Photophysical Properties and OLED Applications of Phosphorescent Platinum(II) Schiff Base Complexes |
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| Authors: | Chi‐Ming Che Prof. Dr. Chi‐Chung Kwok Dr. Siu‐Wai Lai Dr. Andreas F. Rausch Dipl.‐Chem. Walter J. Finkenzeller Dr. Nianyong Zhu Dr. Hartmut Yersin Prof. Dr. |
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| Affiliation: | 1. Department of Chemistry and HKU‐CAS Joint Laboratory on New Materials, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China), Fax: (+852)?2857‐1586;2. Institut für Physikalische und Theoretische Chemie, Universit?t Regensburg, 93040 Regensburg (Germany), Fax: (+49)?941‐943‐4488 |
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| Abstract: | The syntheses, crystal structures, and detailed investigations of the photophysical properties of phosphorescent platinum(II) Schiff base complexes are presented. All of these complexes exhibit intense absorption bands with λmax in the range 417–546 nm, which are assigned to states of metal‐to‐ligand charge‐transfer (1MLCT) 1[Pt(5d)→π*(Schiff base)] character mixed with 1[lone pair(phenoxide)→π*(imine)] charge‐transfer character. The platinum(II) Schiff base complexes are thermally stable, with decomposition temperatures up to 495 °C, and show emission λmax at 541–649 nm in acetonitrile, with emission quantum yields up to 0.27. Measurements of the emission decay times in the temperature range from 130 to 1.5 K give total zero‐field splitting parameters of the emitting triplet state of 14–28 cm?1. High‐performance yellow to red organic light‐emitting devices (OLEDs) using these platinum(II) Schiff base complexes have been fabricated with the best efficiency up to 31 cd A?1 and a device lifetime up to 77 000 h at 500 cd m?2. |
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| Keywords: | organic light‐emitting diodes phosphorescence platinum Schiff bases triplet state |
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