摘要/Abstract

以反式七元瓜环（iQ[7]）和七元瓜环（Q[7]）作为主体分子，一对氨基酸对映体L-3-（2-萘基）-丙氨酸（L-NA）及D-3-（2-萘基）-丙氨酸（D-NA）为客体分子，利用紫外-可见吸收光谱、荧光光谱、等温滴定量热分析、基质辅助激光解吸电离飞行时间质谱以及核磁共振技术等手段，对比探究了这两种具有不同空腔大小的七元瓜环与这一对氨基酸对映体之间的自组装模式的异同点，实验结果表明：这四组主客体包结物具有相同的作用模式，均为瓜环的空腔包结了客体分子的萘环部分而客体分子的氨基及羧酸部分位于瓜环的端口外侧，主客体均以1∶1的作用比相互配位形成较为稳定的超分子自组装体，同时发现两种七元瓜环对L/D-NA手性对映体的分子选择性略有不同.
关键词: 反式七元瓜环, 七元瓜环, 对映体, 氨基酸, 自组装
The interaction of a pair of amino acid enantiomers, L-3-(2-naphthyl)-alanine (L-NA) and D-3-(2-naphthyl)-alanine (D-NA), with cucurbit[7]uril (Q[7]) and inverted cucurbit[7]uril (iQ[7]) was investigated, respectively, by using NMR spectroscopy, electronic absorption spectroscopy, fluorescence spectroscopies, isothermal titration calorimetry (ITC) experiments and MALDI-TOF mass spectrometry. Furthermore, the similarities and differences of the self-assembly patterns between the two kinds of cucurbituril with different cavity sizes and this pair of amino acid enantiomers were also researched. The results obtained from the experiment revealed that the naphthyl groups of amino acids were all entrapped in the cavity of the Q[n]s, whereas the other section of amino acids remained outside the portal and thus resulted in a more stable supramolecular self-assembly at a 1:1 ratio. Meanwhile, we found that the two different kinds of cucurbit[7]urils showed a slightly different selectivity for the L/D-NA chiral enantiomer.
Key words: inverted cucurbit[7]uril, cucurbit[7]uril, enantiomer, amino acid, self-assembly


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