Halogen‐bonding boosting the high performance X‐ray imaging of organic scintillators

Abstract

AbstractOrganic scintillators with efficient X‐ray excited luminescence are essential for medical diagnostics and security screening. However, achieving excellent organic scintillation materials is challenging due to low X‐ray absorption coefficients and inferior radioluminescence (RL) intensity. Herein, supramolecular interactions are incorporated, particularly halogen bonding, into organic scintillators to enhance their radioluminescence properties. By introducing heavy atoms (X = Cl, Br, I) into 9,10‐bis(4‐pyridyl)anthracene (BPA), the formation of halogen bonding (BPA‐X) enhances their X‐ray absorption coefficient and restricts the molecular vibration and rotation, which boosts their RL intensity. The RL intensity of BPA‐Cl and BPA‐Br fluorochromes increased by over 2 and 6.3 times compared to BPA, respectively. Especially, BPA‐Br exhibits an ultrafast decay time of 8.25 ns and low detection limits of 25.95 ± 2.49 nGy s−1. The flexible film constructed with BPA‐Br exhibited excellent X‐ray imaging capabilities. Furthermore, this approach is also applicable to organic phosphors. The formation of halogen bonding in bromophenyl‐methylpyridinium iodide (PYI) led to a fourfold increase in RL intensity compared to bromophenyl‐methyl‐pyridinium (PY). It suggests that halogen bonding serves as a promising and effective molecular design strategy for the development of high‐performance organic scintillator materials, presenting new opportunities for their applications in radiology and security screening.