The reactions of [{M(mu-OMe)(cod)}(2)] (M = Rh, Ir; cod = 1,5-cyclooctadiene) with p-tolylamine, alpha-naphthylamine, and p-nitroaniline gave complexes with mixed-bridging ligands, [{M(cod)}(2)(mu-NHAr)(mu-OMe)]. Similarly, the related complexes [{Rh(cod)}(2)(mu-NHAr)(mu-OH)] were prepared from the reactions of [{Rh(mu-OH)(cod)}(2)] with p-tolylamine, alpha-naphthylamine, and p-nitroaniline. The reactions of [{Rh(mu-OR)(cod)}(2)] (R = H, Me) with o-nitroaniline gave the mononuclear complex [Rh(o-NO2C6H4NH) (cod)]. The syntheses of the amido complexes involve a proton exchange reaction from the amines to the methoxo or hydroxo ligands and the coordination of the amide ligand. These reactions were found to be reversible for the dinuclear complexes. The structure of [{Rh(cod)}(2)(mu-NH{p-NO2C6H4})(mu-OMe)] shows two edge-shared square-planar rhodium centers folded at the edge with an anti configuration of the bridging ligands. The complex [{Rh(cod)}(2)(mu-NH{alpha-naphthyl})(mu-OH)] cocrystallizes with [{Rh(mu-OH)(cod)}(2)] and THF, forming a supramolecular aggregate supported by five hydrogen bridges in the solid state. In the mononuclear [Rh(o-NO2C6H4NH) (cod)] complex the o-nitroamido ligand chelates the rhodium center through the amido nitrogen and an oxygen of the nitro group.