Aydonat Simay, Campagna Davide, Kumar Sourabh, Storch Sonja, Neudecker Tim, Göstl Robert
Department of Chemistry and Biology, University of Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany.
DWI─Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
J Am Chem Soc. 2024 Nov 20;146(46):32117-32123. doi: 10.1021/jacs.4c13319. Epub 2024 Nov 7.
Current approaches to the discovery of mechanochemical reactions in polymers are limited by the interconnection of the zero-force and force-modified potential energy surfaces since most mechanochemical reactions are force-biased thermal reactions. Here, carbamoyloximes are developed as a mechanophore class in which the mechanochemical reaction rates counterintuitively increase together with the thermal stability. All carbamoyloxime mechanophores undergo force-induced homolytic bond scission at the N-O bond, and their mechanochemical scission rate increases with the degree of substitution on the α-substituent. Yet, carbamoylaldoximes react to both heat and light with a pericyclic elimination, while carbamoylketoximes undergo thermal decomposition at high temperature and photochemical homolytic scission only from the triplet state. Thereby, the mechanochemical and thermal reaction trajectories are separated, and the thermal stability increases alongside the mechanochemical reaction kinetics. This approach may play an important role in the future of systematic mechanochemical reaction discovery.
由于大多数机械化学反应是力偏向热反应，聚合物中机械化学反应的当前发现方法受到零力和力改性势能面相互连接的限制。在此，氨基甲酰肟被开发为一类机械基团，其中机械化学反应速率与热稳定性反常地一起增加。所有氨基甲酰肟机械基团在N-O键处发生力诱导的均裂键断裂，并且它们的机械化学断裂速率随着α-取代基上的取代度增加而增加。然而，氨基甲酰醛肟通过周环消除对热和光都有反应，而氨基甲酰酮肟在高温下发生热分解，并且仅从三重态进行光化学均裂。因此，机械化学反应轨迹和热反应轨迹是分开的，并且热稳定性随着机械化学反应动力学而增加。这种方法可能在未来系统的机械化学反应发现中发挥重要作用。
