Supramolecular nesting of cyclic polymers
Supramolecular nesting of cyclic polymers
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DOI：
10.1038/nchem.2182
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发表时间：
2015-04-01
期刊：
影响因子：
21.8
通讯作者：
Anderson, Harry L.
中科院分区：
文献类型：
--
作者：
Kondratuk, Dmitry V.;Perdigao, Lusm. A.;Anderson, Harry L.
模板定向合成的进展使得直接从简单的组分创造具有蛋白质样尺寸的人工分子成为可能。这些合成的大分子具有自组织的倾向，这让人想起生物聚合物。在这里，我们报告的单分散环状卟啉聚合物的合成，直径高达21纳米（750个C-C键）。环状和线性拓扑结构的特性粘度的比率为0.72，表明这些聚合物在溶液中表现为几乎理想的柔性链。当沉积在金表面上时，环状聚合物显示出一种新的二维超分子组织模式，结合了封装和嵌套;一个纳米环采用近圆形构象，从而允许第二个纳米环以紧密折叠的构象被捕获在其周边内。扫描隧道显微镜显示，嵌套发生在结合堆叠纳米环在真空下沉积时，而当它们在环境条件下直接从溶液中沉积时，存在堆叠或嵌套，但不是两者的组合。
Advances in template-directed synthesis make it possible to create artificial molecules with protein-like dimensions, directly from simple components. These synthetic macromolecules have a proclivity for self-organization that is reminiscent of biopolymers. Here, we report the synthesis of monodisperse cyclic porphyrin polymers, with diameters of up to 21 nm (750 C-C bonds). The ratio of the intrinsic viscosities for cyclic and linear topologies is 0.72, indicating that these polymers behave as almost ideal flexible chains in solution. When deposited on gold surfaces, the cyclic polymers display a new mode of two-dimensional supramolecular organization, combining encapsulation and nesting; one nanoring adopts a near- circular conformation, thus allowing a second nanoring to be captured within its perimeter, in a tightly folded conformation. Scanning tunnelling microscopy reveals that nesting occurs in combination with stacking when nanorings are deposited under vacuum, whereas when they are deposited directly from solution under ambient conditions there is stacking or nesting, but not a combination of both.