【作者】 张婷；

【导师】 黄斌；

【作者基本信息】 江西师范大学 ， 化学工程， 2021， 硕士

【摘要】 发展综合性能优异的功能有机分子和聚合物材料,对更好地满足高新技术领域的日益需求具有较大的意义。本文在综合文献和课题组前期工作的基础上,设计并制备了几种含4,5-二（4-氰基苯基）-1H-咪唑结构的共轭发光小分子,以及氟化含四芳基咪唑结构聚酰胺、聚酰亚胺的功能性聚合物,并对其结构和性能进行了分析表征。论文的主要工作如下:以1,2-二（4-氰基苯基）乙二酮分别与4-（9H-咔唑-9-基）苯甲醛、对苯二甲醛,以及4-三氟甲基苯胺和4-（9H-咔唑-9-基）苯甲醛进行Debus-Radziszewski反应,合成了2-[4-（9H-咔唑-9-基）苯基]-4,5-二（4-氰基苯基）-1H-咪唑（1）、1,4’-二[4,5-二（4-氰基苯基）-1H-咪唑-2-基]苯（2）、1-（4-三氟甲基苯基）-2-[4-（9H-咔唑-9-基）苯基]-4,5-二（4-氰基苯基）-1H-咪唑（3）等3种共轭发光小分子。研究表明,化合物2的紫外吸收波长和荧光发射波长均表现出明显的红移现象,其四氢呋喃溶液和固体粉末状态均呈亮黄色荧光发射;化合物1和3固体粉末呈现蓝色或深蓝色荧光。化合物3具有聚集诱导荧光增强（AIEE）效应,而化合物1和2则存在一定程度的聚集诱导淬灭（ACQ）效应;此外,三种化合物均具有溶剂化效应,都能与Fe³⁺发生络合反应,导致分子荧光被抑制;对不同浓度Fe³⁺的荧光检测表明,它们均具有非常好的灵敏性,检出限分别为4.43×10^-5M、6.47×10^-5M和8.98×10^-5M,其中,化合物1的选择性最好。类似地,将1,2-二（4-三氟甲基苯基）乙二酮、4-硝基苯甲醛、4-硝基苯胺进行Debus-Radziszewski反应,制得1,2-二（4-硝基苯基）-4,5-二[4-（三氟甲基）苯基]-1H-咪唑,经钯碳催化水合肼还原,得到新型的二胺单体—1,2-二（4-氨基苯基）-4,5-二[4-（三氟甲基）苯基]-1H-咪唑（5）,继而将其与芳二酰氯发生低温溶液缩聚反应,制得了一系列氟化含1,2,4,5-四芳基-1H-咪唑结构的聚酰胺。结果表明,该系列聚酰胺的光学性能得到明显改善,存在一定的黄色荧光特性;常温下易溶于DMSO,DMF,NMP,DMAc,THF和丙酮等极性溶剂。同时,所制得的聚合物均为无定型结构,具有较高的耐热性,在氮气气氛中,热失重5%的分解温度高达420 ^oC。在上述基础上,将1,2-二（4-氨基苯基）-4,5-二[4-（三氟甲基）苯基]-1H-咪唑分别与均苯四甲酸酐等二酸酐进行缩聚反应,得到聚酰胺酸,继而通过化学环化得到了6种新型氟化含四芳基-1H-咪唑结构单元的聚酰亚胺;所得聚合物均为无定型结构,几乎没有明显的玻璃化转变;在氮气气氛中,热失重5%的分解温度高达400 ^oC,常温下可溶于NMP、DMF、DMAc、DMSO、THF和三氯甲烷等极性溶剂。此外,由于三氟甲基和咪唑基团的引入,聚合物的DMF稀溶液呈现出较好的光学性能。更多还原

【Abstract】 It is of great significance to develop functional organic molecule and polymer materials with excellent comprehensive properties to meet the increasing demand of high-tech field.Based on the literatures and the previous work of our research group,several conjugated luminescent molecules with 4,5-bis（4-cyanophenyl）-1H-imidazole structure,and the fluorinated polyamides and polyimides containing tetraarylimidazole moieties were designed and prepared,and their structures and properties were analyzed and characterized.The main work of this paper was as follows:Debus-Radziszewski reaction was carried out between 1,2-bis（4-cyanophenyl）ethylenedione with 4-（9H-carbazole-9-yl）benzaldehyde,terephthaldicarboxaldehyde,as well as 4-trifluoromethylaniline and 4-（9H-carbazole-9-yl）benzaldehyde,respectively.And the corresponding 2-[4-（9H-carbazole-9-yl）phenyl]-4,5-bis（4-cyanophenyl）-1H-imidazole（1）,1,4’-bis[4,5-di（4-cyanophenyl）-1H-imidazol-2-yl]benzene（2）and 1-（4-trifluoromethylphenyl）-2-[4-（9H-carbazol-9-yl）phenyl]-4,5-di（4-cyanophenyl）-1H-imidazole（3）were obtained.The results showed that the UV-vis absorption wavelength and fluorescence emission wavelength of the compound 2 had a red shift phenomenon,and its tetrahydrofuran solution and solid powder were bright yellow fluorescence emission,and the solid powders of compound 1 and 3 showed blue or dark blue fluorescence.Compound 3 exhibited aggregation-induced enhancement（AIEE）effect,while compounds 1 and 2 had aggregation-induced quenching（ACQ）effect to some extent.In addition,all three compounds had solvation effect,which could complexate with Fe³⁺,which led to the inhibition of molecular fluorescence;And the fluorescence detection of different concentrations of Fe³⁺showed that they were very sensitive,and the detection limit was 4.43×10^-5M,6.47×10^-5M and 8.98×10^-5M,respectively.Among them,the selectivity of compound 1 was the best.1,2-di（4-nitrophenyl）-4,5-bis（4-trifluoromethylphenyl）-1H-imidazolewas synthesized by Debus-Radziszewski reaction of 1,2-di（4-trifluoromethylphenyl）ethanedione,4-nitrobenzaldehyde and 4-nitroaniline using similar method as above.A new diamine monomer,1,2-di（4-aminophenyl）-4,5-bis（4-trifluoromethylphenyl）-1H-imidazole,was prepared by reduction of the dinitro intermediate with hydrazine hydrate combined with palladium carbon catalyst.Then,a series of fluorinated polyamides containing 1,2,4,5-tetraaryl-1H-imidazole in the main chain were prepared by low temperature solution polycondensation of the new diamine monomer with aromatic diacyl chlorides.The results show that the optical properties of the obtained polyamides are improved obviously,and there was a certain yellow fluorescence characteristic for them.All the prepared polyamides were easily soluble in DMSO,DMF,NMP,DMAC,THF and acetone at room temperature.At the same time,these prepared polymers had amorphous structure and high heat resistance with the decomposition temperature of 5%thermal weight loss as high as 420 ^oC in nitrogen atmosphere.1,2-di（4-aminophenyl）-4,5-bis（4-trifluoromethylphenyl）-1H-imidazoleewas polycondensated with pyromellitic anhydride and other dianhydrides to afford the polyamic acids,respectively,and then six new fluorinated polyimides containing tetraaryl-1H-imidazole moieties were obtained by chemical cyclization of the corresponding polyamic acids.The obtained polymers were amorphous structure,almost without obvious glass transition.In nitrogen atmosphere,the decomposition temperature of 5%thermal weight loss was as high as 400 ^oC.They were soluble in polar solvents such as NMP,DMF,DMAC,DMSO,THF and chloroform at room temperature.In addition,due to the introduction of trifluoromethyl and imidazole groups,the DMAC dilute solution of these new polymers showed better optical properties.更多还原