Supramolecularly Caged Cyclometalated Iridium Complex With a New Imidazole Type Ancillary Ligand for Stable and Bright Green Light‐Emitting Electrochemical Cell

Abstract

ABSTRACT A new imidazole‐based ligand and its cyclometalated iridium (III) complex, namely, [Ir (ppy) 2 (Imdipy)](ClO 4 ): IrL, were designed and successfully synthesized with a combination approach and employed as an emissive layer in the fabrication of light‐emitting electrochemical cell (LEC). This complex exhibits intense structured green emissions centered at 490 and 515 nm with a high photoluminescence quantum yield of 17% in a CH 2 Cl 2 solution. Moreover, an intense structureless yellow‐green emission was observed in its spin‐coated neat film at a maximum wavelength of 540 nm. Compared with archetype complex [Ir (ppy) 2 (bpy)] + , IrL illustrates a 3% higher PL quantum yield (PLQY) with a 100‐nm blue shift in emission, which is attributed to the strong field nature of Imdipy ancillary ligand in IrL. Electrochemical studies confirmed the electrochemical stability of the IrL complex as a consequence of its quasi‐reversible redox behavior in the solution. The IrL‐based LEC shows stable yellow‐green electroluminescence centered at 546‐nm. This study demonstrates the importance of such ligands in achieving optoelectronic devices (LECs and OLEDs) with long lifetime at short wavelengths.

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Identifiers

DOI

10.1002/bio.70234

Journal

Luminescence

Year

2025