The Synthesis Of Porous Organic Polymers And Their Photocatalytic Performance On Selective Oxidation Of Amines And Sulfides

To alleviate the increasing energy crisis and environmental problems,the exploration and development of highly efficient visible-light photocatalysts that can directly convert solar energy into chemical energy have become one of the most cutting-edge topics in materials science.Porous organic polymers（POPs）are emerging as an excellent heterogeneous photocatalysis platform for their inherent porosity furnishing abundant active sites.Moreover,the numerous organic building blocks and diverse synthesis methods provide POPs with broad design space at the molecular level.Thus,it would be convenient to tune their optical band gap,energy level position,and optoelectronic properties to acquire highly active photocatalysts.In particular,conjugated microporous polymers（CMPs）and covalent organic frameworks（COFs）containing extendedπ-conjugation structures have garnered colossal interest in photocatalysis due to their unique advantages.First,with Tz Tz as the electron acceptor building block,a series of Tz Tz-linked CMPs（Tz Tz-CMP-1,Tz Tz-CMP-2,and Tz Tz-CMP-3）with D–A structures were constructed by integrating with phenyl units with C₂,C₃,and D_2hsymmetries.For the well-tailored optoelectronic properties by tuning the design of the electron-donor unit and the synthesis method,Tz Tz-linked CMPs were developed as highly active photocatalysts for blue light-induced selective aerobic oxidation of amines and sulfides.Next,based on molecular design,a stratagem was proposed that extends theπ-conjugation of donor moiety to broaden the light-absorption ability and promote the separation and transport of photogenerated charges of CMP linked by Tz Tz.Subsequently,a D–π–A type of CMP linked by Tz Tz,Tz Tz-CMP-Py,was constructed by extending the donor from benzene to pyrene without affecting the molecular symmetry,which showcased remarkable photocatalytic performance in green light-driven selective oxidation of amines.Furthermore,the effect of the geometry of the building blocks on their photocatalytic performance was investigated in selective aerobic oxidation of sulfides.The results show that the geometry of the building unit directly affects the specific surface area and morphology of CMPs,endowing a significant impact on its optoelectronic properties and subsequent photocatalytic activities.Last,β-ketoenamine linked 2D COFs containing ordered D–A structures were successfully synthesized at different temperatures with 2,4,6-triformylphloroglucinol（Tp）and 4,7-bis（4-aminophenyl）-2,1,3-benzothiadiazole（BTD）as building blocks.Further,we constructed cooperative photocatalysis between theβ-ketoenamine linked COFs and small molecule 2,2,6,6-tetramethylpiperidine-N-oxyl（TEMPO）to deliver the selective aerobic oxidation of amines and sulfides.Specifically,the selective aerobic oxidation of amines into imines was exceptionally established by cooperative photocatalysis of Tp-BTD-25 synthesized at room temperature with TEMPO.The selective aerobic oxidation of sulfides into sulfoxides was outstandingly realized by cooperative photocatalysis of Tp-BTD-150 prepared using a solvothermal method with TEMPO.In summary,by strategically developing functional monomers for constructing D–A structured POPs,a series of robust POPs were designed and synthesized for the selective aerobic oxidation of amines and sulfides under visible light irradiation.Importantly,their structure–activity relationships were in-depth explored,providing a promising platform for selective organic transformations.