Low-Temperature Dynamics at Nano- and Macroscales: Organic Crystal That Exhibits Low-Temperature Molecular Motion and the Thermosalient Effect
José L. Belmonte‐Vázquez, Durga Prasad Karothu, Carl H. Fleischer, Dazaet Galicia‐Badillo, Mauricio Maldonado‐Domínguez, Robert W. Schurko, Liang Li, Pancě Naumov, Braulio Rodríguez‐Molina
Abstract
High Resolution Image Download MS PowerPoint Slide 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 2 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.