具有聚集荧光增强效应的共轭聚合物的合成及自组装行为的研究

发布时间：2018-02-14 06:01

本文关键词： 共轭聚合物聚集诱导发光光物理性质自组装　出处：《兰州大学》2017年硕士论文　论文类型：学位论文

【摘要】：发光共轭聚合物可以有效合成,容易修饰,并且具有高荧光量子产率。在许多情况下,这些应用需要以固态、浓溶液和/或聚集态的形式出现。然而,由于发光体的芳环结构所产生的强烈的π-π相互作用,聚集态通常导致荧光高度衰减或完全淬灭。因此,这种聚集引起的猝灭(ACQ)效应部分地限制了它们的实际应用。另一方面,具有螺旋桨状结构的发光体在稀溶液中不发光,而在浓溶液、固体和/或聚集状态中是显著发射的。这种光物理现象与ACQ效应相反,因此被称为聚集诱导发光(AIE)或聚集诱导的发光增强(AIEE)。AIE发光体可以容易地并入聚合物主链或侧链中,形成高度可用的共轭聚合物。此外,具有炔基的AlE分子可以通过多环三聚,点击反应或共聚产生高分子量的超支化聚合物,所有这些共轭聚合物在溶液中都是弱发光的,但它们的发射在聚集状态时显著增强。基于以上论述,本论文从以下两个方面进行了讨论。第一部分,我们通过Sonogashira交叉偶联反应合成了三种组成相似但结构不同的完全疏水的聚四苯基乙烯(PTPEs),o-TPE-1,m-TPE-1和p-TPE-1。这些共轭聚合物在质量弱化的溶剂中荧光明显增强,表现出了典型的AEE特征。但它们在不同的混合溶剂,如甲苯/甲醇,氯仿/正己烷和氯仿/甲醇中却显示出不同的光谱行为。为了进一步验证这种性质,我们探讨了它们在不同溶液体系中的自组装行为,发现在甲苯/甲醇体系中会形成自支撑膜,并且随着甲醇含量的增加,会逐渐趋向于形成纳米球;在氯仿/甲醇体系中自组装形成尺寸均一的实心纳米球;而在氯仿/正己烷体系中则形成了很漂亮的空心纳米球结构。而且我们发现,它们的形貌和荧光变化具有一定的依懒性。第二部分,我们将具有AIE效应的TPE分子引入到二苯并咪唑吡啶Pt(II)配合物中,对它们进行了详细表征,包括核磁,红外光谱,紫外-可见吸收光谱和荧光光谱。从紫外-可见光谱中我们发现在315 nm处出现四苯基乙烯的吸收波长,而在310-390 nm范围内出现了咪唑吡啶的特征吸收。接下来探讨了它们在THF/H2O中的荧光变化,发现随着水含量的增加,TPE单体分子的荧光减弱,相对应的聚集态的荧光逐渐增强。同时,随着水含量的增加Pt···Pt相互作用的发射逐渐增强。我们期望它具有好的光物理性质并伴随形貌变化,在未来有机光电,分子器件和荧光传感等存有潜在价值。
[Abstract]:Luminescent conjugated polymers can be efficiently synthesized, easily modified, and have high fluorescence quantum yields. In many cases, these applications need to take the form of solid, concentrated solutions and / or aggregated states. Due to the strong 蟺-蟺 interaction produced by the aromatic ring structure of luminators, the aggregation states usually lead to high fluorescence attenuation or complete quenching. Therefore, the quenching effect caused by this aggregation partially limits their practical application. Phosphors with propeller-like structures do not emit light in dilute solutions, but are emitted significantly in concentrated solutions, solids and / or aggregates. This photophysical phenomenon is contrary to the ACQ effect. Thus, the luminescence intensifier AIEEN. AIE, called agglomeration induced luminescence (AIEE) or agglomeration induced luminescence, can easily be incorporated into the main or side chain of the polymer to form highly usable conjugated polymers. In addition, AlE molecules with acetylene groups can be polymerized through polycyclic trimerization. Click reaction or copolymerization to produce hyperbranched polymers of high molecular weight, all of which are weakly luminescent in solution, but their emission increases significantly when aggregated. This paper discusses the following two aspects. The first part, Through Sonogashira cross-coupling reaction, we have synthesized three kinds of completely hydrophobic poly (tetraphenylethylene) (PTPES) with similar composition but different structure. The fluorescence of these conjugated polymers in the weakening solvent is obviously enhanced. But they exhibit different spectral behaviors in different mixed solvents such as toluene / methanol, chloroform / n-hexane and chloroform / methanol. We investigated their self-assembly behavior in different solution systems. It was found that self-supporting membranes were formed in toluene / methanol system and tended to form nanospheres with the increase of methanol content. In chloroform / methanol system, we self-assemble solid nanospheres of uniform size, while in chloroform / n-hexane system we have very beautiful hollow nanospheres, and we find that, In the second part, the TPE molecules with AIE effect were introduced into the complexes of PtTX II with dibenzimidazole pyridine, and they were characterized in detail, including NMR and IR spectra. UV-Vis absorption spectra and fluorescence spectra. From the UV-Vis spectrum, we found the absorption wavelength of tetraphenylethylene at 315 nm. The characteristic absorption of imidazopyridine appeared in the range of 310-390nm. Then the fluorescence changes of imidazopyridine in THF/H2O were discussed. It was found that the fluorescence of monomeric molecules decreased with the increase of water content, and the fluorescence of the corresponding aggregates gradually increased. With the increase of water content, the emission of Pt 路路Pt interaction gradually increases. We expect that it will have good photophysical properties and accompanied by morphological changes, which has potential value in the future, such as organic photoelectricity, molecular devices and fluorescence sensing.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.24

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