吸电子基团调控苯基喹啉类铱配合物的合成及光物理性能

以2,2,6,6-四甲基庚二酮(tmd)为辅助配体,2,4-二取代基苯基-4-甲基喹啉(2,4-2R-mpq)为主配体,在主配体中苯基的2位和4位同时引入氟(F)、甲氧基(MeO)或三氟甲基(CF₃),合成出3个铱磷光配合物(2,4-2R-mpq)₂Ir(tmd)(R=F (1)、MeO(2)、CF³(3))。通过元素分析、核磁共振谱和单晶X射线衍射表征了配合物的组成和分子结构。通过紫外可见吸收光谱、光致发光光谱和理论计算对配合物的光物理性能进行了研究。结果表明：3个配合物的晶体均为三斜晶系,空间群均为■,呈稍微扭曲的八面体构型。配合物1、2和3在溶液状态下的发射波长分别为570、582和604 nm,溶液中量子产率分别为96%、80%和80%。在主配体中苯基的2位和4位同时引入F或MeO,配合物电子云发生聚集,而引入CF₃,配合物的电子云分散。与配合物3相比,配合物1和2的发射波长发生了显著的蓝移。

Synthesis and photophysical properties of phenylquinoline iridium complexes controlled by electron-withdrawing groups

To study the effect of substituents on iridium phosphorescent complexes, fluorine, methoxy, or trifluoromethyl were introduced into positions 2 and 4 of phenyl at the same time to obtain 2, 4-disubstituted phenyl-4-methylquinoline (2, 4-2R-mpq). Three new iridium phosphorescent complexes (2, 4-2R-mpq)₂Ir(tmd) (R=F (1), MeO (2), CF₃ (3)) were synthesized by using 2, 2, 6, 6-tetramethylheptanedione (tmd) as the auxiliary ligand, and 2, 4-2R-mpq with the electron-withdrawing group as the main ligands. The compositions and chemical structures of the complexes were characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction. The three iridium complexes belong to the triclinic system with the P1 space group. The photophysical properties of the complexes were studied by UV-Vis absorption spectroscopy, photoluminescence spectroscopy, and theory calculation. The results indicate that complexes 1, 2, and 3 with the photoluminescence quantum yields of 96%, 80%, and 80% exhibited maximum emission peaks at 570, 582, and 604 nm, respectively. When F and MeO are introduced into the 2 and 4 positions of phenyl on the main ligand, the electron cloud of complexes 1 and 2 are aggregated, while the CF₃ is introduced, and the electron cloud of the complex is dispersed. Compared with complex 3, the emission wavelengths of complexes 1 and 2 had a significant blue shift. Different from traditional cognition, the methoxyl group represents an electron-withdrawing group.