Highly Luminescent Nonclassical Binuclear Manganese(II) Complex Scintillators for Efficient X-ray Imaging
Zijian Zhou, Haixing Meng, Feiyang Li, Tianxiang Jiang, Yafeng Yang, Shujuan Liu, Qiang Zhao
Abstract
Scintillators can be widely applied to the fields of radioactivity detection, space exploration, and medical diagnosis and have attracted great attention. Recently, manganese(II) complexes with high-efficiency phosphorescent emission are expected to be good candidates for new scintillator materials. Herein, we design and synthesize a series of novel nonclassical binuclear neutral manganese(II) complexes with unique coordination modes, in which the crystal structures of CP1 and CP2 contain both four-coordinated and six-coordinated manganese(II) centers and CP3 is formed as a binuclear five-coordinated dichloro-bridged dimer. The single crystals of CP1 – CP3 exhibit excellent stability, which can be attributed to their nonionic structures. They all exhibit intense red emission under UV and X-ray irradiation. Among the three manganese(II) complexes, CP1 demonstrates the best luminescence efficiency and X-ray scintillation performance with a high photoluminescence quantum yield (PLQY) of 91.9%, a relative light yield of 21037 photons MeV –1, and a detection limit of 34.45 nGy air s –1 . Moreover, X-ray imaging based on CP1 scintillator screen demonstrates a spatial resolution of nearly 6 lp mm –1 . As far as we know, this is the first report about stable binuclear neutral manganese(II) complexes for X-ray imaging and opens a new avenue for exploring novel scintillator materials.