School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China.
Department of Chemistry, College of Sciences, Shanghai University, Shanghai, 200444, China.
Angew Chem Int Ed Engl. 2023 Jun 12;62(24):e202304591. doi: 10.1002/anie.202304591. Epub 2023 May 4.
Lanthanide upconversion luminescence in nanoparticles has prompted continuous breakthroughs in information storage, temperature sensing, and biomedical applications, among others. Achieving upconversion luminescence at the molecular scale is still a critical challenge in modern chemistry. In this work, we explored the upconversion luminescence of solution dispersions of co-crystals composed of discrete mononuclear Yb(DBM) Bpy and Eu(DBM) Bpy complexes (DBM: dibenzoylmethane, Bpy: 2,2'-bipyridine). The 613 nm emission of Eu was observed under excitation of Yb at 980 nm. From the series of molecular assemblies studied, the most intense luminescence was obtained for a 1 : 1 molar ratio of Yb : Eu , resulting in a high quantum yield of 0.67 % at 2.1 W cm . The structure and energy transfer mechanism of the assemblies were fully characterized. This is the first example of an Eu -based upconverting system composed of two discrete mononuclear lanthanide complexes present as co-crystals in non-deuterated solution.
镧系元素上转换发光在纳米粒子中引发了信息存储、温度感应和生物医学应用等领域的持续突破。在分子尺度上实现上转换发光仍然是现代化学的一个关键挑战。在这项工作中，我们研究了由离散单核 Yb(DBM)Bpy 和 Eu(DBM)Bpy 配合物（DBM：二苯甲酰甲烷，Bpy：2,2'-联吡啶）组成的共晶在溶液分散体中的上转换发光。在 980nm 的 Yb 激发下观察到 Eu 的 613nm 发射。在所研究的一系列分子组装体中，Yb:Eu 的摩尔比为 1:1 时获得了最强的发光，在 2.1W/cm 的量子产率为 0.67%。组装体的结构和能量传递机制得到了充分的表征。这是首例由两个离散单核镧系配合物组成的基于 Eu 的上转换体系，以非氘代溶液中的共晶形式存在。
