Rare Earth Complex-Based Functional Materials: From Molecular Design and Performance Regulation to Unique Applications

ConspectusRare earth (RE) elements, due to their unique electronic structures, exhibit excellent optical, electrical, and magnetic properties and thus have found widespread applications in the fields of electronics, optics, and biomedicine. A significant advancement in the use of RE elements is the formation of RE complexes. RE complexes, created by the coordination of RE ions with organic ligands, not only offer high molecular design flexibility but also incorporate features such as a broad absorption band and efficient energy transfer of organic ligands. Through the "antenna effect", organic ligands can transfer energy to RE ions, enhancing their luminescence efficiency. Moreover, the modification of the ligands can influence the local environment of the RE ions, thereby regulating their electronic structures and energy-level distributions. This makes it one of the important avenues for the efficient development and utilization of RE resources.The meticulous design of organic ligands during molecular synthesis enables the precise construction and regulation of RE complex structures, which are essential for probing molecular-level structure-performance relations and developing functional materials in fields such as optoelectronics, sensing, and catalysis/energy. Despite notable advancements, challenges persist in refining synthesis methodologies, innovating RE complex-based materials, enhancing stability, gaining better control over device functionality, and realizing high-value applications. This Account summarizes the recent advancements in molecular design and performance regulation achieved by our research group, particularly focusing on the synthesis and functional regulation of RE complex-based materials. We have employed strategies such as coordination self-assembly, in situ coordination, and microstructural evolution to achieve the precise synthesis and functional modulation of RE complex-based materials. These approaches have allowed us to finely tune properties such as the luminescence, electrical performance, and catalytic performance of various material systems. Consequently, we have made considerable strides in multidimensional optical information storage, the development of intelligent biological probes, the preparation of nanocatalysts, and the enhancement of inorganic-organic hybrid perovskite solar cell devices. Finally, we are committed to conducting an in-depth analysis of the challenges and opportunities that arise from the precise synthesis methods, performance regulation strategies, and innovative applications of RE complex-based functional materials. Additionally, we aim to propose potential solutions to current issues. This Account comprehensively summarizes the developments in RE complex-based materials to stimulate innovative thinking and new research directions and to establish a foundation for function-oriented precise synthesis methods.