Pan Xiuhong, Lan Linfeng, Zhang Hongyu
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University Qianjin Street Changchun 130012 P. R. China
Chem Sci. 2024 Sep 27;15(42):17444-52. doi: 10.1039/d4sc05005c.
Flexible organic crystals, capable of transmitting light and responding to various external stimuli, are emerging as a new frontier in optoelectronic materials. They hold immense potential for applications in molecular machines, sensors, displays, and intelligent devices. Here, we report on flexible organic crystals based on single-component enantiomeric organic compounds, demonstrating multi-stimuli-responsive circularly polarized light (CPL). These crystals exhibit remarkable elasticity, responsiveness to light and acid vapors, and tunable circularly polarized optical signals. Upon exposure to acid vapors, the fluorescence of the crystals shifts from initial yellow emission to green emission, attributable to the protonation-induced inhibition of excited-state intramolecular proton transfer. Under UV irradiation, the fluorescence emission undergoes a red-shift, resulting from the molecular transformation from an enol configuration to a ketone configuration. Notably, both processes are reversible and can be restored under daylight. The integration of reversible fluorescence changes under light and acid vapors stimuli, CPL signals, and flexible optical waveguides within a single crystal paves the way for the application of organic crystals as all-organic chiral functional materials.
能够传输光线并对各种外部刺激做出响应的柔性有机晶体，正成为光电子材料领域的一个新前沿。它们在分子机器、传感器、显示器和智能设备等应用中具有巨大潜力。在此，我们报道了基于单一组分对映体有机化合物的柔性有机晶体，其展现出多刺激响应圆偏振光（CPL）。这些晶体具有显著的弹性、对光和酸蒸气的响应性以及可调节的圆偏振光信号。暴露于酸蒸气时，晶体的荧光从最初的黄色发射转变为绿色发射，这归因于质子化诱导的激发态分子内质子转移的抑制。在紫外线照射下，荧光发射发生红移，这是由于分子从烯醇构型转变为酮构型所致。值得注意的是，这两个过程都是可逆的，并且在日光下可以恢复。在单个晶体中集成光和酸蒸气刺激下的可逆荧光变化、CPL信号以及柔性光波导，为有机晶体作为全有机手性功能材料的应用铺平了道路。
