离子型嘧啶铱(Ⅲ)配合物的合成、晶体结构及发光性能

Syntheses,Crystal Structures and Photophysical Properties of Ionic Iridium(Ⅲ) Pyrimidine Complexes

以嘧啶类化合物为环金属配体,2,2′-联吡啶为副配体成功制备了4种离子型环金属铱配合物:[(PPM)_2Ir(bpy)]PF_6(1),[(MPPM)2_Ir(bpy)]PF_6(2),[(DFPPM)_2Ir(bpy)]PF_6(3),[(MDFPPM)_2Ir(bpy)]PF_6(4)(PPM=2-苯基嘧啶,MPPM=4,6-二甲基-2-苯基嘧啶,DFPPM=2-(2,4-二氟苯基)嘧啶,MDFPPM=4,6-二甲基-2-(2,4-二氟苯基)嘧啶,bpy=2,2′-联吡啶)。配合物的结构通过质谱、核磁进行了表征,测试了配合物4的单晶结构。通过紫外-可见(UV-Vis)吸收光谱、荧光光谱和含时密度泛函理论(TD-DFT)对其光物理性能进行了研究。结果表明:4的晶体的空间构型为单斜,空间群为P21/c;3和4的最高占据轨道(HOMO)主要定域于金属Ir(Ⅲ)和环金属配体的苯环上,最低未占有轨道(LUMO)主要定域于副配体bpy上;配合物在溶液状态下为绿光发射,波长在513~561nm之间,量子效率在6.7%~64.0%之间。

A series of cyclometalated iridium（Ⅲ） complexes：[（PPM）2Ir（bpy）]PF6 （1）,[（MPPM）2Ir（bpy）]PF6 （2）,[（DFPPM）2Ir（bpy）]PF6 （3）,[（MDFPPM）2Ir（bpy）]PF6 （4） （PPM=2-phenylpyrimidine, MPPM=4,6-dimethyl-2-phenyl-pyrimidine, DFPPM=2-（2,4-difluorophenyl）pyrimidine, MDFPPM=2-（2,4-difluorophenyl）-4,6-dimethylpyrimidine, bpy=2,2＇-bipyridine） were synthesized with pyrimidine compounds as cyclometalated ligand and 2,2＇-bipyridine as ancillary ligand. New iridium（Ⅲ） complexes were characterized by the NMR and mass spectroscopies, and the single crystal structures of complex 4 was measured. The photophysical properties of the complexes were studied by ultraviolet-visble （UV-Vis） absorption, photoluminescence and time-dependent density functionaltheory （TD-DFT） calculation. X-ray diffraction studies have revealed that complex 4 belongs to monoclinic system with space group of P21/c. A theoretical calculation reveals that the HOMO of 3 and 4 is mainly distributed on the iridium ion and the phenyl group of the cyclometalated ligands, while the LUMO is mainly centered on the ancillary ligand bpy. In CH2Cl2 solution, the iridium（Ⅲ） complexes 1 and 2 exhibit yellow-green emissions with peak at 561 and 572 nm, respectively, while the iridium（Ⅲ） complexes 3 and 4 exhibit green emissions with peak at 501 and 513 nm, respectively. The iridium（Ⅲ） complexes had quantum efficiencies between 6.7% and 64.0%.