Construction Of Imine-Based Covalent Organic Frameworks And Their Applications

As a novel class of organic porous polymers,covalent organic frameworks(COFs)have showed great potential applications in many fields,such as heterogeneous catalysis,gas storage,optoelectronic devices,and fluorescence sensing.At present,construction of functionalized COF materials has become the hot research topic in this field.In this thesis,several functional COFs were designed and synthesized for the applications in fluorescence sensing and heterogeneous catalysis.In Chapter I,the introduction of COFs,including dynamic chemical reactions,synthetic methods and applications,has been described.In addition,sulf-functionalized nanoporous materials,especially applications in chemosensing device and lithium batteries,have been briefly introduced.In Chapter II,a novel COF material,COF-LZU60,was unexpectedly synthesized.which was initially designed as a fluorescent sensor containing thiol functional groups.COF-LZU60 possessed a large BET surface area(1593 m2/g)and a relatively uniform pore size distribution(2.3 nm).Moreover,COF-LZU60 exhibited unique optical properties and showed excellent photocatalytic activities.COF-LZU60 could catalyze the dehydrogenation coupling reaction with high yields(75%)in the presence of visible light and could be recycled.In Chapter III,a new 3D COF,COF-LZU69,was synthesized with linear thioether-functionalized monomers and tetrahedral monomers.COF-LZU69 has excellent fluorescence properties and a small BET surface area(57 m2/g).The superb fluorescence properties could provide COF-LZU69 with great potential in the sensing applications.