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The reaction of Ir4(CO)12 with potassium hydroxide in methanol and/or with sodium in tetrahydrofuran leads to the carbonyliridate anions [HIr4(CO)11]−, [Ir6(CO)22]2−, [Ir8(CO)20]2−, [Ir6(CO)15]2− and [Ir(CO)4]− obtained as salts with bulky cations. From these, the tetranuclear carbonyl hydride H2Ir4(CO)11 and the hexanuclear carbonyl compound Ir6(CO)16 are also obtained.

The reaction of [Ir(CO) 2 (PPh 3 )μ(SO 2 )] 2 with p -substituted aryldiazonium salts gave the compounds {[Ir(CO) 2 (PPh 3 )] 2 μ(N 2 C 6 H 4 R)μ(SO 2 )} + BF4 - , in which a molecule of sulphur dioxide has been replaced by a molecule of aryldiazenate. Treatment of these products with HBF 4 gave the protonated derivatives {[Ir(CO) 2 (PPh 3 )] 2 μ(NNHC 6 H 4 R)μ(SO 2 )} 2+ 2 BF 4 - , while alkali halides gave the non electrolytes [Ir(CO)(PPh3)] 2 μ(X)μ(N 2 C 6 H 4 R)μ(SO 2 ), which have halogen bridging two iridium atoms.

The reaction of IrH3(PPh3)3 with p-anisyldiazonium tetrafluoroborate gives an insertion product which very easily undergoes orthometalation, yielding [IrH(PPh3)3NHNC6H3OMe]+BF4− (V), the structure of which is tentatively assigned. By reaction with halides X−, the metalated fluoborate gives the neutral IrHX(PPh3)2NHNC6H3OMe, which with halogens X2 affords IrX2(PPh3)2NHNC6H3OMe, the structure of which has previously been determined.

The preparation of Ir2(CO)6(PPh3)2 by a new route is described, as are the reaction of this compound with hydrogen, mercury, tin(II) chloride, hydrogen halides and halogens, leading to new monophosphine carbonyl iridium compounds. The [Ir(CO)3PPh3]- anion has been isolated as the tris(phenanthroline)nickel salt.

The compounds obtained by reaction of 2-alkenols with tricarbonylbis(triphenylphosphine)iridium cation in basic medium, are alkenyloxycarbonyl derivatives, in which the alkenyloxycarbonyl moiety is chelated through a σ and a η bond.

The reaction of IrH3(PPh3)2 with p-substituted aryldiazonium salts gives the compounds [IrH2(NHNC6H4R)(PPh3)2]+BF4- at low temperature (-10°C) and the o-metalated complexes [I rH(NHN C6H3R)(PPh3)2]+BF4- (R  F, OCH3) at 40–50°C. The reactions of the o-metalated complexes with CO, PPh3, NaI and HCl have been studied.

The reaction of Ir2(CO)6(PPh3)2 with p-substituted aryldiazoniurn salts gives the o-metalated complexes [Ir(CO)2(NHNC6H3R) (PPh3)]22+ 2BF4−. These react with KOH in ethanol to give the deprotonated derivatives, and with halogens to give halogenated derivatives by cleavage of the carbonmetal bond.