Iridium(III) Complexes with [?2, ?1, 0] Charged Ligand Realized Deep-Red/Near-Infrared Phosphorescent Emission
Journal
Chemistry - A European Journal
Journal Volume
28
Journal Issue
2
Date Issued
2022
Author(s)
Abstract
A series of [?2, ?1, 0] charged-ligand based iridium(III) complexes of [Ir(bph)(bpy)(acac)] (1), [Ir(bph)(2MeO-bpy)(acac)] (2), [Ir(bph)(2CF3-bpy)(acac)] (3), [Ir(bph)(bpy)(2tBu-acac)] (4) and [Ir(bph)(bpy)(CF3-acac)] (5), which using biphenyl as dianionic ligand [?2], acetylacetone (or its derivatives) as monoanionic ligand [?1], and 2,2′-bipyridine (or its derivatives) as neutral ligand [0] were designed and synthesized. The chemical structures were well characterized. All of the ligands have simple chemical structures, thus further making the complexes have excellent thermal stability and are easy to sublimate and purify. Phosphorescent characteristics with short emission lifetime were demonstrated for these emitters. Notably, all of the complexes exhibit remarkable deep red/near infrared emission, which is quite different from the reported [?1, ?1, ?1] charged-ligand based iridium(III) complexes. The photophysical properties of these complexes are regularly improved by introducing electron-donating or -withdrawing groups into [?1] or [0] charged-ligand. The related organic light-emitting diodes exhibited deep red/near infrared emission with acceptable external quantum efficiency and low turn-on voltage (<2.6 V). This work provides a new idea for the construction of new type phosphorescent iridium(III) emitters with different valence states of [?2, ?1, 0] charged ligands, thus offering new opportunities and challenges for their optoelectronic applications. ? 2021 Wiley-VCH GmbH
Subjects
Acetone
Chemical stability
Infrared devices
Iridium compounds
Ligands
Phosphorescence
Structure (composition)
Synthesis (chemical)
Acetylacetone
Bipyridines
Charged ligands
Dianionic ligands
Iridium complex
Near Infrared
Near-infrared
Near-infrared emissions
Phosphorescent emission
Organic light emitting diodes (OLED)
SDGs
Type
journal article