Fluorescent Lanthanide Anthracene Frameworks for High‐Resolution Cellular Imaging and Iron(II) Sensing

ABSTRACT Three fluorescent lanthanide (La/Dy) anthracene frameworks were synthesized under solvothermal conditions using the semi‐flexible anthracene‐derived zwitterionic ligand 9, 10‐bis[ (4‐carboxylato) pyridin‐1‐ium‐1‐ylmethyl]anthracene (BCPA): Dy (BCPA) 2 (H 2 O) 4 ·Cl 3 ·DMF·EtOH· (H 2 O) 3 · (S) n (MOF‐1), La (BCPA) 2 (H 2 O) ·Cl 3 · (H 2 O) 2 · (S) n (MOF‐2), and Dy (BCPA) (H 2 O) 4 ·Cl 3 · (S) n (MOF‐3), where S represents disordered solvent molecules. MOF‐1 features a 1D chain architecture, whereas MOF‐2 and MOF‐3 crystallize into 3D frameworks. MOF‐1 exhibits nanometer‐scale particle size, strong photoluminescence, and high solubility in water/DMSO mixtures, making it an efficient probe for high‐resolution live‐cell imaging in HCT‐15 cells with minimal cytotoxicity. In contrast, porous 3D architectures of MOF‐2 and MOF‐3, combined with their robust fluorescence, enable sensitive Fe 2 + detection, displaying higher quenching efficiency and lower detection limits than MOF‐1. Therefore, despite their identical chemical compositions, the dimensionality‐induced differences in morphology and surface accessibility provide a rational basis for the observed divergence in biological imaging versus chemical sensing applications.