| In the present luminescent materials field,the bonded polymer-rare earth complexes which launch the fluorescence are a kind of very important materials,which has a very broad application prospects in high-tech fields such as photoluminescence,electroluminescence,photoelectric communication,laser and solar energy conversion.This materials has both excellent luminescence properties of small molecule rare earth complexes,and at the same time also has good mechanical properties and is easy to be processed to be high polymer,especially it is easy to be film.Moreover,compared with luminescent materials of the doped polymer-rare earth complexes which formed by small molecule rare earth complexes doped with the polymer,the luminescent material of bonding type polymer-rare earth complexes presents the characteristics of the internal homogeneous phase.All these features are very useful for its practical applications.At present,there are relatively few research reports on the successful bonding polymer-rare earth complexes,which need to be developed vigorously to meet the demand of high and new science and technology.By elaborate molecular design and effective macromolecular reaction,this study has bonded the three different types bidentate schiff base ligands,whichareacetaldehyde/aminopyridinetype,acetaldehyde/aminophenoltype,furfural/aniline type and furfural/cyclohexylamine bidentate schiff base ligands,in the side chain of macromolecule of polysulfone,forming macromolecular ligands.Then macromolecular ligands respectively coordinate with Eu???and Tb???ions,several kinds of new type polymer-rare earth complexes luminescence materials were to be carried out.The luminescence properties and luminescence mechanism of these complexes were investigated.The structure and the relationship between the fluorescence properties and the luminescence principle were in-depth studied.This paper research has great scientific significance and important application value on the development and design of bond-type polymer-rare earth complexes materials.Firstly,theluminescentpolymer-rareearthcomplexeswhichhas acetaldehyde/aminopyridine bidentate Schiff base were synthesized.Therefore,the acetaldehyde/aminopyridine bidentate Schiff bases were prepared first.The esterification reaction,which belongs to nucleophilic substitution reaction between the chloromethylation polysulfone?CMPSF?and glyoxylic acid?GA?was carried out,and aldehyde?AL?as a group was bonded on the side chain of PSF,resulting in the modified PSF,PSF-AL.The Schiff base reaction was conducted between the aldehyde group of PSF-AL and the primary amino group of o-aminopyridine?OA?and m-aminopyridine?MA?respectively,the two types of acetaldehyde/aminopyridine bidentate Schiff bases AOA and AMA were synthesised and bonded on the polysulfone?PSF?side chain,and two bidentate Schiff base ligand-functionalized PSFs,PSF-AOA and PSF-AMA were obtained.The chemical structure of these functionalized polysulfone and intermediate structure were fully characterized by FTIR and 1H-NMR spectra.The influence of main factors on esterification reaction was investigated,and the reaction conditions were optimized.The experimental results show that between the above two steps,Esterification reaction between CMPSF and GA is critical step,and experimental results show that the polarity of solvents and reaction temperature were two most important factors affecting the reaction.Suitable reaction conditions as follows:the suitable solvent is strong polar N,N-dimethyl acetamide?DMAC?,the appropriate reaction temperature is 75?.Under this condition,and with anhydrous sodium carbonate as an acid binding agent,modified polysulfone PSF-AL was prepared,the bonding amount of AL on which was 1.62 mmol/g.The functionalized polysulfone PSF-AOA and PSF-AMA can be obtained through Schiff base reaction,the bonding amount of AOA on which was 1.28mmol/g,the bonding amount of AMA on which was 1.31mmol/g.Next,making the two different structures of bidentate Schiff base functionalized polysulfone PSF-AOA and PSF-AMA,sequentially coordinated with Eu???and Tb???ion,luminous binary polymer-rare earth complexes containing acetaldehyde/aminopyridine bidentate Schiff base were synthesized successfully;and 1,10-phenanthroline?Phen?as the second ligand,the luminous ternary polymer-rare earth complexes were also obtained.The chemical structures of these complexes were characterized by ultraviolet absorption spectrum?UV?and infrared spectroscopy.Their light-emitting principle and fluorescent properties were investigated deeply,and.the fluorescence quantum efficiency of the complexes was measured.Experimental results show that binary polymer-rare earth complexes PSF-?AOA?3-Tb???and PSF-?AMA?3-Tb???emit stong characteristic fluorescence of Tb???ion?green light?,but complexes formed by the two macromolecule bases and Eu???ion have no characteristic fluorescence.The results show that triplet energy level of bonding ligand AOA and AMA,both match with the resonance level of Tb???ion,can sensitize fluorescence emission of Tb???ion,a strong intramolecular energy transfer,namely Antenna effect was happened.Compared with the fluorescence intensity of PSF-?AMA?3-Tb???and PSF-?AOA?3-Tb???,the former is higher than the latter.it reveals the base AMA which can formseveral stable five membered rings is more stable than the base AOA which can form several stable four membered rings,more easily sensitize Tb???ion on some degree.The f luorescence emission intensity of two kinds of ternary complexes,PSF-?AOA?3-Tb???-?Phen?1 and PSF-?AMA?3-Tb???-?Phen?1 is much stronger than the corresponding binary complexes,fully show the two roles of small molecular ligands Phen:collaborative coordination and replace the coordinated water molecules.The luminous intensity of the film is higher than that of the complex solution.Then,luminous polymer-rare earth complexes containing acetaldehyde/aminophenol type bidentate Schiff base were successfully prepared based on the modified polysulfone PSF-AL as precursors.By the Schiff Base reaction between PSF-AL and O-aminophenol?OAP?and m-aminophenol?MAP?respectively,two acetaldehyde/aminophenol type bidentate Schiff base OAPB and MAPB synchronously synthesis and bonded on the polysulfone side chain,then obtaining Another structure of bidentate Schiff base ligand-functionalized PSFs,PSF-OAPB and PSF-MAPB were obtained.The chemical structures of these functionalized polysulfone were fully characterized by FTIR and1H-NMR spectra.Next,making the two different structures of bidentate Schiff base functionalized polysulfone PSF-OAPB and PSF-MAPB,coordinated with Tb???ion and Eu???ion respectively,luminous binary and ternary polymer-rare earth complexes were synthesized respectively.The chemical structures of these complexes were characterized by ultraviolet absorption spectrum?UV?and infrared spectroscopy.Their light-emitting principle and fluorescent properties were investigated deeply and the fluorescence quantum efficiency of the complexes was measured,more over,the relationship between the chemical structure and the luminescence properties was investigated.Experimental results show that binary polymer-rare earth complexes PSF-?OAPB?3-Tb???and PSF-?MAPB?3-Tb???emit intense characteristic fluorescence of Tb???ion?green light?,but the complexes formed by the two macromolecule bases and Eu???ion have no characteristic fluorescence either.The results show that triplet energy level of bonding ligand OAPB and MAPB,both match with the resonance level of Tb???ion,can strongly sensitize fluorescence emission of Tb???ion.Compared with the fluorescence intensity of the complexes containing acetaldehyde/aminopyridine bidentate Schiff base ligands above,the complexes containing aldehydetype/aminophenol bidentate Schiff base ligands have stronger fluorescence emission intensity and higher fluorescence quantum efficiency,it reveals the triplet state of aldehydetype/aminophenol bidentate Schiff base ligands OAPB and MAPB match more to Tb???ion than acetaldehyde/aminopyridine bidentate Schiff base ligands AOA and AMA,has better ability and efficiency of transfer energy to Tb???ion.In contrast with the binary complexes PSF-?OAPB?3-Tb???and PSF-?MAPB?3-Tb???,the latter has stronger fluorescence emission intensity.It shows that the ligand MAPB which can form a six membered chelating ring compared with the ligand OAPB which can form a five membered chelating ring,and the ligand MAPB which has slightly larger the conjugated system,on the degree of sensitization to Tb???ion is stronger than the ligand OAPB.Similarly,the fluorescence emission intensity of ternary complexes is much stronger than the corresponding binary complexes.The luminous intensity of the film is higher than that of the complex solution.At last,luminous polymer-rare earth complexes containing furfural/primary amine type bidentate Schiff base were also prepared through further molecular design.The Friedel-alkylation reaction between the chloromethylated polysulfone?CMPSF?and furfural?FF?was carried out,furfural?FF?as a group was bonded on the side chain of PSF,resulting in the modified PSF,PSF-FF.The Schiff base reaction was conducted between the furfural group of PSF-FF and the primary amino group of aniline?AN?and cyclohexylamine?CA?respectively,the two kinds of furfural/primary amine type bidentate Schiff bases,FA and FC were synthesised synchronously in the side chain of PSF,and two bidentate Schiff base ligand-functionalized PSFs,PSF-FA and PSF-FC were obtained.The chemical structure of these functionalized polysulfone and intermediate structure were fully characterized by FTIR and 1H-NMR spectra.The influence of main factors on Friedel-alkylation reaction was investigated,and the reaction conditions were optimized.Luminous binary and ternary polymer-rare earth complexes was synthesized by making the polymer ligands PSF-FA and PSF-FC coordinated with Eu???ion and Tb???ion,respectively.The chemical structures of these complexes were characterized by ultraviolet absorption spectrum?UV?and infrared spectroscopy.Their light-emitting principle and fluorescent properties were delved into,and the relationship between luminescence mechanism and chemical structure and luminescence properties was investigated.The experimental results show that between the above two steps,Friedel–Crafts reaction between CMPSF and FF is critical step,and experimental results show that the polarity of solvents and reaction temperature were two most important factors affecting the reaction.The suitable solvent is strong polar N,N-dimethyl acetamide?DMAC?,the appropriate reaction temperature is 70?.Under this condition,and with Sn Cl4 is as an catalyst,modified polysulfone PSF-FF was prepared,the bonding amount of FF on which was 1.53mmol/g.Via the Schiff base reaction,the functionalized polysulfone PSF-FA and PSF-FC can be obtained,the bonding amount of FA on which was 1.25 mmol/g,the bonding am ount of FC on which was 1.20mmol/g.Experimental results of luminescent properties of polymer-rare earth complexes show that binary polymer-rare earth complexes PSF-?FA?3-Eu???emits strong characteristic fluorescence of Eu???ion?red light?,and PSF-?FC?3-Tb???emits intensity characteristic fluorescence of Tb???ion?green light?.It revels that the triplet energy level of bonding ligand FA,the structure of whic is a larger conjugated system,match with the resonance level of Eu???,whlie the triplet energy level of bonding ligand FC,the structure of which is a smaller conjugated system,match with the resonance level of Tb???,The two ligands can sensitize the different rare earth ions.In addition,the study found that in contrast of the furfural/primary amine type binary complexes PSF-?FA?-Eu???and salicylic aldehyde/primary amine type polymer-Eu???binary complex,the fluorescence emission intensity is higher,fully display that ligands containing five numbered aromatic heterocyclic have stronger sensitization effect.to Eu???ions... |
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