Department of Chemistry, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States.
J Am Chem Soc. 2022 Jan 26;144(3):1125-1129. doi: 10.1021/jacs.1c12108. Epub 2022 Jan 12.
Polymers that release functional small molecules under mechanical stress potentially serve as next-generation materials for catalysis, sensing, and mechanochemical dynamic therapy. To further expand the function of mechanoresponsive materials, the discovery of chemistries capable of small molecule release are highly desirable. In this report, we detail a nonscissile bifunctional mechanophore (i.e., dual mechano-activated properties) based on a unique mechanochemical reaction involving norborn-2-en-7-one (NEO). One property is the release of carbon monoxide (CO) upon pulsed solution ultrasonication. A release efficiency of 58% is observed at high molecular weights ( = 158.8 kDa), equating to ∼154 molecules of CO released per chain. The second property is the bright cyan emission from the macromolecular product in its aggregated state, resulting in a turn-on fluorescence readout coincident with CO release. This report not only demonstrates a unique strategy for the release of small molecules in a nonscissile way but also guides future designs of force-responsive aggregation-induced emission (AIE) luminogens.
在机械应力下释放功能性小分子的聚合物有可能成为下一代催化、传感和机械化学动态治疗的材料。为了进一步扩展机械响应材料的功能，人们非常希望发现能够释放小分子的化学物质。在本报告中，我们详细介绍了一种基于独特机械化学反应的不可裂解双功能机械点（即双机械激活特性），该反应涉及降冰片-2-烯-7-酮（NEO）。一种特性是在脉冲溶液超声处理时释放一氧化碳（CO）。在高分子量（= 158.8 kDa）时，观察到 58%的释放效率，相当于每链释放约 154 个 CO 分子。第二种特性是聚合态大分子产物的亮青色发射，导致与 CO 释放一致的荧光开读。本报告不仅展示了一种非裂解方式释放小分子的独特策略，还为力响应聚集诱导发射（AIE）发光团的未来设计提供了指导。
