【作者】 石岩；

【导师】 李希友；

【作者基本信息】 山东大学 ， 无机化学， 2014， 博士

【摘要】 茈二酰亚胺(Perylene tetracarboxylic acid diimide,简称PDI)类衍生物具有优异的热和光化学稳定性,对可见区的光有很强的吸收。是一种具有独特的光物理和光化学性质的有机光电材料。在太阳能转化、电致发光、以及生物荧光探针等领域有广泛的应用前景。近年来,对其光物理性质的研究愈来愈受到关注,并逐渐成为研究的热点。为了满足PDI化合物在不同领域的应用,通过对其结构进行化学修饰,以控制茈二酰亚胺类化合物的结构,进而获得新颖的光电性质是十分必要的,也是行之有效的方法之一。在作为半导体材料的应用中,茈二酰亚胺化合物要求具有十分优秀的自组装能力,容易形成有序的分子聚集体。但是,如何修饰一个分子才能使其具有好的组装性质和优良的光电性质,一直是困扰人们的难题也是人们关注的焦点。本论文主要以改善分子的自组装性质为目的,尝试设计合成结构新颖的平面共轭的花二酰亚胺类/酞菁类化合物,研究其自组装性质以及结构和性能间的联系。我们的工作主要集中在以下几个方面：第一章：概述了PDI类衍生物的发展历史、研究背景、基本性质、合成方法以及研究意义；含多功能团的苝二酰亚胺类/酞菁类衍生物的合成及性能为本文的创新点。第二章：通过花四羧酸二酐与相应的胺在高稀释的溶液中进行缩合反应,合成了一系列的以三键、苯基联接的,在湾位置具有不同长度的花二酰亚胺的二聚体。这些二聚体分别有两个三键、四个三键和两个苯基、六个三键和四个苯基链接。分别测定了这些化合物的稳态吸收和荧光光谱,计算了这些化合物的荧光量子产率。这些化合物的吸收光谱和荧光光谱随湾位置链接基长度的不同,其变化有很大不同。吸收光谱、荧光光谱以及荧光量子产率结果表明,这些化合物在溶液中发生了明显的聚集。通过X-射线衍射法(X-ray)和原子力显微镜(AFM)研究了其固态的聚集体形貌。两个三键链接的花二酰亚胺二聚体形成均匀的固体膜,另两个化合物形成纳米线。研究结果表明,三键和亚苯基能有效的扩展共轭链的长度并能增加分子间的π-π相互作用,该研究对设计新颖的纳米有机材料具有一定的指导意义。第三章：酞菁是一种共轭大环体系的化合物,其衍生物与其它有机半导体材料相比,具有良好的化学稳定性和热稳定性。我们设计并合成了苯环链接的共平面双酞菁铜配合物。在酞菁环的周围引入了吸电子基团,调节HOMO和LUMO能级,使之成为在空气中稳定的双极性有机半导体材料。利用在溶液中的quasi-Langmuir-Shaer (QLS)的方法,得到了非常有序的薄膜,并制作成器件,以供研究使用。测试其OFET’性质,得到了电子和空穴迁移率分别是1.7×10-1和2.3×10-4cm2V-1s-1.与单核酞菁铜配合物相比,由只能在N2中测得的单一的OFET性质转变成空气中稳定的双极性OFET。实验结果表明,通过调整分子结构,可以得到理想的双极有机半导体材料。第四章：通过柔性链将富电子的功能基团与花二酰亚胺相连,可以有效的提高其电导能力。将芘引入到花二酰亚胺的湾位置后的分子结构由核磁氢谱,质谱及元素分析鉴定。化合物的聚集体是通过溶剂缓慢挥发得到的。形貌特征由扫描电镜(SEM)和XRD测得。其电导率经测试后可达4.85×10-4S cm-1,有望作为有机半导体材料。更多还原

【Abstract】 Perylene tetracarboxylic diimide (PDI) derivatives are important molecular building blocks that are currently being investigated for use in a variety of photoactive organic materials because of their low light and thermal fading rates, high luminescence efficiency, wide absorption and emission bands in visible region, and variable optoelectronic properties. They have been applied in nanoscale field-effect transistors, light-harvesting solar cells, photovoltaic devices, light emitting diodes, and as robust organic dyes that are resistant to photobleaching.Driven by the demands of diverse applications, the modification on molecular structure of PDI aimed at changing the photophysical properties has attracted a lot of research interest in the past decade. However, how to control the properties by modifying on the molecular structure has always been a disturbing problem. In this paper, we designed and synthesis a series of new PDI compounds aimed at modifying their self-assemble process and controlling the structure of the assembly. The structure-property relationship is discussed. The research work of this thesis includes:In chapter1, the research on the synthesis, properties and applications of perylene diimide derivatives have been reviewed. The topic of special photophysical properties of PDI compounds in special media is selected as the focus of this part.In chapter2, perylene tetracarboxylic diimides (PDIs) dimers linked with conjugated chain of different length at the bay positions, namely two alkyne groups, four alkyne groups and two phenylenes, and six alkyne groups and four phenylenes, have been synthesized. Their photophysical properties in room temperature were studied by steady state absorption and emission spectra, the fluorescence quantum yield were calculated. The UV-vis absorption and fluorescence spectra of these three compounds show different concentration-dependent behaviors, which depend on the conjugated chain of different length at the bay positions. Significant aggregation in organic solvents was revealed by the electronic absorption and emission spectra as well as the fluorescence quantum yield calculation. The aggregation behavior of these compounds in the solid state was investigated by X-ray diffraction (XRD), and the morphology of the aggregates was examined by atomic force microscopy (AFM). The aggregation of dimer1with two alkynes at the1and7positions results uniform solid film, whereas dimer2and3with more alkynes and phenylenes at the bay positions formed one-dimensional rod-like aggregates with the aspect ratio of the latter significantly larger than the former. The results of this research revealed that ethynyl and phenyls are suitable linkages to extend the effective conjugation length and enhance π-π interaction. These results will be helpful in guiding the design of new organic molecules for the self-assemble organic functional materials in molecular electronic devices.In chapter3, A soluble binuclear phthalocyaninato copper (Ⅱ) complex, Cu2[Pc(COOC8H17)6]2(1), with planar molecular structure and extended conjugation system, has been designed and synthesized. By fusing two phthalocyanine rings side by side and introducing electron withdrawing groups at periphery positions, the energy levels of HOMO and LUMO have been tuned successfully into the range of an air-stable ambipolar organic semiconductor required as revealed by the electrochemical studies. With the help of a solution-based quasi-Langmuir-Shaer (QLS) method, thin solid films of this compound were fabricated and organic field effect transistors (OFETs) based on these QLS thin solid films were constructed. Because of the promising electrochemical properties as well as the high ordered packing structure of the molecules in the thin solid films, the OFETs performed excellent ambipolar operating properties, with the electron and hole mobility in air as high as1.7X10-1and2.3X10-4cm2V-1s-1, respectively. For comparison purpose, mononuclear compound Cu[Pc(COOC8H17)8](2) was comparatively studied. The QLS thin solid films of this compound possess similar ordered structure with that of Cu2[Pc(COOC8H17)6]2(1), but the OFETs based on the thin solid films of this compound can only show n-type properties under nitrogen atmosphere with an extremely small electron mobility of1.6X10-4cm2V-1s-1. This result suggests that extension on the conjugation system of an aromatic compound with multiple electron withdrawing groups can tune the molecule into an air stable ambipolar organic semiconductor.In chapter4, One perylenetetracarboxylic diimide (PDI) derivatives (PDI1) linked with pyrene by flexible chain at the bay positions was synthesized and the molecular structure was characterized by1H NMR, MALDI-TOF mass spectra as well as elemental analysis. The molecular self-assembly were prepared from solution via a slow evaporation of solvent. The properties of these molecular aggregates were studied by electronic absorption and fluorescence spectra. The morphologies and structures were examined by scanning electronic microscopy (SEM) and X-ray diffraction (XRD) techniques. The conducting properties were evaluated by current-voltage (I-V) measurements. The results revealed highly ordered structure for these molecular self-assembly. The thin solid film fabricated from these molecular self-assembly show an electric conductivity as high as4.85×10-4S cm-1under the ambient light, which means this compound might be used as a semiconductor in nano-electronics.更多还原