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Electroluminescent Properties of LECs Based on Ionic Transition Metal Complexes Using Tetrazole-Based Ancillary Ligand

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Abstract

Light-emitting electrochemical cells (LECs) are a promising type of electroluminescent device for display and lighting applications. In this study, LECs based on ionic iridium complexes utilizing a tetrazole based ancillary ligand were fabricated and their electrical properties were investigated. Two new iridium(III) complexes with tetrazole based ancillary ligands, namely, [Ir(ppy)2(tetrazole)]PF6 (complex 1) and [Ir(dfppy)2(tetrazole)]PF6 (complex 2) (where ppy is 2-phenylpyridine, dfppy is 2-(2,4-difluorophenyl)pyridine, tetrazole is 5-bromo-2-(2-methyl-2H-tetrazol-5-yl)-pyridine and PF6 is hexafluorophosphate), have been synthesized and characterized. These synthesized complexes were used for the fabrication of LEC devices. LECs based on complex 1 result in orange light emission (576 nm) with the Commission Internationale de l’Eclairage (CIE) coordinates of (0.45, 0.49), while complex 2 emits green (518 nm) electroluminescence with the CIE coordinates of (0.33, 0.49). Our work suggests that the light emission of cationic iridium complexes can easily be tuned by the substituents on the cyclometalated ligands.

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Acknowledgments

This work was supported by the Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (NRF-2013R1A1A4A03009795) and the BK 21 PLUS Center for Advanced Chemical Technology (21A20131800002), Republic of Korea.

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  1. Department of Polymer Science and Chemical Engineering, Pusan National University, Busan, 609-735, South Korea

    Yiseul Kwon & Youngson Choe

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  1. Yiseul Kwon
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  2. Youngson Choe
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Correspondence to Youngson Choe.

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Kwon, Y., Choe, Y. Electroluminescent Properties of LECs Based on Ionic Transition Metal Complexes Using Tetrazole-Based Ancillary Ligand. J Solution Chem 43, 1710–1721 (2014). https://doi.org/10.1007/s10953-014-0225-9

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