Institute for New Energy Materials and Low Carbon Technologies, Tianjin University of Technology, Tianjin, 300384, China.
College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China.
Small. 2022 Apr;18(14):e2106587. doi: 10.1002/smll.202106587. Epub 2021 Dec 19.
Multi-emission materials have come to prominent attention ascribed to their extended applications other than single-emission ones. General and robust design strategies of a single matrix with multi-emission under single excitation are urgently required. Metal-organic frameworks (MOFs) are porous materials prepared with organic ligands and metal nodes. The variety of metal nodes and ligands makes MOFs with great superiority as multi-emission matrices. Guest species encapsulated into the channels or pores of MOFs are the additional emission sites for multi-emission. In this review, multi-emission MOFs according to the different excitation sites are summarized and classified. The emission mechanisms are discussed, such as antenna effect, excited-state intramolecular proton transfer (ESIPT) and tautomerism for dual-emission. The factors that affect the emissions are revealed, including ligand-metal energy transfer and host-guest interaction, etc. Multi-emission MOFs could be predictably designed and prepared, once the emissive factors are controlled rationally in combination with the different multi-emission mechanisms. Correspondingly, new and practical applications are realized, including but not limited to ratiometric/multi-target sensing and bioimaging, white light-emitting diodes, and anti-counterfeiting. The design strategies of multi-emission MOFs and their extensive applications are reviewed. The results will shed light on other multi-emission systems to develop the structure-derived functionality and applications.
多发射材料因其在单一激发下具有多种发射的扩展应用而受到广泛关注。迫切需要开发一种单一基质的通用且稳健的多发射设计策略。金属有机骨架（MOFs）是由有机配体和金属节点制备的多孔材料。金属节点和配体的多样性使 MOFs 具有作为多发射基质的巨大优势。客体物种封装在 MOFs 的通道或孔中，是多发射的额外发射位点。在这篇综述中，根据不同的激发位点对多发射 MOFs 进行了总结和分类。讨论了发射机制，例如双发射的天线效应、激发态分子内质子转移（ESIPT）和互变异构。揭示了影响发射的因素，包括配体-金属能量转移和主体-客体相互作用等。一旦合理控制发光因素并结合不同的多发射机制，就可以对多发射 MOFs 进行可预测的设计和制备。相应地，实现了新的实际应用，包括但不限于比率/多目标传感和生物成像、白光发光二极管和防伪。综述了多发射 MOFs 的设计策略及其广泛的应用。这些结果将为开发基于结构的功能和应用提供其他多发射系统的启示。
