Regioselective Syntheses of Imidazo[4,5-b]pyrazin-2-ylidene-Based Chelates and Blue Emissive Iridium(III) Phosphors for Solution-Processed OLEDs

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Qin Xue
  • Hui Yang
  • Shek-Man Yiu
  • Ye-Xin Zhang
  • Guohua Xie

Detail(s)

Original languageEnglish
Pages (from-to)8797-8805
Journal / PublicationInorganic Chemistry
Volume61
Issue number23
Online published2 Jun 2022
Publication statusPublished - 13 Jun 2022

Abstract

Six homoleptic Ir(III) complexes bearing imidazo-[4,5-b]pyrazin-2-ylidene chelates were successfully designed and synthesized. Narrowband blue emission (λmax = 466-485 nm) and broadened green emission (λmax = 518-532 nm) in degassed toluene solution with high photoluminescent quantum yields in the range of 75-81 and 45-48% were observed for ƒ-timpz, t2impz, and t2empz as well as m-timpz, t2impz, and t2empz, respectively. In addition, the tert-butylphenyl cyclometalate is more electron donating than N-phenyl cyclometalate and, hence, all tert-butylphenyl-substituted derivatives, that is, m- and ƒ-t2impz and m- and ƒ-t2empz, give more red-shifted emission in comparison to that of m- and ƒ-timpz. Moreover, solution-processed OLED with ƒ-t2empz (20 wt %) as the dopant gave electrophosphorescence at 474 nm with maximum external quantum efficiency (max. EQE) of 5.1%, while hyper-OLED with assistant sensitizer ƒ-t2empz (10 wt %) and the multi-resonance thermally activated delayed fluorescence emitter BCzBN (0.5 wt %) afforded narrowband emission centered at 485 nm and max. EQE up to 17.4%, confirming the high potential of this class of Ir(III) metal phosphors.

Research Area(s)

  • LIGHT-EMITTING-DIODES, HIGH-EFFICIENCY, ENERGY-TRANSFER, COMPLEXES, DOPANT

Citation Format(s)

Regioselective Syntheses of Imidazo[4,5-b]pyrazin-2-ylidene-Based Chelates and Blue Emissive Iridium(III) Phosphors for Solution-Processed OLEDs. / Yan, Jie; Xue, Qin; Yang, Hui; Yiu, Shek-Man; Zhang, Ye-Xin; Xie, Guohua; Chi, Yun.

In: Inorganic Chemistry, Vol. 61, No. 23, 13.06.2022, p. 8797-8805.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review