High‐Resolution X‐Ray Circular Polarization Imaging Enabled by Luminescent Photopolymerized Chiral Metal‐Organic Polymers

Abstract Scintillators can convert the ionizing radiation into visible light and are crucial in X/γ‐ray detectors. Commercial detectors often use multiple scintillators with photodetector arrays, where optical crosstalk can degrade the performance. Chiral scintillators, emitting circularly polarized light, offer a promising solution for regulating the direction of light propagation to enhance X‐ray detecting merits. Here novel chiral metal‐organic polymers have been developed via photopolymerization, using chiral polymeric monomers and 0D Mn(II)‐based organic‐metal halide hybrid scintillators, achieving luminescence dissymmetry factors ( g lum ) of 5.823 × 10 −2 and −2.877 × 10 −2 . Two such scintillators, (atpp) 2 MnCl 4 ·0.5H 2 O (MnCl 4 − 1 ) and (atpp) 2 MnBr 4 (MnBr 4 − 2 ), exhibit excellent X‐ray scintillation rooted in tetrahedral [MnX 4 ] 2− crystal field. Compound MnBr 4 − 2 , with heavier bromine atoms, shows superior performance with a detection limit of 0.117 µGy air s −1 , compared to 0.330 µGy air s −1 of MnCl 4 − 1 , both surpassing the medical diagnostic standard of 5.50 µGy air s −1 . The chiral metal‐organic polymer film derived from MnBr 4 − 2 has achieved a resolution up to 14.84 lp mm −1 , exceeding medical standards for dental (2.0 lp mm −1 ) and breast cancer (10.0 lp mm −1 ) imaging. These advancements in chiral scintillators hold significant promise for high‐resolution X‐ray medical imaging applications.