Hierarchical Self-Assembly of Metallo-Supramolecular Nanospheres

A study was conducted to demonstrate the formation of vesicles through synthesis of novel coordination oligomers by metal-directed self-assembly. The assemblies were prepared, with yields of 90% and 95%, by mixing equimolar amounts of bidentate dipyridyl-substituted ligand and the bis- (diphenylphosphino)-propane (dppp)M-triflate(OTf)2 precursors. These assemblies were also stirred in CH2Cl2 for 2 hours and precipitated by slow addition of diethyl ether. Oligomers were observed up to the M6L74+complex, while it was found that assembly formation is not restricted to small cycles. It was also demonstrated that an nuclear magnetic resonance (NMR) titration of bis-(diphenylphosphino)- propane (dppp)M(Pt)-triflate(OTf)2 precursors in a solution of bidentate dipyridyl-substituted ligand, provides similar results.