Photoresponsive self-assembly and self-organization of hydrogen-bonded supramolecular tapes.
Photoresponsive self-assembly and self-organization of hydrogen-bonded supramolecular tapes.
复制标题
DOI：
10.1002/chem.200501468
复制
发表时间：
2006-05
期刊：
影响因子：
--
通讯作者：
S. Yagai;T. Iwashima;K. Kishikawa;Shoichiro Nakahara;T. Karatsu;Akihide Kitamura
中科院分区：
文献类型：
--
作者：
S. Yagai;T. Iwashima;K. Kishikawa;Shoichiro Nakahara;T. Karatsu;Akihide Kitamura
自组装的构建块易于功能化，能够实现程序化的分层组织，使我们能够创造各种功能纳米材料。我们之前已经证明，N，N'-二取代4,6-二氨基嘧啶-2(1 H)- 1 (DAP)，一种鸟嘌呤-胞嘧啶杂交分子，是在溶液中形成带状超分子聚合物的通用构建块。在本研究中，DAP被偶氮苯侧链功能化。1H NMR、UV/Vis和动态光散射研究证实，在微摩尔体系下，烷烃溶剂中存在纳米级带状超分子聚合物。x射线衍射和偏振光学显微镜显示，在较高浓度（毫摩尔浓度）下，超分子聚合物分层组织成层状超结构，形成有机凝胶。值得注意的是，偶氮苯侧链即使在超分子聚合物中也是光异构的，由于它们在刚性氢键支架的支持下松散堆积，使我们能够建立光可控的超分子聚合和高阶组织的带状超分子聚合物成层状超结构。
Self-assembling building blocks that are readily functionalizable and capable of achieving programmed hierarchical organization have enabled us to create various functional nanomaterials. We have previously demonstrated that N,N'-disubstituted 4,6-diaminopyrimidin-2(1 H)-one (DAP), a guanine-cytosine hybridized molecule, is a versatile building block for the creation of tapelike supramolecular polymer species in solution. In the current study, DAP was functionalized with azobenzene side chains. 1H NMR, UV/Vis, and dynamic light scattering studies confirmed the presence of nanometer-scale tapelike supramolecular polymers in alkane solvents at micromolar regimes. At higher concentrations (millimolar regimes), the supramolecular polymers hierarchically organized into lamellar superstructures to form organogels, as shown by X-ray diffraction and polarized optical microscopy. Remarkably, the azobenzene side chains are photoisomerizable even in the supramolecular polymers, owing to their loosely packed state supported by the rigid hydrogen-bonded scaffold, enabling us to establish photocontrollable supramolecular polymerization and higher order organization of the tapelike supramolecular polymers into lamellar superstructures.