Effective manipulation of the electronic effects and its influence on the emission of 5-substituted tris(8-quinolinolate) aluminum(III) complexes
Effective manipulation of the electronic effects and its influence on the emission of 5-substituted tris(8-quinolinolate) aluminum(III) complexes
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DOI：
10.1002/chem.200501403
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发表时间：
2006-06-02
影响因子：
4.3
通讯作者：
Anzenbacher, Pavel, Jr.
中科院分区：
文献类型：
--
作者：
Montes, Victor A.;Pohl, Radek;Anzenbacher, Pavel, Jr.
三（8-喹啉酸酯）铝（III） （Alq(3)）独特的电子传输和发射特性使得该材料广泛用于小分子有机发光二极管（OLED）的制造。到目前为止，制备稳定且易于处理的红/绿/蓝（RGB）发光的Alq(3)衍生物的努力只取得了有限的成功。在本文中，我们描述了各种取代基的电子性质如何通过芳基或芳基间隔剂投射到最高HOMO密度（C5）的位置，可以用于有效的发射调谐，以获得蓝色，绿色和红色发射材料。该合成策略包括四种不同的途径，用于将供电子和吸电子的芳基或芳基乙基取代基连接到喹啉酸环的5位上。成功地调整了覆盖整个可见光谱（λ =450-800 nm）的发射颜色。此外，发现光团的光物理性质与各自取代基的哈米特常数相关，为预测新材料的光学性质提供了有力的策略。我们还证明了取代基的电子性质通过对喹啉酸配体的HOMO能级的有效修饰影响了所得到的配合物的发射性质。
The unique electron-transport and emissive properties of tris(8-quinolinolate) aluminum(III) (Alq(3)) have resulted in extensive use of this material for small molecular organic light-emitting diode (OLED) fabrication. So far, efforts to prepare stable and easy-to-process red/green/blue (RGB)-emitting Alq(3) derivatives have met with only a limited success. In this paper, we describe how the electronic nature of various substituents, projected via an arylethynyl or aryl spacer to the position of the highest HOMO density (C5), may be used for effective emission tuning to obtain blue-, green-, and red-emitting materials. The synthetic strategy consists of four different pathways for the attachment of electron-donating and electron-withdrawing aryl or arylethynyl substituents to the 5-position of the quinolinolate ring. Successful tuning of the emission color covering the whole visible spectrum (lambda=450-800 nm) was achieved. In addition, the photophysical properties of the luminophores were found to correlate with the Hammett constant of the respective substituents, providing a powerful strategy with which to predict the optical properties of new materials. We also demonstrate that the electronic nature of the substituent affects the emission properties of the resulting complex through effective modification of the HOMO levels of the quinolinolate ligand.