【作者】 冯君茜；

【导师】 李希友；

【作者基本信息】 山东大学 ， 无机化学， 2009， 博士

【摘要】 苝二酰亚胺（Perylene tetracarboxylic acid diimide,简称PDI）类衍生物具有优异的热和光化学稳定性,对可见区到红外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,以控制苝二酰亚胺类化合物的性质,是获得具有新颖的光电性质的PDI新材料重要手段之一。用相同取代基接在PDI的不同位置或不同取代基接在PDI的相同位置都将对其性质会产生巨大的影响。这在过去的工作中,人们把一些小分子的,如酚氧基、仲胺基、苯基、氰基以及卤素氟、氯、引入到PDI中,同时也把一些较大功能团,如PDI本身、卟啉、酞菁、环糊精、BODIPY、杯芳烃、富勒烯等和PDI连接在一起。把PDI单元与多个功能团取代基结合在一个分子中,可以获得具有新颖的光电性质的化合物。这些不同的取代基赋予PDI化合物许多新颖的光电性质。基于此,我们设计合成了一系列含有多功能团的苝二酰亚胺衍生物并对其性能进行了研究。以下是本文的主要工作:第一章:概述了PDI及其衍生物的发展历史、研究背景、基本性质、合成方法以及研究意义。第二章:通过苝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嗪环联接的,在湾位置具有不同取代基的苝二酰亚胺的二聚体环芳（cyclophane）。这些取代基为别为1,7-二酚氧基,1,7-二哌啶基和1,6,7,12-四酚氧基苝二酰亚胺。成功地分离了1,7-二哌啶基苝二酰亚胺构成的两种同分异构体。分别测定了这些化合物的稳态吸收和荧光光谱,测定了这些化合物的荧光量子产率和荧光寿命。在这些环状化合物中,苝二酰亚胺分子被强迫呈面对面地构象,共轭体系之间的强烈的相互作用,使得分子的吸收光谱发生较大蓝移。它们的吸收光谱和发射光谱随取代基的不同,变化较大。1,7-二哌啶基苝二酰亚胺构成的两种同分异构体的吸收光谱与计算结果一致。所测得的这些化合物的第一氧化还原电位与对应单体相比较大升高,并且与计算的HOMO和LUMO的能级变化相一致。结果证明,苝二酰亚胺环之间的相对位置决定了两个环之间的相互作用的大小,进而决定分子的光物理性质,分子结构微小的变化,可以引起光物理性质很大的变化。这一结论对设计和制备具有新结构和新性质的PDI超分子衍生物具有十分重要的意义。第三章:通过苝酰亚胺单酐与胺的缩合反应,合成了3个以三嗪环联接的,在湾位置具有不同取代基的含3个PDI单元的苝二酰亚胺三聚体化合物（trimer）。三嗪环与PDI单元之间的C-N-C键可自由旋转,使这些分子具有较大的灵活性。较容易呈现共平面的构象,因而特别有利于生成面对面聚集体。这些化合物的吸收光谱和荧光光谱随溶液浓度的变化而变化,并且随湾位置取代基的不同,其变化有很大不同。吸收光谱、荧光光谱以及荧光量子产率的结果表明,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。1,7-二酚氧基的trimer形成纳米线,而1,7-二哌啶基和1,6,7,12-四酚氧基的trimers形成纳米粒子。研究结果表明,具有柔性结构的三聚体与具有类似结构的刚性化合物一样,能自组装成有序的纳米结构。该研究对设计新颖的纳米有机材料具有一定的指导意义。第四章:以无水氯化锌为催化剂,将含活泼甲基的2-甲基喹啉连接到PDI单元的酰亚胺N的位置,合成了两个含PDI单元和硼氟荧光体单元（BODIPY）的新颖荧光染料。这些化合物具有很多优良的性能,例如,最大吸收波长和最大发射波长大大红移,具有较高的荧光量子产率和较强的电子接受能力,是潜在的有价值的n型有机半导体材料。第五章:以无水氯化锌为催化剂,将含活泼甲基的基团连接到PDI单元的羰基氧的位置,合成了几个性能优异的新型荧光染料。这些化合物的最大吸收波长和最大发射波长大大红移,并且具有较高的荧光量子产率和较强的电子接受能力。它们与BF₃-Et₂O反应,生成含PDI单元的BODIPY分子。另外,它能选择性络合不同的金属离子,并伴随吸收光谱和荧光光谱的显著变化,为潜在的荧光探针。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 optoelectronic properties.They have been used in organic field-effect transistors, light-harvesting solar cells,photovoltaic devices,light emitting diodes,and robust organic dyes that are resistant to photobleaching.These dyes have generated great interest because of their outstanding photochemical and thermal stability,ease of synthetic modification,and desirable optical and redox characteristics.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.The different substituents in the same position of PDI and the same substituents in the different positions of PDI lead to significant on changes on the photoelectric properties of new dyes greatly.These substituents are either small groups such as phenoxy groups,aryls,cyclic secondary amines,cyano groups,and halogens or large functional moieties such as PDI,Phthalocyanines, porphyrins,BODIPY,cyclodextrin,Fullerene,calixarene,and so on.To create a new PDI dye with novel photophysical and photochemical properties,the combinationof PDI and multifunctional groups in one molecule is a rational design.So,in this paper, we described the synthesis of a series of new PDIs with novel photophysical properties.In chapter 1,the research of synthesis,properties and applications of these perylene diimide derivatives were reviewed.In chapter 2,cyclophanes of perylene tetracarboxylic diimides（PDIs） with different substituents at the bay positions,namely four phenoxy groups at the 1,7-positions,four piperidinyl groups at the 1,7-positions,and eight phenoxy groups at the 1,6,7,12-positions of the two PDI rings,have been synthesized by the condensation of perylene dianhydride with amine in a dilute solution.These novel cyclophanes were characterized by ¹H NMR spectroscopy,MALDI-TOF mass spectrometry,electronic absorption spectroscopy,and elemental analysis.The conformational isomers of cyclophanes substituted with four piperidinyl groups at the 1,7-positions were successfully separated by preparative TLC.The main absorption band of the cyclophanes shifts significantly to the higher energy side in comparison with their monomeric counterparts,which indicates significantπ-πinteraction between the PDI units in the cyclophanes.Nevertheless,both the electronic absorption and fluorescence spectra of the cyclophanes were found to change along with the number and nature of the side groups at the bay positions of the PDI ring. Time-dependent DFT calculations on the conformational isomers with four piperidinyl groups at the 1,7-positions reproduce well their experimental electronic absorption spectra.Electrochemical studies reveal that the first oxidation and reduction potentials of the PDI ring in the cyclophanes increase significantly compared with those of the corresponding monomeric counterparts,in line with the change in the energy of the HOMO and LUMO according to the theoretical calculations.In chapter 3,three perylene tetracarboxylic diimide（PDI） trimers substituted with different side groups at the bay positions were prepared with the triazine ring as a linkage.The free rotation of C-N-C bonds between the triazine ring and the PDI unit provide these molecules with some flexibility.The UV-vis absorption and fluorescence spectra of these three compounds show different concentration-dependent behaviors,which depend on the side groups 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 were investigated by X-ray diffraction（XRD）,while the morphology of the aggregates was examined by atomic force microscopy（AFM）.The aggregation of trimer 1 with two phenoxy groups at the 1 and 7 positions results in long nanofibers whereas trimers 2 and 3 with dipiperidinyl groups or tetraphenoxyl groups at the bay positions form only particles.The results of this research revealed that PDI trimers with flexible structures can also self-assemble into large ordered aggregates such as those with rigid structure.This information is believed to be useful in the design of novel nanoorganic materials.In chapter 4,two novel fluorescent dyes based on perylene tetracarboxylic diimides synthesized by anhydrous ZnCl₂ catalized condensation between dianhydried and methyl quinoline.Significant features,such as longer wavelength absorption and emission,high fluorescence quantum yields,and strong electron accepting abilities, are observed for these new PDIs.Further reaction of these compounds with BF₃-Et₂O gives two compounds with advantage of both PDI and BODIPY.In chapter 5,several novel fluorescent dyes based on perylene tetracarboxylic diimides（PDIs） were prepared by a catalytic nucleophilic addition of an activated methyl group to carbonyl group.The compounds yield show several significant features compared with the conventional PDIs,such as longer wavelength absorption and emission,high fluorescence quantum yields and strong electron withdrawing abilities.Same side group at different position of the PDI ring will induce significant changes of UV/Vis absorption and fluorescence spectra,which can be ascribed to the different distribution of the frontier molecular orbital.Most importantly,the novel compounds can either reacted with BF₃-Et₂O to form new BODIPY analogues or selectively coordinate with different metal ions accompanied with significant changes on the absorption and fluorescence spectra.These properties make them good candidate for the application as fluorescence sensor.更多还原