Synthes Is Of A Novel Salen Schiff Base And Its Application In Copolymerization And Ion Recognition

In this paper,four SalenCo catalysts were synthesized and their catalytic activities were compared,and the synthesized polymers were characterized and studied under the optimum conditions.In this paper,the recognition effect of the synthesis of Schiff bases and quaternary ammonium salts on the more than ten kinds of metal ions was studied.Specific research contents are as follows:By using o-cresol as the raw material,a new type of Salen ligand was synthesized by five steps:acylation reaction,hydrogenation reaction,aldehyde reaction,iodine substitution reaction and condensation reaction,and the synthesis conditions were optimized.The optimum synthesis conditions were studied by orthogonal experiment,the optimum reaction condition for the acylation reaction was-16?,the reactant ratio n?o-cresol?:n?AlCl₃?=1/3.1,reaction time was 24 h,the yield was 60.4%.The optimum condition of the hydrogenation reaction is the reaction temperature is 10? reactant ratio n?compound 1?:n?triethylsilane?=1/2.5,reaction time was 6 h,the yield was 62%.Quaternary ammonium salts were synthesized on the basis of synthetic Salen ligand with three ethylamine,two other quaternary ammonium salts contain OAc-and NO3-were synthesized by changing the anions on quaternary ammonium salts,a series of SalenCoX catalysts were synthesized by complexation of these three quaternary ammonium salts with cobalt acetate anhydrous.The study found that the catalytic activity of the catalyst 9 containing 2,4-dinitrophenol was the highest,the optimum polymerization conditions were optimized,the optimum polymerization conditions are as follows:the polymerization temperature is 30?,the polymerization pressure is 2MPa,and the polymerization time is about 24 h.And the four polymers catalyzed synthesis under the optimum conditions were characterized and studied by thermodynamics,results show catalyst 9 is the best,the glass transition temperature of-70? the highest polycarbonate content of 0.583.At the same time,the gel permeation chromatography?GPC?was used to analyze the molecular weight distribution of a series of catalysts synthesized in this paper,the structures of the intermediates and target products were characterized by 1H NMR and IR spectra.In this paper,the synthesized Schiff bases and quaternary ammonium salts were used to study the ion recognition of the more than ten kinds of metal ions(Na⁺,K⁺,Mg²⁺,Al³⁺,Zn²⁺,Ag⁺,Pb²⁺,Co²⁺,Li⁺,Ba²⁺,Ni²⁺,Ca²⁺,Cd²⁺,La³⁺,Cu²⁺,Mn²⁺,and so on),the effect of Schiff base and quaternary ammonium salt on metal ions was tested by UV-Vis absorption spectroscopy.The experimental results show that both Schiff bases and quaternary ammonium salts are sensitive to Zn²⁺ and have high selectivity.By means of UV-Vis absorption spectroscopy,the results showed that the complexation ratio of Schiff base and quaternary ammonium salt with Zn²⁺ was 1:1.