Synthesis,Structures And Catalytic Oxidation Of Styrene Of Vanadium Complexes With Acylhydrazone Schiff Bases

Hydrazones are a kind of special Schiff bases,which are prepared by the condensation reactions of hydrazides and aldehydes or ketones.Hydrazones have excellent coordination capability and versatile coordination modes,which can form hydrazone Schiff base complexes with most of the metal ions.It has received remarkable attention in biological medicine,analytic chemistry,metal corrosion,light,electric,magnetic,as well as catalytic fields.In recent years,the study on the activity of acylhydrazone Schiff base vanadium complexes is more active than the normal Schiff base complexes.During coordination,acylhydrazones Schiff bases can make the metal ions more stable at various oxidation states,which leads to the catalytic application of hydrazone Schiff base complexes.In this paper,a series of vanadium complexes with hydrazone ligands have been studied for their catalytic oxidation activity on styrene.Fifteen new hydrazone vanadium complexes have been prepared and studied the catalytic property of the vanadium complexes with hydrazones derived from 3-bromo-5-chlorosalicylaldehyde.The influence factors of the catalytic property were analyzed.In general,the catalytic results are good.The thesis is divided into three parts:1.The research backgrounds on hydrazone complexes are reviewed.The research of the hydrazone Schiff base complexes on biological medicine,functional materials and catalytic aspects were detailed introduced.2.The synthesis and structural analysis of the complexes(1)Three new mononuclear vanadium complexes with hydrazone ligands derived from 3,5-dibromosalicylaldhyde were prepared and characterized by IR spectroscopy,UV spectroscopy,differential thermal analysis and elemental analysis.Crystal structures of the complexes were further confirmed by single crystal X-ray diffraction.(2)Five new mononuclear vanadium complexes with hydrazone ligands derived from 3-methoxysalicylaldhyde and various secondary ligands such as ethyl maltol,2-hydroxybenzohydroxamic acid,acetohydroxamic acid were prepared and characterized by IR spectroscopy,UV spectroscopy,differential thermal analysis and elemental analysis.The influence of the secondary ligands on the crystal structures of the complexes was studied.Crystal structures of the complexes were further confirmed by single crystal X-ray diffraction.(3)Seven new mononuclear vanadium complexes with hydrazone ligands derived from 3-bromo-5-chlorosalicylaldhyde were prepared and characterized by IR spectroscopy,UV spectroscopy,differential thermal analysis and elemental analysis.Crystal structures of the complexes were further confirmed by single crystal X-ray diffraction.3.Some of the vanadium complexes were determinated for their catalytic oxidation property on styrene.The factors that affect the catalytic processes were analyzed.As a result,the solvent used,the quantity of H2O2,the reaction time and the reaction temperature can influence the catalytic process.