The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis ...The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis and FTIR. The results of the XRD patterns and SEM photographs indicate that the complex is composed of a lot of bar-shaped crystal grain with 5～10 μm long. The results of the photoluminescence show that the complex emitted the characteristic green fluorescence of Tb (3+).展开更多
The fluorescence of two Tb 3+ aminopolyphosphonic (L 1) acid Phen triple complex (L 1=ethylenediaminetetrakis (methylphosphonic) (EDTP) and ethylaminobis (methylphosphonic) (EDP)) in solution was reported.It was found...The fluorescence of two Tb 3+ aminopolyphosphonic (L 1) acid Phen triple complex (L 1=ethylenediaminetetrakis (methylphosphonic) (EDTP) and ethylaminobis (methylphosphonic) (EDP)) in solution was reported.It was found that fluorescence of Tb L 1 Phen solution apparently increased as compared with that of Tb Phen complex,indicating that Tb L 1 Phen triple complex was formed.The fluorescence was strongest at pH 7.0.Fluorescence for both L 1=EDTP and EDP increase with addition of L 1 and Phen,but excess of ligands did not affect the fluorescence,thus indicating there is cooperation effect between L 1 and Phen.The change of the fluorescence among different complex was also explained according to the enhancing or quenching effect of ligands.展开更多
Centrin is a member of the EF-hand super family that plays critical role in the centrosome duplication and separation. To investigate the role of Asp37 in the process of metal-binding and conformational change of cili...Centrin is a member of the EF-hand super family that plays critical role in the centrosome duplication and separation. To investigate the role of Asp37 in the process of metal-binding and conformational change of ciliate Euplotes octocarinatus centrin (EoCen), the mutant D37K, in which aspartic acid 37 had been replaced by lysine, was first obtained by the site-directed mutagenesis. Then 2-p-toluidinylnaphthalene-6- sulfonate (TNS) was used as a fluorescence probe to detect the conformational change of the protein. The results show that the metal- binding capability of the site I of EoCen was lost by the mutation of Asp37→Lys. In comparison the Tb3+-saturated EoCen, the hydrophobic surface of D37K, which is exposed by the binding of Tb3+, has shrunk sharply, suggesting that Asp37 plays an important role in maintaining the proper conformation of EoCen in the presence of Tb3+. Meanwhile, the conditional binding constants of TNS with Tb3+-loaded EoCen and D37K were obtained, K(Tb3+-EoCen-TNS)=(7.38 ±0.25)×105 M-1 and K(Tb3+-D37K-TNS)=(1.16±0.05)×106 M-1.展开更多
A new ligand, N,N′-Bis(6-methyl-2-pyridine-N-oxide)-1,3-propane (L), and some binary lanthanide complexes (Ln=Eu^(3+), Tb^(3+)) were synthesized and characterized in detail. The composition of the binary complexes wa...A new ligand, N,N′-Bis(6-methyl-2-pyridine-N-oxide)-1,3-propane (L), and some binary lanthanide complexes (Ln=Eu^(3+), Tb^(3+)) were synthesized and characterized in detail. The composition of the binary complexes was determined as LnL(NO_3)_3. They are 1∶1 electrolytes in DMF. The complexes have strong characteristic line fluorescence emission spectra, and it is also found that TbL(NO_3)_3 complex has stronger luminescence intensity than EuL(NO_3)_3 in solid state and in methanol.展开更多
Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, ...Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, and fluorescence spectra were also measured to identify the complexes. Elemental analysis showed that the compositions of these complexes were Tb（p-BrBA）3- H20, Tb（p-CIBA）3- 2H20, Tb（p-FBA）3- H20, Tb（o-FBA）3·2H20, Tb（o-CIBA）3· H20, and Tb（o-BrBA）3. H20, respectively. The monodispersed Ag@SiO2 core-shell nanoparticles with silica thicknesses of 10, 15, and 25 nm were success- fully prepared and characterized by transmission-electron microscopy. Fluorescence intensities of the complexes were detected before and after Ag@SiO2core-shell nanoparticles were added; the enhancement times were related to the silica-shell thick- ness. The fluorescence enhancement times were largest when the thickness of the silica shell was 25 nm. The mechanism may be attributed to the localized surface-plasmon resonance. Furthermore, the enhancement effect of terbium fluoro-benzoate complexes was the strongest in these complexes. This result may be attributed to the hydrogen bond between the hydroxyl on the surface of the silica shell and the fluorine atom.展开更多
A new ligand, N,N-BIS (6-metyl-2-pyridinecarboxylamide-N-oxide)-1,2-ethane (L) and six lanthanide(Ⅲ) complexes (RE=La, Sm, Eu, Tb, Gd, Yb) were synthesized and characterized in detail. The results indicated that the ...A new ligand, N,N-BIS (6-metyl-2-pyridinecarboxylamide-N-oxide)-1,2-ethane (L) and six lanthanide(Ⅲ) complexes (RE=La, Sm, Eu, Tb, Gd, Yb) were synthesized and characterized in detail. The results indicated that the composition of the binary complexes was determined as [REL(H2O)(NO3)2]NO3·nH2O (n=0-2), and the Eu3+ complex had bright red fluorescence in solid state. Three complexes of Eu3+, Tb3+, and Gd3+ with 6-methylpicolinic acid N-oxide (L’) were also synthesized. The relative intensity of sensitized luminescence for Eu3+ increased in the following order: L>L’. The phosphorescence spectra of the Gd3+ complexes at 77 K were measured. The energies of excited triplet state for the ligands were 20704 cm-1 (L) and 20408 cm-1 (L’). The facts that the ligands sensitized Eu3+ strongly and the order of the emission intensity for Eu3+ complexes were explained by ΔE(T-5D). This meant that the triplet energy level of the ligand was the main factor to influence RE3+ luminescence.展开更多
文摘The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis and FTIR. The results of the XRD patterns and SEM photographs indicate that the complex is composed of a lot of bar-shaped crystal grain with 5～10 μm long. The results of the photoluminescence show that the complex emitted the characteristic green fluorescence of Tb (3+).
文摘The fluorescence of two Tb 3+ aminopolyphosphonic (L 1) acid Phen triple complex (L 1=ethylenediaminetetrakis (methylphosphonic) (EDTP) and ethylaminobis (methylphosphonic) (EDP)) in solution was reported.It was found that fluorescence of Tb L 1 Phen solution apparently increased as compared with that of Tb Phen complex,indicating that Tb L 1 Phen triple complex was formed.The fluorescence was strongest at pH 7.0.Fluorescence for both L 1=EDTP and EDP increase with addition of L 1 and Phen,but excess of ligands did not affect the fluorescence,thus indicating there is cooperation effect between L 1 and Phen.The change of the fluorescence among different complex was also explained according to the enhancing or quenching effect of ligands.
文摘Centrin is a member of the EF-hand super family that plays critical role in the centrosome duplication and separation. To investigate the role of Asp37 in the process of metal-binding and conformational change of ciliate Euplotes octocarinatus centrin (EoCen), the mutant D37K, in which aspartic acid 37 had been replaced by lysine, was first obtained by the site-directed mutagenesis. Then 2-p-toluidinylnaphthalene-6- sulfonate (TNS) was used as a fluorescence probe to detect the conformational change of the protein. The results show that the metal- binding capability of the site I of EoCen was lost by the mutation of Asp37→Lys. In comparison the Tb3+-saturated EoCen, the hydrophobic surface of D37K, which is exposed by the binding of Tb3+, has shrunk sharply, suggesting that Asp37 plays an important role in maintaining the proper conformation of EoCen in the presence of Tb3+. Meanwhile, the conditional binding constants of TNS with Tb3+-loaded EoCen and D37K were obtained, K(Tb3+-EoCen-TNS)=(7.38 ±0.25)×105 M-1 and K(Tb3+-D37K-TNS)=(1.16±0.05)×106 M-1.
文摘A new ligand, N,N′-Bis(6-methyl-2-pyridine-N-oxide)-1,3-propane (L), and some binary lanthanide complexes (Ln=Eu^(3+), Tb^(3+)) were synthesized and characterized in detail. The composition of the binary complexes was determined as LnL(NO_3)_3. They are 1∶1 electrolytes in DMF. The complexes have strong characteristic line fluorescence emission spectra, and it is also found that TbL(NO_3)_3 complex has stronger luminescence intensity than EuL(NO_3)_3 in solid state and in methanol.
基金supported by the National Natural Science Foundation of China(21161013)the Natural Science Foundation of Inner Mongolia(2011MS0202)the Opening Foundation for Significant Fundamental Research of Inner Mongolia(2010KF03)
文摘Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, and fluorescence spectra were also measured to identify the complexes. Elemental analysis showed that the compositions of these complexes were Tb（p-BrBA）3- H20, Tb（p-CIBA）3- 2H20, Tb（p-FBA）3- H20, Tb（o-FBA）3·2H20, Tb（o-CIBA）3· H20, and Tb（o-BrBA）3. H20, respectively. The monodispersed Ag@SiO2 core-shell nanoparticles with silica thicknesses of 10, 15, and 25 nm were success- fully prepared and characterized by transmission-electron microscopy. Fluorescence intensities of the complexes were detected before and after Ag@SiO2core-shell nanoparticles were added; the enhancement times were related to the silica-shell thick- ness. The fluorescence enhancement times were largest when the thickness of the silica shell was 25 nm. The mechanism may be attributed to the localized surface-plasmon resonance. Furthermore, the enhancement effect of terbium fluoro-benzoate complexes was the strongest in these complexes. This result may be attributed to the hydrogen bond between the hydroxyl on the surface of the silica shell and the fluorine atom.
基金Project supported by the National Natural Science Foundation of China (29571013)
文摘A new ligand, N,N-BIS (6-metyl-2-pyridinecarboxylamide-N-oxide)-1,2-ethane (L) and six lanthanide(Ⅲ) complexes (RE=La, Sm, Eu, Tb, Gd, Yb) were synthesized and characterized in detail. The results indicated that the composition of the binary complexes was determined as [REL(H2O)(NO3)2]NO3·nH2O (n=0-2), and the Eu3+ complex had bright red fluorescence in solid state. Three complexes of Eu3+, Tb3+, and Gd3+ with 6-methylpicolinic acid N-oxide (L’) were also synthesized. The relative intensity of sensitized luminescence for Eu3+ increased in the following order: L>L’. The phosphorescence spectra of the Gd3+ complexes at 77 K were measured. The energies of excited triplet state for the ligands were 20704 cm-1 (L) and 20408 cm-1 (L’). The facts that the ligands sensitized Eu3+ strongly and the order of the emission intensity for Eu3+ complexes were explained by ΔE(T-5D). This meant that the triplet energy level of the ligand was the main factor to influence RE3+ luminescence.
