含噻吩基席夫碱类化合物的合成及其光化学性能研究

发布时间：2018-01-07 10:07

本文关键词：含噻吩基席夫碱类化合物的合成及其光化学性能研究　出处：《新疆大学》2015年硕士论文　论文类型：学位论文

【摘要】：有机光致变色材料是一类在光信息存储、分子开关、光学镜片、光学防伪等领域最具有应用潜力的高性能功能材料。目前大量研究集中在对已有的光致变色化合物进行改性和复合,然而新的化合物的合成、新的光致变色体系的开发仍然是推动这一领域发展的动力。本文以噻吩基席夫碱化合物为研究对象,合成了11种新化合物,并对这些化合物的组成、结构与光化学性能进行了表征和测试,分析了化合物的光致变色机理,总结了这类化合物的结构与光化学性能之间的关系,为新型光致变色材料的研究、开发与应用提供了科学依据和理论基础。第一章合成了9个噻吩甲醛缩氨基硫脲类化合物。利用1H-NMR、13C-NMR、质谱、X-ray单晶衍射表征了这些化合物的组成与结构,采用紫外-可见吸收光谱和荧光发射光谱分析了这些化合物的光化学性能及反应动力学。发现3个噻吩甲醛缩氨基硫脲化合物在固态下具有紫外光变色,可见光消色的光致变色性能,讨论了噻吩环5位的取代基对化合物光致变色速率的影响,并运用变色前后的红外谱图和单晶结构,解释了其变色机理;其它6个噻吩甲醛缩甲基氨基硫脲和噻吩甲醛缩苯基氨基硫脲化合物在固态下均不具有光致变色性能,但具有有机小分子发光性能,并运用理论计算解释了化合物的发光机理;选择了一种荧光性能最好的化合物噻吩-2-甲醛缩苯基氨基硫脲S2C-PTSC与聚苯乙烯(PS)复合,制备了一种具有与粉末相同性能的薄膜。此外,我们还发现了噻吩-2-甲醛缩苯基氨基硫脲3个化合物在溶液中具有光致变色性能,探讨了溶剂极性对其变色性能的影响。第二章在前一部分的基础上,在噻吩上引入了一个苯环,合成了2种光致变色化合物:苯并噻吩-2-甲醛缩4-苯基氨基脲[BS2C-PSC]和苯并噻吩-2-甲酮缩4-苯基氨基脲[BS2T-PSC]光致变色化合物。通过对它们的组成、结构及性能进行研究,发现化合物BS2T-PSC具有不可逆的变色性能,而化合物BS2C-PSC具有紫外光变色和可见光褪色的光致变色性能,同时还具有热增幅现象、荧光性能和良好的抗疲劳性能。根据晶体结构和变色前后的红外光谱,提出了该类化合物的变色机理为酮式与醇式结构互变的质子转移。此外,将化合物BS2C-PSC与聚苯乙烯复合制备出了一种与粉末具有相似性质的薄膜,在信息存储和智能窗帘等领域具有潜在的应用。
[Abstract]:Organic photochromic materials are a class of optical information storage, molecular switches, optical lenses. Optical anti-counterfeiting and other fields have the most potential of high-performance functional materials. At present, a large number of studies focused on the existing photochromic compounds to modify and composite, however, the synthesis of new compounds. The development of new photochromic system is still the driving force to promote the development of this field. In this paper, 11 new compounds have been synthesized and their compositions have been studied by taking thiophene Schiff base compounds as the research object. The structure and photochemical properties were characterized and tested, the photochromic mechanism of the compounds was analyzed, and the relationship between the structure and photochemical properties of these compounds was summarized, which is a new type of photochromic materials. In chapter 1, nine thiophene formaldehyde thiosemicarbazones were synthesized. 1H-NMR-13C-NMR-MS was used. The composition and structure of these compounds were characterized by X-ray single crystal diffraction. The photochemical properties and reaction kinetics of these compounds were analyzed by UV-Vis absorption spectra and fluorescence emission spectra. It was found that three thiophene formaldehyde thiosemicarbazone compounds had UV photochromism in solid state. The photochromic properties of visible photochromic compounds are discussed. The influence of the 5-position substituents of thiophene ring on the photochromic rate of the compounds is discussed. The mechanism of photochromic reaction is explained by the infrared spectra and single crystal structure before and after discoloration. The other six thiophene formaldehyde methyl thiosemicarbazone and thiophene formaldehyde phenyl thiosemicarbazone compounds have no photochromic properties in the solid state, but have the photoluminescence properties of organic small molecules. The luminescence mechanism of the compounds was explained by theoretical calculation. A novel compound, thiophene -2-formaldehyde thiosemicarbazone (S2C-PTSC) and polystyrene (PS), was selected to prepare a thin film with the same properties as the powder. We also found that thiophene-2-formaldehyde phenylthiosemicarbazone had photochromic properties in solution and discussed the effect of solvent polarity on its discoloration performance. Chapter 2 was based on the former part. Two photochromic compounds, benzothiophene -2-formaldehyde, 4-phenylsemicarbazone, were synthesized by introducing a benzene ring into thiophene. [BS2C-PSC] and benzothiophene 2-methyl ketone 4-phenylsemicarbazone. [By studying the composition, structure and properties of photochromic compounds, it is found that compound BS2T-PSC has irreversible discoloration property. The compound BS2C-PSC has the photochromic properties of UV and visible light fading, and also has the phenomenon of thermal increase. According to the crystal structure and infrared spectrum before and after discoloration, the chromotropic mechanism of this kind of compounds is the proton transfer between ketone and alcohol. A kind of thin film with similar properties to powder was prepared by compound BS2C-PSC and polystyrene, which has potential applications in the field of information storage and intelligent curtain.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O626.12;TB34

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