【作者】 张静；

【导师】 朱东霞；

【作者基本信息】 东北师范大学 ， 分析化学， 2010， 硕士

【摘要】 有机电致发光器件（OLEDs）在当今社会人类知识的获得和生活质量的改善方面扮演着越来越重要角色,有着巨大的应用潜力和广阔的商业前景,而发光电化学池（LECs）是有机电致发光器件的一个重要分支。近年来离子型过渡金属配合物（iTMCs）由于能够应用于发光电化学池而备受瞩目。离子型过渡金属配合物具有离子传导性,以经典的离子型金属配合物[Ru（bpy）₃]²⁺（PF₆^-）₂为例,PF₆^-的平衡离子在外加电压下能够重组,这种行为可以在每个电极附近产生离子空间电荷（其余PF₆^-在阳极,无补偿的[Ru（bpy）3]2+则在阴极）,以协助电子电荷注入,甚至可以使电子更好地从空气稳定的金属电极注入,此种器件就类似于所谓的发光电化学电池（LECs）;另外,离子型过渡金属配合物发光效率极高,其发光量子率可达100%,从这些材料中产生的辐射几乎全部来自三重态辐射。在器件制备方面,离子型过渡金属配合物一般可直接旋涂成膜。这些性能都表明单层膜离子型过渡金属配合物完全可以被制成高效能有机电致发光器件。离子型铱配合物除了具备中性铱配合物所具备的发光效率高、发射波长可调等优点外,还具有一些中性铱配合物所不具备的特性,使之有可能成为一种更好的电致发光材料。首先,与中性铱配合物相比,离子型铱配合物的合成条件更温和;其次,基于离子型铱配合物的发光材料可以采用惰性金属（如金）作电极得到高效电致发光器件;再次,这类配合物具有稳定的氧化一还原可逆性,有利于提高器件稳定性;另外,由于此类配合物携带电荷和抗衡离子,所以有利于载流子注入和迁移,降低器件能耗。但是,由于此类配合物携带电荷,导致这类配合物与疏水的共轭主体材料之间的相容性差,从而影响其在电致发光器件中的应用。本论文所研究的主要内容是解决配合物与疏水的共轭主体材料之间的相容性问题,对配体分子结构进行改性,设计、合成出新型的、具有较高发光效率的离子型配合物,从而获得高亮度,低电压,高效率的高效电致发光器件。本论文研究内容如下:1.设计、合成了两种含有1,3,4-噁二唑和吡啶基团的新型的N^N配体mptop和ptop,其中mptop代表2-（2-吡啶基）-5-（4-甲基苯基）-1,3,4-噁二唑2-（5-phenyl-[1,3,4]oxadiazol-2-yl）-pyridine,ptop代表2-（2-吡啶基）-5-苯基-1,3,4噁二唑2-（5-p-Tolyl-[1,3,4]oxadiazol-2-yl）-pyridine及其两种配体的离子型铱的配合物[Ir（mptop）（ppy）₂]⁺（PF₆^-）和[Ir（ptop）（ppy）₂]⁺（PF₆^-）。大量研究表明,1,3,4-噁二唑具有优良的电子传输性、良好的发光性能、热稳定性及化学稳定性,是一类应用和研究最广的电子传输材料之一。我们合成了以1,3,4-噁二唑作为结构单元的新型N^N配体。在此类配体的基础上合成了一系列离子型铱配合物,通过红外光谱、核磁及单晶结构解析等手段对配合物结构进行了表征。2.我们对这些配合物的光物理、电化学性质进行了详细的研究。通过对配合物的紫外-可见吸收、光致发光性质及量化计算的研究,详细讨论了这些配合物的激发态性质,阐明了配体的化学结构与配合物的光物理和电化学性质之间的关系。3.分别制备了两种配合物的发光电化学池器件,从器件的启亮电压、响应时间、最大亮度、发光效率及寿命等方面研究了配合物分子结构的改变对器件性能的影响。更多还原

【Abstract】 Nowdays, organic light emitting diodes（OLEDs） are planing increasingly important role in the acquisition of knowledge and improvement quality of life for people,They have Has great potential and broad prospects for business,However, light-emitting electrochemical cells（LECs） are an important branchs of OLEDs.Recently dramatic advances have been achieved in the field of LECs, which are being developed for display and lighting applications. Ionic transition metal complexes （iTMCs） offer an alternative to such processing associated with conventional OLEDs.Their excellent stability in multiple redox states implies that electronic charges can be readily injected and transported. Furthermore, iTMCs such as [Ru（bpy）₃]²⁺（PF₆^-）2 are ionically conducting as the PF₆^- counterions can redistribute under an applied bias. This action creates an ionic space charge near each electrode (excess PF₆^- at the anode and uncompensated [Ru（bpy）₃]²⁺ at the cathode), which serves to assist electronic charge injection, even to the point of efficiently injecting electrons from air-stable metals. In this manner, these devices are similar to the socalled light-emitting electrochemical cells （LECs）, which are fabricated by dispersing salts into organic semiconductors. Additionally, the luminescence efficiency of iTMCs can be extremely high, with photoluminescence quantum yields approaching 100%, as emission from these materials arises almost exclusively from triplet states. As for processing, iTMCs can generally be spin cast directly from solution. These properties indicate that efficient electroluminescent devices can be fabricated from single-layer iTMC devices.Charged iridium（Ir） complexes have many other features except for high quantum efficiencies and easily tunable emission wavelength that may make them one of the finest candidates for lightings, displays and light-emitting electrochemical cells （LECs）. First, the synthesis condition of charged Ir complexes is much milder than that of neutral ones. Second, inert metal electrodes resistant to oxidation in air, such as Au and Pt, can be used in efficient devices based on charged Ir complexes. Third, further improving the stability of devices can be expected due to their excellent redox stabilities. In addition, charged Ir complexes are endorsed with the properties of charge transfer, consequently lowering power consumptions of devices. However, for the blend system of charged Ir complexes into hydrophobic host materials, the problem of phase separation is more serious them that of neutral Ir complexes due to the poor compatibility. And this problem is an obstacle to their applications in organic electronics. In order to solve this problem, modify the structure of ligands should to be done, and design, synthesize novel ionic iridium（Ir） complexes of high luminous efficiency to arrive LEC of high luminescence, high efficiency, This dissertation is comprised of the follow two parts:1、Two novel ligands （mptop and ptop） contain 1,3,4--oxadiazole and pyridine were designed and synthesized, and two ionic iridium（Ir） complexes [Ir（mptop）（ppy）₂]⁺（PF₆^-）and [Ir（ptop）（ppy）₂]⁺（PF₆^-） were prepared, where mptop is 2-（5-p-Tolyl-[1,3,4]oxadiazol-2-yl）- pyridine, ptop is 2-（5-Phenyl-[1,3,4]oxadiazol-2-yl）-pyridine, Compounds containing 1,3,4-oxadiazole（OXA） which possess excellent electron affinity, good light-emitting, thermal stability, and chemical stability characteristic, are commonly used as electron transporting and hole blocking materials in OLEDs. All of the complexes were characterized by IR, 1HNMR and X-Ray diffraction. Initiative study showed that the complexes were expected to be a good candidate for lighting and display application.2、Photophysical and electrochemical properties of these complexes were investigated, By study the UV-visible absorption spectrum, fluorescence emission spectrum and theoretical calculations of the complexes, we received that complexes with different ligands showed different optoelectronic properties and all complexes exhibited intense and long-live emission, clarified that the relationship between chemical structure and complexes,properties in photophysics and electrochemistry.3.We fabricated organic red light-emitting electrochemical cells （LECs） based on the two complexes [Ir（mptop）（ppy）₂]⁺（PF₆^-） and [Ir（ptop）（ppy）₂]⁺（PF₆^-） respectively. from devices, start-up voltage, response time, maximum brightness, luminous efficiency and device life, we studied the molecular structure of the complex changes in the impact on device performance.更多还原