPh₂), [Ir(CO)₂Cl(PMe₃)₂] and [Ir(CO)-(PMe₃)₄]⁺. The reaction can be viewed as an unusual type of oxidative addition and this is supported by the need for strongly electron-donating phosphines for reaction to occur. The complex [Ir(CO)₂F(COF)-(PEt₃)₂]⁺ reacts with SiH₃X (X = CN, NCS or NCO) to give acyl complexes [Ir(CO)₂F(COX)(PEt₃)₂]⁺ and with BF₃ to give [Ir(CO)₃F(PEt₃)₂]²⁺. This dication reacts further with PMe₃ to give an acyl product with PMe₃ bound to a carbonyl ligand. The complex [Ir(CO)₃(PPh₃)₂]⁺ reacts with XeF₂+ BF₃ to give [Ir(CO)₃F(PPh₃)₂]²⁺. Products were characterised using ¹⁹F, ³¹P and ¹³C NMR spectroscopy.