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Abstract：
The advent of covalent adaptable networks (CANs) through the incorporation of dynamic covalent bonds has led to unprecedented properties of macromolecular systems, which can be engineered at the molecular level. Among the various types of stimuli that can be used to trigger chemical changes within polymer networks, light stands out for its remote and spatiotemporal control under ambient conditions. However, most examples of photoactive CANs need to be transparent and they exhibit slow response, side reactions, and limited light penetration. In this vein, it is interesting to understand how molecular engineering of optically active dynamic linkages that offer fast response to visible light can impart \"living\" characteristics to CANs, especially in opaque systems. Here, the use of carbazole-based thiuram disulfides (CTDs) that offer dual reactivity as photoactivated reshuffling linkages and iniferters under visible light irradiation is reported. The fast response to visible light activation of the CTDs leads to temporal control of shape manipulation, healing, and chain extension in the polymer networks, despite the lack of optical transparency. This strategy charts a promising avenue for manipulating multifunctional photoactivated CANs in a controlled manner.
摘要：
通过结合动态共价键的共价适应网络（CAN）的出现导致了大分子系统前所未有的特性，可以在分子水平上设计。在可用于触发聚合物网络内化学变化的各种类型的刺激中，光因其在环境条件下的远程和时空控制而脱颖而出。然而,大多数光敏CAN的例子需要是透明的，并且它们表现出缓慢的响应，副反应,和有限的光穿透力。在这种情况下，我们有兴趣了解提供快速响应可见光的光学活性动态连接的分子工程如何赋予CAN“活”特征，尤其是在不透明的系统中。这里,我们报告了基于咔唑的秋兰姆二硫化物（CTD）的使用，该化合物在可见光照射下提供双重反应性，例如光活化的洗牌键和引发剂。CTD对可见光激活的快速响应导致形状操纵的时间控制，愈合，和聚合物网络中的扩链，尽管缺乏光学透明度。该策略描绘了以受控方式操纵多功能光活化CAN的有希望的途径。本文受版权保护。保留所有权利。
