Pressure-Induced Luminescence Enhancement Retained after Decompression in a Gadolinium-Based Metal–Organic Framework

Luminescent metal–organic frameworks (MOFs) are emerging as versatile platforms for molecular sensing, yet their emissive performance is often compromised by guest-induced quenching. However, strategies aiming to reactivate such luminescence-quenched states remain limited to date. Here, we demonstrate that high-pressure engineering provides an effective approach to address this challenge in the stored triclinic phase of Gd-MOF. After a compression–decompression cycle up to 16 GPa, the material exhibits an approximately 6-fold luminescence enhancement when quenched to ambient conditions, while largely retaining its broadband framework-related emission profile. In situ synchrotron X-ray diffraction results reveal an irreversible isostructural transition in the pressure range of ∼4–7 GPa, accompanied by abnormal framework softening, a volume collapse of ∼10.33 Å3 (∼3.38%), and pronounced anisotropic lattice compression. The structural transition and subsequent hysteretic recovery indicate that the initial framework environment is not fully restored after pressure release. Together with the moderate luminescence enhancement observed during compression, these results suggest that pressure-induced modification of the pore-guest environment may contribute to the enhanced emissive state, while retained framework distortion may provide an additional contribution. This work identifies high-pressure treatment as a feasible strategy for converting guest-sensitive porous frameworks from quenched states into more emissive states.