A light-driven pseudo[4]rotaxane encoded by induced circular dichroism in a hydrogel
A light-driven pseudo[4]rotaxane encoded by induced circular dichroism in a hydrogel
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DOI：
10.1002/adfm.200600981
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发表时间：
2007-03-23
影响因子：
19
通讯作者：
Tian, He
中科院分区：
文献类型：
--
作者：
Ma, Xiang;Wang, Qiaochun;Tian, He
以α-环糊精(α-环糊精)和瓜环[7]脲(CB[7])为基础，以简便的方法制备了一种光驱动的拟[4]轮烷1。参考的拟[2]轮烷2和拟[3]轮烷2‘是通过将α-CyD和CB[7]插入哑铃3而得到的，从而分别包括一个偶氮苯单元和两个紫精部分。假[4]轮烷1中的环状大环可被光化学激发为穿梭结构，并伴有明显的诱导圆二色谱(ICD)信号。研究了这些拟轮烷的ICD性能，包括水溶液中的ICD、变温ICD、配伍水凝胶体系中的ICD和固态薄膜中的ICD，以确定它们的构象。在拟[4]轮烷1中光驱动的CyD大环的穿梭比在基于CyD的拟[2]轮烷2中更容易，尤其是在非溶液介质中。这可以归因于CB[7]包含的部分的空间利用，这有助于α-Cyd的移动。
A light-driven pseudo[4]rotaxane 1, based on alpha-cyclodextrin (alpha-CyD) and cucurbit[7]uril (CB[7]), is prepared in an easy and convenient manner. The reference pseudo[2]rotaxane 2 and pseudo[3]rotaxane 2' are obtained via the insertion of alpha-CyD and CB[7] onto the dumbbell 3, thus including an azobenzene unit and two viologen moieties, respectively. The CyD macrocycle in pseudo[4]rotaxane 1 can be photochemically stimulated to shuttle accompanied with obvious induced circular dichroism (ICD) signals. The ICD performances of these pseudorotaxanes, including ICD in aqueous solution, variable-temperature ICD, ICD in confected hydrogel systems and in solid-state films, are investigated for their conformational identification. The photo-driven shuttling of the CyD macrocycle in pseudo[4]rotaxane 1 is easier than in the CyD-based psuedo[2]rotaxane 2, especially in non-solution media. This can be attributed to the space exploitation of CB[7]-included parts, which aid the movement of alpha-CYD.