School of Chemistry , University of St. Andrews , St. Andrews KY16 9AJ , Scotland.
Inorg Chem. 2018 Nov 19;57(22):14450-14462. doi: 10.1021/acs.inorgchem.8b02818. Epub 2018 Nov 1.
Improving the spatial alignment of emitting molecules has long been a goal of organic-light-emitting-diode development to improve device efficiencies and to generate polarized emission. Herein we describe a simple approach employing Sonogashira coupling with alkyne iridium(phenylpyridine)(acetylacetone) synthons (2-5) to generate eight linear iridium complexes (6-13) with crystallographically determined lengths of up to 5 nm. By embedding these "long" complexes into a polymer matrix and stretching it, an improvement of the polarization ratio of unstretched and stretched films of up to 7.1 times was achieved. Additionally, through the inclusion of "twists" in the complexes, the electronic coupling between the iridium center and substituent was controlled, giving a system where the emission behavior is independent of the length.
提高发射分子的空间排列一直是有机发光二极管发展的目标，以提高器件效率并产生偏振发射。在此，我们描述了一种简单的方法，采用 Sonogashira 偶联与炔烃铱（苯吡啶）（乙酰丙酮）合成物（2-5）生成八个线性铱配合物（6-13），其晶体学确定的长度长达 5nm。通过将这些“长”配合物嵌入聚合物基质并拉伸它，未拉伸和拉伸薄膜的偏振比提高了 7.1 倍。此外，通过在配合物中包含“扭曲”，控制了铱中心和取代基之间的电子耦合，从而得到一个发射行为与长度无关的系统。
