Synthesis and photophysical properties of ternary β-diketonate europium(III) complexes incorporating bipyridine and its derivatives

• Published in: Dyes and pigments 2022-01, Vol.197, p.109879, Article 109879
• Main Authors: Al-Busaidi, Idris Juma, Ilmi, Rashid, Zhang, Danyang, Dutra, José D.L., Oliveira, Willyan F., Al Rasbi, Nawal K., Zhou, Liang, Wong, Wai-Yeung, Raithby, Paul R., Khan, Muhammad S.
• Format: Article
• Language: English
• Subjects: Energy transfer mechanism; Organic light emitting diodes; Photoluminescence; β-diketone
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2021.109879

Two new octa-coordinated ternary europium(III) complexes of the type [Eu(btfa)3(Br2-bpy)] (Eu-1) and [Eu(btfa)3(PhE2-bpy)] (Eu-2) (where btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, Br2-bpy = 5,5′-dibromo-2,2′-bipyridine, PhE2-bpy 5,5′-bis(phenylethynyl)-2,2′-bipyridine) together with a previously reported complex [Eu(btfa)3(bpy)] (Eu-3) have been synthesized. The complexes have been characterized by analytical and spectroscopic methods. The photophysical properties of the complexes have also been analyzed both experimentally and theoretically. The contribution of each ligand to the sensitized Eu(III) photoluminescence (PL) has been analyzed and is discussed. An energy transfer (ET) mechanism is proposed and discussed for the sensitized Eu(III) emission using experimental and theoretical data. The Eu(III) complex incorporating the parent bpy showed impressive performance as a double-emitting layer (EML) red organic light emitting diodes (R-OLEDs). [Display omitted] •Ancillary ligand PhE2-bpy was obtained by the reaction of Br2-bpy & phenylacetylene.•Photoluminescent europium complexes (Eu-1–Eu-3) were synthesized and characterized.•Complexes were investigated by detailed photophysical measurements.•Energy transfer mechanism is proposed using experimental and theoretical data.•A red emitting OLED was fabricated using Eu-3 complex with EQE = 2.14% & B = 428 cd/m.