Synthesis And Properties Of Novel Pyrazolone Carboxylic Acid And Schiff Base Quinoline Derivatives And Their Complexes With Europium And Terbium

Pyrazolone carboxylic acid and Schiff base quinoline derivatives have been widely applied in the area of luminous functional materials,industry and life sciences because of their excellent optical activity,diverse ways of coordination and strong ability of coordination.Six novel pyrazolone carboxylic acid derivatives and six novel Schiff base quinoline derivatives have been designed and synthesized in this paper,and they were characterized by 1H NMR,13C NMR,mass spectra,et al.Their complexes with Eu(?)and Tb(?)were prepared,and characterized by molar conductivity,UV spectra,infrared spectra and elemental analysis as well as thermal analysis.The fluorescence properties and electrochemical properties of the complexes were also studied.The main research work are as follows:(1)The 1-phenyl-3-methy 1-5-pyrazolone derivatives was prepared from ethyl acetoacetate and para-substituted phenylhydrazine,then the 1-phenyl-3-methyl-4-chloracetyl-5-pyrazolone was prepared from 1-phenyl-3-methyl-5-pyrazolone derivatives and chloracetyl chloride.At last,a series of novel pyrazolone carboxylic acid derivatives were synthesized by the reaction of 1-phenyl-3-methyl-4-chloracetyl-5-pyrazolone derivatives and terephthalic acid,and their corresponding complexes with Eu(?)and Tb(?)were also prepared.The electrochemical properties of the Eu(?)and Tb(?)complexes were investigated,the results indicate that the HOMO energy level and LUMO energy level of the complexes substituted by the donative elecrton group is higher than that of the complexes substituted by the electrophilic group.In addition,changes in substituents and central ions have no significant effect on bandgap values.The fluorescence properties and fluorescence quantum yield of the Eu(?)and Tb(?)complexes were investigated,the results indicate that all of the complexes show the characteristic fluorescence of central ion,and the fluorescence intensity and fluorescence quantum yield of the target complexes are affected by the type of substituent in the corresponding ligand.The introduction of electron-donating group in the ligands increased the luminescence intensity and fluorescence quantum yield,whereas,the introduction of electrophilic group in the ligands decreased the luminescence intensity and fluorescence quantum yield.The difference in luminescence properties is also significant when different central ions are combined with the same ligand,this is related to a factor that whether the triplet state energy level of the target ligand matches the lowest excited state of central ion.The fluorescence intensity and fluorescence quantum yield of terbium complexes in this series were significantly better than that of europium complexes.The luminescence intensity of TbL4(NO3)3·EtAc was much stronger than that of terbium complex of phenanthroline,and its fluorescence quantum yield also reached 0.67,which indicates that TbL4(NO3)3 EtAc has vast potential to be developed as luminescence materials in the future.(2)2-formyl-8-hydroxyquinoline was prepared from 2-methyl-8-hydroxy-quinoline and acetic anhydride,then the 2-chloro-N-acetylaniline derivatives was prepared from para-substituted aniline and chloroacetyl chloride,and then 2-formyl-8-oxo-N-phenylacetamide quinoline derivatives was prepared from 2-chloro-N-acetylaniline derivatives and 2-formyl-8-hydroxyquinoline.At last,a series of novel Schiff base quinoline derivatives were synthesized by the reaction of 2-formyl-8-oxo-N-phenylacetamide quinoline derivatives and benzamide,and their corresponding complexes with Eu(III)and Tb(III)were also prepared.The electrochemical properties of the Eu(III)and Tb(III)complexes were investigated,the results indicate that the HOMO energy level and LUMO energy level of the complexes substituted by the donative elecrton group is higher than that of the complexes substituted by the electrophilic group.In addition,changes in substituents and central ions have no significant effect on bandgap values.The fluorescence properties and fluorescence quantum yield of the europium complexes were investigated,the results indicate that all of the complexes show the characteristic fluorescence of central ion,and the fluorescence intensity and fluorescence quantum yield of the target complexes are affected by the type of substituent in the corresponding ligand.The introduction of electron-donating group in the ligands increased the luminescence intensity and fluorescence quantum yield,whereas,the introduction of electrophilic group in the ligands decreased the luminescence intensity and fluorescence quantum yield.The difference in luminescence properties is also significant when different central ions are combined with the same ligand,this is related to a factor that whether the triplet state energy level of the target ligand matches the lowest excited state of central ion.In this series,the fluorescence intensity of europium complexes are strong and the fluorescence quantum yield are high,while the terbium complexes does not even exhibit characteristic fluorescence.The luminescence intensity of EuY4(NO3)3·2H2O reached 4588,and its fluorescence quantum yield also reached 0.55,which indicates that EuY4(NO3)3·2H2O has vast potential to be developed as luminescence materials in the future.