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南京邮电大学的马云、刘淑娟、赵强等研究人员近期成功研制了适用于白光LED和X射线成像应用的多功能手性五配位锰(II)配合物。 该研究团队报道了一对基于氧化膦的手性锰(II)配合物，即R/S-[(L)2MnBr]Br，其中L代表5,5′-双(二苯基氧化膦)-4,4′-双-1,3-苯二氮杂唑。这些配合物展现了独特的五配位晶体结构，并具备出色的稳定性。 值得一提的是，R/S-[(L)2MnBr]Br在室温条件下发出强烈的红色光芒，并展现出卓越的圆偏振发光特性，其发光不对称因子分别达到+1.56×10−2和-1.94×10−2。通过将S-[(L)2MnBr]Br与商用荧光粉结合，研究团队成功制备了色温为4512 K的白光发光二极管，其显色指数高达96.9。 此外，研究人员还观察到目标化合物具有特殊的闪烁性能，并成功展示了分辨率高达11.9 lp mm−1的X射线成像。 这一研究成果为多功能手性锰基发光材料的未来发展提供了重要启示。 Figure 1: a) A schematic diagram illustrating the procedure for growing R/S-[(L)2MnBr]Br single crystals. b) Crystal structures of R-[(L)2MnBr]Br (depicted on the left) and S-[(L)2MnBr]Br (shown on the right). c) Visual representations of R/S-[(L)2MnBr]Br crystals illuminated by ultraviolet light. Figure 2a and 2b present the excitation and emission spectra of R/S-[(L)2MnBr]Br, respectively. Meanwhile, Figure 2c and 2d depict the time-resolved PL decay curves of R/S-[(L)2MnBr]Br, respectively. Figure 3 a) Presents the CPL spectra of R/S-[(L)2MnBr]Br. b) Illustrates the glum of R/S-[(L)2MnBr]Br. c) Provides comparisons between glum and PLQY values for R/S-[(L)2MnBr]Br alongside representative manganese(II)-based chiral materials. d) Exhibits the DC spectra of R/S-[(L)2MnBr]Br. Figure 4 presents the following: a) The EL emission spectrum of the white LED that utilizes S-[(L)2MnBr]Br at a current of 60 mA. b) The chromaticity diagram from the 1931 Commission Internationale de L’Eclairage (CIE) for this white LED. c) A comparison of EL spectra from the white LED under varying drive currents. d) A demonstration of the linear correlation between EL intensity and the applied drive current. Figure 5 presents the following: a) The absorption coefficients of both R/S-[(L)2MnBr]Br and LuAG:Ce are displayed. b) An examination of the RL spectrum for R-[(L)2MnBr]Br as it varies under different dose rates. c) A determination of the lowest detection limit achievable with R-[(L)2MnBr]Br. d) A comparative analysis of the RL intensity spectra between R/S-[(L)2MnBr]Br and the reference LuAG:Ce scintillator, normalized based on their X-ray attenuation efficiencies. e) An evaluation of the irradiation stability exhibited by R/S-[(L)2MnBr]Br scintillators when subjected to cyclical X-ray illumination. f) An assessment of the humidity stabilities of R/S-[(L)2MnBr]Br, conducted at an X-ray dose rate of 4.5 mGyair s−1. Figure 6 presents the following: a) Photographs of the R-[(L)2MnBr]Br scintillation screen captured under daylight conditions and upon exposure to UV irradiation. b) The PL spectrum specifically related to the R-[(L)2MnBr]Br scintillation screen. c) Additional photographs of the R-[(L)2MnBr]Br scintillation screen, demonstrating its appearance at various bending angles when illuminated with UV light. d) X-ray images of a leaf-shaped metal bookmark, captured using the R-[(L)2MnBr]Br scintillation screen in its flat state. e) X-ray images of the same leaf-shaped metal bookmark, but this time with the R-[(L)2MnBr]Br scintillation screen in a curved state. f) A side-by-side comparison of a photograph and its corresponding X-ray image, both featuring the standard X-ray test-pattern plate. g) The Modulation Transfer Function (MTF) curve associated with the R-[(L)2MnBr]Br scintillation screen, recorded at an X-ray dose rate of 189 µGyair s−1.
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