The new phosphors Bi2ZnB2O7:Ln3+ (Ln3+=Eu3+,Dy3+) were synthesized by solid-state reaction technique.The obtained phosphors were investigated by means of X-ray powder diffraction (XRD),photoluminescence excitation and...The new phosphors Bi2ZnB2O7:Ln3+ (Ln3+=Eu3+,Dy3+) were synthesized by solid-state reaction technique.The obtained phosphors were investigated by means of X-ray powder diffraction (XRD),photoluminescence excitation and emission spectra with the aim of enhancing the fundamental knowledge about the luminescent properties of Eu3+ and Dy3+ ions in the Bi2ZnB2O7 host lattice.XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7.The excitation and emission spectra of Bi2ZnB2O7:Ln3+ (Ln3+=Eu3+,Dy3+) at room temperature show the typical 4f-4f transitions of Eu3+ and Dy3+,respectively.The hypersensitive transitions of 5D0→7F2 (Eu3+) and 4F9/2→6H13/2 (Dy3+) are relatively higher than those of the insensitive transitions in Bi2ZnB2O7.It is conceivable that the Bi2ZnB2O7 structure provides asymmetry sites for activators (Eu3+,Dy3+).The optimum concentrations of Eu3+ and Dy3+ ions in Bi2ZnB2O7 phosphors are both x=0.05.展开更多
Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregn...Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
A new 3D coordination polymer,namely,[Yb_3(μ_3-OH)_3(μ_2-OH)(DDLA)_(2.5)(BIPY)](1,H_2DDLA = 2,2-dipyridyl-4,4-dicarboxylic acid,BIPY = 2,2?-bipyridine),has been synthesized via solvothermal method. The complex cryst...A new 3D coordination polymer,namely,[Yb_3(μ_3-OH)_3(μ_2-OH)(DDLA)_(2.5)(BIPY)](1,H_2DDLA = 2,2-dipyridyl-4,4-dicarboxylic acid,BIPY = 2,2?-bipyridine),has been synthesized via solvothermal method. The complex crystallizes in triclinic,space group P1 with a = 7.7339(4),b = 15.6699(8),c = 17.2221(9) ?,α = 68.8630(10),β = 88.1890(10),γ = 88.1740(10)°,V = 1945.27(17) ?~3,Z = 2,D_c = 2.296 g·cm^3,μ(MoKα) = 1.075 mm^(-1),F(000) = 1268,S = 1.068,R = 0.0263 and wR = 1.067 for 5176 observed reflections with I > 2σ(I). Compound 1 contains a unique alternating double trinucleate {[Yb_3(μ_3-OH)_2OH]_2}_n chain,in which Yb^(3+) is bridged through μ_3-OH and μ_2-OH two coordination modes. The alternating double trinucleate chains are further extended into a 3D structure through DDLA^(2-) ligands by different coordination modes. The photoluminescence spectra show 1 is highly sensitized by the characteristic emission of Yb^(3+) in the NIR region.展开更多
Two novel complexes, namely {[Cd(AIP)(4,4?-bpy)]·1.3DMF}n(1) and [Cd(AIP)(2,2?- bpy)]n(2), have been synthesized through solvothermal reaction(H2AIP = 5-aminoisophthalic acid, 2,2?-bpy = 2,2?-bipyridine, 4,4?-bpy...Two novel complexes, namely {[Cd(AIP)(4,4?-bpy)]·1.3DMF}n(1) and [Cd(AIP)(2,2?- bpy)]n(2), have been synthesized through solvothermal reaction(H2AIP = 5-aminoisophthalic acid, 2,2?-bpy = 2,2?-bipyridine, 4,4?-bpy = 4,4?-bipyridine, and DMF = N,N?-dimethylformamide) and structurally determined by single-crystal X-ray diffraction. Complex 1 shows a three-dimensional(3D) layer-pillar framework with rectangular channels, while complex 2 displays a two-dimensional(2D) wave net architecture. Furthermore, 1 and 2 were characterized by elemental analysis, infrared spectra(IR), thermal gravimetric analyses(TGA) and fluorescence measurements. The luminescent properties of 1 dispersed in various organic solvents have been investigated systematically, demonstrating high selectivity for acetone via the fluorescence quenching effect.展开更多
The title complex, [Cu(phen)_2I][Bi(phen)I_4], has been successfully synthesized by a solution method. Its crystal structure was determined by X-ray diffraction method, and crystallizes in triclinic, space group P1 wi...The title complex, [Cu(phen)_2I][Bi(phen)I_4], has been successfully synthesized by a solution method. Its crystal structure was determined by X-ray diffraction method, and crystallizes in triclinic, space group P1 with a = 10.3876(2), b = 14.4258(5), c = 14.7128(5) ?, α = 82.569(8), β = 73.442(7), γ = 79.299(8)°, V = 2069.68(11) ?3, Z = 2, Dc = 2.323 g/cm3, F(000) = 1318, μ(Mo Kα) = 13.132 mm–1 and T = 293(2) K. The final R = 0.0472 and w R = 0.1147 for 6027 observed reflections with I > 2σ(I). In the structure of the title compound, [Bi(phen)I4]– provides us an opportunity to survey the influence of coordination component on the structure of the cation in the [Cu(phen)2I][Y] system. X-ray diffraction and luminescent spectrum study of the complex are also described.展开更多
The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m...The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.展开更多
Phosphors of yttrium aluminium garnet activated by cerium ion, a kind of yellow luminescent materials for white LED lighting, were synthesized via solid-state reaction route in air and then reducing atmospheres.Therma...Phosphors of yttrium aluminium garnet activated by cerium ion, a kind of yellow luminescent materials for white LED lighting, were synthesized via solid-state reaction route in air and then reducing atmospheres.Thermal analysis was conducted by DTA/TGA.Moreover, XRD patterns of phosphors show that pure cubic phase of Y3 Al5 O12 is formed.Microstructures of the powders were observed by SEM.Luminescent spectra of the phosphors were also characterized by a spectrophotometer.The effect of sintering time on excitation and emission properties of the YAG: Ce3+ powders were systematically studied, resulting a best range of sintering time, 300 ～ 400 min, for maximal relative luminescent intensity.展开更多
Five coordination compounds, namely [Ni2(5-Fnic)2(H2 O)4](1), [Ni(5-Fnic)(μ-5-Fnic)(H2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4’-bipy}n(3), [Pb2(μ-5-Fnic)2(μ3-5-Fnic)2(H2 O)2]n(4), and [Pb(5-Fnic)2(4,4’-bip...Five coordination compounds, namely [Ni2(5-Fnic)2(H2 O)4](1), [Ni(5-Fnic)(μ-5-Fnic)(H2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4’-bipy}n(3), [Pb2(μ-5-Fnic)2(μ3-5-Fnic)2(H2 O)2]n(4), and [Pb(5-Fnic)2(4,4’-bipy)(H2 O)](5), have been constructed hydrothermally using 5-FnicH(5-FnicH = 5-fluoronicotinic acid), H2 biim(H2 biim = 2,2’-biimidazole), 4,4’-bipy(4,4’-bipy = 4,4’-bipyridine), NiCl2×6 H2 O, CdCl2×H2 O and PbCl2. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Structures of 1~5 range from discrete 0 D monomers(1 and 5) to 1 D coordination polymers(2 and 4) and 2 D metal-organic network(3). A broad structural diversity of 1~5 is guided by the type of the metal(Ⅱ) node and the introduction of auxiliary ligands. The magnetic(for 2) and luminescent(for 3~5) properties were also investigated and discussed.展开更多
A new 3D Cd(II) coordination polymer, [Cd(Hpidc)]n(1, H3 pidc = 2-(pyrid-2-yl)-1H-imidazole-4,5-dicarboxy acid), has been prepared and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray di...A new 3D Cd(II) coordination polymer, [Cd(Hpidc)]n(1, H3 pidc = 2-(pyrid-2-yl)-1H-imidazole-4,5-dicarboxy acid), has been prepared and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray diffraction. Compound 1 crystallizes in orthorhombic, space group Fdd2 with a = 22.833(9), b = 25.536(9), c = 7.437(3) A, V = 4336(3) A3, Z = 16, Dc = 2.105 Mg·m-3, μ = 2.025 mm-1, F(000) = 2656, and the final R = 0.0261 and w R = 0.0636. The structure determination reveals that 1 exhibits a rare 3D 3-connected lig net with a point symbol of(82·10). In addition, the solid state properties such as thermogravimetric analysis and luminescence of 1 were also studied.展开更多
Two fascinating Zn(II)entangled coordination polymers,[Zn(eoba)(bbi)]_n·nH_2O(1)and[Zn(boba)(bbi)_(1/2)]_n(2),(bbi=1,1?-(1,4-butanediyl)-bis(imidazole),H_2eoba=4,4?-(ethane-1,2-diyldioxy)-dibenzoic acid,H_2boba=4...Two fascinating Zn(II)entangled coordination polymers,[Zn(eoba)(bbi)]_n·nH_2O(1)and[Zn(boba)(bbi)_(1/2)]_n(2),(bbi=1,1?-(1,4-butanediyl)-bis(imidazole),H_2eoba=4,4?-(ethane-1,2-diyldioxy)-dibenzoic acid,H_2boba=4,4?-(butane-1,4-diyldioxy)-dibenzoic acid),were obtained by hydrothermal technology and characterized by elemental analysis,infrared spectrum,thermogravimetric analysis and single-crystal X-ray diffraction.1 is a rare 2D→3D example with a 3-fold parallel interpenetration and polycatenaned architecture.2 features a scarce2D→2D example with a 3-fold parallel interpenetrating network which possesses polyrotaxane and polycatenane characters.Moreover,the luminescent properties of 1 and 2 have been discussed.展开更多
Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different sca...Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different scanning calorimeter, scanning electron microscopy, and photoluminescence spectrofluorimeter. Several peaks at 351, 389, 425, 452, and 472 nm appeared in photoluminescence excitation spectrum, which matched well with the emission of the ultraviolet (UV) and blue-light emitting diode (LED) chips. Upon excitation at 389 nm UV light, intense emissions centered at 484, 575 and 668 nm were attributed to the transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2 of Dy3+, respectively. The chromaticity coordinates and correlative color temperatures have been calculated and presented in the Commission International de I'Eclairage (CIE) diagrams. The results indicated that Gd1.9(MoO4)3:Dy0.13+ with CIE coordinates of (x=0.38, y=0.41) and the correlative color temperature of 4134 K is a potential candidate for white LEDs.展开更多
A new Cd(Ⅱ) coordination polymer, [Cd_(0.5)(nba)(bib)_(0.5)]_(2n)(1, Hnba = 4-nitrobenzoic acid, bib = 1,4-bis(imidazol-1-yl)-butane), was synthesized at room temperature condition and characterized by IR spectra, el...A new Cd(Ⅱ) coordination polymer, [Cd_(0.5)(nba)(bib)_(0.5)]_(2n)(1, Hnba = 4-nitrobenzoic acid, bib = 1,4-bis(imidazol-1-yl)-butane), was synthesized at room temperature condition and characterized by IR spectra, elemental analyses, single-crystal and powder X-ray diffractions. Complex 1 belongs to the monoclinic system, C2/c space group, with a = 26.0600(14), b = 6.7889(4), c = 16.5825(9) ?, β = 118.8120(10)°, V = 2570.6(2) ?3, Z = 4. It shows one-dimensional chains and is further linked by π-π stacking interactions to yield a three-dimensional supramolecular structure. Thermal stability and luminescence of 1 were investigated.展开更多
BaMgAl10O17:Eu blue phosphors were synthesized and the effect of doping Er3+ and Nd3+ ions in the phosphoron the luminescent properties was investigated. When the content of Er3+ and Nd3+ ions is small, the phosphor r...BaMgAl10O17:Eu blue phosphors were synthesized and the effect of doping Er3+ and Nd3+ ions in the phosphoron the luminescent properties was investigated. When the content of Er3+ and Nd3+ ions is small, the phosphor remains sin-gle phase and the luminescent intensity of Eu2+ increases effectively. When Er3+ is doped, the shape of the excitation spec-trum of the phosphor in the UV (ultraviolet) region remains unchanged. As Nd3+ is doped in the phosphor, the location andintensity of the two excitation peaks, and the emission intensity ratio excited by corresponding UV change dramaticallyowing to the alternation of crystal field splitting and level barycenter of 4f65d configuration of Eu2+ ion.展开更多
Two new coordination polymers(CPs) based on two new tetrazole-based ligands, namely, [Cu(TPP)]n(HTTP = 4-(3-(2 H-tetrazol-5-yl)phenyl)pyridine, 1) and {[Cd_2(TBCA)_2(H_2O)_2]·-H_2O}n(H_2TBCA = 3?-(2 H-tetrazol-5-...Two new coordination polymers(CPs) based on two new tetrazole-based ligands, namely, [Cu(TPP)]n(HTTP = 4-(3-(2 H-tetrazol-5-yl)phenyl)pyridine, 1) and {[Cd_2(TBCA)_2(H_2O)_2]·-H_2O}n(H_2TBCA = 3?-(2 H-tetrazol-5-yl)biphenyl-4-carboxylic acid, 2), were synthesized via solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a(3,6)-connected rtl network topology based on binuclear secondary building units(SBUs). Compound 2 presents a 2D framework composed of 1D SUBs formed by both carboxyl and tetrazole groups. The 2D network is linked into a 3D framework via various hydrogen bonds. They represent two examples of CPs construct from rigid 5-substitued tetrazole-based ligands with relatively longer spacer. The thermal stabilities and luminescent properties of compounds 1 and 2 were also explored.展开更多
Two lanthanide coordination polymers, [Eu(HL)(L)(H_2O)2]n(1) and [Tb(H_(0.5)L)_2]_n(2), based on bifunctional 5-(1H-imidazol-1-yl) isophthalic acid(H_2L), are hydrothermally synthesized and characterized by both singl...Two lanthanide coordination polymers, [Eu(HL)(L)(H_2O)2]n(1) and [Tb(H_(0.5)L)_2]_n(2), based on bifunctional 5-(1H-imidazol-1-yl) isophthalic acid(H_2L), are hydrothermally synthesized and characterized by both single-crystal and powder X-ray diffraction analyses, and FT-IR. In compound 1, the basic inorganic building unit of the coordination network is the dinuclear [Eu_2(COO)_6] cluster. Each [Eu_2(COO)_6] cluster connects four HL^- ligands and each HLligand links two [Eu_2(COO)_6] clusters, resulting in a 2D coordination layer. The adjacent 2 D layers are further connected via neighboring inter-layer hydrogen bonds to give a 3D supramolecular structure. In compound 2, the Tb^(3+) is coordinated to six oxygen atoms. Each Tb^(3+) ion connects six ligands and each ligand links three Tb^(3+) ions, leading to a 3D coordination polymeric network which exhibits remarkably high thermal stability up to 500 °C. Furthermore, due to the successful incorporation of Tb^(3+), compound 2 displays characteristic luminescent emission in the solid state at room temperature. The combination of high thermal stability and fluorescent property of compound 2 would make it as a promising light-emitting material.展开更多
Mn2+ has been synthesized by a new sulfurizing flux method, and the phosphors prepared in this way is relatively stable in water. The fluorescent spectra of CaS host and CaS: Mn2+ have been measured at room temperatur...Mn2+ has been synthesized by a new sulfurizing flux method, and the phosphors prepared in this way is relatively stable in water. The fluorescent spectra of CaS host and CaS: Mn2+ have been measured at room temperature. The luminescent centers formed by O2- ions may be responsible for the host’s blue - green emission. The complete disappearance of this emission in CaS: Mn2+ system confirms that there exists efficient energy transfer from the host to the Mn2+ centers. The decay characteristics have been performed. The photoluminescence decay of CaS: Mn2+ consists of slow and fast components due to the single and paired Mn2+ centers, respectively.展开更多
A novel synthesis process, based on the polyacrylamide gel method, was used to prepare Ce-doped YAG phosphor powders. Effects of heat treatment parameters, temperature and holding time, the fluxes, and atmosphere on m...A novel synthesis process, based on the polyacrylamide gel method, was used to prepare Ce-doped YAG phosphor powders. Effects of heat treatment parameters, temperature and holding time, the fluxes, and atmosphere on microstructure and particle morphology as well as luminescent properties of YAG:Ce3+ phosphor powders were studied by X-ray powder diffractometry, scanning electron microscopy, and fluorescence spectrophotometry. The results show that the formation temperature (1 000 ℃) of pure YAG phase is significant low when being synthesized by the polyacrylamide gel method, compared with solid-state reaction. For luminescent properties, the intensity of emission of YAG:Ce3+ phosphor increases steadily with increasing temperature from 900 ℃ to 1 300 ℃ and prolonging holding time from 100 min to 400 min. But blue shift phenomenon is observed for 400 min calcination. Fluxes as BaF2 and H3BO3 can enhance the intensity of emission of phosphor due to the improvement of crystallization of YAG and the stabilization of trivalence cerium ion in YAG host lattice at high temperature. Weak reduction atmosphere can contribute to improvement of the emission intensity of YAG:Ce3+ phosphor powders.展开更多
Two coordination polymers, namely [Pb(Hbtc)(phen)]n(1) and {[Cd3(btc)2(H2O)4]·2H2O}n(2, H3btc = biphenyl-2,5,3'-tricarboxylic acid, phen = 1,10-phenanthroline), were assembled. Single-crystal X-ray diffractio...Two coordination polymers, namely [Pb(Hbtc)(phen)]n(1) and {[Cd3(btc)2(H2O)4]·2H2O}n(2, H3btc = biphenyl-2,5,3'-tricarboxylic acid, phen = 1,10-phenanthroline), were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a zigzag chain 1D coordination network, which is further extended into a 3D supramolecular architecture via O–H···O hydrogen bonds and π-π packing interactions. Compound 2 features a 3D open framework based on a tricadmium(II) subunit, generating a trinodal 4,4,6-connected net with the 4,4,6T24 topology defined by the point symbol of(44·62)3(46·69)2. Thermal stability and luminescent properties of both compounds were studied and discussed.展开更多
Four types of luminescent properties of metal-organic frameworks（MOFs） with formulas [Cd（1,2-BIYB）2（H2O）2]n·n（AQ-1,5-DAD）（1）, [Cd（AQ-1,5-DAD）（1,3-BIYB）2]n（2）, [Cd（1,3-BIYB）]n·n（AQ-1,5-DAD...Four types of luminescent properties of metal-organic frameworks（MOFs） with formulas [Cd（1,2-BIYB）2（H2O）2]n·n（AQ-1,5-DAD）（1）, [Cd（AQ-1,5-DAD）（1,3-BIYB）2]n（2）, [Cd（1,3-BIYB）]n·n（AQ-1,5-DAD）·n H2O（3）, and [Zn（1,4-BIYB）2]n·n（AQ-1,5-DAD）2·6H2O（4）,（Na2AQ-1,5-DAD = anthraquinone-1,5-disulfonic acid disodium, 1,2-BIYB = 1,2-bis（imidazol-1-ylmethyl）benzene, 1,3-BIYB = 1,3-bis（imidazol-1-ylmethyl）benzene, 1,4-BIYB = 1,4-bis（imidazol-1-ylmethyl）benzene） have been synthesized based on a rare sulfonate and imidazole Co-ligand system under different conditions. The structural features of four types of MOFs 14 are as follows: MOFs 1 show a 3D supramolecular compound in which the double one-dimensional chains are further cross-linked by hydrogen bonds. 2 exhibits a 2D network constructed by two different 1D chains. 3 features a 2D supramolecular network, in which the 1D chains and AQ-1,5-DAD are arranged alternately through hydrogen bonds. 4 posseses a 3D supramolecular structure constructed by a 2D network and one-dimensional hydrogen bonding chains. All compounds 14 are characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis. The luminescence properties of 14 have been investigated.展开更多
基金supported by the National Natural Science Foundation of China (No.20501023)the Youth Research Fund Project of Guangzhou Research Institute of Non-ferrous Metals
文摘The new phosphors Bi2ZnB2O7:Ln3+ (Ln3+=Eu3+,Dy3+) were synthesized by solid-state reaction technique.The obtained phosphors were investigated by means of X-ray powder diffraction (XRD),photoluminescence excitation and emission spectra with the aim of enhancing the fundamental knowledge about the luminescent properties of Eu3+ and Dy3+ ions in the Bi2ZnB2O7 host lattice.XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7.The excitation and emission spectra of Bi2ZnB2O7:Ln3+ (Ln3+=Eu3+,Dy3+) at room temperature show the typical 4f-4f transitions of Eu3+ and Dy3+,respectively.The hypersensitive transitions of 5D0→7F2 (Eu3+) and 4F9/2→6H13/2 (Dy3+) are relatively higher than those of the insensitive transitions in Bi2ZnB2O7.It is conceivable that the Bi2ZnB2O7 structure provides asymmetry sites for activators (Eu3+,Dy3+).The optimum concentrations of Eu3+ and Dy3+ ions in Bi2ZnB2O7 phosphors are both x=0.05.
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
基金financially supported by the National Natural Science Foundation of China(21503183)Dr.Scientific research Foundation of Yanan university(YDBK2015-02)
文摘A new 3D coordination polymer,namely,[Yb_3(μ_3-OH)_3(μ_2-OH)(DDLA)_(2.5)(BIPY)](1,H_2DDLA = 2,2-dipyridyl-4,4-dicarboxylic acid,BIPY = 2,2?-bipyridine),has been synthesized via solvothermal method. The complex crystallizes in triclinic,space group P1 with a = 7.7339(4),b = 15.6699(8),c = 17.2221(9) ?,α = 68.8630(10),β = 88.1890(10),γ = 88.1740(10)°,V = 1945.27(17) ?~3,Z = 2,D_c = 2.296 g·cm^3,μ(MoKα) = 1.075 mm^(-1),F(000) = 1268,S = 1.068,R = 0.0263 and wR = 1.067 for 5176 observed reflections with I > 2σ(I). Compound 1 contains a unique alternating double trinucleate {[Yb_3(μ_3-OH)_2OH]_2}_n chain,in which Yb^(3+) is bridged through μ_3-OH and μ_2-OH two coordination modes. The alternating double trinucleate chains are further extended into a 3D structure through DDLA^(2-) ligands by different coordination modes. The photoluminescence spectra show 1 is highly sensitized by the characteristic emission of Yb^(3+) in the NIR region.
基金the National Natural Science Foundation of China(21501178)Natural Science Funds of Fujian Province(No.2014H0055)for financial support of this work
文摘Two novel complexes, namely {[Cd(AIP)(4,4?-bpy)]·1.3DMF}n(1) and [Cd(AIP)(2,2?- bpy)]n(2), have been synthesized through solvothermal reaction(H2AIP = 5-aminoisophthalic acid, 2,2?-bpy = 2,2?-bipyridine, 4,4?-bpy = 4,4?-bipyridine, and DMF = N,N?-dimethylformamide) and structurally determined by single-crystal X-ray diffraction. Complex 1 shows a three-dimensional(3D) layer-pillar framework with rectangular channels, while complex 2 displays a two-dimensional(2D) wave net architecture. Furthermore, 1 and 2 were characterized by elemental analysis, infrared spectra(IR), thermal gravimetric analyses(TGA) and fluorescence measurements. The luminescent properties of 1 dispersed in various organic solvents have been investigated systematically, demonstrating high selectivity for acetone via the fluorescence quenching effect.
文摘The title complex, [Cu(phen)_2I][Bi(phen)I_4], has been successfully synthesized by a solution method. Its crystal structure was determined by X-ray diffraction method, and crystallizes in triclinic, space group P1 with a = 10.3876(2), b = 14.4258(5), c = 14.7128(5) ?, α = 82.569(8), β = 73.442(7), γ = 79.299(8)°, V = 2069.68(11) ?3, Z = 2, Dc = 2.323 g/cm3, F(000) = 1318, μ(Mo Kα) = 13.132 mm–1 and T = 293(2) K. The final R = 0.0472 and w R = 0.1147 for 6027 observed reflections with I > 2σ(I). In the structure of the title compound, [Bi(phen)I4]– provides us an opportunity to survey the influence of coordination component on the structure of the cation in the [Cu(phen)2I][Y] system. X-ray diffraction and luminescent spectrum study of the complex are also described.
基金supported by Natural Science Foundation of Hebei Province(202140)
文摘The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.
文摘Phosphors of yttrium aluminium garnet activated by cerium ion, a kind of yellow luminescent materials for white LED lighting, were synthesized via solid-state reaction route in air and then reducing atmospheres.Thermal analysis was conducted by DTA/TGA.Moreover, XRD patterns of phosphors show that pure cubic phase of Y3 Al5 O12 is formed.Microstructures of the powders were observed by SEM.Luminescent spectra of the phosphors were also characterized by a spectrophotometer.The effect of sintering time on excitation and emission properties of the YAG: Ce3+ powders were systematically studied, resulting a best range of sintering time, 300 ～ 400 min, for maximal relative luminescent intensity.
基金supported by Guangdong Province Higher Vocational Colleges&Schools Pearl River Scholar Funded Scheme(2015,2018)the Natural Science Foundation of Guangdong Province(No.2016A030313761)+3 种基金the Pearl River Scholar Foundation of Guangdong Industry Polytechnic(RC2015-001)the Opening Foundation of MOE Key Laboratory of MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of Chemistry Sun Yat-Sen University(2016)Innovation Team Project on University of Guangdong Province(2017GKCXTD001,2017GWCXTD002)Outstanding youth fund project of Guangdong Industry Polytechnic(QN 2018-007)
文摘Five coordination compounds, namely [Ni2(5-Fnic)2(H2 O)4](1), [Ni(5-Fnic)(μ-5-Fnic)(H2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4’-bipy}n(3), [Pb2(μ-5-Fnic)2(μ3-5-Fnic)2(H2 O)2]n(4), and [Pb(5-Fnic)2(4,4’-bipy)(H2 O)](5), have been constructed hydrothermally using 5-FnicH(5-FnicH = 5-fluoronicotinic acid), H2 biim(H2 biim = 2,2’-biimidazole), 4,4’-bipy(4,4’-bipy = 4,4’-bipyridine), NiCl2×6 H2 O, CdCl2×H2 O and PbCl2. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Structures of 1~5 range from discrete 0 D monomers(1 and 5) to 1 D coordination polymers(2 and 4) and 2 D metal-organic network(3). A broad structural diversity of 1~5 is guided by the type of the metal(Ⅱ) node and the introduction of auxiliary ligands. The magnetic(for 2) and luminescent(for 3~5) properties were also investigated and discussed.
基金Supported by the NSRF of Hubei Provincial Education Office of China(Q20141201)the SRASF of Yichang of Hubei Province(A13-302a-02)
文摘A new 3D Cd(II) coordination polymer, [Cd(Hpidc)]n(1, H3 pidc = 2-(pyrid-2-yl)-1H-imidazole-4,5-dicarboxy acid), has been prepared and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray diffraction. Compound 1 crystallizes in orthorhombic, space group Fdd2 with a = 22.833(9), b = 25.536(9), c = 7.437(3) A, V = 4336(3) A3, Z = 16, Dc = 2.105 Mg·m-3, μ = 2.025 mm-1, F(000) = 2656, and the final R = 0.0261 and w R = 0.0636. The structure determination reveals that 1 exhibits a rare 3D 3-connected lig net with a point symbol of(82·10). In addition, the solid state properties such as thermogravimetric analysis and luminescence of 1 were also studied.
基金Supported by the Science and Technology Development plan of Jilin Province(20150520006JH)Science and Technology Research Project of Education Department of Jilin province(2016219,JJKH20180776KJ)Science and Technology Development plan of Siping City(2013055)
文摘Two fascinating Zn(II)entangled coordination polymers,[Zn(eoba)(bbi)]_n·nH_2O(1)and[Zn(boba)(bbi)_(1/2)]_n(2),(bbi=1,1?-(1,4-butanediyl)-bis(imidazole),H_2eoba=4,4?-(ethane-1,2-diyldioxy)-dibenzoic acid,H_2boba=4,4?-(butane-1,4-diyldioxy)-dibenzoic acid),were obtained by hydrothermal technology and characterized by elemental analysis,infrared spectrum,thermogravimetric analysis and single-crystal X-ray diffraction.1 is a rare 2D→3D example with a 3-fold parallel interpenetration and polycatenaned architecture.2 features a scarce2D→2D example with a 3-fold parallel interpenetrating network which possesses polyrotaxane and polycatenane characters.Moreover,the luminescent properties of 1 and 2 have been discussed.
基金Project supported by the National Natural Science Foundation of China (50872036)
文摘Polycrystalline Gd2(MoO4)3:Dy3+ phosphors have been synthesized by high temperature solid-state reaction method. The phosphors were characterized with X-ray diffractometer, thermogravimetric analysis and different scanning calorimeter, scanning electron microscopy, and photoluminescence spectrofluorimeter. Several peaks at 351, 389, 425, 452, and 472 nm appeared in photoluminescence excitation spectrum, which matched well with the emission of the ultraviolet (UV) and blue-light emitting diode (LED) chips. Upon excitation at 389 nm UV light, intense emissions centered at 484, 575 and 668 nm were attributed to the transitions of 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2 of Dy3+, respectively. The chromaticity coordinates and correlative color temperatures have been calculated and presented in the Commission International de I'Eclairage (CIE) diagrams. The results indicated that Gd1.9(MoO4)3:Dy0.13+ with CIE coordinates of (x=0.38, y=0.41) and the correlative color temperature of 4134 K is a potential candidate for white LEDs.
基金supported by the Science and Technology Development Project of Jilin Provincial Science&Technology Department(201205080)the Science and Technology Research Projects of the Education Office of Jilin Province(No.2013.384)
文摘A new Cd(Ⅱ) coordination polymer, [Cd_(0.5)(nba)(bib)_(0.5)]_(2n)(1, Hnba = 4-nitrobenzoic acid, bib = 1,4-bis(imidazol-1-yl)-butane), was synthesized at room temperature condition and characterized by IR spectra, elemental analyses, single-crystal and powder X-ray diffractions. Complex 1 belongs to the monoclinic system, C2/c space group, with a = 26.0600(14), b = 6.7889(4), c = 16.5825(9) ?, β = 118.8120(10)°, V = 2570.6(2) ?3, Z = 4. It shows one-dimensional chains and is further linked by π-π stacking interactions to yield a three-dimensional supramolecular structure. Thermal stability and luminescence of 1 were investigated.
文摘BaMgAl10O17:Eu blue phosphors were synthesized and the effect of doping Er3+ and Nd3+ ions in the phosphoron the luminescent properties was investigated. When the content of Er3+ and Nd3+ ions is small, the phosphor remains sin-gle phase and the luminescent intensity of Eu2+ increases effectively. When Er3+ is doped, the shape of the excitation spec-trum of the phosphor in the UV (ultraviolet) region remains unchanged. As Nd3+ is doped in the phosphor, the location andintensity of the two excitation peaks, and the emission intensity ratio excited by corresponding UV change dramaticallyowing to the alternation of crystal field splitting and level barycenter of 4f65d configuration of Eu2+ ion.
基金financially supported by the National Natural Science Foundation of China(No.21473062)Guizhou Z [(2015)4002]Guizhou GNYL[(2017)008] of Guizhou Province,China
文摘Two new coordination polymers(CPs) based on two new tetrazole-based ligands, namely, [Cu(TPP)]n(HTTP = 4-(3-(2 H-tetrazol-5-yl)phenyl)pyridine, 1) and {[Cd_2(TBCA)_2(H_2O)_2]·-H_2O}n(H_2TBCA = 3?-(2 H-tetrazol-5-yl)biphenyl-4-carboxylic acid, 2), were synthesized via solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a(3,6)-connected rtl network topology based on binuclear secondary building units(SBUs). Compound 2 presents a 2D framework composed of 1D SUBs formed by both carboxyl and tetrazole groups. The 2D network is linked into a 3D framework via various hydrogen bonds. They represent two examples of CPs construct from rigid 5-substitued tetrazole-based ligands with relatively longer spacer. The thermal stabilities and luminescent properties of compounds 1 and 2 were also explored.
基金Financially supported by the Natural Science Foundation of Shandong Province(ZR2014BQ035)the National Natural Science Foundation of China(21501086,21671093)+3 种基金the Tai-Shan Scholar Research Fund of Shandong ProvinceLiaocheng University and college students’ innovative training program(201410447009,201410447010)the financial supports from Liaocheng University(318051401)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Two lanthanide coordination polymers, [Eu(HL)(L)(H_2O)2]n(1) and [Tb(H_(0.5)L)_2]_n(2), based on bifunctional 5-(1H-imidazol-1-yl) isophthalic acid(H_2L), are hydrothermally synthesized and characterized by both single-crystal and powder X-ray diffraction analyses, and FT-IR. In compound 1, the basic inorganic building unit of the coordination network is the dinuclear [Eu_2(COO)_6] cluster. Each [Eu_2(COO)_6] cluster connects four HL^- ligands and each HLligand links two [Eu_2(COO)_6] clusters, resulting in a 2D coordination layer. The adjacent 2 D layers are further connected via neighboring inter-layer hydrogen bonds to give a 3D supramolecular structure. In compound 2, the Tb^(3+) is coordinated to six oxygen atoms. Each Tb^(3+) ion connects six ligands and each ligand links three Tb^(3+) ions, leading to a 3D coordination polymeric network which exhibits remarkably high thermal stability up to 500 °C. Furthermore, due to the successful incorporation of Tb^(3+), compound 2 displays characteristic luminescent emission in the solid state at room temperature. The combination of high thermal stability and fluorescent property of compound 2 would make it as a promising light-emitting material.
基金the National Natural Science Foundation of China (No.4977099)
文摘Mn2+ has been synthesized by a new sulfurizing flux method, and the phosphors prepared in this way is relatively stable in water. The fluorescent spectra of CaS host and CaS: Mn2+ have been measured at room temperature. The luminescent centers formed by O2- ions may be responsible for the host’s blue - green emission. The complete disappearance of this emission in CaS: Mn2+ system confirms that there exists efficient energy transfer from the host to the Mn2+ centers. The decay characteristics have been performed. The photoluminescence decay of CaS: Mn2+ consists of slow and fast components due to the single and paired Mn2+ centers, respectively.
文摘A novel synthesis process, based on the polyacrylamide gel method, was used to prepare Ce-doped YAG phosphor powders. Effects of heat treatment parameters, temperature and holding time, the fluxes, and atmosphere on microstructure and particle morphology as well as luminescent properties of YAG:Ce3+ phosphor powders were studied by X-ray powder diffractometry, scanning electron microscopy, and fluorescence spectrophotometry. The results show that the formation temperature (1 000 ℃) of pure YAG phase is significant low when being synthesized by the polyacrylamide gel method, compared with solid-state reaction. For luminescent properties, the intensity of emission of YAG:Ce3+ phosphor increases steadily with increasing temperature from 900 ℃ to 1 300 ℃ and prolonging holding time from 100 min to 400 min. But blue shift phenomenon is observed for 400 min calcination. Fluxes as BaF2 and H3BO3 can enhance the intensity of emission of phosphor due to the improvement of crystallization of YAG and the stabilization of trivalence cerium ion in YAG host lattice at high temperature. Weak reduction atmosphere can contribute to improvement of the emission intensity of YAG:Ce3+ phosphor powders.
基金Funded by the National Natural Science Foundation of Shanxi Province(No.2013011011-6)the Subject Team of Taiyuan University of Science and Technology
文摘Two coordination polymers, namely [Pb(Hbtc)(phen)]n(1) and {[Cd3(btc)2(H2O)4]·2H2O}n(2, H3btc = biphenyl-2,5,3'-tricarboxylic acid, phen = 1,10-phenanthroline), were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a zigzag chain 1D coordination network, which is further extended into a 3D supramolecular architecture via O–H···O hydrogen bonds and π-π packing interactions. Compound 2 features a 3D open framework based on a tricadmium(II) subunit, generating a trinodal 4,4,6-connected net with the 4,4,6T24 topology defined by the point symbol of(44·62)3(46·69)2. Thermal stability and luminescent properties of both compounds were studied and discussed.
基金supported by the National Natural Science Foundation of China(21503183)Yanan university field scientific research projects(YDBK2015-02)
文摘Four types of luminescent properties of metal-organic frameworks（MOFs） with formulas [Cd（1,2-BIYB）2（H2O）2]n·n（AQ-1,5-DAD）（1）, [Cd（AQ-1,5-DAD）（1,3-BIYB）2]n（2）, [Cd（1,3-BIYB）]n·n（AQ-1,5-DAD）·n H2O（3）, and [Zn（1,4-BIYB）2]n·n（AQ-1,5-DAD）2·6H2O（4）,（Na2AQ-1,5-DAD = anthraquinone-1,5-disulfonic acid disodium, 1,2-BIYB = 1,2-bis（imidazol-1-ylmethyl）benzene, 1,3-BIYB = 1,3-bis（imidazol-1-ylmethyl）benzene, 1,4-BIYB = 1,4-bis（imidazol-1-ylmethyl）benzene） have been synthesized based on a rare sulfonate and imidazole Co-ligand system under different conditions. The structural features of four types of MOFs 14 are as follows: MOFs 1 show a 3D supramolecular compound in which the double one-dimensional chains are further cross-linked by hydrogen bonds. 2 exhibits a 2D network constructed by two different 1D chains. 3 features a 2D supramolecular network, in which the 1D chains and AQ-1,5-DAD are arranged alternately through hydrogen bonds. 4 posseses a 3D supramolecular structure constructed by a 2D network and one-dimensional hydrogen bonding chains. All compounds 14 are characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis. The luminescence properties of 14 have been investigated.
