Mechanical Force Enables an Anomalous Dual Ring-Opening Reaction of Naphthodipyran
Mechanical Force Enables an Anomalous Dual Ring-Opening Reaction of Naphthodipyran
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DOI：
10.1021/jacs.2c08817
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发表时间：
2022-12-02
影响因子：
15
通讯作者：
Robb, Maxwell J.
中科院分区：
文献类型：
--
作者：
McFadden, Molly E.;Osler, Skylar K.;Robb, Maxwell J.
表现出超出典型二元响应的复杂机械致变色行为的多模态机械光团能够通过颜色的离散变化来区分多个应力状态。萘并二吡喃光开关含有两个吡喃环稠合到中心萘核，并代表了一个潜在的有前途的多峰反应框架。然而，两个吡喃部分的同时开环先前已被证明无法通过光化学活化。在这里，我们证明了通过共价连接的聚合物链提供给萘并二吡喃的机械力产生了具有独特的近红外吸收特性的难以捉摸的双环开环二聚物产物。捕获与三氟化硼使得mercury染料的热持久性，并揭示了明显的顺序开环行为，从先前研究的机械载体的反应性下施加的高应变率由超声诱导的溶剂动力学链延伸。
Multimodal mechanophores that exhibit complex mechanochromic behavior beyond the typical binary response are capable of distinguishing between multiple stress states through discrete changes in color. Naphthodipyran photoswitches contain two pyran rings fused to a central naphthalene core and represent a potentially promising framework for multimodal reactivity. However, the concurrent ring opening of both pyran moieties has previously proven inaccessible via photochemical activation. Here, we demonstrate that mechanical force supplied to naphthodipyran through covalently linked polymer chains generates the elusive dual ring-opened dimerocyanine product with unique near-infrared absorption properties. Trapping with boron trifluoride renders the merocyanine dyes thermally persistent and reveals apparent sequential ring-opening behavior that departs from the reactivity of previously studied mechanophores under the high strain rates imposed by ultrasound-induced solvodynamic chain extension.