Preparation Of Novel Azine Derivatives And Their Fluorescence Application In Sensors

Along with the continuous improvement of people’s living standards, theprivate health has become a topic of increasing concern. 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. Therefore, the fast and accurate detection method for trace ions, has become an important subject of scientific research in recent years.Common lipid soluble fluorescent probe structuresexhibited typical concentration quenching effect, resulting in its limited using as high efficiency and sensitivity probes for cations and anions in aqueous environment. In this thesis, we designed and fabricated a new type of fluorescent probe with salicylaldehyde azine and hydrazine group(SAH). Thanks for the intramolecular hydrogen bonding between phenol hydroxyl group and lone pair electron in nitrogen atom, the special fluorescence process was constructed based on fast proton transfer state(ESIPT state fluorescence), and the dual wavelength fluorescence was monitored; and the ratio of radiative transition would be improved under the locking effect, and the high efficiency fluorescent was realized for the probe in aggregated state in the water(AIE characteristic). At the same time, the action of coordination properties between lone pair electrons and empty orbitals of the metal, the probe had the strong coordination ability, andcompleted the rapid identification of ions. In this thesis, the two series of SAH derivative were mainly designed and synthesized. They were all systematically chartered by NMR spectra for structures, UV-Vis and fluorescence test, and sensing properties.(1) Fluorescent probe based on single salicylaldehyde azine and hydrazine group(s-SAH): In Chapter 2, two kinds of new types-SAH probe was designed and prepared, namely as FAS and DBAS. They showed remarkable ESIPT and AIE properties under the action of intramolecular hydrogen bonding, and the “turn-off” probe for the copper ion and the “turn-on” probe for iron and mercury ions were observed. In Chapter 3, the six novel fluorescent probes deviating fromFAS and DBAS were prepared by adjusting the substituent structure, namely as O-FAS, N-FAS, D-FAS, N-DBAS, 2N-DBAS and 3N-DBAS.We discussed the effects of the intramolecular hydrogen bonding, electron and synergistic reactionon the probe of the ESIPT, AIE, pH stability and ion sensing selectivity and sensitivity. Some excellent fluorescent probesbased on s-SAH were selected.(2) Fluorescent probe based on double salicylaldehyde azine and hydrazine group(d-SAH): In Chapter 4, the salicylaldehyde azine(SAA) was chosen as a model compound, and the N-SAA and TPE-SAA structures were prepared as comparedto investigate the expanding conjugate effects on fluorescence probe(ESIPT and AIE characters) and ion recognition(sensitivity and selectivity). In Chapter 5, the expansion of conjugation degree at para-position of phenolic hydroxyl group was realized by turning electron donating groups structure, the CN-SAA, TPA-SAA and Cz-SAA were preparedfor comparing the influence of electronic effect on the probe ESIPT, AIE properties and ion sensing selectivity and sensitivity(anionic, cationic). Luckily, the high efficiency specific probe structure for copper ion and fluorine ion was selected.Through the structural adjustment and detailed spectroscopic studies, we develop a new type of fluorescent probe structure based on SAH, and preferably obtained some excellent probe structure, which all give contribution forthe relationship between the structures and properties from SAH-based materials.