Study On The Preparation And Catalytic Olefin Epoxidation Performance Of Salen-(Mn) Based POPs

Porous organic polymers(POPs)are a new class of green,stable,secure materials with porous structure.Because of many advantages such as large specific surface area,controllable pore,tough structure and high thermal stability,etc.they have been widely applied in gas storage,heterogeneous catalysis,metal loading and other research fields.In particular,many POPs can be synthesized from by-structural units that have catalytic activity(e.g.porphyrins,Salen),make the POPs effective catalysts.The biomimetic Salen catalyst was found in recent decades it has many advantages such as more easily synthesized than porphyrin,controllable electronic environment of catalytic center,the substituents can be varied and easy to combine different primary structural unit,so it is widely used in a variety of catalytic reaction.Especially its application in asymmetric synthesis has been widely recognized by researchers.This thesis carried out two part works.First,Salen-(Mn)-based Mn-POP-4 was prepared through the catalytically active center Salen-(Mn)monomer and tetrakis(4-ethynyl-phenyl)methane by Sonogashira-Hagihara coupling reaction.It was characterized by means of XPS,SEM,UV-Vis,TEM,IR,EDS,ICP and N2 adsorption.Olefin epoxidation using 2,2-dimethyl-2H-chromene as a substrate was studied.Second,Salen-(Mn)-based Mn-POP-3 was prepared through the catalytically active center Salen-(Mn)monomer and 1,3,5-benzene via Sonogashira-Hagihara coupling reaction.It was characterized by means of XPS,TEM,UV-Vis,PXRD,SEM,IR,EDS,ICP and N2 adsorption.And the olefin epoxidation with cyclohexene as substrate was optimized.The conversion and selectivity of different substrates as well as the recyclability of the catalyst have been studied.Sonogashira-Hagihara coupling reaction can be used to prepare POP catalysts with uniform particles in large quantities.There is almost not activity of Mn-POP-4 for the oxidation of 2,2-dimethyl-2H-chromene by the indicated oxidant(H2O2,NaCIO and PhIO),while,Mn-POP-3 shows high catalytic activity for the oxidation of cyclohexene and other simple olefins when oxygen acts as oxidant,and it can be recycled at least five times without the loss of activity.