Supramolecular chirality formation of bisazobenzene-substituted polydiacetylene LB films.
Supramolecular chirality formation of bisazobenzene-substituted polydiacetylene LB films.
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DOI：
10.1016/j.jcis.2010.11.059
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发表时间：
2011-02
影响因子：
9.9
通讯作者：
Xiujuan Pan;Hao Jiang;Yali Wang;Zhangyuan Lei;Gang Zou;Qi-jin Zhang;Keyi Wang
中科院分区：
文献类型：
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作者：
Xiujuan Pan;Hao Jiang;Yali Wang;Zhangyuan Lei;Gang Zou;Qi-jin Zhang;Keyi Wang
为了研究侧链头基的立体规整填充对聚二乙炔主链螺旋结构形成的确切影响，成功地合成了较大尺寸的双偶氮苯取代二乙炔单体4-(4-硝基苯偶氮)偶氮苯-10，12-五糖二诺酸酯(BNADA)。尽管BNADA分子是非手性的，但由于双偶氮苯发色团的过度堆积，BNADA Langmuir-Blodgett(LB)膜表现出宏观的超分子手性。在圆偏振紫外光(CPUL)照射下，由于双偶氮苯发色团的大小和较低的光致异构化速率，双偶氮苯发色团始终保持着超分子螺旋。而对于聚二乙炔主链，高分子链的螺旋方向应由双偶氮苯发色团的立体规则堆积效应和CPUL与二乙炔二聚体相互作用的竞争决定。
In order to investigate the exact effect of stereoregular packing of head group in the side chain on the helical structure formation of polydiacetylene backbone, the larger size of bisazobenzene-substituted diacetylene monomer, 4-(4-nitrophenylazo) azobenzene-10, 12-pentacosadiynoate (BNADA) was synthesized successfully. Owing to overcrowded packing of bisazobenzene chromophores, the BNADA Langmuir–Blodgett (LB) films showed macroscopic supramolecular chirality, although BNADA molecules were achiral. Under circularly polarized UV light (CPUL) irradiation, supramolecular helix of bisazobenzene chromophores always maintained, due to the large size and lower photo-isomerization rate of bisazeobenzene chromophores. While for polydiacetylene backbone, the helical direction of the polymer chain should be decided by the competition of the effect of stereoregular packing of bisazobenzene chromophores and the interaction between the CPUL and the diacetylene dimer.