电子及位阻效应对2-（2-羟苯基）苯并噻唑衍生物荧光性能影响研究

发布时间：2018-05-04 02:49

本文选题：激发态分子内质子转移 + 2-(2-羟苯基)苯并噻唑　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：基于激发态分子内质子转移(ESIPT)的荧光传感器由于其双波长比率检测、较大的斯托克斯(Stokes)位移等特性引起了人们广泛关注,并在荧光探针、发光材料、激光染料、紫外过滤等方面得以广泛应用。然而,分子内氢键的强度对于ESIPT荧光分子的光物理性质具有决定性的影响,并且ESIPT荧光分子的发光特性容易受外界因素的影响。另外,一般的有机荧光染料具有聚集诱导淬灭的特点,从而限制了其在许多方面的应用。近几年来具有高荧光量子产率(Фf)的固体荧光有机材料得到了人们广泛的关注。本研究通过Sonogashira-偶联反应合成一系列以碳碳三键为连接臂的基于2-(2-羟苯基)苯并噻唑(HBT)衍生物ESIPT的分子,在苯酚环5’位修饰不同哈米特常数(σ)的取代基。利用紫外-可见吸收光谱和荧光光谱初步研究取代基对ESIPT荧光分子的发光性质影响。实验数据显示σ越大的HBT衍生物其分子内氢键越强,这使得其受外部因素破坏的可能性越小,酮式发射越强,荧光发射蓝移,量子产率越大。理论计算和晶体分析与实验结果相吻合。更为重要的是,甲氧酰基与氰基修饰的两个HBT衍生物不像其他的HBT衍生物和母体HBT在磷酸冲液中表现出阴离子发射,而是表现出酮式发射。这一研究结果为设计可应用于生物医学方面的新型ESIPT染料提供了一定的实验和理论方面的指导。另外,通过简单的Suzuki偶联反应合成两个以碳碳双键为连接臂的HBT衍生物:苯乙烯基修饰的HBT(HBT-s-Ph)和二苯乙烯基修饰的HBT(HBT-d-Ph)。在甲苯溶剂中,由于HBT-s-Ph的分子内氢键强于的HBT-d-Ph,其Фf比HBT-d-Ph的稍微大一些;但在晶体形态下,它们的Фf均有明显的提高,且HBT-d-Ph的Фf高达78%,是HBT-s-Ph的两倍。晶体结构表明HBT-d-Ph的发射显著增强,是由于垂直苯基导致独特的堆积模式引起的。因此,这种设计方法有望被应用到制备光学显示器上的高性能发光与传感材料、生物与学成像等方面。
[Abstract]:The fluorescence sensor based on excited intramolecular proton transfer spectroscopy (ESIPT) has attracted much attention due to its dual wavelength ratio detection, large Stokes Stokes shift and so on, and has attracted much attention in fluorescent probes, luminescent materials, laser dyes, and so on. Ultraviolet filtration has been widely used. However, the intensity of intramolecular hydrogen bonds has a decisive effect on the photophysical properties of ESIPT fluorescence molecules, and the luminescence properties of ESIPT fluorescence molecules are easily affected by external factors. In addition, general organic fluorescent dyes have the characteristics of agglomeration induced quenching, which limits their applications in many fields. In recent years, solid fluorescent organic materials with high fluorescence quantum yield (F) have been paid more and more attention. In this study, we synthesized a series of ESIPT derivatives based on 2-dihydroxyphenyl) benzothiazolium (HBT) derivatives by Sonogashira-coupling reaction, and modified the substituents of different Hammett constants (蟽) at the 5 'site of phenol ring. The effects of substituents on the luminescence properties of ESIPT fluorescence molecules were studied by UV-Vis absorption and fluorescence spectra. The experimental data show that the larger the 蟽, the stronger the intramolecular hydrogen bond of the HBT derivatives, which makes it less likely to be destroyed by external factors, the stronger the ketone emission is, the more blue the fluorescence emission is, and the higher the quantum yield is. The theoretical calculation and crystal analysis are in agreement with the experimental results. More importantly, the two HBT derivatives modified by methoxy and cyanoyl do not exhibit anion emission in phosphoric acid solution, but ketone emission, unlike other HBT derivatives and parent HBT. The results provide some experimental and theoretical guidance for the design of new ESIPT dyes for biomedical applications. In addition, two HBT derivatives were synthesized by simple Suzuki coupling reaction: styrene-modified HBTT-s-Phand and diphenyl vinyl-modified HBT-d-Phine. In toluene solvent, because the intramolecular hydrogen bond of HBT-s-Ph is stronger than that of HBT-d-Phand, its F is slightly larger than that of HBT-d-Ph, but in crystal morphology, its F is obviously increased, and the HBT-d-Ph has the highest F of 78, which is twice as high as that of HBT-s-Ph. The crystal structure indicates that the emission of HBT-d-Ph increases significantly due to the unique stacking pattern of perpendicular phenyl. Therefore, this design method is expected to be applied to the fabrication of high performance luminescent and sensing materials, biological and scientific imaging on optical displays.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O626.25

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