Yildiz Deniz, Baumann Christoph, Mikosch Annabel, Kuehne Alexander J C, Herrmann Andreas, Göstl Robert
DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany.
Institute for Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
Angew Chem Int Ed Engl. 2019 Sep 9;58(37):12919-12923. doi: 10.1002/anie.201907436. Epub 2019 Jul 19.
The development of methods to detect damage in macromolecular materials is of paramount importance to understand their mechanical failure and the structure-property relationships of polymers. Mechanofluorophores are useful and sensitive molecular motifs for this purpose. However, to date, tailoring of their optical properties remains challenging and correlating emission intensity to force induced material damage and the respective events on the molecular level is complicated by intrinsic limitations of fluorescence and its detection techniques. Now, this is tackled by developing the first stress-sensing motif that relies on photon upconversion. By combining the Diels-Alder adduct of a π-extended anthracene with the porphyrin-based triplet sensitizer PtOEP in polymers, triplet-triplet annihilation photon upconversion of green to blue light is mechanochemically activated in solution as well as in the solid state.
开发检测大分子材料损伤的方法对于理解其机械失效以及聚合物的结构-性能关系至关重要。为此，机械荧光团是有用且灵敏的分子基序。然而，迄今为止，调整它们的光学性质仍然具有挑战性，并且由于荧光及其检测技术的固有局限性，将发射强度与力诱导的材料损伤以及分子水平上的相应事件相关联很复杂。现在，通过开发第一个依赖于光子上转换的应力传感基序来解决这个问题。通过将π-扩展蒽的狄尔斯-阿尔德加合物与聚合物中基于卟啉的三重态敏化剂PtOEP相结合，溶液和固态中的绿色到蓝光的三重态-三重态湮灭光子上转换通过机械化学方式被激活。
