Study On Ion Probe Based On Triazine Structure And Preliminary Study On Organic Porous Materials

Ions have an indispensable influence on the environment and the growth and reproduction of living things.The right amount of ions is beneficial,but excessive amounts can cause major hazards such as environmental pollution and life-threatening diseases.Therefore,the detection of ions is the focus of environmental science and life science research.At present,the ion detection method has the defects of complicated synthesis method,high cost,and poor stability.Ion probes are widely used because of their high sensitivity,good selectivity and fast response.Therefore,the design and synthesis of ion probes with good selectivity,high sensitivity and convenient detection are of great significance for ion detection.In addition,organic porous materials are a class of structurally ordered,functionally controllable materials linked by covalent bonds.Such materials have better application prospects in gas storage,separation,photovoltaic materials and catalysis,but the design and construction of covalent organic porous materials are still the focus of research in this field.Meanwhile,the 1,3,5-s-triazine is a nitrogen-containing aromatic heterocyclic ring having a large conjugated structure it has excellent properties in terms of thermal stability,photoelectric properties,chemical resistance,high strength,and high modulus.The paper focuses on the homotriazine structure with good thermal stability,and synthesize 1,3,5-tris-（4-aminophenyl）triazine（TAPT）with p-aminobenzonitrile and trifluoromethanesulfonic acid as raw materials.Then explore the following:On the one hand,TAPT is combined with salicylaldehyde,2,3-dihydroxybenz-aldehyde,o-tert-butyl salicylaldehyde and 2-thiophenecarboxaldehyde to synthesize four ion probes（TAPT-SCD,TAPT-DIH,TAPT-SCD-L and TAPT-SF）,the structures of the products were characterized by ¹H NMR,¹³C NMR,ESI-MS and FT-IR,the recognition performance of ion probes on ions was investigated by Spectral means.The effects of acid-base,time,and other ion on the identification of ion probes have been explored.Among the four ion probes,TAPT-SF has good thermal stability,and Hg²⁺can be detected by UV absorption spectroscopy and fluorescence spectroscopy.TAPT-SCD can recognize F^-by UV absorption spectroscopy and fluorescence spectroscopy.TAPT-DIH can recognize Hg²⁺with high selectivity;TAPT-SCD-L can recognize Zn²⁺by high fluorescence selection.All four probes have good acid and alkali resistance.On the other hand,five kinds of-CH=N-linked organic porous materials（COF1,COF2,COF3,COF4 and COF5）was constructed by reacting TAPT with different structural dialdehydes.The structure of the products were characterized by FT-IR,SEM,BET and so on.Then COF4 is studied in depth.The method for constructing covalent organic porous materials is feasible to carry out that it can be pretreated by liquid nitrogen freezing cycle and suffered solvothermal reaction,then washed with acetone.The synthetic organic porous material has high thermal stability.The specific surface area of COF4 was 327.80 m²/g by BET.The SEM and XRD diffraction show that the crystallinity of COF4 is very poor,but the crystallinity is improved after loading Co²⁺,and COF4 has strong hydrophobicity.