We have synthesized one novel Schiff-base ligand by modifying the aromatic aldehyde:H2L1(H2L1=N,N?-bis(2-oxy-acetate-3-methoxyl)benzylpropylene-ethanediamine).[Co(Ⅱ)L1]2·2 EtOH(1)was prepared by the reaction bet...We have synthesized one novel Schiff-base ligand by modifying the aromatic aldehyde:H2L1(H2L1=N,N?-bis(2-oxy-acetate-3-methoxyl)benzylpropylene-ethanediamine).[Co(Ⅱ)L1]2·2 EtOH(1)was prepared by the reaction between H2L1 and CoCl2·6H2O in the solvent of C2H5OH.The title compound was structurally characterized by elemental analysis,IR,H NMR and single-crystal X-ray diffraction.Complex 1 crystallizes in monoclinic,space group C2/c with a=29.472(3),b=13.4842(13),c=15.1848(15)?,β=115.626(1)°,V=5441.0(9)?3,C28H22CoN2O8.50,Mr=581.41,Dc=1.420 g/cm^3,μ(Mo Kα)=0.685 mm-1,F(000)=2392,Z=8,the final R=0.0541 and wR=0.1565(I>2s(I)).The Co(Ⅱ)atom is hexa-coordinated,furnishing a triangular prism geometry.It is interesting that the H-bond intersections formed a one-dimensional chain structure.In this paper,we research the synthesis,characterization,oxygen respiratory,antibacterial activity,and photoluminescent property of complex 1.展开更多
A three-dimensional coordination polymer,[Zn2(L)2(bpp)(H2O)2]n(H2L=2,5-dicarboxylic acid-3,4-ethylene dioxythiophene,bpp=1,3-di(4-pyridyl)propane),was synthesized with high yield under solvothermal reaction conditions...A three-dimensional coordination polymer,[Zn2(L)2(bpp)(H2O)2]n(H2L=2,5-dicarboxylic acid-3,4-ethylene dioxythiophene,bpp=1,3-di(4-pyridyl)propane),was synthesized with high yield under solvothermal reaction conditions and structurally characterized by elemental analysis,infrared spectra,thermogravimetric analysis,powder X-ray diffraction and single-crystal X-ray diffraction analysis.It crystallizes in orthorhombic space group Pnma with a=16.6542(9),b=18.0868(10),c=10.7528(5)?,V=3239.0(3)?3,Z=4,Dc=1.684 g/cm3,Mr=821.38,Dc=1.684 g/cm3,μ=1.683 mm-1,F(000)=1672,R=0.0466,wR=0.0933 and S=1.066.The compound exhibits a three-dimensional structure,which can be simplified into a 2-fold interpenetrated pcu topological network.Moreover,it displays luminescence emission in the solid state at room temperature.展开更多
Two N-donor ligands mediated Cd(II) coordination polymers, namely, [Cd(L)(dmpz)_2]_n(1) and {[Cd(L)(atr)_(0.5)(H_2O)](H_2O)}n(_2)(H_2 L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole,...Two N-donor ligands mediated Cd(II) coordination polymers, namely, [Cd(L)(dmpz)_2]_n(1) and {[Cd(L)(atr)_(0.5)(H_2O)](H_2O)}n(_2)(H_2 L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole, and atr = 4-amino-1,2,4-triazole), have been produced. Their structures were characterized by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional(1 D) chain structure and is finally extended into a three-dimensional(3 D) supramolecular architecture though hydrogen bonding interactions. Compound 2 features a two-dimensional(2 D) network with 4-connected sql topology based on dinuclear Cd(II) clusters as nodes, which is also assembled into a 3 D supramolecular architecture through hydrogen bonding interactions. Furthermore, compounds 1 and 2 exhibit high thermal stabilities and intense fluorescent emission in the solid, and can be explored as potential luminescent materials.展开更多
We have obtained vertically aligned ZnO nanowire arrays synthesized by microwave-assisted heating method with different growth time.From the room-temperature PL measurement,the strong deep-level emission and weak near...We have obtained vertically aligned ZnO nanowire arrays synthesized by microwave-assisted heating method with different growth time.From the room-temperature PL measurement,the strong deep-level emission and weak near band edge(NBE)emission can be seen.The deep-level emissions became weaker and deep-level emissions became stronger when the samples were annealed at 300℃for 30 min,meanwhile,the NBE emission peaks get red-shifted with growth time,and the longer the growth time,the more the peak shifting.This phenomenon can be attributed that the diameter of ZnO nanowires increases with growth time.This PL emission phenomenon is important in research of optoelectronic application.展开更多
The solvothermal reaction of CdCl2·2.5H2O with terephthalic acid yields two new three-dimensional(3D)cadmium(II)coordination polymers(CPs),namely{[Cd(C8H4O4)Cl]·C2H8N}n and[Cd(C8H4O4)]n,we use the abbreviati...The solvothermal reaction of CdCl2·2.5H2O with terephthalic acid yields two new three-dimensional(3D)cadmium(II)coordination polymers(CPs),namely{[Cd(C8H4O4)Cl]·C2H8N}n and[Cd(C8H4O4)]n,we use the abbreviations CP1 and CP2 to refer to them,respectively.The compounds are characterized in detail by single-crystal X-ray diffraction,powder X-ray diffraction,IR spectroscopy,elemental analysis and thermogravimetric analysis(TGA).The results indicate that compounds CP1 and CP2 are 3D frameworks,and both the compounds feature a uninodal 4-connected framework with a dia net.The empty spaces of such 3D framework are filed by the other two identical frameworks,leading to a 3-fold interpenetrated network.In addition,the photochemical properties of the frameworks are also investigated.The two frameworks show strong solid-state fluorescence emission at 463 and 503 nm,respectively,which are obvious red-shift compared to the emission of ligand.展开更多
An unprecedented one-dimensional coordination polymer [Ag2(PhP O3 H)2(DPPP)]n(1) based on phenylphosphonic acid(Ph PO3 H2) and 1,3-bis(diphenyphosphino)propane(DPPP) has been synthesized and characterized by IR, eleme...An unprecedented one-dimensional coordination polymer [Ag2(PhP O3 H)2(DPPP)]n(1) based on phenylphosphonic acid(Ph PO3 H2) and 1,3-bis(diphenyphosphino)propane(DPPP) has been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal-X-ray diffraction analyses revealed that the complex crystallizes in triclinic system, space group P(16). The coordination geometry of each Ag(I) ion is planar trigonal. Two kinds of rings were found in 1, such as the four-membered ring with Ag2 O2 and the eight-membered ring with Ag2 O4 P2 constructed by PhP O3 H- ligands, which were then connected by DPPP ligands forming a zigzag type chain. Moreover, the light absorption and luminescent property of 1 were also investigated.展开更多
Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,w...Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical Eu3+ ion red emission,assigned to the transitions between the first excited state(5D0) and the multiplet(7F0-4).Owing to the incorporation of the europium complex into the PS fiber matrix and the subsequent distortion of the symmetry around the lanthanide ions by the capping PS,the polarization of the Eu3+ ions was enhanced,which increased the probability for electronic dipole allowed transitions.The monochromaticity(5D0→7F2/5D0→7F1) around the Eu3+ ions was also efficiently improved.Judd-Ofelt intensity parameters(Ω2 and Ω4) were determined from the emission spectra based on the 5D0→7F2 and 5D0→7F4 electronic transitions,respectively.The results showed that the Ω2 values of the composite nanofibers were apparently higher than that of the pure complex,indicating an increased covalency degree in the europium first coordination shell due to the modification of PS matrix.The modification of the polymer matrix also resulted in much higher thermal stability of the composite fibers than that of the pure complex.展开更多
The green-emitting(Ce,Tb)MgAl11O19(CTMA) phosphor was prepared by the conventional high temperature solid-state reaction method.The effect of fluxes on the crystal structure,particle morphology,size distribution and p...The green-emitting(Ce,Tb)MgAl11O19(CTMA) phosphor was prepared by the conventional high temperature solid-state reaction method.The effect of fluxes on the crystal structure,particle morphology,size distribution and photoluminescence properties of CTMA phosphor was investigated by means of the X-ray powder diffraction,scanning electron microscopy and photoluminescence spectrum.The results showed that the addition of appropriate amount of MgF2-H3BO3 flux improved the phase purity of CTMA phosphor,and influenced the growth of different crystal plane;furthermore,the particle morphology of CTMA phosphor became regular and size distribution narrowed.In addition,the CTMA phosphor prepared with MgF2-H3BO3 flux displayed higher photoluminescence intensity than that of the phosphor prepared with MgF2,H3BO3 or without flux.As a result,the optimum content of fluxes was 0.10 mol/mol MgF2 and 0.04 mol/mol H3BO3,and the maximum photoluminescence intensity of the CTMA phosphor prepared with MgF2-H3BO3 flux was 167% of that of the phosphor prepared without flux.展开更多
A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,...A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,and energy transfer from Eu^(2+)to Tb^(3+) and Eu^(2+)to Mn^(2+) in Sr_(2)Ca_(2)La(PO_(4))_(3)O were investigated in details.Tunable emission color from blue to blueish green or orange can be observed under 365 nm near-ultraviolet excitation based on the energy transfer from Eu^(2+) to Tb^(3+)or Mn^(2+) ions by varying the ratio of Eu^(2+)/Tb^(3+)or Eu^(2+)/Mn^(2+) ions.White light was obtained with chromaticity coordinates of(0.3558,0.3500)in the Sr_(2)Ca_(2)La(PO_(4))_(3)O:0.04Eu^(2+),0.08Tb^(3+),0.40Mn^(2+) phosphor,suggesting their potential applications in white light emitting diodes.展开更多
A series of RE^(3+)(RE=Eu∕Tb∕Ce)-activated Sr_4La(PO_4)_3O(SLPO) phosphors are synthesized with a hightemperature solid-state reaction method. The photoluminescence properties, thermal stability, morphology,and CIE ...A series of RE^(3+)(RE=Eu∕Tb∕Ce)-activated Sr_4La(PO_4)_3O(SLPO) phosphors are synthesized with a hightemperature solid-state reaction method. The photoluminescence properties, thermal stability, morphology,and CIE values of the SLPO:Eu^(3+)∕Tb^(3+)∕Ce^(3+)phosphors are investigated. Under 394 nm excitation, the SLPO:Eu^(3+)exhibits red emission, and the SLPO:Tb^(3+)presents a green emission upon 379 nm excitation, while Ce^(3+)-doped SLPO has a broad emission band ranging from 370 to 650 nm under 337 nm excitation. The investigation results indicate that the SLPO:Eu^(3+)∕Tb^(3+)∕Ce^(3+)phosphors can be effectively excited by nearultraviolet light and may have the potential to serve as red-, green-, and blue-emitting phosphors for applications in white light-emitting diodes.展开更多
In this work two isomeric semi-rigid multi-carboxylate ligands 3,5-bi(3-carboxyphenoxy)benzoic acid(3-H_3BCP), 3,5-bi(4-carboxyphenoxy)benzoic acid(4-H_(3)BCP) and two rigid ligands(bis-triazole 4-(4-(4H-1,2,4-triazol...In this work two isomeric semi-rigid multi-carboxylate ligands 3,5-bi(3-carboxyphenoxy)benzoic acid(3-H_3BCP), 3,5-bi(4-carboxyphenoxy)benzoic acid(4-H_(3)BCP) and two rigid ligands(bis-triazole 4-(4-(4H-1,2,4-triazol-4-yl)phenyl)-4 H-1,2,4-triazole(L^(1)), 2-(1H-pyrazol-3-yl)pyrazine(L^(2))) have been employed to react with Cd(Ⅱ) salts under similar solvothermal reactions. Two novel Cd(Ⅱ) mixed-ligand coordination polymers, namely, {[Cd_3(3-BCP)_(2)(L^(1))]·3H_(2)O}n(1) and [Cd(4-HBCP)(L^(2))]_n(2), have been isolated. 1 displays a rare 2D cluster-based network while 2 displays a 3D supramolecular network through weak interactions. Solid-state luminescent properties and thermal analyses of 1 and 2 also have been determined, indicating strong fluorescent emissions and good thermal stabilities. Different coordination modes of two semi-rigid multi-carboxylate ligands and L^(1) and L^(2) also have been briefly discussed, which also reveal the great potential in the construction of these novel mixed-ligand luminescent frameworks with diverse structural motifs and unique functional properties.展开更多
Two N-donor auxiliary ligands mediated Zn(Ⅱ) coordination polymers, namely, {[Zn(Hnbta)-(bimm)](3H2O)}n(1) and {[Zn1.5(nbta)(pyim)(H2O)](2H2O)}n(2)(H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bimm = bis(imidazo...Two N-donor auxiliary ligands mediated Zn(Ⅱ) coordination polymers, namely, {[Zn(Hnbta)-(bimm)](3H2O)}n(1) and {[Zn1.5(nbta)(pyim)(H2O)](2H2O)}n(2)(H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bimm = bis(imidazol-1-yl)methane and pyim = N-(4-pyridylmethyl)imidazole), have been prepared by the hydrothermal reaction. Their structures were determined by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional(1D) chain structure, while compound 2 features a two-dimensional(2D) network. In addition, they both exhibit high thermal stabilities and photoluminescent properties in the solid, and can be explored as potential luminescent materials.展开更多
N-containing Ce_(2)Si_(2.5)Al_(0.5)O_(3.5)N_(3.5)(CeSiAlON) melilite was synthesized at 1550 and 1600℃ for 5 h from CeO_(2),Si,Al,and Al_(2)O_(3) in nitrogen by using Y_(2)O_(3) and transition-metal nitrates(Co(NO_(3...N-containing Ce_(2)Si_(2.5)Al_(0.5)O_(3.5)N_(3.5)(CeSiAlON) melilite was synthesized at 1550 and 1600℃ for 5 h from CeO_(2),Si,Al,and Al_(2)O_(3) in nitrogen by using Y_(2)O_(3) and transition-metal nitrates(Co(NO_(3))_(2)·6 H_(2) O and Ni(NO_(3))_(2)·6 H_(2)O) as additives.The effects of Y_(2)O_(3) and transition-metal nitrates on the phase,microstructures and photoluminescence properties of CeSiAlON melilite were studied.The incorporation of Y_(2)O_(3) can promote the reaction of raw materials to a low degree,and results in a unit cell shrinkage of CeSiAlON due to the smaller radius of Y atom than that of Ce atom.The transition-metal nitrates can accelerate the reaction clearly and facilitate the formation of CeSiAlON fibers.The photoluminescence(PL) properties of CeSiAlON melilite presents a board violet emission band because of the 5 d-4 f transitions of Ce^(3+),and the additives can enhance the PL emission intensities of specimen significantly.展开更多
Tri-doped Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+)samples exhibit a broad band r...Tri-doped Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+)samples exhibit a broad band ranging from 320 to 500 nm.At 77 K,the emission spectra of Ca_(9)LiY_(2/3)(PO_(4))7:Ce^(3+)samples present two obvious emission peaks,indicating that Ce^(3+)ions occupy two different kinds of lattice sites(Ca(1/2)and Ca(3)),As a good sensitizer for Tb^(3+),Ce^(3+)ions in Ca_(9)LiY_(2/3)(PO_(4))_(7)lattice can effectively transfer part of energy to Tb^(3+),and the energy trans fer mechanism is determined to be dipole-dipole interaction.Consequently,the emitting color for Ce^(3+)and Tb^(3+)co-doped Ca_(9)LiY_(2/3)(PO_(4))_(7)samples can be tuned from bluish violet to green.In order to further enlarge the emission gamut,Mn^(2+)ions as red emission components were added,forming tri-doped single-phase Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors.The Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors exhibit tunable emission properties through controlling the relative doping concentration of Ce^(3+),Tb^(3+)and Mn^(2+).Especially,Ca_(9)LiY_(2/3)(PO_(4))_(7):0.09 Ce^(3+),0.12 Tb^(3+),0.30 Mn^(2+)can emit warm white light.The sample shows good thermal stability.At 150℃,the emission intensity for Ce^(3+)(360 nm),Tb^(3+)(545 nm)and Mn^(2+)(655 nm)decreases to 63%,69%,and 72%of its initial intensity,respectively.Moreover,the sample obtains good stability after 10 cycles between room temperature and150℃.展开更多
Cu-doped borate glass co-doped with SnO2nanoparticles is fabricated by melt quenching.The structure and morphology of the samples are examined by X-ray diffraction and field emission scanning electron microscopy.Up-co...Cu-doped borate glass co-doped with SnO2nanoparticles is fabricated by melt quenching.The structure and morphology of the samples are examined by X-ray diffraction and field emission scanning electron microscopy.Up-conversion enhancement is observed in the photoluminescence(PL) and thermoluminescence(TL) intensities of the glass.PL emission spectra are identified in the blue and green regions,and a fourfold increase in emission intensity may be observed in the presence of embedded SnO2nanoparticles.The glow curve is recorded at 215 C,and fourfold increases in TL intensity are obtained by addition of 0.1 mol% SnO2nanoparticles to the glass.Higher TL responses of the samples are observed in the energy range of 15-100 KeV.At energy levels greater than ~0.1 MeV,however,flat responses are obtained.The activation energy and frequency factor of the second-order kinetic reaction are calculated by the peak shape method.展开更多
基金supported by the National Natural Science Foundation of China(No.21878120)。
文摘We have synthesized one novel Schiff-base ligand by modifying the aromatic aldehyde:H2L1(H2L1=N,N?-bis(2-oxy-acetate-3-methoxyl)benzylpropylene-ethanediamine).[Co(Ⅱ)L1]2·2 EtOH(1)was prepared by the reaction between H2L1 and CoCl2·6H2O in the solvent of C2H5OH.The title compound was structurally characterized by elemental analysis,IR,H NMR and single-crystal X-ray diffraction.Complex 1 crystallizes in monoclinic,space group C2/c with a=29.472(3),b=13.4842(13),c=15.1848(15)?,β=115.626(1)°,V=5441.0(9)?3,C28H22CoN2O8.50,Mr=581.41,Dc=1.420 g/cm^3,μ(Mo Kα)=0.685 mm-1,F(000)=2392,Z=8,the final R=0.0541 and wR=0.1565(I>2s(I)).The Co(Ⅱ)atom is hexa-coordinated,furnishing a triangular prism geometry.It is interesting that the H-bond intersections formed a one-dimensional chain structure.In this paper,we research the synthesis,characterization,oxygen respiratory,antibacterial activity,and photoluminescent property of complex 1.
文摘A three-dimensional coordination polymer,[Zn2(L)2(bpp)(H2O)2]n(H2L=2,5-dicarboxylic acid-3,4-ethylene dioxythiophene,bpp=1,3-di(4-pyridyl)propane),was synthesized with high yield under solvothermal reaction conditions and structurally characterized by elemental analysis,infrared spectra,thermogravimetric analysis,powder X-ray diffraction and single-crystal X-ray diffraction analysis.It crystallizes in orthorhombic space group Pnma with a=16.6542(9),b=18.0868(10),c=10.7528(5)?,V=3239.0(3)?3,Z=4,Dc=1.684 g/cm3,Mr=821.38,Dc=1.684 g/cm3,μ=1.683 mm-1,F(000)=1672,R=0.0466,wR=0.0933 and S=1.066.The compound exhibits a three-dimensional structure,which can be simplified into a 2-fold interpenetrated pcu topological network.Moreover,it displays luminescence emission in the solid state at room temperature.
基金supported by the National Natural Science of Foundation of China(No.21671094)
文摘Two N-donor ligands mediated Cd(II) coordination polymers, namely, [Cd(L)(dmpz)_2]_n(1) and {[Cd(L)(atr)_(0.5)(H_2O)](H_2O)}n(_2)(H_2 L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole, and atr = 4-amino-1,2,4-triazole), have been produced. Their structures were characterized by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional(1 D) chain structure and is finally extended into a three-dimensional(3 D) supramolecular architecture though hydrogen bonding interactions. Compound 2 features a two-dimensional(2 D) network with 4-connected sql topology based on dinuclear Cd(II) clusters as nodes, which is also assembled into a 3 D supramolecular architecture through hydrogen bonding interactions. Furthermore, compounds 1 and 2 exhibit high thermal stabilities and intense fluorescent emission in the solid, and can be explored as potential luminescent materials.
基金by the National Natural Science Foundation of China(Nos.61874058 and 51861145301)the Nanjing University of Posts and Telecommunications under Research Projects(Nos.NY220036 and NY217096)the Nanjing University of Posts and Telecommunications Foundation(Nos.JUH219002 and JUH219007)。
文摘We have obtained vertically aligned ZnO nanowire arrays synthesized by microwave-assisted heating method with different growth time.From the room-temperature PL measurement,the strong deep-level emission and weak near band edge(NBE)emission can be seen.The deep-level emissions became weaker and deep-level emissions became stronger when the samples were annealed at 300℃for 30 min,meanwhile,the NBE emission peaks get red-shifted with growth time,and the longer the growth time,the more the peak shifting.This phenomenon can be attributed that the diameter of ZnO nanowires increases with growth time.This PL emission phenomenon is important in research of optoelectronic application.
基金Natural Science Foundation of Fujian Province,China(No.2019J01774)Scientific Research Start-up Foundation of Fujian University of Technology,China(No.GY-Z19168)Research Development Foundation of Fujian University of Technology,China(No.GY-Z160120)。
文摘The solvothermal reaction of CdCl2·2.5H2O with terephthalic acid yields two new three-dimensional(3D)cadmium(II)coordination polymers(CPs),namely{[Cd(C8H4O4)Cl]·C2H8N}n and[Cd(C8H4O4)]n,we use the abbreviations CP1 and CP2 to refer to them,respectively.The compounds are characterized in detail by single-crystal X-ray diffraction,powder X-ray diffraction,IR spectroscopy,elemental analysis and thermogravimetric analysis(TGA).The results indicate that compounds CP1 and CP2 are 3D frameworks,and both the compounds feature a uninodal 4-connected framework with a dia net.The empty spaces of such 3D framework are filed by the other two identical frameworks,leading to a 3-fold interpenetrated network.In addition,the photochemical properties of the frameworks are also investigated.The two frameworks show strong solid-state fluorescence emission at 463 and 503 nm,respectively,which are obvious red-shift compared to the emission of ligand.
基金financially supported by the National Natural Science Foundation of China (No. 21702005)the Foundation of the Henan Joint International Research Laboratory of Nanocomposite Sensing Materialsthe Foundation of Anyang Institute of Technology (YPY2019003)。
文摘An unprecedented one-dimensional coordination polymer [Ag2(PhP O3 H)2(DPPP)]n(1) based on phenylphosphonic acid(Ph PO3 H2) and 1,3-bis(diphenyphosphino)propane(DPPP) has been synthesized and characterized by IR, elemental analyses, thermogravimetric analyses and X-ray diffraction technique. Single-crystal-X-ray diffraction analyses revealed that the complex crystallizes in triclinic system, space group P(16). The coordination geometry of each Ag(I) ion is planar trigonal. Two kinds of rings were found in 1, such as the four-membered ring with Ag2 O2 and the eight-membered ring with Ag2 O4 P2 constructed by PhP O3 H- ligands, which were then connected by DPPP ligands forming a zigzag type chain. Moreover, the light absorption and luminescent property of 1 were also investigated.
基金supported by the National Natural Science Foundation of China (50503002)the National High-Tech Research Developing Foundation (863,2003AA324030)+2 种基金National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China (2006BAE03B)Program for New Century Excellent Talents in University (NCET)Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT,IRT0807)
文摘Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical Eu3+ ion red emission,assigned to the transitions between the first excited state(5D0) and the multiplet(7F0-4).Owing to the incorporation of the europium complex into the PS fiber matrix and the subsequent distortion of the symmetry around the lanthanide ions by the capping PS,the polarization of the Eu3+ ions was enhanced,which increased the probability for electronic dipole allowed transitions.The monochromaticity(5D0→7F2/5D0→7F1) around the Eu3+ ions was also efficiently improved.Judd-Ofelt intensity parameters(Ω2 and Ω4) were determined from the emission spectra based on the 5D0→7F2 and 5D0→7F4 electronic transitions,respectively.The results showed that the Ω2 values of the composite nanofibers were apparently higher than that of the pure complex,indicating an increased covalency degree in the europium first coordination shell due to the modification of PS matrix.The modification of the polymer matrix also resulted in much higher thermal stability of the composite fibers than that of the pure complex.
基金supported by the Independent Innovation Sci-Tech Foundation for Beijing Rapid-Growth Corporation
文摘The green-emitting(Ce,Tb)MgAl11O19(CTMA) phosphor was prepared by the conventional high temperature solid-state reaction method.The effect of fluxes on the crystal structure,particle morphology,size distribution and photoluminescence properties of CTMA phosphor was investigated by means of the X-ray powder diffraction,scanning electron microscopy and photoluminescence spectrum.The results showed that the addition of appropriate amount of MgF2-H3BO3 flux improved the phase purity of CTMA phosphor,and influenced the growth of different crystal plane;furthermore,the particle morphology of CTMA phosphor became regular and size distribution narrowed.In addition,the CTMA phosphor prepared with MgF2-H3BO3 flux displayed higher photoluminescence intensity than that of the phosphor prepared with MgF2,H3BO3 or without flux.As a result,the optimum content of fluxes was 0.10 mol/mol MgF2 and 0.04 mol/mol H3BO3,and the maximum photoluminescence intensity of the CTMA phosphor prepared with MgF2-H3BO3 flux was 167% of that of the phosphor prepared without flux.
基金Project supported by the Natural Science Research of Jiangsu Higher Education Institutions of China (19KJA150011,18KJB140002,17KJA460004)。
文摘A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,and energy transfer from Eu^(2+)to Tb^(3+) and Eu^(2+)to Mn^(2+) in Sr_(2)Ca_(2)La(PO_(4))_(3)O were investigated in details.Tunable emission color from blue to blueish green or orange can be observed under 365 nm near-ultraviolet excitation based on the energy transfer from Eu^(2+) to Tb^(3+)or Mn^(2+) ions by varying the ratio of Eu^(2+)/Tb^(3+)or Eu^(2+)/Mn^(2+) ions.White light was obtained with chromaticity coordinates of(0.3558,0.3500)in the Sr_(2)Ca_(2)La(PO_(4))_(3)O:0.04Eu^(2+),0.08Tb^(3+),0.40Mn^(2+) phosphor,suggesting their potential applications in white light emitting diodes.
基金supported by the National Natural Science Foundation of China(NSFC)(No.11604115)the Educational Commission of Jiangsu Province of China(NO.17KJA460004)
文摘A series of RE^(3+)(RE=Eu∕Tb∕Ce)-activated Sr_4La(PO_4)_3O(SLPO) phosphors are synthesized with a hightemperature solid-state reaction method. The photoluminescence properties, thermal stability, morphology,and CIE values of the SLPO:Eu^(3+)∕Tb^(3+)∕Ce^(3+)phosphors are investigated. Under 394 nm excitation, the SLPO:Eu^(3+)exhibits red emission, and the SLPO:Tb^(3+)presents a green emission upon 379 nm excitation, while Ce^(3+)-doped SLPO has a broad emission band ranging from 370 to 650 nm under 337 nm excitation. The investigation results indicate that the SLPO:Eu^(3+)∕Tb^(3+)∕Ce^(3+)phosphors can be effectively excited by nearultraviolet light and may have the potential to serve as red-, green-, and blue-emitting phosphors for applications in white light-emitting diodes.
基金Scientific Research Project of Tianjin Education Commission(2018KJ250)National Natural Science Foundation of China(21501196)。
文摘In this work two isomeric semi-rigid multi-carboxylate ligands 3,5-bi(3-carboxyphenoxy)benzoic acid(3-H_3BCP), 3,5-bi(4-carboxyphenoxy)benzoic acid(4-H_(3)BCP) and two rigid ligands(bis-triazole 4-(4-(4H-1,2,4-triazol-4-yl)phenyl)-4 H-1,2,4-triazole(L^(1)), 2-(1H-pyrazol-3-yl)pyrazine(L^(2))) have been employed to react with Cd(Ⅱ) salts under similar solvothermal reactions. Two novel Cd(Ⅱ) mixed-ligand coordination polymers, namely, {[Cd_3(3-BCP)_(2)(L^(1))]·3H_(2)O}n(1) and [Cd(4-HBCP)(L^(2))]_n(2), have been isolated. 1 displays a rare 2D cluster-based network while 2 displays a 3D supramolecular network through weak interactions. Solid-state luminescent properties and thermal analyses of 1 and 2 also have been determined, indicating strong fluorescent emissions and good thermal stabilities. Different coordination modes of two semi-rigid multi-carboxylate ligands and L^(1) and L^(2) also have been briefly discussed, which also reveal the great potential in the construction of these novel mixed-ligand luminescent frameworks with diverse structural motifs and unique functional properties.
基金supported by the grants from Luoyang normal university。
文摘Two N-donor auxiliary ligands mediated Zn(Ⅱ) coordination polymers, namely, {[Zn(Hnbta)-(bimm)](3H2O)}n(1) and {[Zn1.5(nbta)(pyim)(H2O)](2H2O)}n(2)(H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bimm = bis(imidazol-1-yl)methane and pyim = N-(4-pyridylmethyl)imidazole), have been prepared by the hydrothermal reaction. Their structures were determined by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional(1D) chain structure, while compound 2 features a two-dimensional(2D) network. In addition, they both exhibit high thermal stabilities and photoluminescent properties in the solid, and can be explored as potential luminescent materials.
基金supported by the National Natural Science Foundation of China (51862024,51772140,51962023)the Natural Science Foundation of Jiangxi Province (20171ACB21033,20192ACBL21047)。
文摘N-containing Ce_(2)Si_(2.5)Al_(0.5)O_(3.5)N_(3.5)(CeSiAlON) melilite was synthesized at 1550 and 1600℃ for 5 h from CeO_(2),Si,Al,and Al_(2)O_(3) in nitrogen by using Y_(2)O_(3) and transition-metal nitrates(Co(NO_(3))_(2)·6 H_(2) O and Ni(NO_(3))_(2)·6 H_(2)O) as additives.The effects of Y_(2)O_(3) and transition-metal nitrates on the phase,microstructures and photoluminescence properties of CeSiAlON melilite were studied.The incorporation of Y_(2)O_(3) can promote the reaction of raw materials to a low degree,and results in a unit cell shrinkage of CeSiAlON due to the smaller radius of Y atom than that of Ce atom.The transition-metal nitrates can accelerate the reaction clearly and facilitate the formation of CeSiAlON fibers.The photoluminescence(PL) properties of CeSiAlON melilite presents a board violet emission band because of the 5 d-4 f transitions of Ce^(3+),and the additives can enhance the PL emission intensities of specimen significantly.
基金Project supported by the National Natural Science Foundation of China(51672265)the Natural Science Foundation of Shandong Province(ZR2018JL016)+1 种基金the Applied Basic Research Plan of Qingdao(18-2-2-15-jch)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(RERU2019003)。
文摘Tri-doped Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+)samples exhibit a broad band ranging from 320 to 500 nm.At 77 K,the emission spectra of Ca_(9)LiY_(2/3)(PO_(4))7:Ce^(3+)samples present two obvious emission peaks,indicating that Ce^(3+)ions occupy two different kinds of lattice sites(Ca(1/2)and Ca(3)),As a good sensitizer for Tb^(3+),Ce^(3+)ions in Ca_(9)LiY_(2/3)(PO_(4))_(7)lattice can effectively transfer part of energy to Tb^(3+),and the energy trans fer mechanism is determined to be dipole-dipole interaction.Consequently,the emitting color for Ce^(3+)and Tb^(3+)co-doped Ca_(9)LiY_(2/3)(PO_(4))_(7)samples can be tuned from bluish violet to green.In order to further enlarge the emission gamut,Mn^(2+)ions as red emission components were added,forming tri-doped single-phase Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors.The Ca_(9)LiY_(2/3)(PO_(4))_(7):Ce^(3+),Tb^(3+),Mn^(2+)phosphors exhibit tunable emission properties through controlling the relative doping concentration of Ce^(3+),Tb^(3+)and Mn^(2+).Especially,Ca_(9)LiY_(2/3)(PO_(4))_(7):0.09 Ce^(3+),0.12 Tb^(3+),0.30 Mn^(2+)can emit warm white light.The sample shows good thermal stability.At 150℃,the emission intensity for Ce^(3+)(360 nm),Tb^(3+)(545 nm)and Mn^(2+)(655 nm)decreases to 63%,69%,and 72%of its initial intensity,respectively.Moreover,the sample obtains good stability after 10 cycles between room temperature and150℃.
基金RMC, UTM for providing research funding to complete this work
文摘Cu-doped borate glass co-doped with SnO2nanoparticles is fabricated by melt quenching.The structure and morphology of the samples are examined by X-ray diffraction and field emission scanning electron microscopy.Up-conversion enhancement is observed in the photoluminescence(PL) and thermoluminescence(TL) intensities of the glass.PL emission spectra are identified in the blue and green regions,and a fourfold increase in emission intensity may be observed in the presence of embedded SnO2nanoparticles.The glow curve is recorded at 215 C,and fourfold increases in TL intensity are obtained by addition of 0.1 mol% SnO2nanoparticles to the glass.Higher TL responses of the samples are observed in the energy range of 15-100 KeV.At energy levels greater than ~0.1 MeV,however,flat responses are obtained.The activation energy and frequency factor of the second-order kinetic reaction are calculated by the peak shape method.
