Unraveling the forming mechanism of hierarchical helices via self-assembly of an achiral supramolecular polymer brush
Unraveling the forming mechanism of hierarchical helices via self-assembly of an achiral supramolecular polymer brush
复制标题
DOI：
10.1039/c5py00163c
复制
发表时间：
2015-05
影响因子：
4.6
通讯作者：
Shanshan Liu;Qibin Chen;Yujie Sheng;Jincheng Shen;C. Peng;Honglai Liu
中科院分区：
文献类型：
--
作者：
Shanshan Liu;Qibin Chen;Yujie Sheng;Jincheng Shen;C. Peng;Honglai Liu
开发具有受控螺旋方向的超分子螺旋组装体并揭示分层螺旋的形成机制以模仿生物自组织和生理过程仍然是主要挑战。在这项工作中，通过聚乙烯吡咯烷酮（PVP）的酮基和对十二烷基苯酚（PDP）的酚羟基之间形成氢键制备了一种瓶刷状超分子聚合物，并通过1H NMR和FT-IR光谱进行了表征。 CD 光谱显示出未分裂的棉花效应，表明这种超分子聚合物刷 (PVP-PDP) 中出现了螺旋结构。特别是，通过 TEM 和 AFM 方法获得了分层螺旋形成的直接实验证据。我们提出了 PVP-PDP 的分级螺旋或超螺旋从一级结构到二级结构、三级结构甚至四级结构的详细结构转变，这是由于将大体积的 PDP 悬垂并入 PVP 主链和邻位氢键的结合位点而产生的。
Developing supramolecular helical assemblies with a controlled helix sense and revealing the forming mechanism of hierarchical helices for mimicking biological self-organization and physiological processes remain major challenges. In this work, a bottlebrush-like supramolecular polymer is prepared through the formation of a hydrogen bond between the keto group of polyvinylpyrrolidone (PVP) and the phenolic hydroxyl group of p-dodecylphenol (PDP), characterized by 1H NMR and FT-IR spectroscopy. CD spectra show an unsplit Cotton effect, suggesting the emergence of a helical structure in this supramolecular polymer brush (PVP–PDP). In particular, straightforward experimental evidence for the formation of hierarchical helices is obtained via TEM and AFM methods. We propose a detailed structural transition of the hierarchical helix or superhelix of PVP–PDP from primary to secondary, tertiary and even quaternary structures, resulting from the incorporation of bulky pendant PDP into the PVP backbone and the binding site of the hydrogen bond at ortho-position.