Construction And Properties Of Two New Crystalline Porous Organic Materials

Porous Organic Materials?POMs?refer to porous materials formed by lingking simple organic moleculars units with covalent bonds or non-covalent bonds.Because of their great application prospects in many fields such as catalysis,gas storage and separation,proton conduction,electrochemistry and drug delivery,they have drawn considerable arttention over the past dacade by researchers.In this context,covalent organic frameworks?COFs?and hydrogen-bonded organic frameworks?HOFs?,as crystalline organic porous materials,have become pioneers in this field.This dissertation mainly focuses on design and synthesis of new COFs and HOFs,and exploration of their new applications.In the first chapter,we detailedly summarize the background and current development of COFs and HOFs,which consists of four aspects:their initial developments,types of linkages,synthesis methods and applications.In the second chapter,we designed the synthesis of benzooxazole or benzothiazole linked heteropore COFs,and planed to investigate their properties and applications in photochemistry.To overcome the low stability of the imine-linked heteropore COFs previously reported by our group.In this work,the strategy of in situ linker-exchange-mediated COF-to-COF transformation was designed to achieve the syhthesis of the two types of COFs.By this way,the chemical stability of heteropore COFs could be improved.On the other hand,the introduction of benzooxazole or benzothiazole units into the COFs skeletons was expected to bring new properties to this kind of heteroporous COFs.By now we have successfully synthesized the pre-conversion COF precursor?COF-DMBA?,and the transformation conditions are still being screened.In the thirdly chapter,we repot the construction of a new HOF which exhibits the same crystalline structure and permanent porosity when different solvent systems are used.And its adsorption property on water vapor adsorption was also investigated.Through solvent screening,it was found that SIOC-HOF-1 could be obtained in six different solvent systems?Dio?n-BuOH?Mes/n-BuOH=1?Dio/n-BuOH=1?Dio/Tol=1?Dio/o-DCB=1?.Experimental results from powder X-ray diffraction?PXRD?and N₂ isothermal adsorption-desorption experiments indicated that all the products obtained from these six solvent systems have the same crystalline structure and permanent porosity.Moreover,SIOC-HOF-1 displays excellent stability,as evidenced by the retention of its good crystallinity and uniform pore structure after soaking in CHCl₃,5 M HCl,Tol and EtOH for one week or left at room temperature for two months.In addition,this HOF has a good adsorption capacity to water vapor?279.27cm³/g,298 K?.