Luminescent MOFs are premier sensing platforms, typically governed by guest-induced quenching. While conventional thermal or chemical reactivation methods often suffer from structural degradation, pressure engineering offers a cleaner, more efficient route for optical reconfiguration. Here, we demonstrate a remarkable sixfold luminescence enhancement in a triclinic Gd-MOF following a 16 GPa compression–decompression cycle. In situ synchrotron XRD reveals an irreversible isostructural transition at ~4–5 GPa, concomitant with a ~10 ų volume collapse and partial guest expulsion from the pores. Analysis of lattice descriptors shows that the incomplete relaxation of the a-axis and β angle manifests a pronounced structural hysteresis, which stabilizes a metastable pore geometry. This modified framework precludes guest re-entry into quenching sites and mitigates non-radiative decay, thereby transmuting structural memory into permanent, enhanced luminescence.
 

MOF, High pressure, Diamond anvil cell, Luminescence, Phase transition