Mechanism of Self-Assembly Process and Seeded Supramolecular Polymerization of Perylene Bisimide Organogelator
Mechanism of Self-Assembly Process and Seeded Supramolecular Polymerization of Perylene Bisimide Organogelator
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DOI：
10.1021/ja511952c
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发表时间：
2015-03-11
影响因子：
15
通讯作者：
Wuerthner, Frank
中科院分区：
文献类型：
--
作者：
Ogi, Soichiro;Stepanenko, Vladimir;Wuerthner, Frank
研究了一种由苝酰二亚胺芳香支架和两个酰胺取代基组成的原型有机凝胶分子的超分子聚合机理。这种分子通过协同成核生长过程自组装成细长的一维纳米纤维。热力学和动力学分析已被应用于发现条件（温度、溶剂、浓度），其中自发成核可以通过在非活性构象中捕获单体而延迟，导致延迟时间超过1小时。成核过程中的独特动力学被证实为组装和拆卸过程循环中的热滞后。在迟滞回路内适当的条件下，加入预组装的纳米纤维种子，导致种子末端的种子聚合，这是一种活的超分子聚合过程。这些结果表明，种子聚合并不局限于通路外聚集体隔离单体反应物的特殊情况，而可能适用于大量已知的和来自大家族分子的有待开发的分子，这些分子可以自组装成一维纳米纤维结构。从我们的种子聚合的机理的见解，我们断言，协同成核生长的超分子聚合伴随着热滞后是可以控制在一个生活的方式。
The mechanism of supramolecular polymerization has been elucidated for an archetype organogelator molecule composed of a perylene bisimide aromatic scaffold and two amide substituents. This molecule self-assembles into elongated one-dimensional nanofibers through a cooperative nucleation-growth process. Thermodynamic and kinetic analyses have been applied to discover conditions (temperature, solvent, concentration) where the spontaneous nucleation can be retarded by trapping of the monomers in an inactive conformation, leading to lag times up to more than 1 h. The unique kinetics in the nucleation process was confirmed as a thermal hysteresis in a cycle of assembly and disassembly processes. Under appropriate conditions within the hysteresis loop, addition of preassembled nanofiber seeds leads to seeded polymerization from the termini of the seeds in a living supramolecular polymerization process. These results demonstrate that seeded polymerizations are not limited to special situations where off-pathway aggregates sequester the monomeric reactant species but may be applicable to a large number of known and to be developed molecules from the large family of molecules that self-assemble into one-dimensional nanofibrous structures. Generalizing from the mechanistic insight into our seeded polymerization, we assert that a cooperative nucleation-growth supramolecular polymerization accompanied by thermal hysteresis can be controlled in a living manner.