Construction And Properties Of Covalent Organic Framework Materials Based On Multicomponent Reactions

Covalent organic frameworks(COFs)are a new type of crystalline porous polymer materials assembled by covalent bonds using small organic molecules as the building blocks,also known as "organic zeolite".The advantages of highly ordered pore structure,good chemical stability and adjustable function make COFs materials show great application prospects in heterogeneous catalysis,adsorptive separation,biomedical and other fields.However,the most widely studied COFs materials with imine linkage are assembled based on dynamic covalent bonding strategies,and often suffer from the defects of poor chemical stability,which limits their efficient application under relatively harsh conditions such as strong acids,strong bases,and reducing systems.Therefore,the development of chemically stable COFs material synthetic methodology based on multicomponent reactions(abbreviated as MCR)will have important theoretical significance and practical value.In this thesis,povarov and Kabachnik-Fields reactions were used to synthesize two types of highly stable COFs materials with quinoline and α-aminophosphonate repeat linkage,respectively,and their applications in heterogeneous catalysis,heavy metal ion adsorption and antimicrobial were also explored:Ⅰ.The quinoline-linked and imidazolium sulfonic acid ionic liquid-decorated COF(abbreviated as COF-IM-SO3H)was synthesized via incorporation of three-component in situ Povarov reaction and subsequent postsynthetic modification.COF-IM-SO3H can be a highly efficient Br?nsted acid catalyst to promote the Biginelli reaction under solvent-free condition with excellent reusability.In addition,COF-IM-SO3H was composited with chitosan to readily realize the COF-based composite aerogel catalytic monolith(with 80 wt%COF-IM-SO3H)through ice templating technology,which can be applied as a fixed-bed catalytic reactor to achieve the hundred-fold amplification of the Biginelli reaction.Ⅱ.The α-aminophosphonate linked porphyrin-based COF(abbreviated as APCOF-1)was synthesized via a three-component in situ Kabachnik-Fields reaction at room temperature.Due to the concomitant bioactive α-aminophosphonate and photosensitive porphyrin species,the obtained APCOF-1 exhibited highly efficient solar-powered bactericidal ability.Meanwhile,the strong chelating ability of α-aminophosphonate moiety endowed APCOF-1 with the functionality for capturing Cd(Ⅱ)and other heavy metal ions from simulated sewage.Moreover,a helical tube-like APCOF-1@chitosan aerogel-based setup(with 50 wt%APCOF-1)was fabricated and can be a continuous flow-through water purifier model to achieve scaled-up sunlight-driven removal of hazardous materials.