【作者】 卫慧波； 卞江； 卞祖强； 黄春辉；

【Author】 Wei Huibo~1 Bian Jiang~1 Bian Zuqiang~(*,1) Huang Chunhui~(*,1) (1 Beijing National Laboratoiy for Molecular Sciences,State Key Laboratory of Rare Earth Materials Chemistiy and Applications,College of Chemistry and Molecular Engineering,Peking University, Beijing,100871,China)

【机构】 北京分子科学国家实验室稀土材料化学与应用国家重点实验室 北京大学；

【摘要】 我们合成了四种不同类型的Ir-Eu双金属配合物,并通过TD-DFT（含时的密度泛函理论）方法计算研究了这些体系中铱配合物的电子跃迁能级。具体方法是采用晶体结构作为初始结构,进行三重态结构优化寻找能量最低的几何构型,在此基础上进行TD-DFT计算,模拟其三重态发射光谱。从计算结果中可以估计铱配合物发光对应三重态电子跃迁的轨道来源,并指认轨道的电子云分布。通过计算,我们发现能够实现有效的铱-铕能量传递关键在于两点:1、Ir配合物最低的激发三重态（3MLCT）最好位于桥联配体上,这样Ir配合物三重激发态的能量可以聚集在桥联配体上而进行能量传递;2、此位于桥联配体上的Ir配合物三重激发态（3MLCT）具有高低合适的能级,能够把Ir配合物的能量传递到Eu的⁵D₀能级。过高或过低的能级都不能够实现高效的能量传递。在Ir-Eu双金属体系中,桥联配体不仅作为分子桥来连接Ir配合物和Eu中心离子,而且作为能量桥来实现从Ir到Eu的能量传递。更多还原

【Abstract】 We designed and synthesized four novel Ir(Ⅲ)-Eu(Ⅲ) heteronuclear complexes and then studied the electrical energy levels of the iridium complexes by TD-DFT(Time-dependent density functional theory).Calculations were carried out at optimized triplet geometries using single crystal structure as the preliminary construction.From the triplet excited states calculation,we can estimate the emission spectrum and identify corresponding molecular orbitals involved in the electrical transition. Electron cloud distribution of each molecular orbital can be detected as well. Theoretical studies indicate that there are two key factors determining whether efficient energy transfer can happen between Ir(Ⅲ) complex and Eu(Ⅲ).Firstly,the lowest triplet excited state of the iridium complex must locate on that of the bridging ligand.Secondly,the energy level of the lowest triplet excited state must be suitable for transfer energy to 5D0 state of the europium center.Lower or higher energy level always prohibits efficient energy transfer between them.更多还原