Selective formation of RhCu-kofo-2 without the formation of adventitious mixed-metal RhCu PWs could be achieved in direct MOP synthesis from Cu2(OAc)4 and Rh2(OAc)4 in DMA. Even though the Rh-Rh metal bond in the Rh2(OAc)4 precursor has a substantially lower bond strength than the Rh-O dative bonds, the Rh2 dimer is fully retained in the mixed metal MOP because the synthetic conditions provide an effective pathway for ligand replacement but not metal-metal 20 bond cleavage . The decisive factor in determining the size of mobile components during MOP synthesis, therefore, is the relative lability of different bonds rather than their strength (Fig. , brown scale). ).