A Flexible Fluorescent SCC-MOF for Switchable Molecule Identification and Temperature Display

Flexible luminescent metal-organic frameworks (MOFs) sensitive to physical and chemical variation demonstrate potential application in sensing, but are commonly limited to ones incorporating specialized chromophores, so that the design, preparation, and reversible well-defined crystallographic transitions of such materials remain a great challenge. Here, an easily prepared flexible luminescent silver-chalcogenolate cluster based metal-organic framework (SCC-MOF), Ag(10)bpy, exceptionally distinguishes chloromethanes CH2Cl2, CHCl3, and CCl4 by different fluorescent responsive signals, which originated from its crystalline dipole moment orientation relative to chromophores. Moreover, glass-to-fluid transition of the distinctly responsive species in the crystalline pore is demonstrated to modulate striking chromism with scarce segmented emission among MOFs, resulting from subtle dynamic solvation of chromophores. Retention of single crystallinity enables elucidation of the relationship between distinct fluorescent response and complicated structural variation at the molecular level. This new type of flexible emissive SCC-MOF is potentially useful for the development of versatile sensing and switching fluorescent materials.