Belmonte-Vázquez José L, Karothu Durga Prasad, Fleischer Carl H, Galicia-Badillo Dazaet, Maldonado-Domínguez Mauricio, Schurko Robert W, Li Liang, Naumov Panče, Rodríguez-Molina Braulio
Instituto de Química (IQ), Universidad Nacional Autónoma de México (UNAM), Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, México.
Departamento de Química Orgánica, Facultad de Química (FQ), Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Ciudad de México 04510, México.
Chem Mater. 2025 May 1;37(9):3373-3383. doi: 10.1021/acs.chemmater.5c00171. eCollection 2025 May 13.
The thermosalient effect is a rarely observed, potentially very useful and at the present, unpredictable mechanical response during a phase transition that is thought to hold the potential for rapid and clean energy conversion devoid of gaseous products. Here, we report the serendipitous discovery of a rare instance of a thermosalient organic solid that exhibits the effect below room temperature. The crystals of this carbazole-based material are dynamic at both molecular and macroscopic scales. Using variable temperature synchrotron X-ray diffraction and variable-temperature solid-state nuclear magnetic resonance (ssNMR), we thoroughly examined the hysteretic structural transition in this material, emphasizing its macroscopic reconfigurability. We discovered unexpected large-amplitude molecular oscillations in the low-temperature phase, which challenge conventional assumptions about salient materials. Notably, we combined H ssNMR with computational modeling to reveal this dual-scale dynamism, setting the groundwork for advancements in energy-efficient actuators, sensors, and intelligent materials. This work might open new avenues for developing crystalline materials that can be implemented in innovative devices operating seamlessly across various scales.
热致跳跃效应是一种在相变过程中很少被观察到、可能非常有用且目前无法预测的力学响应，人们认为它具有实现无气态产物的快速清洁能源转换的潜力。在此，我们报告了偶然发现的一种罕见的热致跳跃有机固体，它在室温以下表现出这种效应。这种咔唑基材料的晶体在分子和宏观尺度上都是动态的。利用变温同步辐射X射线衍射和变温固态核磁共振（ssNMR），我们深入研究了该材料中的滞后结构转变，强调了其宏观可重构性。我们在低温相中发现了意想不到的大幅度分子振荡，这对关于跳跃材料的传统假设提出了挑战。值得注意的是，我们将氢ssNMR与计算模型相结合，以揭示这种双尺度动态特性，为节能致动器、传感器和智能材料的发展奠定了基础。这项工作可能为开发可用于跨各种尺度无缝运行的创新设备的晶体材料开辟新途径。
