Reactions between Ir(C2Ph)(CO)2(PPh3)2 and iron carbonyls (Fe(CO)5, Fe2(CO)9 have given FeIr clusters Fe2Ir(μ3-C2Ph)(CO)9-n(PPh3)n (n = 1 (8), 2) and FeIr2(μ3-PhC2C2Ph)(CO)7(PPh3)2 (9). The Rh analogue of 8 was obtained similarly. Substitution of IrPPh3 by PEt3, and addition of PEt3 to Cα of the acetylide ligand in 8 gave zwitterionic Fe2Ir(μ3-PhC2PEt3)(CO)8(PEt3) (12), which on heating was converted to Fe2Ir(μ3-C2Ph)(CO)7(PEt3)2 by migration of PEt3 from C to Ir. Related complexes containing clustr-bonded PR3 were obtained with PMe2Ph and P(OMe)3. Complexes 8, 9 and 12 were fully characterised by X-ray crystallography.