Phosphorescent Platinum(II) Complexes Derived from Multifunctional Chromophores: Synthesis, Structures, Photophysics, and Electroluminescence
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- 作者：Ze He ; Wai-Yeung Wong ; Xiaoming Yu ; Hoi-Sing Kwok ; Zhenyang Lin
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：December 25, 2006
- 年：2006
- 卷：45
- 期：26
- 页码：10922 - 10937
- 全文大小：649K
- 年卷期：v.45,no.26(December 25, 2006)
- ISSN：1520-510X
文摘
The synthesis and structural, photophysical, electrochemical, and electroluminescent properties of a novel class oftrifunctional Pt(II) cyclometalated complexes are reported in which the hole-transporting triarylamine, electron-transporting oxadiazole, and electroluminescent metal components are integrated into a single molecule. Theseneutral metal chelates display good thermal stability (>250 
C under N2) and morphological stability. All of themexhibit intense ligand-centered fluorescence and phosphorescence in fluid solutions at room temperature, but theemission spectra become largely dominated by triplet emission bands in CH2Cl2 glass at 77 K. Substituents withdifferent electronic properties were introduced into the bipolar cyclometalating ligands to fine-tune the absorptionand emissive characteristics of the compounds, and the results were correlated with theoretical calculations usingdensity functional theory. A comparison of the photophysics and electrochemistry of our multifunctional systems tothose only derived from each of the constituent components was also made and discussed. These Pt complexescan be vacuum-sublimed and applied as emissive dopants for the fabrication of vapor-deposited electrophosphorescentorganic light-emitting devices (OLEDs), which generally exhibit good device performance with efficiencies up to3.6%, 11.0 cd A-1, and 5.8 lm W-1. While the electroluminescence energy resembles that recorded in fluid solutionsfor these Pt emitters, these monochromatic OLEDs can emit tunable colors by varying the aryl ring substituentsand the level of doping. Saliently, single dopant white-light electroluminescence, triggered by the simultaneousfluorescence/phosphorescence emission of the metal complexes and a variation of applied driving voltages, hasalso been realized based on some of these multifunctional complexes with peak electrophosphorescence efficienciesof 6.8 cd A-1 and 2.6%.
C under N2) and morphological stability. All of themexhibit intense ligand-centered fluorescence and phosphorescence in fluid solutions at room temperature, but theemission spectra become largely dominated by triplet emission bands in CH2Cl2 glass at 77 K. Substituents withdifferent electronic properties were introduced into the bipolar cyclometalating ligands to fine-tune the absorptionand emissive characteristics of the compounds, and the results were correlated with theoretical calculations usingdensity functional theory. A comparison of the photophysics and electrochemistry of our multifunctional systems tothose only derived from each of the constituent components was also made and discussed. These Pt complexescan be vacuum-sublimed and applied as emissive dopants for the fabrication of vapor-deposited electrophosphorescentorganic light-emitting devices (OLEDs), which generally exhibit good device performance with efficiencies up to3.6%, 11.0 cd A-1, and 5.8 lm W-1. While the electroluminescence energy resembles that recorded in fluid solutionsfor these Pt emitters, these monochromatic OLEDs can emit tunable colors by varying the aryl ring substituentsand the level of doping. Saliently, single dopant white-light electroluminescence, triggered by the simultaneousfluorescence/phosphorescence emission of the metal complexes and a variation of applied driving voltages, hasalso been realized based on some of these multifunctional complexes with peak electrophosphorescence efficienciesof 6.8 cd A-1 and 2.6%.