Reactions of the dimers [{(η 5 -C 5 Me 5 )MCl(μ-Cl)} 2 ] (M=Rh, Ir) with the ligand NMe(PPh 2 ) 2 in 1:2 molar ratio afford the mononuclear cationic complexes [(η 5 -C 5 Me 5 )MCl{η 2 -P,P'-(Ph 2 P) 2 NMe}]Cl (M=Rh 1, Ir 2). Similar iodide complexes, [(η 5 -C 5 Me 5 )MCl{η 2 -P,P'-(Ph 2 P) 2 NMe}]I (M=Rh 3, Ir 4), can be prepared by N-functionalization of co-ordinated dppa ligand in complexes [(η 5 -C 5 Me 5 )MCl{η 2 -P,P'-(Ph 2 P) 2 NH}]BF 4 . The tetrafluoroborate derivatives, [(η 5 -C 5 Me 5 )MCl{η 2 -P,P'-(Ph 2 P) 2 NMe}]BF 4 (M=Rh 5, Ir 6) are prepared by reaction of complexes 1-4 with AgBF 4 in acetone. All the compounds described are characterised by microanalysis, IR and NMR ( 1 H, 3 1 P{ 1 H}) spectroscopy. The crystal structure of complex 5 is determined by X-ray diffraction methods. The complex exhibits a pseudo-octahedral molecular structure with a C 5 Me 5 group occupying three co-ordination positions and a bidentate chelate P,P'-bonded ligand and a chloride atom completing the co-ordination sphere.