FORMATION OF IRIDIUM FLUOROACYL COMPLEXES BY REACTION OF IRIDIUM CARBONYLS WITH XEF2 AND REACTIONS OF THESE TO GENERATE UNUSUAL ACYL COMPLEXES

Fluoroacyl complexes of iridium have been prepared by reaction of XeF2 with the iridium carbonyl complexes [lr(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)3(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 F-19, P-31 and C-13 NMR spectroscopy.