高效红光铱配合物的合成、光物理性质和理论计算

On synthesis,photophysical properties and theoretical study of a high efficiency red iridium complex

以1−(3−氟苯基)异喹啉(3F−piq)为环金属配体,4,4′−二叔丁基−2,2′−联吡啶(dtb-bpy)为中性配体,六氟磷酸根为阴离子成功合成了一种离子型铱配合物[(3F−piq)_(2)Ir(dtb-bpy)](PF_(6))(Ir1).晶体结构表明中心离子Ir的几何构型为扭曲八面体构型.在327 nm的激发条件下,配合物Ir1在CH_(2)Cl_(2)溶液中的发射峰位于590 nm,为明亮的红光,量子效率为55%.电化学研究表明,配合物Ir1在0.8~1.5 V(vs.Ag^(+)/Ag)范围内出现一对可逆的氧化还原峰,归属于Ir^(3+)/Ir^(4+)的氧化还原过程.理论计算表明最高占据分子轨道(HOMO)主要分布在金属铱的d轨道和环金属配体上,而最低空分子轨道(LUMO)主要分布于中性配体上.

A cationic iridium cyclometalated complex[(3F−piq)_(2)Ir(dtb-bpy)](PF_(6))(Ir1)with 1-(3-fluorophenyl)isoquinoline(3F−piq)as a cyclometalated ligand,4,4′-di-tert-butyl-2,2′-bipyridine(dtb-bpy)as a neutral ligand and hexafluorophosphate as an anion has been synthesized successfully.X-ray crystallographic analysis reveals that the iridium center adopts a distorted octahedral coordination geometry.Upon excitation at 327 nm,the complex Ir1 exhibit strong red phosphorescence(λ_(em)=590 nm)with quantum efficiencies of 55%in oxygen-free dichloromethane solution at room temperature.Electrochemical study shows a quasireversible oxidation with potentials at 0.80−1.50 V(vs.Ag^(+)/Ag),which is attributed to the redox process of Ir^(3+)/Ir^(4+).Theoretical calculation shows that the highest occupied molecular orbital(HOMO)mostly distribute over the d orbitals of the iridium atom and the cyclometalated ligand,while the lowest unoccupied molecular orbital(LUMO)is mainly localized on the neutral ligand.