Rath Bibhuti Bhusan, Gallo Gianpiero, Dinnebier Robert E, Vittal Jagadese J
Department of Chemistry, National University of Singapore, Singapore 117543.
Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany.
J Am Chem Soc. 2021 Feb 3;143(4):2088-2096. doi: 10.1021/jacs.0c12363. Epub 2021 Jan 21.
Thermally responsive crystals hold great potential for their use as actuating materials by acting as energy transducers to convert heat energy to mechanical work. Control over defined phase transition temperature with rapid reconfiguration is of great advantage for actuation. The thermosalient (TS) effect is a rarely observed phenomenon in coordination polymers (CPs), let alone the reversibility of thermosalience in CPs. Herein, we report the reversible TS effect in a one-dimensional CP due to the martensitic phase transition during both heating and cooling cycles. The TS effect was preceded by anisotropic thermal expansion showing high expansion coefficients. In addition, the nonmolecular crystals show reversible contraction and recovery during multiple heating-cooling cycles due to the self-restorative shape memory effect. The reversible actuation of the CP could be repeated for 20 heating-cooling cycles in differential scanning calorimetry experiments, suggesting its great potential as a multicyclic actuator. Such thermal responsive behavior is unique in metal-organic materials.
热响应晶体作为能量转换器将热能转化为机械功，用作驱动材料具有巨大潜力。通过快速重新配置来控制特定的相变温度对驱动非常有利。热突出（TS）效应在配位聚合物（CPs）中是一种很少观察到的现象，更不用说CPs中热突出的可逆性了。在此，我们报道了一种一维CP中由于加热和冷却循环期间的马氏体相变而产生的可逆TS效应。TS效应之前是具有高膨胀系数的各向异性热膨胀。此外，由于自恢复形状记忆效应，非分子晶体在多个加热-冷却循环中显示出可逆收缩和恢复。在差示扫描量热法实验中，CP的可逆驱动可以重复20个加热-冷却循环，表明其作为多循环致动器具有巨大潜力。这种热响应行为在金属有机材料中是独特的。
