Synthesis Of Salamo Type Fluorescent Chemical Sensors Based On Nitrogen-heterocycle Modification And Their Recognitions For Various Cations And Anions

In recent years,the environmental problems and health problems caused by industrial production are becoming more and more serious,and heavy metal ions and toxic anion pollution bring many invariables to human society.With the development of industry,chemical sensors have been widely studied and have received extensive attention in the fields of food safety,environmental health,and biotechnology.In this thesis,several nitrogen-heterocyclic modified Salamo-based chemical sensors were designed and synthesized,characterized and investigated,and the sensor molecules were applied to food and water samples to explore the recognition ion performance.Meanwhile,the detection mechanisms were investigated by NMR and mass spectrometry.The main contents are divided into the following sections.1.The potential application values of fluorescent chemical sensors in daily production and life were briefly introduced,and the chemical sensor recognition mechanisms as well as design ideas through chemical principles were also introduced.several anions and cations were recognized and detected by photochemical sensors in recent years as well as the research progress respectively.2.A novel sensor PNS for continuous recognition of Cu²⁺ions and S^2-ions was designed and synthesized to specifically recognize Cu²⁺ions among 16 cations by fluorescence spectroscopy in DMSO:H₂O（9:1 v/v）solution.The color of PNS solution changed from colorless to yellow when Cu²⁺ions were added under fluorescent light,and the purple fluorescence of PNS solution was quenched at excitation wavelengths of 301 and 365 nm.The PNS-Cu complex formed by sensor PNS and Cu²⁺ions could further identify S^2-ions by fluorescence spectroscopy.the LOD values of the two substances,Cu²⁺ions and S^2-ions,were 1.21×10^-8 and 5.58×10^-9 M,respectively.In addition,single crystals of the PNS-Cu complex were obtained,which verified the principle of this continuous identification process.3.Two new single-armed nitrogen-heterocyclics Salamo-based chemosensors with similar structures,PDNS and PZNS,were synthesized to specifically recognize Al³⁺among 17 cations by fluorescence spectroscopy in DMSO:H₂O（1:1 v/v）solution,and the color of PDNS and PZNS changed from yellow to colorless when Al³⁺was added under daylight.At excitation wavelengths of 361 and 365 nm,the solutions of PDNS and PZNS changed to intense green-blue fluorescence.In addition,PDNS/PZNS was found to have excellent binding ability with Al³⁺,and the limit of detection was calculated to be(LOD=6.25×10^-9/1.26×10^-9 mol·dm^-3).In addition,sensor PZNS can detect Al³⁺in solution systems with water content up to 90%,and the applicable p H range is 3～12.Compared with other Salamo-based sensors,the detection conditions of PZNS and PDNS were broader and more practical.PZNS can also identify CN^-in fluorescence spectra.PZNS can also be used for the daily production and daily life of Al³⁺in water systems.4.The derivatives of Salamo-basedl igands,2,2’-[ethylenedioxybis（azetidinyl）]pyridine（L）,were synthesized,and characterized by nuclear magnetic hydrogen spectroscopy and infrared,and single crystals of three transition metal ions were synthesized,and the corresponding crystal data were obtained by X-ray single crystal diffraction,and the data were analyzed.