Solvent-Mediated Central Metals Transformation from a Tetranuclear NiII Cage to a Decanuclear CUII Pocket

When a well-designed tetranuclear Ni-II cage [Ni-4(bppdca)(2)(H(2)bppdca)(4)(SO4)(2)(H2O)(6)]center dot H2O center dot CH3OH (1; H(2)bppdca = N,N'-bis(pyridin-3-yl)-2,6-pyridinedicarbox-amide) was immersed into the methanol solution of CuSO4, a novel decanuclear Cu-II complex [Cu-10(H(2)bppdca)(4)(SO4)(8)(mu 3OH)(4)(CH3OH)(H2O)(4)]center dot 11H(2)O center dot 2CH(3)OH (2) would be obtained through central metals transformation. We propose that the transformation is a recurrent dissolving-exchange-crystallization process with a solvent-mediated mechanism confirmed by visual evidence. Direct reaction of H(2)bppdca and CuSO4 in the absence of 1 affords different products.