Aqueous anion receptors through reduction of subcomponent self-assembled structures

To prepare new functional covalent architectures that are difficult to synthesize using conventional organic methods, we developed a strategy that employs metal-organic assemblies as precursors, which are then reduced and demetalated. The host-guest chemistry of the larger receptor thus prepared was studied using NMR spectroscopy and fluorescence experiments. This host was observed to strongly bind aromatic polyanions in water, including the fluorescent dye molecule pyranine with nanomolar affinity, thus allowing for the design of an indicator-displacement assay. Self-assembled precursors could be reduced and demetalated in high yields to generate two new covalent architectures. These organic molecules display high aqueous solubility, and the larger cage strongly binds aromatic polyanions in water, including the fluorescent dye molecule pyranine (with nanomolar affinity), thus allowing for the design of an indicator-displacement assay.