Giant Isotope Effect in Metal–Organic Frameworks Boosts Unprecedented Photo‐ and Radio‐Luminescence Enhancement

Isotope effect (IE) has emerged as a powerful strategy for tailoring the photophysical properties of luminescent systems, yet its application in solid materials remains limited. Herein, we presented a simple and general in situ deuteration strategy to synthesize a series of deuterated metal-organic frameworks (MOFs) with enhanced emission performance. One resulting MOF (EuBTC-D) exhibits an IE-triggered comprehensive luminescence enhancement (4.15-fold longer lifetime and 3.49-fold higher quantum yield) that surpasses all reported solid-state deuterated materials. The giant isotope effect is attributed to the drastic suppression of non-radiative decay in EuBTC-D, where deuteration effectively freezes the molecule thermal motions of the water-rich framework and stabilizes the long-lived triplet excitons. Furthermore, the scope of IE is further extended to radioluminescence, yielding upgraded X-ray detection sensitivity and imaging resolution. This work establishes isotopic engineering as a versatile and powerful Isotope effect, Metal-organic framework, Photoluminescence, Radioluminescencetool for developing advanced luminescent MOFs and scintillating materials.