中国科学院福建物质结构研究所尤磊团队报道了光诱导C–N、C–O和C–S键的形成/断裂使共价体系具有可切换的稳定性/降解性。相关研究成果于2021年11月19日发表在《美国化学会杂志》。

共价键的操纵可以获得可降解、可回收和可持续的材料。然而，稳定性和可降解性之间存在内在冲突。

该文中，研究人员报告了三种类型的共价键（C–N、C–O和C–S），通过在动态共价系统的平衡态和非平衡态之间进行光开关的光控制形成/断裂，实现了光寻址稳定性和可切割性的双重好处。二噻吩基熔融醛环-链互变异构体的光环化打开反应性，分别高效可逆地结合/释放胺、醇和硫醇。光环逆转后，系统转变为动力学锁定的平衡形式，使共价组装具有显著的鲁棒性。反应耦合能够远程和定向控制各种平衡范围，并进一步扩大了范围。

通过在需要时锁定和解锁与光的共价键，生物活性分子的捕获/释放、表面的修饰以及显示定制稳定性和可降解性/可回收性的聚合物的创建都证明了该效用。用于开关物质的光开关动态共价反应的多功能工具箱会吸引很多人。

附：英文原文

Title: Light-Induced Formation/Scission of C–N, C–O, and C–S Bonds Enables Switchable Stability/Degradability in Covalent Systems

Author: Yu Hai, Hebo Ye, Ziyi Li, Hanxun Zou, Hanwei Lu, Lei You

Issue&Volume: November 19, 2021

Abstract: The manipulation of covalent bonds could be directed toward degradable, recyclable, and sustainable materials. However, there is an intrinsic conflict between properties of stability and degradability. Here we report light-controlled formation/scission of three types of covalent bonds (C–N, C–O, and C–S) through photoswitching between equilibrium and nonequilibrium states of dynamic covalent systems, achieving dual benefits of photoaddressable stability and cleavability. The photocyclization of dithienylethene fused aldehyde ring–chain tautomers turns on the reactivity, incorporating/releasing amines, alcohols, and thiols reversibly with high efficiency, respectively. Upon photocycloreversion the system is shifted to kinetically locked out-of-equilibrium form, enabling remarkable robustness of covalent assemblies. Reaction coupling allows remote and directional control of a diverse range of equilibria and further broadens the scope. Through locking and unlocking covalent linkages with light when needed, the utility is demonstrated with capture/release of bioactive molecules, modification of surfaces, and creation of polymers exhibiting tailored stability and degradability/recyclability. The versatile toolbox for photoswitchable dynamic covalent reactions to toggle matters on and off should be appealing to many endeavors.

DOI: 10.1021/jacs.1c09958

Source: https://pubs.acs.org/doi/10.1021/jacs.1c09958