Synthesis of Discrete Conjugated Fluorene‐Azo Oligomers for the Investigation of Azobenzene Position‐Dependent Physical Properties and Photoresponsive Behavior
Synthesis of Discrete Conjugated Fluorene‐Azo Oligomers for the Investigation of Azobenzene Position‐Dependent Physical Properties and Photoresponsive Behavior
复制标题
离散共轭芴偶氮低聚物的合成用于研究偶氮苯位置依赖性物理性质和光响应行为
DOI：
10.1002/macp.202100092
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发表时间：
2021-06
影响因子：
2.5
通讯作者：
Xiulin Zhu
中科院分区：
文献类型：
--
作者：
Min Liu;Xianheng Shi;Lishan Li;Ji;ong Zhang;Zhihao Huang;Wei Zhang;Nianchen Zhou;Zhengbiao Zhang;Xiulin Zhu
众所周知，大分子结构，包括组成、拓扑和序列，在很大程度上决定了共轭聚合物/低聚物的性质。为了准确地理解结构诱导的性质，具有分子定义结构的离散齐聚物/聚合物是理想的模型，因为它们提供了截然不同的非统计结果。本文基于CuAAC“Click”化学，通过逐步链生长策略，有效地制备了一系列沿主链具有不同位置偶氮苯单元(即序列)的离散共轭荧偶氮齐聚物。位置相关行为对齐聚物的性质有明显的影响，如溶液和薄膜状态下的热性质、光学性质和光响应行为。此外，在紫外光照射下，9，9-二辛基-9，9-二辛基-荧烯低聚物对9，9-二辛基-荧烯的光降解作用较低，而在溶液中则表现出位置依赖性的光降解。用密度泛函理论计算了荧偶氮齐聚物的优化构型和UV-Vis吸收光谱。实验结果和理论分析表明，偶氮苯的位置可能在决定序列强制构象变化导致的荧偶氮齐聚物的性质中起主导作用。毫无疑问，这项工作可以为基于精确序列定义的聚合物结构的结构-性质关系提供更深入的见解。
It is well known that macromolecular structure, including composition, topology and sequence, significantly determines the properties of conjugated polymers/oligomers. To accurately understand the structure-induced properties, discrete oligomers/polymers with molecularly defined structures are the ideal model because they provide distinct nonstatistical results. Herein, a series of discrete conjugated fluorene-azo oligomers with different positions of the azobenzene units along the main chain (i.e., sequence) are efficiently prepared based on CuAAC “click” chemistry via a stepwise chain-growth strategy. Position-dependent behavior has an evident impact on the properties of oligomers, such as thermal properties, optical properties and photoresponsive behavior in both solution and thin film states. In addition, the fluorene-azo oligomers show less photodegradation of 9,9-dioctyl-fluorene in the solid-state than oligofluorene during UV light irradiation; however, position-dependent photodegradation is found in solution. Optimized configurations and UV–vis absorption spectra of fluorene-azo oligomers are calculated by density functional theory. Experimental results and theoretical analysis indicate that the location of azobenzene can play a dominant role in determining the properties of fluorene-azo oligomers resulting from sequence-mandated conformational changes. Undoubtedly, this work can provide deeper insight into the structure–property relationships based on precisely sequence-defined polymer structures.
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DOI：
10.1002/chin.200029276
发表时间：
2000-07
期刊：
ChemInform
影响因子：
--
作者：
J. Delaire;K. Nakatani
通讯作者：
J. Delaire;K. Nakatani
影响因子：
15
作者：
Pfeifer, Sebastian;Zarafshani, Zoya;Lutz, Jean-Francois
通讯作者：
Lutz, Jean-Francois
影响因子：
21.8
作者：
Barnes, Jonathan C.;Ehrlich, Deborah J. C.;Johnson, Jeremiah A.
通讯作者：
Johnson, Jeremiah A.
影响因子：
2.5
作者：
L. Angiolini
通讯作者：
L. Angiolini
影响因子：
4.5
作者：
Bing Wu;Wei Wang;Jilei Wang;Shang Li;Yan-Bing He
通讯作者：
Bing Wu;Wei Wang;Jilei Wang;Shang Li;Yan-Bing He