Theoretical study on photophysical properties of cyclometalated cationic iridium(III) complexes containing dipyrido[3,2-f:2¡ä,3¡ä-h]quinoxaline ligand

详细信息    查看全文

• 作者：Juanjuan Su ; Xiaobo Sun ; Godefroid Gahungu ; Xiaochun Qu ; Yuqi Liu ; Zhijian Wu
• 关键词：Iridium ; OLED ; Phosphorescence ; Density functional theory ; Blue emission
• 刊名：Synthetic Metals
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：162
• 期：15-16
• 页码：1392-1399
• 全文大小：887 K

文摘

We report a theoretical analysis of a family of cyclometalated cationic iridium(III) complexes: [Ir(C^N)₂(N^N)]⁺ [N^N = dipyrido[3,2-m>fm>:2¡ä,3¡ä-m>hm>]quinoxaline(dpq), HC^N = 1-phenylpyrazole(Hppz) (1); HC^N = 7,8-benzoquinoline(Hbzq) (2); HC^N = 2-phenylquinoline(Hpq) (3); HC^N = 1-(2,4-diflourophenyl) pyrazole(Hdfppz) (4), HC^N = 1-(2,4-dimethylphenyl) pyrazole(Hdmppz) (5), HC^N = 1-(2,4-diflourophenyl)-1,2,4-triazole(Hdfptz) (6)] by using density functional theory (DFT) method to investigate their optoelectronic properties and understand the phosphorescent efficiency mechanism. Complexes 1-3 exhibit green to yellow luminescence. The different quantum efficiencies of 1-3 in methanol (MeOH), acetonitrile (CH₃CN), and dichloromethane (CH₂Cl₂) solvents have been explained by calculated results. Complexes 4 and 5 show different trend in the absorption and emission spectra comparing with 1 due to the added different substituent on the phenyl of ppzH. The emission wavelength of the assumed complex 6 bearing the triazole in C^N ligand is blue-shifted to the blue region. We suggest complex 6 might be a potential candidate as blue-emitting material.