pH-Controlled selection between one of three guests from a mixture using a coordination cage host.
pH-Controlled selection between one of three guests from a mixture using a coordination cage host.
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DOI：
10.1039/c5sc01475a
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发表时间：
2015-07-15
期刊：
影响因子：
8.4
通讯作者：
Ward MD
中科院分区：
文献类型：
--
作者：
Cullen W;Thomas KA;Hunter CA;Ward MD
我们演示了使用简单的 pH 波动来控制配位笼宿主从水溶液中选择三种不同客体之一。我们演示了使用简单的 pH 波动来控制配位笼宿主从水溶液中选择三种不同客体之一。不同客体之间的切换基于这样的事实：中性有机客体由于疏水效应而在笼中牢固结合，但对于酸性或碱性客体，带电（质子化或去质子化）形式是亲水性的并且不结合。使用的客体是金刚烷-1,3-二羧酸 (H2A)，它在中性时在低 pH 下结合，但在去质子化时则不结合； 1-氨基-金刚烷 (B)，在高 pH 条件下呈中性时结合，但质子化时不结合；环壬酮 (C) 的结合不依赖于 pH 值，因此是中性 pH 下的默认客体。因此，pH 值的增加可以使宿主在三种不同结合态笼·H2A（低 pH 值）、笼·C（中等 pH 值）和笼·B（高 pH 值）之间连续可逆地切换。
We demonstrate the use of a simple pH swing to control the selection of one of three different guests from aqueous solution by a coordination cage host. We demonstrate the use of a simple pH swing to control the selection of one of three different guests from aqueous solution by a coordination cage host. Switching between different guests is based on the fact that neutral organic guests bind strongly in the cage due to the hydrophobic effect, but for acidic or basic guests, the charged (protonated or deprotonated) forms are hydrophilic and do not bind. The guests used are adamantane-1,3-dicarboxylic acid (H2A) which binds at low pH when it is neutral but not when it is deprotonated; 1-amino-adamantane (B) which binds at high pH when it is neutral but not when it is protonated; and cyclononanone (C) whose binding is not pH dependent and is therefore the default guest at neutral pH. Thus an increase in pH can reversibly switch the host between the three different bound states cage·H2A (at low pH), cage·C (at medium pH), and cage·B (at high pH) in succession.