Pressure-Induced Luminescence in Crystalline Porous Materials: Material System, Optical Behavior, and...

Pressure-induced luminescence (PIL), activated through diamond anvil cell (DAC) techniques, has emerged as a vibrant research frontier with promising applications in sensing, data storage, and optoelectronics. Crystalline porous materials (CPMs), encompassing metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs), offer a uniquely versatile platform for studying and engineering this phenomenon. Their inherent characteristics-modular design, tunable topology, structural flexibility, and well-defined porosity-enable not only reversible and highly tunable piezochromic luminescence but also provide critical insights into fundamental structure-property relationships under mechanical stress. This review systematically consolidates recent advancements in the PIL of CPMs. We first establish the operational principles of the DAC as the principal pressure-generating tool. We then categorize and analyze PIL behaviors across the three major CPM families, elucidating how intrinsic factors-bonding nature (coordinative, covalent, or hydrogen-bonding), framework dimensionality, ligand chromophores, metal-node electronics, guest-framework interactions, and mechanical flexibility-govern optical responses to hydrostatic pressure generated by a DAC. Key paradigms, including reversible piezochromism, pressure-induced emission enhancement (PIEE), emission quenching, and ambient-retained luminescence, are discussed with representative studies. A dedicated comparative analysis synthesizes design principles and performance trade-offs across material systems. Finally, current challenges and perspectives are outlined to provide guidance for developing efficient, controllable, and multifunctional piezochromic materials with promising applications in advanced photonic technologies.