Mechanochemical Reactivity of a 1,2,4‐Triazoline‐3,5‐dione‐Anthracene Diels‐Alder Adduct
Mechanochemical Reactivity of a 1,2,4‐Triazoline‐3,5‐dione‐Anthracene Diels‐Alder Adduct
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1,2,4—三唑啉—3,5—二酮—蒽二酮—桤木加合物的机械化学反应性
DOI：
10.1002/asia.202300850
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Chang, Chia‐Chih
中科院分区：
文献类型：
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作者：
Chang, Hao‐Chun;Liang, Min‐Chieh;Luc, Van‐Sieu;Davis, Chelsea;Chang, Chia‐Chih
在应力下产生荧光部分的力响应分子为应力传感和材料损伤评估提供了一种手段。在这项工作中，我们报告了一种基于桤木加合物-Anof 4，4 ′-（4，4 ′-二苯基亚甲基）-bis-（1，2，4-triazoline-3，5-dione）和引发剂取代的蒽的机械载体，该机械载体可以通过脉冲超声和压缩活化在块体材料中进行逆向桤木（rDA）反应。通过比较从马来酰亚胺和蒽中获得的Diels-桤木加成物MAL-与C-N键和C-C键在键断裂位点的影响来阐明。经历rDa反应的敏感性与键能密切相关，因此含有C-N键的C-N键降解得更快，因为C-N键比C-C键弱。具体而言，在脉冲超声波作用下的聚合物降解动力学结果表明，含α-An的聚合物的速率常数为1.59×10− 5 min −1，而MAL-An（C-C键）的速率常数为1.40×10− 5 min −1。在交联的聚合物网络中引入Anchore-Anas证明了利用Anchore-Anas作为替代力响应探针来可视化机械损伤的可行性，其中荧光可以由于力加速的逆Diels-桤木反应而“打开”。
Force‐responsive molecules that produce fluorescent moieties under stress provide a means for stress‐sensing and material damage assessment. In this work, we report a mechanophore based on Diels‐Alder adductTAD‐Anof 4,4′‐(4,4′‐diphenylmethylene)‐bis‐(1,2,4‐triazoline‐3,5‐dione) and initiator‐substituted anthracene that can undergo retro‐Diels‐Alder (rDA) reaction by pulsed ultrasonication and compressive activation in bulk materials. The influence of having C−N versus C−C bonds at the sites of bond scission is elucidated by comparing the relative mechanical strength ofTAD‐Anto another Diels‐Alder adductMAL‐Anobtained from maleimide and anthracene. The susceptibility to undergo rDa reaction correlates well with bond energy, such that C−N bond containingTAD‐Andegrades faster C−C bond containingMAL‐Anbecause C−N bond is weaker than C−C bond. Specifically, the results from polymer degradation kinetics under pulsed ultrasonication shows that polymer containingTAD‐Anhas a rate constant of 1.59×10−5min−1, whileMAL‐An(C−C bond) has a rate constant of 1.40×10−5min−1. Incorporation ofTAD‐Anin a crosslinked polymer network demonstrates the feasibility to utilizeTAD‐Anas an alternative force‐responsive probe to visualize mechanical damage where fluorescence can be “turned‐on” due to force‐accelerated retro‐Diels‐Alder reaction.