Iridium Complexes Embedding Rigid D-A-Type Coordinated Cores: Facile Synthesis and High-Efficiency Near-Infrared Emission in Solution-Processed Polymer Light-Emitting Diodes

作者：Liu, Denghui; You, Caifa; Li, Mengke; Wang, Sai; Zhang, Kai; Zhang, Bin; Yu, Junting^*; Liu, Yu; Su, Shi-Jian^*; Zhu, Weiguo^*

来源：Journal of Organometallic Chemistry, 2021, 931: 121615.

DOI：10.1016/j.jorganchem.2020.121615

• Near-infrared emission
• Iridium complex
• C<^>N ligand
• PLEDs

Two near-infrared (NIR)-emitting iridium(III) complexes of (Me-BIPz)(2)Ir(acac) and (tBu-BIPz)(2)Ir(acac), (i.e. Ir-1 and Ir-2 ) are designed and synthesized, which contain methyl and t-butyl substituted 14-phenyl-14H-benzo[a]indolo[3,2-c]phenazine (BIPz), respectively with a rigid D-A-type coordinated core. The influence of the rigid D-A skeleton and the attached groups on photoelectronic properties of iridium complexes is primarily investigated. An advanced external quantum efficiency (EQE) of 2.65% with a radiant emittance of 13057 mW Sr-1 m -2 at 746 nm is obtained in the Ir-2-doped polymer light-emitting devices. This EQE value is 1.5 times higher than that in the Ir-1-doped devices. Furthermore, this type of iridium complexes exhibits better NIR-emitting properties than most of the reported iridium complexes containing the C<^>N ligand with two coordinated aryl rings. The results indicate that the rigid coordinated core of C<^>N ligand is an effective strategy to construct high-efficiency NIR-emitting iridium complexes.

• 单位
  湖南科技大学; 常州大学; 湘潭大学