Synthesis, Characterization And Catalytic Activity Of Salicylaldehyde Schiff Base Ni-Ln Complexes

Schiff bases are kind of ligands with easy preparation,high yields and strong coordination ability,and their applications in the fields of biochemistry,medicine,catalysis,and electrochemistry have always been research hotspot.Schiff base ligands can coordinate with transition and rare earth metals to form d-f heteropolynuclear metal complicated.This heteropolynuclear complex not only possesses complex and novel structures,but also exhibits unique properties and application prospects in the field of catalysis.Therefore,in this thesis,four salicylaldehyde Schiff ligands were designed and synthesized,combined with metal salts to form 10 Ni-ln Heteropolynuclear metal complexes,and their catalytic properties for the oxidation of styrene were explored.This article is divided into four parts:1.An overview of Schiff bases and their complexes,a brief introduction to the application of complexes in various research fields,and an emphasis on their research progress and application in catalysis.2.Use 3-ethoxysalicylaldehyde with 2-amino-4-methylphenol,2-amino-5-methylphenol,2-amino-3-methylphenol,2-amino-4-tertiary Four ligands were synthesized from butylphenol,namely:2-（（3-ethoxy-2-hydroxybenzylidene）amino）-4-methylphenol(C₁₆H₁₇O₃N)（H₂L~1）,2-（（3-Ethoxy-2-hydroxybenzylidene）amino）-5-methylphenol(C₁₆H₁₇O₃N)（H₂L~2）,2-（（3-ethoxy-2-hydroxybenzylidene）amino）-3-methyl phenol(C₁₆H₁₇O₃N)（H~2L~3）,2-（（3-ethoxy-2-hydroxybenzylidene）amino）-4-tert-butylphenol(C₁₉H₂₃O₃N)（H₂L~4）.The four ligands were characterized by infrared and ultraviolet spectroscopic analysis,hydrogen NMR and carbon spectroscopy.3.Ten heteromultinuclear Schiff base Ni-Ln Schiff base complexes were synthesized by the reaction of transition metal Ni（II）and rare earth metal Tb（III）,Er（III）,Dy（III）,Tm（III）,Yb（III）with ligands.respectively[Ni₂Dy₂（L~1）₄（NO₃）₂（CH₃OH）₂],[Ni₂Tm₂（L~1）₄（CH₃COO）₂（CH₃OH）₂],[Ni₂Tb₂（L~1）₄（CH₃COO）₂（CH₃OH）₂DMF],[Ni₄Er₄（L~1）₆（NO₃）₄（CH₃O）₂（H₂O）₂（DMF）₂],[Ni₂Yb₂（L~1）₄（NO₃）₂（CH₃OH）₂],[Ni₂Dy₂（L~2）₄（NO₃）₂（DMF）₂],[Ni₂Er₂（L~2）₄（NO₃）₂（DMF）₂],[Ni₂Tb₂（L~3）₄（CH₃COO）₂（DMF）₂],[Ni₂Tb₂（L~4）₄（CH₃COO）₂（DMF）₂],[Ni₂Tm₂（L~4）₄（NO₃）₂（DMF）₂],The synthesis method of the complexes is described in detail.These complexes were characterized by X-ray single crystal diffraction,infrared spectroscopy and ultraviolet spectroscopy.4.The catalytic styrene oxidation reaction test was carried out on some complexes,and the influence of the oxidant H₂O₂ and the amount of solvent acetonitrile on the catalytic process was discussed.It shows that the complex synthesis is necessary and is a potential catalyst for styrene oxidation.