New sky-blue and bluish–green emitting Ir(III) complexes containing an azoline ancillary ligand for highly efficient PhOLEDs
| Autor: | Ganguri Sarada, Yeong-Soon Gal, Sung-Ho Jin, Woosum Cho, Bomi Sim, Jang-Joo Kim, Juho Yoon |
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| Rok vydání: | 2016 |
| Předmět: |
Photoluminescence
Ligand Process Chemistry and Technology General Chemical Engineering chemistry.chemical_element 02 engineering and technology Oxazoline 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences law.invention Metal chemistry.chemical_compound chemistry law visual_art Excited state visual_art.visual_art_medium Fluorine Phosphorescent organic light-emitting diode Solubility 0210 nano-technology |
| Zdroj: | Dyes and Pigments. 131:60-68 |
| ISSN: | 0143-7208 |
| DOI: | 10.1016/j.dyepig.2016.03.053 |
| Popis: | Two Ir(III) complexes containing the chromophoric ancillary ligands 2-(4,5-dihydrooxazol-2-yl)phenol and 2-(1-ethyl-4,5-dihydro-1H-imidazol-2-yl)phenol, and a highly functionalized phenylpyridine derivative, 3-(4-(tert-butyl)pyridin-2-yl)-2,6-difluorobenzonitrile, as a cyclometalating ligand were designed and synthesized. The oxazoline/imidazoline heterocycle of the ancillary ligand has the effect of enhancing the metal to ligand charge transfer transition nature of the emitting excited state and the fluorine and cyano substituents on the ligand have enriched the intersystem crossings, as indicated by the experimental photoluminescence analysis. As a result, the oxazoline and imidazoline containing complexes exhibited high photoluminescence quantum yields of about >90% with bright sky-blue emission at 480 nm and bluish–green light at 495 nm, respectively, along with excellent thermal/morphological stability about 400 °C and good solubility, that make them suitable for both wet- and dry-processes. In particular, the phosphorescent OLEDs fabricated by a dry-process showed the maximum EQEs of 21.9% and 19.7% for the oxazoline and imidazoline containing complexes, respectively. |
| Databáze: | OpenAIRE |
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