Cationic Iridium( III ) Carbonyl Complexes: [Ir(CO) 6 ] 3+ and [Ir(CO) 5 Cl] 2+

The first homoleptic carbonyl cation of a tripositive metal, [Ir(CO) 6 ] 3+ ( 1 ), has been obtained as a thermally stable [Sb 2 F 11 ] − salt. The existence of 1 permits a comparison of the spectroscopic properties in the 5d series of isoelectronic hexacarbonyl species ranging from [Hf(CO) 6 ] 2− to [Ir(CO) 6 ] 3+ . In addition the molecular structure of the related cation [Ir(CO) 5 Cl] 2+ ( 2 ) is reported.