Helically Organized Fullerene Array in a Supramolecular Polymer Main Chain
Helically Organized Fullerene Array in a Supramolecular Polymer Main Chain
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DOI：
10.1021/jacs.0c13326
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发表时间：
2021-03-11
影响因子：
15
通讯作者：
Haino, Takeharu
中科院分区：
文献类型：
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作者：
Hirao, Takehiro;Iwabe, Yoshiki;Haino, Takeharu
迄今为止，超分子化学技术已应用于富勒烯聚合物的合成，使得能够开发一级结构受到良好调控的主链富勒烯聚合物，包括线性、树枝状和网状富勒烯阵列。这些研究成果引发了一项有趣的科学挑战，即创造具有更高结构调控的主链富勒烯聚合物。在这里，我们报告了基于手性二位四杯[5]芳烃主体和哑铃形富勒烯的超分子聚合的螺旋组织富勒烯阵列的制造。手性主体与哑铃形富勒烯之间的分子缔合在溶液中产生了相当大的超分子聚合物，其最高聚合度超过32。非手性哑铃形富勒烯在富勒烯部分通过超分子聚合产生的pi-pi*过渡带中表现出圆二色性。超分子螺旋聚合物的封端实验表明，哑铃形富勒烯的手性扭曲构象是通过超分子聚合定向的。最后，通过原子力显微镜观察超分子聚合物链的螺旋形貌。螺旋主链富勒烯聚合物的成功开发将为富勒烯化学开辟新天地。
To date, supramolecular chemistry techniques have been applied to fullerene polymer synthesis, enabling the development of mainchain fullerene polymers whose primary structure is well regulated, including linear, dendritic, and net-like fullerene arrays. These research achievements have led to an intriguing scientific challenge to create main-chain fullerene polymers with higher structural regulation. Here, we report the fabrication of a helically organized fullerene array based on the supramolecular polymerization of chiral ditopic tetrakiscalix[5]arene hosts and a dumbbell-shaped fullerene. The molecular association between the chiral hosts and the dumbbell-shaped fullerene resulted in sizable supramolecular polymers in solution, with the highest degree of polymerization of more than 32. The achiral dumbbell-shaped fullerene exhibited circular dichroism in the pi-pi* transition bands arising from the fullerene moieties through supramolecular polymerization. End-capping experiments of the supramolecular helical polymers showed that the chirally twisted conformation of the dumbbell-shaped fullerene was directed by supramolecular polymerization. Finally, the helical morphology of the supramolecular polymer chain was visualized by atomic force microscopy. The successful development of helical main-chain fullerene polymers would break new ground in fullerene chemistry.