Phosphorescent Ir(III) complexes derived from purine nucleobases

We report the preparation and the study of new types of neutral and cationic phosphorescent heteroleptic Ir(III) complexes derived from 6-phenylpurine nucleosides and nucleotides. Neutral complexes of general formula Ir(C<^>N)(2)(acac) 7, and 8a-c (HC<^>N = 9-substituted-6-phenyl purine) are orange-red emissive upon photoexcitation, with short lifetimes and good quantum yields (0.42-0.65) in both PMMA films and 2-MeTHF at room temperature. In turn, cationic complexes [Ir(C<^>N)(2)(dtb-bpy)][PF6] 9, 12a and 12c (dtb-bpy = 4,4'-di-tert-butyl-2,2'-dipyridine) are yellow-green emitters with moderate quantum yields (0.24-0.32).

Automated summary

In this study, new types of neutral and cationic phosphorescent complexes derived from 6-phenylpurine nucleosides and nucleotides were prepared and studied. The neutral complexes exhibit orange-red emission upon photoexcitation, while the cationic complexes emit yellow-green light.