Study Of A PH Fluorenscent Probe And Supramolecular Self-assemblies Based On Tetraphenylethylene

The detection of intracellular pH plays an important role for normal cell functions in our lives. And it also influences the environment and food, et al. With excellet sensitivity and selectivity, non-invasivenss, high signal-to-noise and other excellent properties, the fluorescent probe has been more and more attractive. With an excellent AIE effect, tetraphenylethylene (TPE)-based matirials have been widely designed and synthesized. In this dissertation we reported a new fluorenscence probe for the detection of pH. In addition, we also attempted to introduce TPE moiety and DB24C8 into supramolecular self-assemblies.In the first chapter we reported a new amphiphilic molecule fluorescent probe M1 constructed on TPE, which act as a hydrophobic moiety, linked with two potential hydrophilic moieties, secondary amines and the chemical structures of M1 were fully characterized by 1H NMR, 13C NMR, FT-IR. and MS. The probe M1 showed triple-mode fluorescent responses from monomer emission to aggregation-induced emission over the wide-range pH (1.99～ 11.64) detection in THF/H2O (2:8, v/v) solution based on the solvation and AIEE mechanisms. The selectivity experiment over metal cations showed that the M1 exhibited a highly selectivity under complex conditions. Especially, when the pH value changed from 7.02 to 8.50, M1 exhibited as a ratiometric fluorescence probe. The sensor mechanism of M1 was also studied based on the NMR titration and TEM tests. This new finding provided a new method to the utilization of fluorescence with AIE effect to detect pH as expected.In the second chapter we reported three kind supramolecular assemblies based on TPE and DB24C8. The first supramolecular assembly was constructed by M1 and DB24C8. The second one was constructed by M1 and M2, and the M2 was synthesized from TPE moiety and DB24C8. The last one was constructed by M3, which was synthesized from TPE linked with DB24C8-and dibenzylammonium (DBA) through click reaction. The chemical structrus of all the compounds were fully characterized by 1H NMR,13C NMR, and MS. After fluorescent tests, unfortunately we have not obtained the expected fluorescence changes. At the same time, after we attempted different solvents and temperature, we also have not obtained the expected multi stimuli-response sol-gel properities of the assmlies constructed by M1 with M2 and M3 itself, respectively. The falied of these assmelis may caused by the structrus of monomers, the length of chains and the TPE core effect, et al. It needs more experiments to have a better understanding.