Crowned dendrimers: pH-responsive pseudorotaxane formation.
Crowned dendrimers: pH-responsive pseudorotaxane formation.
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DOI：
10.1021/jo0265784
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发表时间：
2003-02
期刊：
影响因子：
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通讯作者：
Jason W. Jones;W. S. Bryant;A. Bosman;R. Janssen;E. Meijer;H. Gibson
中科院分区：
文献类型：
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作者：
Jason W. Jones;W. S. Bryant;A. Bosman;R. Janssen;E. Meijer;H. Gibson
为了将树枝状大分子独特的结构和物理性质引入到超分子组装体中，合成了第一代和第三代双（间苯撑）-32-冠-10-官能化的聚丙烯亚胺树枝状大分子，并研究了它们与百草枯二醇的相互作用。使用（1）H NMR，我们确定，结合到4或16冠醚网站发生在一个反合作的方式，最有可能的结果，空间位阻的影响。在树枝状内部的叔胺质子化后，结合变得独立，即，在统计学上，平均表观缔合常数增加了近5倍;这种效应归因于树枝状聚合物的硬化，这使得其结合位点更容易接近并且不那么拥挤。
With the end goal of incorporating the unique structural and physical properties of dendrimers into supramolecular assemblies, bis(m-phenylene)-32-crown-10-functionalized poly(propyleneimine) dendrimers of the first and third generations have been synthesized and their interaction with paraquat diol has been investigated. Using (1)H NMR, we determined that binding to the 4 or 16 crown ether sites occurred in an anti-cooperative fashion, most likely a result of steric influences. Upon protonation of the tertiary amines in the dendritic interior, binding became independent, i.e., statistical, and the average apparent association constant increased by nearly 5-fold; this effect is attributed to rigidification of the dendrimer, which makes its binding sites more accessible and less crowded.