Mechanophore activation enhanced by hydrogen bonding of diarylurea motifs: An efficient supramolecular force-transducing system
Mechanophore activation enhanced by hydrogen bonding of diarylurea motifs: An efficient supramolecular force-transducing system
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DOI：
10.1002/agt2.50
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发表时间：
2021-06-01
期刊：
影响因子：
18.8
通讯作者：
Otsuka, Hideyuki
中科院分区：
文献类型：
--
作者：
Kida, Jumpei;Aoki, Daisuke;Otsuka, Hideyuki
大分子是有效的机械传感器，用于机械诱导的化学键断裂反应。尽管已经研究了各种类型的聚合物作为机械力载体的有效机械力传感器，但聚合物链的替代品（即小分子）却很少被研究。在本文中，研究了氢键作为小分子机械力传感器在激活本体中的机械响应分子单元（力力团）中的作用。二芳基脲连接基序（被称为强氢键基团）的引入增强了荧光机械载体四芳基丁二腈（TASN）的机械化学活化，与典型大分子传感器的连接一样有效。具有二苯基脲基序的机械活化的 TASN 的电子顺磁共振测量表明，与没有二苯基脲基序的 TASN 相比，其具有更高的碳-碳键解离率。这种高效的超分子力传导系统代表了机械化学领域的一个新概念，即通过简单地改变机械力团的取代基来增强机械化学键断裂，即使在小分子中也是如此。
Macromolecules are efficient as mechanical transducers for mechanically induced chemical bond cleavage reactions. Although various classes of polymers have been studied as effective mechanical-force transducers for mechanophores, alternatives to polymer chains, that is, small molecules, have rarely been studied. In this paper, the role of hydrogen bonding as small-molecule mechanical-force transducers for the activation of mechano-responsive molecular units (mechanophores) in the bulk is investigated. The introduction of diarylurea linkage motifs, which are known as strong hydrogen bonding groups, enhances the mechanochemical activation of the fluorescent mechanophore tetraarylsuccinonitrile (TASN) as effectively as the attachment of a typical macromolecular transducer. Electron paramagnetic resonance measurements of mechanically activated TASN with diphenyl urea motifs demonstrate its higher carbon-carbon bond dissociation ratio compared to that of TASN without diphenyl urea motifs. This efficient supramolecular-force-transducing system represents a new concept in the field of mechanochemistry, namely, the enhancement of mechanochemical bond scission by simply changing the substituents of a mechanophore, even in small molecules.