School of Chemistry and Chemical Engineering, Frontiers Science Centre for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Key Laboratory of Specially Functional Polymeric Materials and Related Technology (ECUST), Ministry of Education, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
J Am Chem Soc. 2020 Jun 17;142(24):10833-10840. doi: 10.1021/jacs.0c03330. Epub 2020 Jun 4.
Constructing hierarchical superstructures to achieve comparable complexity and functions to proteins with four-level hierarchy is challenging, which relies on the elaboration of novel building blocks with complex structures. We present a series of catenated cages with unique structural complexity and tailorability. The rational design was realized as such: A catenane of two symmetric cages (CSC), , with all rigid imine panels was converted to a catenane of two dissymmetric cages (CDC), , with two exterior flexible amine panels, and was tailored from by introducing an additional methyl group on each blade to increase lateral hindrance. s with the most irregular and flexible configuration formed supramolecular dimers, which self-organized into 3D continuous wavelike plank with a three-level hierarchy, previously undiscovered by conventional building blocks. A drastically different 3D triclinic crystalline phase with a four-level hierarchy and trigonal phase with a three-level hierarchy were constructed of distorted s and the most symmetric s, respectively. The wavelike plank exhibited the lowest order, and the triclinic phase had a lower order than the trigonal phase which had the highest order. It correlates with the configuration of the primary structures, namely, the most disordered shape of , the low-order configuration of , and the most ordered geometry of . The catenated cages with subtle structural differences therefore provide a promising platform for the search of emerging hierarchical superstructures that might be applied to proton conductivity, ferroelectricity, and catalysis.
构建具有四级结构的分层超结构以实现与四级结构蛋白质相当的复杂度和功能具有挑战性，这依赖于具有复杂结构的新型构建块的精心设计。我们提出了一系列具有独特结构复杂性和可定制性的连接笼。这种合理的设计是通过以下方式实现的：两个对称笼（CSC），，的轮烷，其所有刚性亚胺板都转化为两个不对称笼（CDC），，的轮烷，其具有两个外部柔性胺板，并且通过在每个叶片上引入额外的甲基基团来增加侧向阻碍，从 定制 。具有最不规则和最灵活构象的 s 形成超分子二聚体，它们自组装成具有三级结构的三维连续波浪状板，这是以前未被常规构建块发现的。具有四级结构的扭曲 s 和具有三级结构的最对称 s 分别构建了具有三级结构的三维斜方晶相和三方相。波浪状板表现出最低的阶数，而斜方晶相的阶数低于具有最高阶数的三方相。这与主链结构的构象相关，即，形状最不规则的 ，低阶配置的 ，和最有序的 。因此，具有细微结构差异的连接笼为寻找新兴的分层超结构提供了有希望的平台，这些超结构可能应用于质子导电性、铁电性和催化。
