Mimicking biological cation-transport based on sphere-surface supramolecular chemistry:: Simultaneous interaction of porous capsules with molecular plugs and passing cations
Mimicking biological cation-transport based on sphere-surface supramolecular chemistry:: Simultaneous interaction of porous capsules with molecular plugs and passing cations
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DOI：
10.1002/chem.200700294
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发表时间：
2007-01-01
影响因子：
4.3
通讯作者：
Mueller, Achim
中科院分区：
文献类型：
--
作者：
Merca, Alice;Haupt, Erhard T. K.;Mueller, Achim
[{（Mo）Mo-5}（12）[Mo-2（配体）}（30）]（n-）型球形胶囊具有20个具有冠醚功能的{Mo 9 O 9}孔，这使得我们能够基于合成工作以及NMR光谱对标题现象进行复杂的研究。主体系统的孔在溶液中特异性地与可以非共价键合的客体（例如甲脒鎓和乙脒鎓阳离子）相互作用，同时对孔具有不同的亲和力。研究了溶液中存在的客体物种与孔隙中存在的客体物种之间的交换，除了完全孔隙关闭和完全开放的极端情况外，还包括逐步孔隙堵塞的极端情况。由于这种选择，有可能首次基于门控孔/通道对被动跨膜阳离子转运进行建模。这些具有适当的尺寸，甚至可以采用不同的结构灵活性，以响应不同的阳离子。目前的调查是基于相关的合成，以及在众多详细的Li-7 NMR研究的Li+运输/交换平衡的依赖于孔隙环境/客人的情况。可以获得一种含有具有硫酸盐配体的胶囊的化合物（2），其中所有孔都被甲脒阳离子堵塞，并且获得另一种相应的化合物，其中另外包封有Ca 2+离子（3）;这些在短暂加热相关溶液时暂时释放一些甲脒堵塞物/客体后被吸收。
Spherical capsules of the type [{(Mo)Mo-5}(12)[Mo-2(ligand)}(30)](n-) exhibiting 20 {Mo9O9} pores with crown ether functions allowed us to perform a sophisticated study of the title phenomenon based on synthetic work as well as NMR spectroscopy. The pores of the host system interact in solution specifically with guests that can be noncovalently bonded, such as formamidinium and acetamidinium cations, while having different affinities to the pores. The exchange between the guest species present in solution and in the pores was investigated, including, besides the extreme scenarios of complete pore closing and complete opening, that of stepwise pore plugging. Because of this option it was possible to model for the first time passive transmembrane cation transport based on gated pores/channels. These have the appropriate dimensions and can even adopt different structure flexibilities in response to different cations. The present investigation is based on related syntheses as well as on numerous detailed Li-7 NMR studies of Li+ transport/exchange equilibria in dependence of the pore environment/guest situations. One compound containing capsules with sulfate ligands (2) could be obtained in which all the pores are plugged with formamidinium cations and another corresponding one was obtained with additionally encapsulated Ca2+ ions (3); these were taken up after temporary release of some of the formamidinium plugs/guests upon short heating of the related solution.