Rigidifying Effect of Metal–Organic Frameworks: Protect the Conformation, Packing Mode, and Blue Fluorescence of a Soft Piezofluorochromic Compound under Pressures up to 8 MPa

We demonstrate that the conformation, packing mode, and blue fluorescence of a soft piezofluorochromic compound can be preserved by structurally fixing it into a solid calcium metal–organic framework (Ca-MOF, LIFM-40), which can survive pressures up to 8 MPa. DFT calculations have been combined with experimental results to indicate that the ligands adopting a specific conformation and packing without π···π interactions are the reasons for its rigidified blue emission.