Topology-Tuned Structural Flexibility Toward Customized Piezofluorochromism in Stable Zirconium MOFs

Albeit serving important roles in high-techs, the rapid development of crystalline pressure-responsive materials still heavily relied on the de novo synthesis. Regarding pressure-responsive metal-organic frameworks (MOFs), their fascinating designability on the metal/ligand component has been extensively utilized, but yet for their network or topology tunability. Derived from the reticular chemistry, we, herein, present a distinctive exploration toward altered piezofluorochromic behaviors of highly-stable MOFs under GPa-level, of which is highly topology-focused. Specifically, each of the three selected organic ligand have yielded its corresponding zirconium-MOFs under csq- and scu-topology, whom all possessed well-behaved, reversible pressure-altered photoluminescence (PL). Comprehensive experimental and theoretical investigations revealed that the intrinsic network flexibility of scu-topology rendered the MOFs with larger PL response sensitivity, while the relatively rigid csq-topology could induce the rarely-reported pressure-induced emission enhancement (PIEE). This observed topology-dependent piezofluorochromism regulation proactively establishes a novel structure-property relationship in crystalline piezofluorochromic materials, while also spearheads a new horizon for customized smart pressure sensors and optoelectronic devices.