| Autor: |
Percástegui EG; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk., Mosquera J; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk., Ronson TK; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk., Plajer AJ; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk., Kieffer M; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk., Nitschke JR; Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW , UK . Email: jrn34@cam.ac.uk. |
| Abstrakt: |
Metal-organic containers are readily prepared through self-assembly, but achieving solubility and stability in water remains challenging due to ligand insolubility and the reversible nature of the self-assembly process. Here we have developed conditions for preparing a broad range of architectures that are both soluble and kinetically stable in water through metal(ii)-templated (M II = Co II , Ni II , Zn II , Cd II ) subcomponent self-assembly. Although these structures are composed of hydrophobic and poorly-soluble subcomponents, sulfate counterions render them water-soluble, and they remain intact indefinitely in aqueous solution. Two strategies are presented. Firstly, stability increased with metal-ligand bond strength, maximising when Ni II was used as a template. Architectures that disassembled when Co II , Zn II and Cd II templates were employed could be directly prepared from NiSO 4 in water. Secondly, a higher density of connections between metals and ligands within a structure, considering both ligand topicity and degree of metal chelation, led to increased stability. When tritopic amines were used to build highly chelating ligands around Zn II and Cd II templates, cryptate-like water-soluble structures were formed using these labile ions. Our synthetic platform provides a unified understanding of the elements of aqueous stability, allowing predictions of the stability of metal-organic cages that have not yet been prepared. |
