A cationic iridium(iii) complex showing aggregation-induced phosphorescent emission (AIPE) in the solid state: Synthesis, characterization and properties

摘要

We report the synthesis and characterization of two cationic iridium(iii) complexes with dendritic carbazole ligands as ancillary ligands, namely, [Ir(ppy) _2L3]PF _6 (1) and [Ir(ppy) _2L4]PF _6 (2), where L3 and L4 represent 3,8-bis(3,6-di-tert-butyl-9H- carbazol-9-yl)-1,10-phenanthroline and 3,8-bis(3′,6′-di-tert-butyl- 6-(3,6-di-tert-butyl-9H-carbazol-9-yl)-3,9′-bi(9H-carbazol)-9-yl)-1, 10-phenanthroline, respectively. Their photophysical properties have been investigated and compared. The results have shown that complex 2 is aggregation-induced phosphorescent emission (AIPE) active and exhibits the highest photoluminescent quantum yield (PLQY) of 16.2% in neat film among the reported cationic Ir(iii) complexes with AIPE activity. In addition, it also enjoys redox reversibility, good film-forming ability, excellent thermal stability as well as off/on luminescence switching properties, revealing its potential application as a candidate for light-emitting electrochemical cells and organic vapor sensing. To explore applications in biology, 2 was used to image cells.