Preparation Of Bidentate Schiff Base-type Oxovanadium (Ⅳ) Complex Immobilized On CPS Microspheres And Its Catalytic Property

The oxovanadium（Ⅳ） complex exhibite very high catalytic activity for hydrocarbons tothe corresponding oxygen compounds,such as alcohols,epoxy compounds and carbonylcompounds.Can also catalyze the oxidation of alcohols and phenols to the correspondinghydroquinones.In this work,Schiff Base-Type Chelating Resin was prepared withchloromethylated polystyrene microspheres （CMCPS） as starting substance and by twopolymer reaction steps.Subsequently,the coordination reaction between SAAM-CPSmicrospheres and vanadyl sulfate was performed,obtaining Schiff base-type oxovanadium（Ⅳ）complex was immobilized microspheres ,and they are used in the oxidation reaction of benzylalcohol and ethylbenzene by molecular oxygen.Examination the catalytic activity andcatalytic selectivity.The result of the study will has obvious scientific significance on thegreening of catalytic oxidation field.In the presence of catalyst KI,the Delepine reaction between the chloromethyl groups ofthe swelled CMCPS microspheres and Hexamethylene tetramine （HMTA） was first carriedout,and the chloromethyl groups of CMCPS microspheres were transformed intoaminomethyl groups,obtaining aminomethyl （AM） group-modified CPSmicrospheres,AMCPS,and then the Schiff base reaction between AMCPS microspheres andsalicylaldehyde （SA） was allowed to be conducted,resulting in Schiff base-type chelatingresin.The aminomethyl group-modification reaction of CMCPS was mainly investigated,andthe effects of main factors on the Delepine reaction were examined.The experimental resultsshow that KI has strong catalytic activity for the rate of the Delepine reaction.The solventpolarity is favourable for the fracture of C-Cl bond of the benzyl chloride group,and can accelerate the Delepine reaction.The increase of the reaction temperature is also advantageousto the reaction. DMSO is a suitable solvent and 80℃is a appropriate temperature.Themicrospheres CPS-[VO（SAAM）₂] were fully characterized by many means such as FYIR,SEM and TGA.The microspheres CPS-[VO（SAAM）₂] were used in the oxidation reaction of benzylalcohol by molecular oxygen,and the catalytic activity was examined.In the oxidation reactionof benzyl alcohol by molecular oxygen,the heterogeneous oxovanadium（Ⅳ） complex catalystCPS-[VO（SAAM）₂] have very high catalytic activity and excellent catalytic selectivity.Underthe mild conditions such as at ordinary pressure of dioxygen and at a lower temperature of90℃,benzyl alcohol can be transformed to benzaldehyde as a single product with a yield of80%.The solvent porlarity effects on the catalytic activity of the catalyst CPS-[VO（SAAM）₂]greatly. The stronger the polarity of the solvent,the higher the activity of the catalystCPS-[VO（SAAM）₂] is and the higher the yield of benzaldehyde is.The microspheres CPS-[VO（SAAM）₂] were used in the oxidation reaction ofethylbenzene by molecular oxygen,and the catalytic activity was examined.At a temperatureof 110℃the yield of acetophenone is 43% with a high selectivity of 97%.The catalystCPS-[VO（SAAM）₂] have excellent cycle and reuse property.