合成了2种含有三苯胺结构的非对称型苝酰亚胺N-(2-乙基己基)-N'-(4-三苯胺)-3,4,9,10-苝二酰亚胺(PDI-ATPA)和4,4',4″-三[N-(2-乙基己基)-3,4,9,10-苝二酰亚胺]-三苯胺(PDI-TATPA).利用核磁共振谱(NMR)、红外光谱(IR)和元素分析等方法表征了2种分子的结构,采用紫外-可见(UV-Vis)吸收光谱和荧光光谱研究了其分子光物理性能及在溶液中的聚集行为,并且对分子轨道、能级和偶极矩进行了分子模拟.研究结果表明,具有星形空间对称结构的苝酰亚胺分子PDI-TATPA在溶液中具有自组装行为;引入的三苯胺结构与苝核形成电子给体-受体结构,发生分子内电子转移(PET),进而导致荧光猝灭.
Two asymmetrical perylene diimides with triphenylamine structure, N-( 2-ethylhexyl )-N'-( 4- triphenylamine) -3, 4, 9, 10-perylene diimide (PDI-ATPA) and 4, 4', 4"-tri [ N-(2-ethylhexyl) -3, 4, 9, 10-perylene diimide]-triphenylamine (PDI-TATPA) , were designed and synthesized, using branched alkyl chain substituted asymmetrical perylene monoanhydride monoimide (AsPDA- I ) as the electron-accepting spe- cies and different functional triphenylamines, 4-aminotriphenylamine (ATPA) and 4, 4', 4"-triaminotripheny- lamine(TATPA), as the electron-donating moieties, respectively. The chemical structures were characterized by proton nuclear magnetic resonance( 1H NMR), Infrared(IR) spectra and elemental analysis. The optical properties and aggregation behavior in solution were investigated by UV-Vis absorption and fluorescence emis- sion spectra. Besides, molecular simulations were carried out to elucidate the molecular orbitals, energy levels and dipole moments of two asymmetrical perylene diimides. The results demonstrated that introducing the tri- phenylamine structure at the imide nitrogen of perylene diimide not only broadens the photo absorption region of perylene diimide but also has no effect on the absorption properties of the perylene core because of nodes in the highes occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) at the imide nitrogen. Photoinduced electron transfer (PET) process take place from the eletron-donating moieties-ATPA and TATPA to the electron-accepting unit-perylene core, which has been confirmed by molecular simulations and lead to the fluorescence quenching. PDI-TATPA showed a star-shaped structure with highly regularity, which has been proven by the simulation data of dipole moment and has caused the self-assembly behavior easily occur in solution. Due to the self-assembly behavior, there are some differences between the UV-Vis spectra of PDI-ATPA and that of PDI-TATPA.