Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
Angew Chem Int Ed Engl. 2017 Jul 24;56(31):9136-9140. doi: 10.1002/anie.201705093. Epub 2017 Jun 27.
Control over the solubility properties of container molecules is a central challenge in host-guest chemistry. Herein we present a simple anion-exchange protocol that allows the dissolution in water of various hydrophobic metal-organic container molecules prepared by iron(II)-templated subcomponent self-assembly. Our process involved the exchange of less hydrophilic trifluoromethanesulfonate anions for hydrophilic sulfate; the resulting water-soluble cages could be rendered water-insoluble through reverse anion exchange. Notably, this strategy allowed cargoes within capsules, including polycyclic aromatic compounds and complex organic drugs, to be brought into water. Hydrophobic effects appeared to enhance binding, as many of these cargoes were not bound in non-aqueous media. Studies of the scope of this method revealed that cages containing tetratopic and tritopic ligands were more stable in water, whereas cages with ditopic ligands disassembled.
控制主体分子的溶解性质是主客体化学的核心挑战。在此，我们提出了一种简单的阴离子交换方案，允许通过铁（II）模板亚基自组装制备的各种疏水性金属有机主体分子在水中溶解。我们的过程涉及用亲水性硫酸盐交换疏水性三氟甲磺酸根阴离子；所得水溶性笼可通过反向阴离子交换变为不溶于水。值得注意的是，该策略允许将胶囊内的货物，包括多环芳烃和复杂的有机药物，带入水中。疏水性效应似乎增强了结合，因为许多这些货物在非水介质中没有结合。对该方法的范围的研究表明，含有四齿和三齿配体的笼在水中更稳定，而具有二齿配体的笼则会分解。
