响应互补刺激的结构有序的软材料容易通过交叉或组合效应控制其空间和时间形态结构配置,例如门控,反馈,形状记忆,或编程。在缺乏通用和稳健的机械性能设计和预测策略的情况下,目前,化学和晶体工程相结合的方法可以提供有用的指南,以识别确定其响应的大小和时间的效应物。这里,我们利用所谓的软分子间相互作用的能力,通过使用卤化来激发有机晶体的机械和光化学活性来激发机械顺应性。从(E)-1,4-二苯基丁-2-烯-1,4-二酮开始,其晶体是易碎和光敏的,我们使用双重和四重卤化来引入卤素键合的平面,这些平面成为分子滑动的界面,渲染材料的机械和光化学塑料。氟化使机械效应进一步多样化,四氟衍生物的晶体也是有弹性的,但也是运动的,显示罕见的光显着剂效应。
Structurally ordered soft materials that respond to complementary stimuli are susceptible to control over their spatial and temporal morphostructural configurations by intersectional or combined effects such as gating, feedback, shape-memory, or programming. In the absence of general and robust design and prediction strategies for their mechanical properties, at present, combined chemical and crystal engineering approaches could provide useful guidelines to identify effectors that determine both the magnitude and time of their response. Here, we capitalize on the purported ability of soft intermolecular interactions to instigate mechanical compliance by using halogenation to elicit both mechanical and photochemical activity of organic crystals. Starting from (E)-1,4-diphenylbut-2-ene-1,4-dione, whose crystals are brittle and photoinert, we use double and quadruple halogenation to introduce halogen-bonded planes that become interfaces for molecular gliding, rendering the material mechanically and photochemically plastic. Fluorination diversifies the mechanical effects further, and crystals of the tetrafluoro derivative are not only elastic but also motile, displaying the rare photosalient effect.