Xilin Yang, Xiuwen Zhou, Ye-Xin Zhang, Deli Li, Chensen Li, Caifa You, Tai-Che Chou, Shi-Jian Su, Pi-Tai Chou, Yun Chi
Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2022 SepFour isomeric, homoleptic iridium(III) metal complexes bearing 5-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene and 6-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene-based cyclometalating chelates are successfully synthesized. The meridional isomers can be converted to facial isomers through acid induced isomerization. The m-isomers display a relatively broadened and red-shifted emission, while f-isomers exhibit narrowed blue emission band, together with higher photoluminescent quantum yields and reduced radiative lifetime relative to the mer-counterparts. Maximum external quantum efficiencies of 13.5% and 22.8% are achieved for the electrophosphorescent devices based on f-tpb1 and m-tpb1 as dopant emitter together with CIE coordinates of (0.15, 0.23) and (0.22, 0.45), respectively. By using f-tpb1 as the sensitizing phosphor and t-DABNA as thermally activated delayed fluorescence (TADF) terminal emitter, hyperluminescent OLEDs are successfully fabricated, giving high efficiency of 29.6%, full width at half maximum (FWHM) of 30 nm, and CIE coordinates of (0.13, 0.11), confirming the efficient Förster resonance energy transfer (FRET) process. © 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.
Xilin Yang, Xiuwen Zhou, Ye-Xin Zhang, Deli Li, Chensen Li, Caifa You, Tai-Che Chou, Shi-Jian Su, Pi-Tai Chou, Yun Chi. Blue Phosphorescence and Hyperluminescence Generated from Imidazo[4,5-b]pyridin-2-ylidene-Based Iridium(III) Phosphors. Advanced science (Weinheim, Baden-Wurttemberg, Germany). 2022 Sep;9(25):e2201150
PMID: 35822668
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