锌-稀土异核金属配合物近红外发光及白光的研究

In recent decades, near-infrared (NIR) emission induced by lanthanide metal in photoelectric device preparation including laser materials, amplifier and light-emitting diode, and other fields of development make it become a hot research topic. However in near-infrared (NIR) complexes, because of the small band gap between the ground state and the excited state, energy is easily dissipated through the non-radiation. At the same time, due to their relatively short fluorescence lifetime, the application is limited. By use of transition metal complexes as ligand to sensitize rare-earth luminescence, to reduce its excitation energy, can obtain high sensitized rare earth near-infrared emission. This project intends to synthetize zinc rare earth heteronuclear metal complexes by use of benzoheterocycle and β-diketone ligands. The zinc complexes as a sensitizer, sensitize near-infrared emission of the rare earth ion and extend the emission lifetime and improve the luminous intensity. At the same time white-light emission can be achieved in heteronuclear complexes from "dual emission" in which complementary light was formed by residual blue light emission in zinc complexes and the red light emission in europium complexes. By adjusting the emission performance of sensitizer and controlling energy transfer rate and efficiency, it is feasible to make use of "dual emission" to develop new luminescent materials with low cost, including those that display white-light emission.

近几十年来，镧系金属诱导的近红外发射在光电器件的制备包括激光材料，放大器和发光二极管等领域的发展使其成为研究热点。然而近红外(NIR)稀土配合物中基态和激发态之间的带隙较小，能量容易通过非辐射消散；同时由于它们的荧光寿命相对较短，应用受到限制。利用过渡金属配合物作为配体敏化稀土发光，降低其激发能量，可以获得高效敏化稀土近红外发光。本项目拟采用苯并杂环与β-二酮两种配体合成锌-稀土异核金属配合物。利用过渡金属锌形成的配合物作为敏化剂，敏化稀土离子近红外发射，延长发光寿命和提高发光强度。同时利用锌配合物的残余青光发射带和以铕为中心的红光发射带，形成互补光，最终导致异核金属配合物具有白光发射性能。此类配合物通过调节敏化剂的发射性能以及控制能量传递速率和效率，充分利用"双重发射"光谱特性，有望开发出合成简单、成本低廉具有白光发射性能的新型发光材料。

近几十年来，镧系金属诱导的近红外发射在光电器件的制备包括激光材料，放大器和发光二极管等领域的发展使其成为研究热点。然而近红外(NIR)稀土配合物中基态和激发态之间的带隙较小，能量容易通过非辐射消散；同时由于它们的荧光寿命相对较短，应用受到限制。利用过渡金属配合物作为配体敏化稀土发光，降低其激发能量，可以获得高效敏化稀土近红外发光。. 本项目采用锌配合物作为前驱体，与β-二酮稀土配合物合成锌-稀土异核金属配合物。设计合成了系列锌-稀土异核金属配合物二十余个，并对其单晶结构及理化性质进行分析。测定所合成的锌-钕，锌-镱，锌-铒异核金属配合物的近红外发光性能，结合配合物的结构和发光性能，总结配合物中能量传递的规律。利用过渡金属锌形成的配合物作为敏化剂，敏化稀土离子近红外发射，延长发光寿命和提高发光强度。同时利用锌配合物的残余青光发射带和以铕为中心的红光发射带，形成互补光，最终导致异核金属配合物具有白光发射性能。此类配合物通过调节敏化剂的发射性能以及控制能量传递速率和效率，充分利用“双重发射”光谱特性，有望开发出合成简单、成本低廉具有白光发射性能的新型发光材料。首次利用镝离子掺杂铕离子实现混稀土配合物的白光发射。首次利用Suzuki偶联反应将大的共轭基团（芴、螺芴）引入类Salen配体，用于稀土配合物的合成，使稀土离子与体积较大的配体配位完全，从而阻止了稀土离子与溶剂分子配位，减弱由于C-H和O-H振动所引起的稀土离子的能量通过非辐射跃迁而消散的过程，从而得到具有较强近红外发光的特性荧光材料。