Core expansion reactions of di- and tetrairidium complexes [Cp*Ir(mu(2)-NCN-N,N)](2) (1; Cp* = eta(5)-C5Me5), [Cp*Ir(mu(3)-NCN-N,N,N)](4) (2), and phosphine derivatives of 1 have been investigated, and it has been revealed that cyanamido ligands in these complexes can change their coordination modes flexibly on reactions with a second transition metal complex. Treatment of diiridium complex 1 with [Cp*IrCl2](2) gives the tetrairidium complex [(Cp*Ir)(2)(mu(3)-NCN-N,N,N')(2)(IrCp*Cl-2)(2)] (6) with mu(3)-kappa N,kappa N,kappa N' cyanoimido(2-) ligands. On the other hand, the reaction of 1 with [PdCl(eta(3)-C3H5)](2) affords the NCN-bridged Ir2Pd4 hexanuclear complex [(Cp*IrCl)(2)(mu(4)-NCN-N,N,N',N')(2){Pd-2(mu-Cl)(eta(3)-C3H5)(2)}(2)] (7) and Ir4Pd4 octanuclear complex [(Cp*Ir)(4)(mu(4)-NCN-N,N,N,N')(4){PdCl(eta(3)-C3H5)}(4)] (8). The NCN-bridges in 7 provide the first example of the crystallographically determined mu(4)-kappa N,kappa N,kappa N',kappa N' carbodiimido(2-) ligand. Complex 8 with mu(4)-kappa N,kappa N,kappa N,kappa N' cyanoimido(2-) ligands can also be synthesized selectively by the reaction of the parent cubane complex 2 with [PdCl(eta(3)-C3H5)](2). Diphosphine derivative of 1, [{Cp*Ir(mu(2)-NCN)}(2)(mu-dppm)] (4; dppm = Ph2PCH2PPh2), behaves differently on reactions with [PdCl(eta(3)-C3H5)](2) and [MCl(cod)](2) (cod = cycloocta-1,5-diene) to form the NCN-bridged Ir2M2 (M = Pd, Rh, Ir) tetranuclear complexes [(Cp*Ir)(2)(mu(3)-NCN-N,N,N')(2)(PdCl(mu(3)-C3H5)}(2)(mu-dppm)] (9) and [(Cp*Ir)(2)(mu(3)-NCN-N,N,N')(2)(MCl(cod)}(2)(mu-dppm)] (11a, M = Rh; 11b, M = Ir), respectively. The molecular structures for 6, 7, 8, 11a, and 11b have been determined by single-crystal X-ray analyses.