Application Of Visible Light Induced Reactions In The Construction Of Benzothiazole-based CMPs And Postmodification Locking Of Imine COFs

Porous organic polymers(POPs)have been widely used in gas adsorption and separation,energy storage,drug delivery,heterogeneous catalysis,photoelectric materials and other important research fields due to their advantages of large specific surface area,light mass,excellent pore properties and easy modifications.The traditional methods for constructing porous organic polymers often confront strict reaction conditions(e.g.,high reaction temperature,strict water-free and oxygen-free condition,strong acid),tedious operation,poor atomic economy and other problems,which does not accord with the concept of sustainable and green chemistry.Therefore,with the increasingly environmental and energy problems,it is still highly urgent to develop a method of constructing porous organic polymers with more mild,green and easy to operation reaction conditions.Visible-light induced reactions have been widely used in the synthesis of fine chemicals(e.g.,natural products,pharmaceutical molecules),due to their clean,environmentally benign and mild reaction conditions.However,the application of visible-light induced reactions in the construction of porous organic polymers is unprecedented.Accordingly,the research works of this thesis are centred around the application of visible-light induced reaction in the construction and modification of porous organic polymers.The main achievements could be divided into the following two parts:1.Construction of benzothiazole-based CMPs via the visible-light induced condensation/aromatization reaction between o-aminobenzenethiol and benzaldehyde.Starting from 2,5-diamino-1,4-benzothiene-dihydrochloride and 1,3,5-benzenetricarboxaldehyde,benzothiazole-based conjugated microporous polymer(BTCMP)was directly prepared via the visible-light induced condensation/aromatization reaction under mild conditions(room temperature and visible-light irradiation).This is the first time that visible-light induced condensation/aromatization reaction between oaminobenzenethiol and benzaldehyde has been applied to the synthesis of porous organic polymers.Compared with the traditional synthetic strategies,this method possesses the advantages of mild reaction conditions,environmental benign,atomic economy and so on.BT-CMP possesses excellent pore properties and high thermal stability,and shows strong absorption in the visible-light range.Under the irradiation of 24 W blue LED,BT-CMP can effectively catalyze the cross-dehydrogenative coupling reaction between glycine derivatives and indoles(up to 80% yield).2.Visible-light induced [4+2] cycloaddition/aromatization reaction between imine COFs and olefin: rapid synthesis of quinoline-based COFs.Firstly,an imine COFs(TAPB-DMTA-COF)was constructed starting from 2,5-dimethoxybenzene-1,4-diformaldehyde and 1,3,5-tri(4-aminophenyl)benzene.Under the irradiation of 18 W blue LEDs,the more stable quinoline-based COFs(Q-OH-COF)was constructed via the visible-light induced [4+2] cycloaddition/aromatization reaction between TAPBDMTA-COF and 4-hydroxystyrene,in which the imine linkages were modified and locked.Compared with TAPB-DMTA-COF,the crystal structure and pore properties of the modified Q-OH-COF are still better preserved.Under the irradiation of 24 W blue LED,Q-OH-COF can effectively catalyze the cross-dehydrogenative coupling reaction between glycine derivatives and indoles(up to 95% yield),and the condensation/aromatization reaction between o-phenylenediamine and benzaldehyde derivatives(up to 98% yield).