【作者】 雷斌；

【导师】 陈志坚； 张昕； 高源；

【作者基本信息】 天津大学 ， 工程硕士（专业学位）， 2021， 硕士

【摘要】 近年来,氮杂氟硼二吡咯（Aza-BODIPY）染料由于其摩尔吸收系数较高、吸收波长较长、稳定性较高等优异的光物理性质,在光动力治疗及荧光探针等领域有着较为广泛的研究。另一方面此类功能染料的聚集体通常表现出独特的光谱性质,拓展了该类染料的应用价值。因此对于Aza-BODIPY染料聚集行为的相关研究具有重要意义。本论文设计合成了四种Aza-BODIPY 1-4染料,通过¹H NMR,¹³C NMR和HRMS等手段对化合物结构进行了表征。并进一步通过紫外-可见吸收光谱、荧光发射光谱、红外光谱以及AFM等研究了四种功能染料分子各自的聚集性质。对于Aza-BODIPY 1的研究结果表明,由于B,O的螯合导致了整个分子刚性化以及吸收峰和发射峰均向近红外区移动。在H₂O/DMSO混合溶剂中,Aza-BODIPY 1分子形成了最大吸收波长为812 nm的J型聚集体,并通过AFM观察到了其纳米纤维形貌,同时还研究了Aza-BODIPY 1对三氟乙酸的酸敏感性,发现在酸性条件下会形成新的染料物种2·H⁺。对于两亲性染料Aza-BODIPY 2,发现其在甲醇溶液中存在多途径聚集的行为。通过紫外-可见吸收和荧光发射光谱进行了三种聚集体的热力学研究和动力学研究,对变温光谱数据用成核-生长模型或等K模型的拟合,得到聚集体的关键性热力学参数,并研究了亚稳态向稳态的动力学转变过程。研究结果表明,一定条件下,Aza-BODIPY 2在甲醇溶液中会形成两种亚稳态聚集体,一种稳态聚集体,其两种亚稳态均是off-pathway的产物。对于染料Aza-BODIPY 3和Aza-BODIPY 4,在甲基环己烷溶液中均能形成两种不同的聚集体,重点通过TCE溶液的变温¹H NMR证实单体分子可以形成分子内氢键,并进一步通过红外光谱研究了聚集体中分子内和分子间氢键的作用力,证明聚集体I是由于三氮唑与酰胺之间形成分子内氢键作用力而导致的,而聚集体II则是由于相邻分子间通过酰胺基团形成分子间氢键而导致的。本论文对于Aza-BODIPY类染料超分子组装行为的研究及性质调控具有重要意义。更多还原

【Abstract】 In recent years,Aza-BODIPY dyes have been used in photodynamic therapy and fluorescent probes due to their excellent photophysical properties such as high molar absorption coefficient,long absorption wavelength,and high stability.On the other hand,the aggregates of such functional dyes usually exhibit unique spectral properties,which expands the application value of this type of dyes.Therefore,it is of great significance for the related research on the aggregation behavior of Aza-BODIPY dyes.In this thesis,four Aza-BODIPY 1-4 dyes were designed and synthesized,and the structure of compounds were characterized by means of ¹H NMR,¹³C NMR and HRMS.The aggregation properties of the four functional dyes were further studied by UV/Vis absorption spectra,fluorescence emission spectra,infrared spectra and AFM.For Aza-BODIPY 1,the results show that the whole molecule is rigid due to the chelation of B and O,and the absorption and emission peaks move to the near infrared region.In H₂O/DMSO mixed solvent,Aza-BODIPY 1 molecules formed J-type aggregates with the maximum absorption wavelength of 812 nm.The morphology of the nanofibers was observed by AFM.The acid sensitivity of Aza-BODIPY 1 to trifluoroacetic acid was also studied.It was found that a new dye species 2·H⁺was formed under acidic conditions.For the amphiphilic dye Aza-BODIPY 2,it was found that there was a multi-channel aggregation behavior in methanol solution.The thermodynamics and kinetics of the three kinds of aggregates were studied by UV/Vis absorption and fluorescence emission spectra.The key thermodynamic parameters of the aggregates were obtained by fitting the variable temperature spectra with nucleation growth model or equal K model,and the dynamic transition process from metastable state to steady state was studied.The results show that under certain conditions,Aza-BODIPY 2 can form two kinds of metastable aggregates and one kind of stable aggregates in methanol solution,and both metastable states are products of off pathway.For the dyes Aza-BODIPY 3 and Aza-BODIPY 4,two different aggregates can be formed in methylcyclohexane solution.The intermolecular and intramolecular hydrogen bonding forces in the aggregates were further studied by infrared spectroscopy.It was proved that the Agg.I was caused by intramolecular hydrogen bonding between triazole and amide,while the Agg.II was caused by intermolecular hydrogen bonding between adjacent molecules through amide group.This thesis is of great significance for the study of supramolecular assembly behavior and property regulation of Aza-BODIPY dyes.更多还原