Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya 464-8601, Japan.
Department of Chemistry, Graduate School of Science and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan.
J Am Chem Soc. 2021 Feb 24;143(7):2953-2961. doi: 10.1021/jacs.0c13353. Epub 2021 Feb 10.
We report the kinetically controlled supramolecular polymerization of boron-containing π-conjugated molecules, which was enabled by a seeding method based on dual trapping of a metastable state by synergistic intramolecular hydrogen bonding and Lewis acid-based complexation. Planarized triarylborane-based , which bears a diamide chain with chiral alkyl groups, was synthesized. Upon cooling, the solution of monomer afforded a supramolecular polymerization in a cooperative manner to form helical supramolecular nanostructures with intense J-type aggregate emission. In the presence of pyridine, the triarylborane moiety formed a Lewis acid-base complex, which enhances the stabilization of the metastable monomeric state. An assembly incompetent structure with a folded diamide chain conformation and a pyridine moiety axially coordinated to the boron atom is responsible for slowing the spontaneous aggregation. The seeding method was successfully applied to the solution to produce homogeneous nanofibers even at a high (millimolar-level) concentration. This unprecedented kinetic control via dual trapping provides an effective method to achieve seed-initiated polymerization under concentrated conditions.
我们报告了含硼的π共轭分子的动力学控制超分子聚合，这是通过基于协同的分子内氢键和基于路易斯酸的络合双重捕获亚稳态的种晶方法实现的。合成了带有手性烷基二酰胺链的平面化三芳基硼 。在冷却时，单体的溶液以协同方式进行超分子聚合，形成具有强烈 J 型聚集发射的螺旋超分子纳米结构。在吡啶存在下，三芳基硼部分形成路易斯酸碱配合物，增强了亚稳态单体状态的稳定性。具有折叠二酰胺链构象和吡啶部分轴向配位到硼原子的组装能力差的结构负责减缓自发聚集。该种晶方法成功地应用于溶液中，即使在高浓度（毫摩尔级）下也能生成均匀的纳米纤维。这种通过双重捕获的前所未有的动力学控制为在浓缩条件下实现种子引发聚合提供了一种有效方法。
