Tamaki Kenta, Datta Sougata, Hanayama Hiroki, Ganser Christian, Uchihashi Takayuki, Yagai Shiki
Division of Advanced Science and Engineering, Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
Institute for Advanced Academic Research (IAAR), Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
J Am Chem Soc. 2024 Aug 14;146(32):22166-22171. doi: 10.1021/jacs.4c07878. Epub 2024 Jul 25.
The competition between polymer chain folding and aggregation is a critical structuring process that determines the physical properties of synthetic and biopolymers. However, supramolecular polymer systems that exhibit both processes have not yet been reported. We herein introduce a system in which folded supramolecular polymers spontaneously undergo interchain aggregation due to a rearrangement in internal molecular order, converting them into crystalline aggregates. These folded supramolecular polymers slowly crystallize over the course of half a day, due to their characteristic higher-order structures. However, the photoisomerization of the -azobenzene incorporated into the monomer to the isomer leads to unfolding of the polymer, accelerating the intrachain and interchain molecular ordering to a few hours. The intermediate structures visualized by AFM demonstrate that the unfolding is coupled with interchain aggregation.
聚合物链折叠与聚集之间的竞争是一个关键的结构化过程，它决定了合成聚合物和生物聚合物的物理性质。然而，尚未有报道同时展现这两种过程的超分子聚合物体系。我们在此介绍一种体系，其中折叠的超分子聚合物由于内部分子排列的重排而自发地发生链间聚集，将它们转化为结晶聚集体。这些折叠的超分子聚合物由于其特征性的高阶结构，在半天的时间里缓慢结晶。然而，掺入单体中的偶氮苯光异构化为反式异构体导致聚合物展开，将链内和链间分子有序化加速至几小时。通过原子力显微镜观察到的中间结构表明，展开与链间聚集相关联。
