Supramolecular polymerization of hydrogen-bonded rosettes with anthracene chromophores: regioisomeric effect on nanostructures
Supramolecular polymerization of hydrogen-bonded rosettes with anthracene chromophores: regioisomeric effect on nanostructures
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DOI：
10.1038/pj.2016.94
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发表时间：
2017
期刊：
影响因子：
2.8
通讯作者：
Deepak D. Prabhu;Keisuke Aratsu;Mitsuaki Yamauchi;Xu Lin;B. Adhikari;S. Yagai
中科院分区：
文献类型：
--
作者：
Deepak D. Prabhu;Keisuke Aratsu;Mitsuaki Yamauchi;Xu Lin;B. Adhikari;S. Yagai
合成了两个以苯乙炔基蒽为核、十二烷氧基苯基为单元的巴比妥酸区域异构体。紫外-可见光谱研究表明，这两种化合物在甲基环己烷（MCH）中通过协同机制自组装，其π共轭核的堆积方式不同，导致了不同的聚集诱导颜色变化。原子力显微镜的研究表明，形成明确的纤维状超分子聚合物具有不同的拓扑特征，即，圆柱形或螺旋扭曲的形状。对于螺旋扭曲的超分子聚合物，添加少量柠檬烯作为共溶剂诱导了更明显的吸收变化，这表明与纯MCH相比，共溶剂体系中的π-π堆积相互作用增加。分子模拟研究表明，这两种分子形成超分子聚合物，通过形成氢键六聚体超大环（roxene）和不同的扭曲角的蒽发色团相对于巴比妥酸平面可以解释所观察到的光谱和形态学性质的差异。
Two regioisomeric barbituric acid compounds possessing (phenylethynyl) anthracene cores and tridodecyloxy phenyl units were synthesized. UV–Vis spectroscopic studies showed that the two compounds self-assemble by a cooperative mechanism in methylcyclohexane (MCH) with different stacking arrangements of the π-conjugated core, which leads to distinct aggregation-induced color changes. Atomic Force Microscopic studies revealed the formation of well-defined fibrous supramolecular polymers with different topological features, that is, cylindrical or helically twisted shapes. For the helically twisted supramolecular polymer, adding small amounts of limonene as a cosolvent induced more pronounced changes in absorption, which indicated an increased π–π stacking interaction in the cosolvent system compared with that in pure MCH. Molecular modeling studies suggested that the two molecules form supramolecular polymers by forming hydrogen-bonded hexameric supermacrocycles (rosettes) and that different twisting angles of the anthracene chromophore with respect to the barbituric acid plane can explain the observed difference in spectroscopic and morphological properties.