National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Department of Materials Science and Engineering, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
Nat Chem. 2017 May;9(5):493-499. doi: 10.1038/nchem.2684. Epub 2016 Dec 19.
Molecular self-assembly under kinetic control is expected to yield nanostructures that are inaccessible through the spontaneous thermodynamic process. Moreover, time-dependent evolution, which is reminiscent of biomolecular systems, may occur under such out-of-equilibrium conditions, allowing the synthesis of supramolecular assemblies with enhanced complexities. Here we report on the capacity of a metastable porphyrin supramolecular assembly to differentiate into nanofibre and nanosheet structures. Mechanistic studies of the relationship between the molecular design and pathway complexity in the self-assembly unveiled the energy landscape that governs the unique kinetic behaviour. Based on this understanding, we could control the differentiation phenomena and achieve both one- and two-dimensional living supramolecular polymerization using an identical monomer. Furthermore, we found that the obtained nanostructures are electronically distinct, which illustrates the pathway-dependent material properties.
在动力学控制下的分子自组装有望产生通过自发热力学过程无法获得的纳米结构。此外，在这种非平衡条件下可能会发生类似于生物分子系统的时间依赖性演化，从而允许合成具有增强复杂性的超分子组装体。在这里，我们报告了一种亚稳态卟啉超分子组装体分化为纳米纤维和纳米片结构的能力。对分子设计与自组装中路径复杂性之间关系的机制研究揭示了控制独特动力学行为的能量景观。基于这一认识，我们可以控制分化现象，并使用相同的单体实现一维和二维的活超分子聚合。此外，我们发现所得的纳米结构在电子上是不同的，这说明了依赖于途径的材料性质。
