Sky Blue-Emitting Iridium(III) Complexes Bearing Nonplanar Tetradentate Chromophore and Bidentate Ancillary

Abstract

Tetradentate chelates bearing tripodal arranged terpyridine and a functional pyrazole unit (i.e., L1-H and L2-H) were employed in preparation of Ir(III) complexes [Ir(L1)Cl] (1) and [Ir(L2)Cl] (2); subsequent chloride-to-bipyrazolate substitution gave [Ir(L1)(bipz)] (3) and [Ir(L2)(bipz)] (4). Single-crystal X-ray structural studies on 1 and 3 showed the possession of a tetradentate chelate, whereas the remaining cis-sites are occupied by either dual chlorides or the bipz chelate, respectively. Sky blue organic light-emitting diode with peak efficiencies (10.1%, 19.8 cd·A, and 20.4 lm·W) was successfully fabricated using 3 (or 4) as dopant emitter, highlighting the potential application of this class of Ir(III) phosphor.

Bis‐Tridentate Iridium(III) Phosphors with Very High Photostability and Fabrication of Blue‐Emitting OLEDs

“…EQE of 21.6% and 19.6%, CE of 31.7 and 33.8 cd A −1 , PE of 29.3 and 31.2 lm W −1 , and CIE x , y coordinates of (0.17, 0.25) and (0.17, 0.26) respectively. These characteristics are clearly superior to those displayed by other relevant bis‐tridentate Ir(III) emitters18, 29 and fall in the ranking column of typical tris ‐bidentate blue‐emitting Ir(III) phosphors 30. The recorded CIE coordinates are still deviated from the NTSC blue standard (0.14, 0.08), e.g.…”

Synthesis and Characterization of High-Efficiency Red Phosphorescent Iridium(III) Complexes with 1-(4-(Trifluoromethyl)phenyl)isoquinoline Ligand

“…The residue was purified by flash column chromatography (petroleum ether : dichloromethane = 5:1~1:1) to afford the iridium complex 2a as a red solid (55 mg, yield: 45%). 1…”

“…Complex 2b (52 mg, yield: 46%) was obtained by the method similar to the preparation of 2a using 2-(2H-indazol-2-yl)phenol instead of 2-(imidazo[1,2-a]pyridin-2-yl) phenol. 1…”

“…Organic light-emitting diodes (OLEDs) have attracted great attention on the development of modern optoelectronic technologies such as full-color displays and solid-state lighting sources. [1][2][3] Particularly, cyclometalated iridium(III) complexes ([Ir(C^N) 3 ] or [(C^N) 2 Ir(LX)]) are the most valuable emitting materials in the fabrication of OLEDs, owing to their relatively short excited-state lifetime, high phosphorescence efficiency and excellent color-tuning capability. 4,5 As compared to other colors, red electrophosphorescent emitting phosphors are difficult to maintain high device efficiency, since their quantum efficiencies tend to decrease as the emission wavelength increases in accordance with the energy gap law.…”

Highly Luminescent Mono‐ and Dinuclear Cationic Iridium(III) Complexes Containing Phenanthroline‐Based Ancillary Ligand

“…Iridium(III) complexes as phosphorescence emitters have been extensively employed in full‐color organic light‐emitting diode (OLED) displays and white light sources . This is due to their excellent luminescence properties,, such as high quantum yields, long excited‐state lifetimes, good thermal and photochemical stability, and facile emission color tunability , .…”