Zhang Ning-Ning, Zhang Ya-Nan, Li Li, Li Zhen-Yu, Liu Ya-Tong, Dong Yunyun, Yan Yong, Wang Ming-Sheng
School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong 252000, P. R. China.
School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, 454000, P. R. China.
Dalton Trans. 2024 Apr 16;53(15):6547-6555. doi: 10.1039/d3dt04250b.
Metalloviologens, as emerging electron-transfer photochromic compounds, have shown intriguing properties such as radiochromism, photochromism and photoconductance. However, only a limited number of them have been reported so far. Exploration of new metalloviologens is strongly desired. Herein, we report a new solvothermally synthesized metalloviologen complex [CdCl(ND)] (1, ND = 1,5-naphthalenes) that exhibits photochromic and intrinsic white light emission properties. Density functional theory calculation results reveal that the photochromism could be assigned to photoinduced electron transfer from chlorine atoms to ND molecules. The photoinduced charge-separated states are heat/air stable, attributed to the delocalization of ND and strong intermolecular π-π interactions. Besides, complex 1 consistently emits intrinsic white light when excited with 340-370 nm UV light, achieving high color rendering index (CRI) values (82.54-94.04). By adjusting the excitation wavelength, both "warm" and "cold" white light emission can be produced, making it suitable for the application of a white light emitting diode (WLED). Thus, this work demonstrates that the ND-based metalloviologen is not only helpful in producing photochromism, but also beneficial for creating white-light emission.
金属紫精作为新兴的电子转移光致变色化合物，已展现出诸如辐射变色、光致变色和光电导等有趣的性质。然而，到目前为止，仅有有限数量的金属紫精被报道。因此强烈需要探索新型金属紫精。在此，我们报道了一种新的溶剂热合成的金属紫精配合物[CdCl(ND)]（1，ND = 1,5 - 萘二亚胺），其具有光致变色和本征白光发射性质。密度泛函理论计算结果表明，光致变色可归因于氯原子到ND分子的光诱导电子转移。光诱导电荷分离态对热/空气稳定，这归因于ND的离域作用和强分子间π - π相互作用。此外，配合物1在340 - 370 nm紫外光激发下持续发射本征白光，实现了高显色指数（CRI）值（82.54 - 94.04）。通过调整激发波长，既能产生“暖”白光发射，也能产生“冷”白光发射，使其适用于白光发光二极管（WLED）的应用。因此，这项工作表明基于ND的金属紫精不仅有助于产生光致变色，而且有利于实现白光发射。
