Self‐Induced Radioluminescence in Supramolecular Metal Halide Doped with Radioactive Isotope Strontium‐90.

Metal halides have recently garnered significant attention in developing functional materials, predominantly utilizing elements with stable isotopes as chemical components. However, the exploration of metal halides containing radioisotopes remains in its infancy, and their potential functionalities are not yet well understood. Herein, the synthesis and characterization of the first radionuclide‐doped supramolecular metal halide that displays unprecedented self‐induced radioluminescence are reported. The complex of 90Sr@[Sr2(18‐crown‐6 ether)2(H2O)2Cl2)]SbCl5, designated 90Sr‐(18C6@Sr)SbCl5, is synthesized by assembling both stable Sr2+ ions and millicurie‐level radioactive 90Sr2+ ion, co‐crystallized with SbCl52− anions. The inherent beta decays (β− particles) of 90Sr2+ ions from cationic supramolecular scaffoldings continuously ionize the SbCl52− anions, enabling self‐induced radioluminescence. Monte Carlo calculations reveal that ionization and bremsstrahlung processes predominantly generate secondary electrons, contributing to self‐induced radioluminescence. The self‐induced radioluminescence intensity of 90Sr‐(18C6@Sr)SbCl5 is measured to be 5.06 × 1012 counts•s−1•g−1•Ci−1, ≈18 times greater than that of the benchmark Th(NO3)4•5H2O compound. This discovery sheds light on the development of a new class of radioactive decay energy‐converting materials based on organo‐metal halides. [ABSTRACT FROM AUTHOR]