Design,synthesis And Application Of Functionally Oriented Covalent Organic Porous Materials

Organic porous material is a new type of porous material composed of light elements such as C,H,N,and O.It includes covalent organic frameworks（COFs）,conjugated microporous polymers（CMP）,and porous aromatic framework materials（PAF）.This type of material has the characteristics of higher specific surface area,porous structure,and better thermal stability.In addition,through the flexible pre-design of the precursors,organic porous materials have a variety of topological structures and functional units that are easy to branch,thereby improving their application performance in separation,adsorption,heterogeneous catalysis,ect.Based on the above research background,this paper is oriented to the functions of dye adsorption and heterogeneous catalysis,respectively.Through the design of COFs materials,carboxyl and metal cations,and phenanthroline structures were introduced into the organic porous materials.Two kinds of organic porous materials were used as adsorbents and catalysts to remove organic dye Congo red from wastewater and catalyze the tandem reaction of 2-iodoaniline and isothiocyanate.Ⅰ:A new carboxyl-containing COFs（COF-COOH）was fabricated by 1,3,5-triformyl resorcinol（TP）and 4,4’-diamino-[1,1’-biphenyl]-3,3’-dicarboxylic acid（DBA）through Schiff-base reaction.COF-COOH exhibits good adsorption performance for Congo Red（CR）through hydrogen bonding andπ-πstacking.COF-COOCa/COF-COONi was fabricated by the post-modification COF-COOH with Ca²⁺/Ni²⁺,which improves the adsorption capacity of CR.This is because the coordinated metal cations enhance the electrostatic effect between the adsorbent and CR.The maximum adsorption capacities of COF-COOCa and COF-COONi for CR were 704.23 mg/g and 781.25 mg/g,respectively.The removal efficiency of COF-COOCa to CR is 95%,and that of COF-COONi to CR is 96%.This demonstrates that the new metal ion-assisted COFs are viable adsorbents to remove dye pollutants,which are harmful to the environment and to human health,from wastewater.Ⅱ:A phenanthroline-functionalized porous aromatic framework（Phen-PAF）has been synthesized by the Sonogashira reaction between 1,3,5-tris-（4-ethynylphenyl）benzene（TEB）and3,8-dibromo-1,10-phenanthroline（DPHEN）.Phen-PAF was demonstrated to have highly catalytic effect on the tandem reaction between 2-iodoanilines and isothiocyanates,leading to a series of 2-aminobenzothiazole derivatives in good to excellent yield（80-99%）.The reaction was environmental friendly for utilizing water as solvent under mild heating conditions.More importantly,Phen-PAF catalyst can be recycled by simple filtration and drying.Phen-PAF kept its structure and catalytic activity for at least 5 catalytic cycles,which was in accordance with sustainable chemistry.Phen-PAF was,what has been reported so far,the first organic porous heterogeneous catalyst towards the tandem reaction of 2-iodoanilines and isothiocyanates with environmentally friendly solvent,which may enlighten us to design more function-oriented PAF materials as heterogeneous catalysts towards various organic reactions.