Preparation Of Novel Schiff Base And Detection Of There Fluorescence Properties

Along with the rapid development of modern industry and the markedimprovement of people’s living standards, the topic of ecological environment and human health have become increasingly concerned.As important material factors in the metabolic process, anion and cation has played important roles in the whole life cycle, in which, the intake of excess or deficiency will bring undesirable physiological effects.For example, the excess copper ion in food will damage the liver and gallbladder function,the excess aluminum ions will lead to memory loss caused by Alzheimer, and so on. At the same time, the real-time monitoring of various ions in the environment is also an important issue to ensure the quality of our lives. Therefore, the fast and accurate detection method for trace ions, has become an important subject of scientific research in recent years.Owing to the high sensitivity, visibility and tunability, fluorescence probe technique is emerging as one of the most powerful and popular approaches in sensor studies. The structure of Schiff base and its derivatives come to the fore in numerous fluorescent probe structure because of their simple preparation process, strongchelating ion ability, significantsignal response and molecular designflexibility. On the basis of these advantages, the Schiff base and its metal complexes showed important value in the fields of medicine, catalysis and analysis etc.In this thesis, the reaction of salicylaldehyde and aniline derivatives was chosen as a model reaction, and a series of novel Schiff base structure with the ortho-hydroxyl group were prepared. On the one hand, the chelating ability was increasedthrough the synergistic effect between the along pair electron at nitrogen atom and phenolic oxygen negative ion, and the more sensitive detection would be realized. On the other hand, the fluorescence from excited state intramolecular proton transfer(ESIPT) process would be obtained, resulting in the large Stokes shift of the probe, which wouldlead the fluorescence wavelength redshift and expand the potential biological application.Firstly, the four novel salicylaldehyde derivatives were synthesized by Suzuki method, and namely as CN-SA, TPE-SA, TPA-SA and Cz-SA. After the detail spectra analysis, we found that the salicylaldehyde structures also had significant ESIPT states in their fluorescence process and aggregation induced luminescence properties, and the cation selective sensing process were achieved under hydrogen bonds and coordination action.Secondly, the three Salen-typed Schiff base was prepared by choosing the salicylaldehyde above and o-phenyl-diamine as substrate, and named as PDAS, CN-PDAS and TPA-PDAS. Under the study of solvent effect, AIE properties, pH effect and the ion selective experiment of these compounds, we found that the optical properties(ESIPT barriers) and ion chelating ability(the electron cloud density of cavity) could be tuned by adjustingthe para-substituentelectron pulling ability of phenolic hydroxyl group in salicylaldehyde structure, and the more specific(selective) fluorescence probe could be realizedafter optimizing structures.Finally, TPE-DMNS was synthesized from TPE-SA and diaminomaleonitrile, and the deep red fluorescent probe was obtained. In addition to the ESIPT state fluorescence and typical AIE characteristics, it also shows some advantages in ion sensing. And the probe can directly enter into cells and accumulated in the cytoplasm with selectivity, and it was used as single photon or two-photon fluorescence imaging analysis.After the system regulation in structures, we compared the nature of the ESIPT process, AIE properties and sensing effects of new salicylaldehyde and Schiff base derivative structure, and some valuable structure-properties relationship information was obtained, which was benefit for their potential probe application based on Schiff base structures.