具有双光子效应的多核配合物

Two-Photon Absorptive Multinuclear Complexes

双光子吸收材料在上转换发光、生物成像、光动力学治疗、三维微结构加工等领域有着广泛的应用。金属配合物可通过金属中心为模板将数个具有双光子活性的有机配体组合成为复杂的多极体系从而增强双光子效应,还能使所得的双光子吸收材料的稳定性、发光寿命以及光谱的可调性得以优化,其中多核金属配合物的双光子吸收截面表现出的"协同增强"效应更是引起广泛关注。本文选取典型的多核配合物(分为同多核和异多核),重点总结金属离子的种类和数量、配体分子以及配合物的结构等参数对其双光子性能的影响,特别关注多核配合物激发态的结构和能级、能量传递的模式和方向等对其光物理性质的影响机制,希望总结具有双光子活性的多核配合物的分子设计规律。最后,对目前具有双光子活性的多核配合物的制备以及"多核双功能"型配合物的开发研究方面存在的问题进行阐述和展望,以期为新型双光子吸收材料的构筑提供参考。

Two-photon absorption（ TPA） materials have wide range of applications in the upconversion luminescent material,bioimaging,photodynamic therapy,three-dimensional lithographic microfabrication,etc.By using metal centers as template,metal complexes can combine several TPA active organic ligands into a complicate multipolar system to achieve enhanced TPA effect. The resulting two-photon absorptive material also displays better stability,extended emission lifetime and optimized spectral range when compared with the pure ligands. The ＂cooperative enhancement ＂ effect in the TPA cross-section of multinuclear metal complex has drawn broad attention. In this paper,representative multinuclear complexes（ homonuclear and heteronuclear） are selected to study the influencing factors on their TPA properties,such as the type and amount of metal ions,the structure of ligand molecules and complexes, etc. Special attention is paid to the mechanism of their photophysical properties that explain the structure and energy level of the excited states,the mode and direction of energy transfer in the multinuclear complexes,hoping to summarize the molecular design rules for TPA active multinuclear complexes. Finally,the existing problems in the research of multinuclear complexes with two-photon activity are described and studies on the ＂bifunctional multinuclear＂complex are prospected,which will provide an important base for future development of novel two-photon absorptive materials.