Ultra‐High‐Brightness Ln‐MOFs X‐ray Scintillators by Heavy Atoms, Aggregation Effects, and Hydrogen Bonds Restrict Movement

The synergistic effect of the "four-in-one" strategy, which includes the heavy atoms effect, coordination-induced emission (CIE), hydrogen bonds locking effect, and efficient antenna effect, was utilized to significantly enhance the light yield of Tb-SDB-MOF X-ray scintillator. Notably, the efficient heavy atoms effect enhances the X-ray absorption efficiency of Tb-SDB-MOF, synergistically with CIE, hydrogen bonds locking restriction of intramolecular motion (RIM), and an energy-matched antenna effect, producing a scintillation light yield of 69,575 photons MeV⁻¹ - a leading level among lanthanide complexes based X-ray scintillators. Meanwhile, the Tb-SDB-MOF X-ray scintillator exhibited an ultra-low detection limit (20.86 nGy/s), which is 264 times lower than the clinical standard, making it an "ultra-low dose" lanthanide complexes based X-ray scintillator. Moreover, low-concentration formic acid vapor selectively quenched the antenna effect of Tb³⁺ ions within Eu0.08Tb0.92-SDB-MOF, resulting in multistage multicolor luminescence switching from gold→brown→orange→deep-red→red. The Eu-SDB-MOF@Tb-SDB-MOF heterostructure facilitates the development of an advanced multi-functional anti-counterfeiting system by utilizing the highly efficient multicolor luminescence properties of a single crystal. Finally, this work not only opens new avenues for the development of lanthanide complexes based X-ray scintillators with ultrahigh light yield but also expands new horizons for the expansion of multifunctional lanthanide complexes.