Nitrogen Containing Aromatic Polymers:Design,Synthesis And Performance

Nitrogen-containing aromatic compounds have attracted great attention due to their unique properties and diverse functionalities which contribute to their wide applications such as biomedicine,environmental science,optical,energy and so on.Nitrogen-containing aromatic polymers combine the properties of nitrogen-containing aromatic and polymers,which are becoming one of research hotspots.In addition,it is easier to process and apply when introducing nitrogen-containing aromatic units into the polymer.Therefore,the molecular structure of the material will influence to its application.By selecting appropriate functional groups and synthetic methods,a nitrogen-containing aromatic polymer with novel structure and excellent performance will be designed and synthesized to perform controlled preparation of the nitrogen-containing aromatic polymer promising.In this study,from the perspective of the synthesis of nitrogen-containing aromatic polymer materials,nitrogen-containing aromatic polymers with different structures were prepared and characterized.The results are as follows:A water-soluble comb-like porphyrin polymer based on hyaluronic acid?HA?as the main chain and sulfonate substituted tetraphenylporphyrin?DADSP?as side groups,named as HA-g-ADSP,was designed and synthesized,which could be used as a potential photosensitizer in photodynamic therapy?PDT?.This photosensitizer exhibited high-water solubility,low dark cytotoxicity,high photocytoxiticy and high singlet oxygen yield??_?=0.86?.As a novel photosensitizer,HA-g-ADSP has low cytotoxicity in dark and also low photocytotoxicity towards normal cells,but performed enhanced photodynamic activity against cancer cells?HeLa cells?.As a result,HA-g-ADSP with comb-like structure may be a promising photosensitizer for practical photodynamic therapy in the future.A novel telechelic Poly?N-isopropylacrylamide?ended with 4'-?9,10-diphenyl-9,10-dihydropyridine-9-yl?-[1,1'-biphenyl]-4-amine?DPDHR-NH₂?group named as DPDHR-PNIPAM,was designed and synthesized to be used as a potential recyclable Fe³⁺ion detective fluorescent sensor.Firstly,DPDHR-NH₂ as the central part of the fluorescent sensor was synthesized to react with 2-bromoisobutyryl bromide to form initiator.Then,N-isopropylacrylamide as a monomer was initiated by DPDHR-Br to polymerize into telechelic polymer DPDHR-PNIPAM through atom transfer radical polymerization?ATRP?.At room temperature,DPDHR-PNIPAM displayed high-water solubility,highly specific and sensitive towards Fe³⁺detection as low as 1.32×10^-6M.The selectivity of DPDHR-PNIPAM toward Fe³⁺ion experiment showed it was a turn-off fluorescence response in multi-ion-mixed solution.As a thermosensitive polymer,above the lower critical solution temperature?LCST?,the chain of DPDHR-PNIPAM may collapse and change from hydrophilic to hydrophobic to aggregate and separate from water to perform recyclable.Herein,microwave-assisted organic synthesis was carried out to prepare imine-linked porphyrin-based CMPs.Benzo[c][1,2,5]thiadiazole-4,7-dicarbaldehyde?BT?and porphyrin were selected as the construction units of the CMP material?TAPP-BT-CMP?,which possessed rich nitrogen and sulfur sites.Then a new type of composite catalyst?Ag@TAPP-BT-CMP?was successfully obtained by solution infiltration,which was fully characterized by standard methods.Catalytic studies showed that Ag@TAPP-BT-CMP could reduce the various nitroaromatic compounds?NACs?with high efficiency,such as 4-nitrophenol,2-nitrophenol,4-nitroaniline.Ag@ TAPP-BT-CMP could also reduce organic dyes such as Rhodamine B?RhB?,Methylene Blue?MB?and Congo Red?CR?.Moreover,Ag@ TAPP-BT-CMP had good reusability and high recovery.Copper tetraaminoporphyrin?CuTAPP?was reacted with three dialdehyde-substituted linkers?2,6-dihydroxynaphthalene-1,5-dicarbaldehyde?DHNDA?,2,6-dimethoxynaphthalene-1,5-dicarbaldehyde?DMNDA?,and 2,6-dibutoxynaphthalene-1,5-dicarbaldehyde?DBNDA?,respectively?under microwave heating via imine-linked,obtained three types of imine-linked copper porphyrin-based CMPs?CuTAPP-CMPs?,named as CuTAPP-CMP-OH,CuTAPP-CMP-OCH₃,and CuTAPP-CMP-O?CH₂?₃CH₃,respectively.The BET specific surface areas were 223.6,353.5 and 96.5 m²g^-1.The CuTAPP-CMPs can be used for photocatalytic degradation of RhB under visible light.Among the CuTAPP-CMPs,CuTAPP-CMP-OH exhibited high photocatalytic efficiency and wide suitability?photocatalytic degradation of MB,MO and CR under visible light?.CuTAPP was reacted under solvothermal conditions with two trialdehyde-substituted linkers 1,3,5-triformylbenzene?TFB?and 2,4,6-tri?4-aldehyde phenyl?-1,3,5-triazine?TFPT?,respectively,to obtain two kinds of imine linked 3D conjugated microporous polymers?CMPs?TPB-CuTAPP-CMP and TFPT-CuTAPP-CMP.The BET specific surface areas were 398.0 and 286.1 m² g^-1,respectively.Both obtained products could be used as heterogeneous photocatalysts to degrade RhB and MB under visible light with good recyclability.Between them,TFPT-CuTAPP-CMP exhibited high photocatalytic efficiency,which attributed to the introduction of the triazine structure in the materials.1,2,4,5-Tetrakis-?4-formylphenyl?benzene?TFPB?was reacted under solvothermal conditions with tetraaminoporphyrin?TAPP?and CuTAPP,respectively,to obtain two kinds of covalent organic framework based on Schiff base structure TAPP-TFPB-COF and CuTAPP-TFPB-COF.Both of them were micron-scale cube structure stacked by 2-dimensional layers in macroscopic.TAPP-TFPB-COF and CuTAPP-TFPB-COF had micropores structure and the pore size were 1.20 nm and 1.86 nm,respectively.The BET specific surface areas were 1107.3 m²g^-1and 800.4 m²g^-1,respectively.At room temperature,both of them had good adsorption capacity for model dye RhB.In addition,CuTAPP-TFPB-COF can degrade RhB under visible light after saturated RhB adsorption,and the CuTAPP-TFPB-COF had good stability and reusability.