本文要点：
软多孔晶体被认为是第三代智能多孔材料，可以响应外部刺激(如温度、压力和客体分子)而发生结构变形。目前，软多孔晶体的动态相变主要通过基于气体吸附和粉末X射线衍射的定量建模来确定。
在本文中，作者研究了共价有机软多孔晶体在COF-300上的单晶到单晶的结构转变，并鉴定了在室温和高温下由不同客体分子诱导的九种不同的构象异构体。值得注意的是，COF-300即使在280°C也能保持其单晶结构，并能有效吸收熔融态的多环芳烃。
结合PXRD和理论计算研究了构象异构体之间的结构转化动力学。从高能态到低能态的结构转变是一个快速的、能量上有利的过程，而反向转变是一个由浓度梯度驱动的缓慢过程。
Fig. 1 | The schematic representation of the structural transformation of COF-300 at room temperature.
Fig. 2 | The single-crystal-to-single-crystal structural transformation of COF300 at room temperature. a The optical microscopic image of single-crystal COF300 with size ~ 200 μm. b The diamondoid unit and sevenfold-interpenetrated structure of COF-300. c The dimensions of diamondoid units and the angle between neighboring linkers. The channel sizes (d) and the simulated PXRD patterns (e) of COF-300-c, COF-300-ho, COF-300, COF-300-r and COF-300-o.
Fig. 3 | The single-crystal-to-single-crystal structural transformation of COF-300 at melting temperature of polycyclic aromatic hydrocarbon molecules.
Fig. 4 | The kinetics of structural transformations among the conformational isomers of COF-300. a The PXRD patterns of structural transformation from COF-300-ho to COF-300. b From COF-300-c to COF-300. c From COF-300 to COF300-ho.d From COF-300-c to COF-300-ho. e Schematic representation of the structural transformations.
https://doi.org/10.1038/s41467-025-56750-9
