Photoresponsive Circular Supramolecular Polymers: A Topological Trap and Photoinduced Ring-Opening Elongation
Photoresponsive Circular Supramolecular Polymers: A Topological Trap and Photoinduced Ring-Opening Elongation
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DOI：
10.1002/anie.201811237
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发表时间：
2019-03-18
影响因子：
16.6
通讯作者：
Yagai, Shiki
中科院分区：
文献类型：
--
作者：
Adhikari, Bimalendu;Aratsu, Keisuke;Yagai, Shiki
一维大分子链的拓扑结构决定了天然和合成高分子的性质和功能。为了解决这个问题，在超分子聚合物中，我们合成了两个拓扑结构不同的超分子聚合物与固有曲率，圆形和螺旋折叠的纳米纤维，从偶氮苯官能化的超分子roxides。当圆形和螺旋折叠的纳米纤维的混合物暴露于UV光，后者的开放式超分子聚合物的选择性展开观察到作为由反式至顺式的偶氮苯光异构化产生的曲率损害内力的结果。这种独特的敏感性表明，超分子聚合物的拓扑特征决定了它们的机械稳定性。此外，暴露于更极性的介质中的环状超分子聚合物的UV照射导致开环，然后链伸长，从而证明环状超分子聚合物可以作为拓扑动力学陷阱。
Topological features of one-dimensional macromolecular chains govern the properties and functionality of natural and synthetic polymers. To address this issue in supramolecular polymers, we synthesized two topologically distinct supramolecular polymers with intrinsic curvature, circular and helically folded nanofibers, from azobenzene-functionalized supramolecular rosettes. When a mixture of circular and helically folded nanofibers was exposed to UV light, selective unfolding of the latter open-ended supramolecular polymers was observed as a result of the curvature-impairing internal force produced by the trans-to-cis photoisomerization of the azobenzene. This distinct sensitivity suggests that the topological features of supramolecular polymers define their mechanical stability. Furthermore, the exposure of circular supramolecular polymers in more polar media to UV irradiation resulted in ring opening followed by chain elongation, thus demonstrating that the circular supramolecular polymer can function as a topological kinetic trap.