Mixed-carbene cyclometalated iridium complexes with saturated blue luminescence† †Electronic supplementary information (ESI) available: Experimental details, X-ray crystallography summary table, UV-vis excitation spectra, and NMR spectra. CCDC 1879106 and 1879107. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c9sc01386e

• Published in: Chemical science (Cambridge) Vol. 10; no. 25; pp. 6254 - 6260
• Main Authors: Na, Hanah, Cañada, Louise M., Wen, Zhili, I-Chia Wu, Judy, Teets, Thomas S.
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 27.05.2019
• Subjects: Chemistry
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc01386e

A new structural class of mixed-carbene cyclometalated iridium complexes with intense, high-purity blue luminescence are described. Cyclometalated iridium complexes have emerged as top-performing emitters in organic light-emitting diodes (OLEDs) and other optoelectronic devices. A persistent challenge has been the development of cyclometalated iridium complexes with deep blue luminescence that have the requisite color purity, efficiency, and stability to function in color displays. In this work we report a new class of cyclometalated iridium complexes with saturated blue luminescence. These complexes have the general structure Ir(C^C: NHC ) 2 (C^C: ADC ), where C^C: NHC is an N-heterocyclic carbene (NHC) derived cyclometalating ligand and C^C: ADC is a different type of cyclometalating ligand featuring an acyclic diaminocarbene (ADC). The complexes are prepared by a cascade reaction that involves nucleophilic addition of propylamine to an isocyanide precursor followed by base-assisted cyclometalation of the ADC intermediate. All three emit deep blue light with good quantum efficiencies ( Φ PL = 0.13–0.48) and color profiles very close to the ideal primary blue standards for color displays.