Conformation‐Adaptive Transformations of Flexible Frameworks: From Controlled Stimuli‐Responsiveness to Regulated Responsive Behaviors

Abstract

Abstract Synthesizing enzyme‐like porous materials that can regulate responsiveness through conformations remains a challenge. Here, two flexible framework conformers ( FJI‐H29 and FJI‐H41 ) were prepared from a semirigid ligand. They not only exhibit different responses to the same stimuli, but their responsive behaviors can also be regulated precisely. FJI‐H29 is thermosensitive, it can undergo continuous thermal‐driven transformations, from reversible deformations to irreversible reconstruction, and the reconstruction barrier can be further tuned. While FJI‐H41 is sensitive to the kinetic energy generated by solvent removal; when the solvents escape vigorously, it in situ shrinks to a more stable conformer ( FJI‐H43 ); when the solvents escape slowly, it first forms a shape maintaining metastable state ( FJI‐H41' ), then spontaneously transforms into FJI‐H43 . Structural analysis shows the FJI‐H29 is mechanically stable, while its ligands undergo more severe distortion with increasing temperature, enabling it to undergo thermal‐driven reconstruction. Whereas FJI‐H41 is mechanically unstable, so it is prone to undergo desolvent‐driven deformations. FJI‐H43 not only exhibits a temperature‐dependent gate‐open effect for the adsorption of C 2 H 2 and CO 2 but can also be used for one‐step C 2 H 4 purification from C 2 H 2 /C 2 H 4 /CO 2 mixture; but FJI‐H29 does not work. This provides a new strategy for preparing enzyme‐like porous materials.