Synthesis And Performance Research Of Salicylaldehyde Schiff Bases And Their Complexes

Schiff base is a kind of important nitrogen compounds which contain aldehydes and amino compounds.It is simpler to synthesize Schiff base.The structure contains special carbon nitrogen double bonds.Schiff bases have different structures and have different activities because of the different structure of the reactants.Schiff base can be divided into salicylaldehyde Schiff base,amino acid Schiff base,amino Amine Schiff base,guanidine Schiff base,hydrazone Schiff base and other Schiff bases according to reactant.The-C=N-in the Schiff base has good coordination properties,and Schiff bases have been widely used in the fields of coordination chemistry and materials.Schiff base can coordinate with a variety of metal elements.The mononuclear and multi-core Schiff base metal complexes with Schiff base have good bioactivity and optical properties.In this paper,the salicylaldehyde Schiff base was studied in this paper.1.Salicylaldehyde and melamine were used as reactants to synthesize melamine salicylaldehyde Schiff base under oil bath DMF conditions and the products were analyzed by mass spectrometry.Nuclear magnetic,elemental analysis and infrared characterization analysis to verify that the product is the target product;using single-factor experiments and orthogonal experiments to study the ratio of solvent,reaction time,reaction temperature,and the amount of reactant substances to salicylaldehyde melamine Schiff base production The effect of the rate,the best synthesis process was as follows:the solvent was DMF,the reaction time was 4h,the reaction temperature was 115?,the ratio of the salicylaldehyde to melamine was4.5:1,and the temperature was the significant effect on the yield.Factors;Under the optimum conditions,the yield of melamine salicylaldehyde Schiff base was 35.25%.The antibacterial activity of the product Schiff base was studied.Schiff base had a good inhibitory effect on Escherichia coli and Staphylococcus aureus at concentrations of 100 mg/L and 200 mg/L respectively against Escherichia.coli and Staphylococcus aureus.The inhibitory effects were 55.46%and 67.68%,respectively.2.Benzophenamine hydrochloride was synthesized using benzophenone and formamide as reactants,and then reacted with salicylaldehyde to form diphenylamine-salicylaldehyde Schiff base.The product was characterized by IR,MS and NMR.The effects of reaction time,reaction temperature,mass ratio of the reactants and PH on the synthesis reaction were studied by single-factor experiments and orthogonal experiments.The optimal synthesis process was:reaction time 3.5 h,reaction temperature 75?.,mass ratio of reactants.was 1:1.2,PH=9.0,the target Schiff base product yield was 90.12%under this process condition.The antibacterial activity of diphenhydryl-salicylaldehyde Schiff base was studied.The results showed that Schiff base had a good inhibitory effect on Escherichia coli and Staphylococcus aureus when the Schiff base concentration was 50 mg/L and 100 mg/L respectively.The inhibitory effects on Escherichia coli and Staphylococcus aureus were 56.66%and 69.86%,respectively.3.The diphenylamine-salicylaldehyde Schiff base ligand was used to coordinate with Cu,and the product of diphenylamine-salicylaldehyde Schiff base copper complex was analyzed by elemental analysis and infrared characterization.The molecular formula was inferred to be C₄₀H₂₀N₂O₂ and molecular structure.The antibacterial activity of the Schiff base copper complex of diphenylmethylamine was explored,indicating that it has better antibacterial activity than that of the Schiff base ligand.When the Schiff base complex concentration is 50 mg/L,it will affect Escherichia coli and Staphylococcus aureus.The inhibitory effects of Escherichia coli andStaphylococcus aureus were 68.33%and 73.96%,respectively,and the antibacterial effect was better than that of the ligand.4.The ZSM-5 supported dibenzamine salicylaldehyde Schiff base heterodinuclear complex catalyst was synthesized by using diphenylamine-salicylaldehyde Schiff base as ligand and ZSM-5 as the carrier.The catalysts were characterized and analyzed by XRD.The catalytic performance of the catalyst palladium chloride was compared.The characterization of the product confirmed that both of them could catalyze the oxidative carbonylation of phenol.However,the ZSM-5 supported diphenylamine salicylic aldehyde Schiff base type heterodinuclear complex catalyst was called palladium chloride.With better catalytic performance,the yield of diphenyl carbonate reaches 20.35%,which is expected to be used in the production of diphenyl carbonate.