School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.
Macromolecular Architectures, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstraße 18, 76131, Karlsruhe, Germany.
Nat Commun. 2017 Nov 30;8(1):1869. doi: 10.1038/s41467-017-02022-0.
The ability to switch between thermally and photochemically activated reaction channels with an external stimulus constitutes a key frontier within the realm of chemical reaction control. Here, we demonstrate that the reactivity of triazolinediones, powerful coupling agents in biomedical and polymer research, can be effectively modulated by an external photonic field. Specifically, we show that their visible light-induced photopolymerization leads to a quantitative photodeactivation, thereby providing a well-defined off-switch of their thermal reactivity. Based on this photodeactivation, we pioneer a reaction manifold using light as a gate to switch between a UV-induced Diels-Alder reaction with photocaged dienes and a thermal addition reaction with alkenes. Critically, the modulation of the reactivity by light is reversible and the individually addressable reaction pathways can be repeatedly accessed. Our approach thus enables a step change in photochemically controlled reactivity, not only in small molecule ligations, yet importantly in controlled surface and photoresist design.
利用外部刺激在热激活和光化学激活反应通道之间进行切换，这是化学反应控制领域的一个关键前沿。在这里，我们证明了三唑啉二酮的反应性可以通过外部光子场有效地进行调节。具体来说，我们表明它们的可见光诱导聚合导致定量的光失活，从而为其热反应性提供了明确的关闭开关。基于这种光失活，我们开创了一种反应途径，使用光作为门，在光笼烯二烯的 UV 诱导 Diels-Alder 反应和与烯烃的热加成反应之间进行切换。关键是，光对反应性的调节是可逆的，并且可以重复访问单独寻址的反应途径。因此，我们的方法在光化学控制反应性方面实现了重大突破，不仅在小分子连接中，而且在受控表面和光致抗蚀剂设计中也非常重要。
