Electrostatic Potential Tuning-Driven Molecular Rotor Rotation in Isostructural Metal-Organic Frameworks for...

C₃ hydrocarbon separation is a core process for refining high-value-added petrochemical products. However, due to the remarkably similar physicochemical properties of these molecules, metal-organic frameworks (MOFs) typically encounter an inherent adsorption capacity-selectivity trade-off. The dynamic pore characteristics of molecular rotor-functionalized MOFs offer a novel approach to address this challenge. Herein, we propose an electrostatic potential matching strategy to drive the rotation of molecular rotors within MOF, boosting C₃H₆/C₃H₈ separation. By modulating the amino density in MOFs through crystal engineering, three isomorphous MOFs (CoNi-PYZ, CoNi-PYZ-NH₂, and CoNi-PYZ-2NH₂). CoNi-PYZ-2NH₂ with a highly electronegative pore surface precisely matches the C₃H₆ molecules, driving the molecular rotor rotation within the MOF, endowing the framework with unique flexibility, and thereby exhibiting a distinctive gate-opening effect toward C₃H₆. This grants CoNi-PYZ-2NH₂ exceptional C₃H₆/C₃H₈ (50/50, v/v) selectivity (96.5), which is 13.8 and 21.4 times higher than those of CoNi-PYZ and CoNi-PYZ-NH₂ and significantly enhances C₃H₆ uptake at low pressure (30.6 cm³ g^-1 at 0.01 bar and 298 K). Moreover, it exhibits an excellent C₃H₆ storage density of 0.785 kg L^-1. Dynamic breakthrough experiments validate its superior dynamic separation performance. This study establishes an electrostatic potential-driven molecular rotor rotation strategy, providing valuable insights for the development of high-performance adsorbents.