Pressure-promoted ligand to metal energy transfer for emission enhancement of [Tb2(BDC)3(DMF)2(H2O)2]n metal-organic framework

Lanthanide metal-organic frameworks (Ln-MOFs) have received extensive attention in the development of photoluminescent (PL) materials due to their stable structures and unique line-like emission spectroscopic properties. However, in order to prepare Ln-MOFs with high PL quantum yield (PLQY), further improving the sensitization efficiency of the "antenna effect" is essential. Herein, remarkably enhanced PL in [Tb-2(BDC)(3)(DMF)(2)(H2O)(2)](n) MOF is successfully achieved via high-pressure engineering at room temperature. Notably, the PL intensity continues to increase as the pressure increases, reaching its peak at 12.0 GPa, which is 4.4 times that of the initial state. Detailed experimental and theoretical calculations have demonstrated that pressure engineering significantly narrows the bandgap of [Tb-2(BDC)(3)(DMF)(2)(H2O)(2)](n), optimizing both singlet and triplet energy levels. Ultimately, higher antenna effect sensitization efficiency is achieved by promoting intersystem crossing and energy transfer processes. Our work provides a promising strategy for the development of high PLQY Ln-MOFs.