Ogi Soichiro, Takamatsu Aiko, Matsumoto Kentaro, Hasegawa Shintaro, Yamaguchi Shigehiro
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Angew Chem Int Ed Engl. 2023 Aug 21;62(34):e202306428. doi: 10.1002/anie.202306428. Epub 2023 Jul 11.
We have investigated the folding and assembly behavior of a cystine-based dimeric diamide bearing pyrene units and solubilizing alkyl chains. In low-polarity solvents, it forms a 14-membered ring through double intramolecular hydrogen bonds between two diamide units. The spectroscopic studies revealed that the folded state is thermodynamically unstable and eventually transforms into more energetically stable helical supramolecular polymers that show an enhanced chiral excitonic coupling between the transition dipoles of the pyrene units. Importantly, compared to an alanine-based monomeric diamide, the dimeric diamide exhibits a superior kinetic stability in the metastable folded state, as well as an increased thermodynamic stability in the aggregated state. Accordingly, the initiation of supramolecular polymerization can be regulated using a seeding method even under microfluidic mixing conditions. Furthermore, taking advantage of a self-sorting behavior observed in a mixture of l-cysteine- and d-cysteine-based dimeric diamides, a two-step supramolecular polymerization was achieved by stepwise addition of the corresponding seeds.
我们研究了一种带有芘单元和增溶烷基链的基于胱氨酸的二聚二酰胺的折叠和组装行为。在低极性溶剂中，它通过两个二酰胺单元之间的双分子内氢键形成一个14元环。光谱研究表明，折叠态在热力学上是不稳定的，最终会转变为能量上更稳定的螺旋超分子聚合物，该聚合物在芘单元的跃迁偶极之间表现出增强的手性激子耦合。重要的是，与基于丙氨酸的单体二酰胺相比，二聚二酰胺在亚稳态折叠态表现出优异的动力学稳定性，在聚集态表现出更高的热力学稳定性。因此，即使在微流体混合条件下，也可以使用种子法来调控超分子聚合的起始。此外，利用在基于L-半胱氨酸和D-半胱氨酸的二聚二酰胺混合物中观察到的自分类行为，通过逐步添加相应的种子实现了两步超分子聚合。
