To understand the aerosol characteristics in a regional background environment,fine-particle(PM_(2.5),n=228)samples were collected over a one-year period at the Shangdianzi(SDZ)station,which is a Global Atmospheric Wa...To understand the aerosol characteristics in a regional background environment,fine-particle(PM_(2.5),n=228)samples were collected over a one-year period at the Shangdianzi(SDZ)station,which is a Global Atmospheric Watch regional background station in North China.The chemical and optical characteristics of PM_(2.5)were analyzed,including organic carbon,elemental carbon,water-soluble organic carbon,water-soluble inorganic ions,and fluorescent components of watersoluble organic matter.The source factors of major aerosol components are apportioned,and the sources of the fluorescent chromophores are further analyzed.The major chemical components of PM_(2.5)at SDZ were NO_(3)^(-),organic matter,SO_(4)^(2-),and NH_(4)^(+).Annually,water-soluble organic carbon contributed 48%±15%to the total organic carbon.Secondary formation(52%)and fossil fuel combustion(63%)are the largest sources of water-soluble organic matter and water-insoluble organic matter,respectively.In addition,three humic-like and one protein-like matter were identified via parallel factor analysis for excitation–emission matrices.The fluorescence intensities of the components were highest in winter and lowest in summer,indicating the main impact of burning sources.This study contributes to understanding the chemical and optical characteristics of ambient aerosols in the background atmosphere.展开更多
A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characteri...A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characterized by transmission electron micrograph （TEM）, ultraviolet-visible absorption spectra （UV-Vis） and fluorescence spectra （FS）. It was found that the fluorescence intensity of methyl orange （MO） was enhanced by 5 times in the aqueous composite system doped with silver nanoparticles whereas it was reduced by 15% and 20% in composite films with co-mixing and coating structures, respectively. The results indicate that the properties of functional molecules can be greatly improved in composite film with supra molecular structure and that the procedure presented here is effective.展开更多
The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identifi...The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identified by elemental analyses. UV and IR of the complexeshave been investigated. The UV spectra indicated that the complexes' ultraviolet absorption weremainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are differentfrom those of free ligands. The fluorescence properties of them were investigated by usingluminescence spectroscopy, the results showed that only three complexes appear as betterluminescence, they were Eu-benzoic acid, Eu-m-phthalic acid and Eu-phthalic acid, while the othersexhibited the ligands' wideband emission.展开更多
The enhancement effects of Y ( Ⅲ) ions on the fluorescence of Ce ( Ⅲ) in Ce ( Ⅲ)-Y ( Ⅲ)-PMMA (polymethylmethacrylate ) or Ce ( Ⅲ)-Y ( Ⅲ)-PVC (polyvinyl chloride ) complex systems were observed. The influence of ...The enhancement effects of Y ( Ⅲ) ions on the fluorescence of Ce ( Ⅲ) in Ce ( Ⅲ)-Y ( Ⅲ)-PMMA (polymethylmethacrylate ) or Ce ( Ⅲ)-Y ( Ⅲ)-PVC (polyvinyl chloride ) complex systems were observed. The influence of Y ( Ⅲ) ions on the emission spectra of PMMA ligands in PMMA-Y ( Ⅲ) and the fluorescent enhance- ment of Y( Ⅲ) on Ce( Ⅲ) emission in PMMA-Ce-Y by Y( Ⅲ) ion were studied. It was also of interest to note that when Y ( Ⅲ) ions were added into PMMA and into bpy(bipyridine ) , respectively , the emission spectrum of PMMA ligands was split into fine structure bands by Y ( Ⅲ) , and the fluorescence intensities of bpy ligands in bpy-Y ( Ⅲ) complexes were considerably increased.展开更多
A novel compound 4,8,10-trimethyl-2-（3,5-dimethylpyrazol）-pyrido-[2＇,3＇：3,4]-py-razol-[1,5-5-a]-pyrimidine（C17H18N6） has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone ...A novel compound 4,8,10-trimethyl-2-（3,5-dimethylpyrazol）-pyrido-[2＇,3＇：3,4]-py-razol-[1,5-5-a]-pyrimidine（C17H18N6） has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone by substitution and cyclolization.The structure was charac-terized by elemental analysis,1H NMR and IR,and single-crystal structure was determined by X-ray diffraction analysis.The compound crystallizes in the monoclinic system,space group P21/c with a = 8.0338（9）,b = 28.618（3）,c = 7.2688（8）,β = 111.051（2）o,V = 1559.6（3） 3,Z = 4,Dc = 1.305 g/cm3,μ = 0.083 mm-1,Mr = 306.37,F（000） = 648,S = 0.971,the final R = 0.0795 and wR = 0.1746 for 1457 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The results demonstrate that the pyridine,pyrazole and pyrimidine rings are nearly coplanar,which is evident from the dihedral angles among the four rings in the range of 0.13～4.15o.The face-to-face π-π stacking interactions among pyridine,pyrazol and pyrimidine rings result in a supramolecular crystal,in which they seem to be effective in stabilizing the structure.Meanwhile,the fluorescence properties of the title compound were discussed,which showed very strong fluorescence.The calculated results（selected bond lengths,bond angles and torsion angles） are all typical and agree well with the experimental results,which demonstrates that B3LYP/6-31＋G＊ is suitable for the title compound.展开更多
Two metal-organic coordination complexes, [Zn（2,6-ndc）（1,2-bix）]n（1） and [Zn（2,6-ndc）（1,3-bix）]n（2）（2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis（imidazole-1-ylmethyl）-benzene and 1,3-...Two metal-organic coordination complexes, [Zn（2,6-ndc）（1,2-bix）]n（1） and [Zn（2,6-ndc）（1,3-bix）]n（2）（2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis（imidazole-1-ylmethyl）-benzene and 1,3-bix = 1,3-bis（imidazole-1-ylmethyl）-benzene） have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions（π-π packing interactions） only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365（λ（ex） = 329 nm） and 367 nm（λex = 344 nm）, respectively.展开更多
The two-photon fluorescence properties and ultrafast responses of a hyperbranched polyyne （hb-DPP-J2） with triphenylamine as the central core, Diketo-Pyrrolo-Pyrrole as the connecting unit and electron acceptor are ...The two-photon fluorescence properties and ultrafast responses of a hyperbranched polyyne （hb-DPP-J2） with triphenylamine as the central core, Diketo-Pyrrolo-Pyrrole as the connecting unit and electron acceptor are studied. The polymer has a D-π-A-π-D conjugated structure along the extended polyyne w-bridge systems, and the effective condugated unit repeats itself in the whole hyperbranehed polymer chain. The polymer exhibits a large two-photon absorption cross section and high fluorescence quantum yields. The ultrafast dynamic results give a deep understanding of the excited energy transfer processes under excitation, and reveal a long relaxation lifetime of the intramolecular charge transfer （ICT） state.展开更多
We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluore...We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluorescence lifetime and polarized emission cross sections in the visible range are measured and calculated in a temperature range from 77K to 300 K, and the variations of the fluorescence lifetime and spectra are discovered. The reasons for these changes are explained accordingly. The output wavelength of the 720nm laser is first reported on the laser performance by using a fiber-coupled laser diode at the wavelength of 442nm as the pump source, and the maximum cw output power is about 303roW.展开更多
A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aP...A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aPhen with 1,10-Phenanthroline （Phen） were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ^1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis （TG-DTA）. The investigation of fluorescence properties of the complexes Eu（MEP）3·2H2O and Eu（MEP）3Phen showed that the Eu（III） ion could be sensitized efficiently by the ligand to some extent, in partitular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the n-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.展开更多
A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA )2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare ear...A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA )2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare earth complexes in the SiR matrix were investigated. As for the cured rubber, it is found that its fluorescent intensity is relatively low compared with that of uncured rubber. Low temperature is beneficial to dispersion of Eu(TTA )2(phen)(MA) homogeneously. When the amount of rare earth complexes is low, the fluorescent intensity of composites prepared by mechanical blending method above melting point of Eu(TTA )2(phen)(MA) is much higher than that of composites prepared below melting point.展开更多
Series of doped rare earth compiexes-EuxGd(1-x) (CA)3·nH2O (CA = citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth comp...Series of doped rare earth compiexes-EuxGd(1-x) (CA)3·nH2O (CA = citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x) (CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.展开更多
Aniline oligomer composite materials using heteropolyacid H4SiW12O40 as dopant was synthesized, and the effect of the doping concentration on the photoluminescence and surface photovoltaic properties were investigated.
Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and...Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.展开更多
Two new 1-naphthoate-based Pb（Ⅱ） complexes, [Pb（phen）（NA）2]n 1 and [Pb（bpp）（NA）2]n 2 （NA = 1-naphthoate, phen = 1,10-phenanthroline, and bpp = 1,3-bi（4-pyri- dyl）propane）, were hydrothermally synthesize...Two new 1-naphthoate-based Pb（Ⅱ） complexes, [Pb（phen）（NA）2]n 1 and [Pb（bpp）（NA）2]n 2 （NA = 1-naphthoate, phen = 1,10-phenanthroline, and bpp = 1,3-bi（4-pyri- dyl）propane）, were hydrothermally synthesized and structurally characterized. 1 is of monoclinic system, space group C2/c with a = 28.114（3）, b = 10.9601（10）, c = 8.6843（8） , β = 93.3760（10）°, V = 2671.3（4） 3, Dc = 1.814 g/cm3, Mr = 729.73, Z = 4, F（000） = 1416, μ = 6.360 mm-1, the final R = 0.0346 and wR = 0.0948 for 2184 observed reflections with I 〉 2σ（I）. Complex 2 crystallizes in monoclinic, space group C2/c with a = 26.491（2）, b = 8.7773（6）, c = 27.893（2） , β = 113.3020（10）°, V = 5956.8（8）3, Dc = 1.668 g/cm3, Mr = 747.78, Z = 8, F（000） = 2928, μ = 5.706 mm-1, the final R = 0.0211 and wR = 0.0493 for 3677 observed reflections with I 〉 2σ（I）. Both complexes present one-dimensional （1-D） zigzag chains extended by anionic NA linkers for 1 and bridged by neutral bpp connectors for 2, which are further aggregated into 2-D supramolecular networks by interchain π···π stacking interactions. In addition, the two solid-state complexes exhibit different strong emissions at room temperature, suggesting their potential applications as fluorescence materials.展开更多
A preliminary study on a novel free base porphyrin dimer and a zinc prophyrin dimer by comparing their fluorescence properties with those of the corresponding monomers is presented. The fluorescence intensity of the f...A preliminary study on a novel free base porphyrin dimer and a zinc prophyrin dimer by comparing their fluorescence properties with those of the corresponding monomers is presented. The fluorescence intensity of the free base dimer is five times higher than that of the monomer, but the fluorescence intensity of the zinc porphyrin dimer is nearly similar to that of the zinc porphyrin monomer. The emission spectra show that energy transfer occurs between the two units.展开更多
Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally ch...Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26（6）° in 1·H2O·HCl, while co-planar （0.00（7）°） in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl, C-H…Cl, C-H…O and π-π supramolecular interactions. The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.展开更多
Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,...Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.展开更多
Red phosphors Y2O3:Eu were synthesized via molten salt synthesis method with the eutectic mixtures of KNO3-NaNO3 or KCl-NaCl as the fluxes. The as-prepared samples were investigated by means of X-ray powder diffractio...Red phosphors Y2O3:Eu were synthesized via molten salt synthesis method with the eutectic mixtures of KNO3-NaNO3 or KCl-NaCl as the fluxes. The as-prepared samples were investigated by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The results showed that as-synthesized phosphors had good cubic crystallinity and the effect of annealing temperature on crystallinity was significant. Furthermore, different special morphologies of products were ob...展开更多
Optical absorption and fluorescence spectra of Sm3＋-doped zincfluorophosphate glasses with molar composition of 44P2O5＋17K20＋9Al2O3＋（30-χ）ZnF2＋χSm2O3 （χ=0.01 mol.%, 0.05 mol.%, 0.1 mol.%, 0.5 mol.%, 1.0 mol...Optical absorption and fluorescence spectra of Sm3＋-doped zincfluorophosphate glasses with molar composition of 44P2O5＋17K20＋9Al2O3＋（30-χ）ZnF2＋χSm2O3 （χ=0.01 mol.%, 0.05 mol.%, 0.1 mol.%, 0.5 mol.%, 1.0 mol.%, 2.0 and 3.0 mol.%） referred as PKAZFSm were prepared by melt quenching technique and were characterized through Raman, absorption, emission and decay curve analysis. From the absorption spectra, Judd-Ofelt intensity parameters were determined and were used to predict radiative properties such as transition probabilities （AR, radiative lifetimes （τR）, branching ratios （βR）, effective bandwidths （△λeff） and stimulated emission cross-section （σ（λp）） for the excited 4G5/2 luminescent level. The decay curve for the 4G5/2 level was single exponential for lower concentration and became non-exponential for higher concentrations. The non-exponential nature of the decay curves of the 4G5/2 level increased with increase in Sm3＋ ions concentration accompanied by decrease in lifetime due to energy transfer processes among the Sm3＋ ions. The non-exponential decay curves was well fitted to the generalized Inokuti-Hirayama model for S=6, indicating that the energy transfer among optically active ions was of dipole-dipole interaction. The cross-relaxation mechanism responsible for the quenching of lifetimes and the effect of variation of concentration on the spectroscopic properties were also discussed.展开更多
A novel copolymer with fluorescence properties in mesoporous silica SBA-15 was prepared via a combination of surface-initiated reversible addition-fragmentation chain transfer（RAFT） polymerization and ＂click＂ chem...A novel copolymer with fluorescence properties in mesoporous silica SBA-15 was prepared via a combination of surface-initiated reversible addition-fragmentation chain transfer（RAFT） polymerization and ＂click＂ chemistry.A sufficient amount of peroxide groups were introduced into mesoporous silica SBA-15 channel pores and were further used to initiate the RAFT polymerization of styrene and 4-vinylbenzyl azide,resulting in SBA-15 supported polystyrene-co-poly（4-vinylbenzyl azide） copolymer（PS-co-PVBA/SBA-15） hybrid material.The samples were characterized by Fourier transform infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM）,thermogravimetry analysis（TGA）,N_2 adsorption-desorption isotherms and X-ray diffraction（XRD）,respectively.The results show that the styrene and 4-vinylbenzyl azide had copolymerized inside mesoporous silica SBA-15.Subsequently,Npropargyl-carbazole（PC） was connected to PS-co-PVBA/SBA-15 hybrid material via ＂click＂ reaction,resulting in PS-co-PVBC/SBA-15 with carbazole side groups hybrid material.The fluorescence spectrum is dominated by a broad band from 350 nm to 400 nm in narrow region and the maximum peak is 362 nm,indicating the characteristic absorption of the carbazole group of PS-co-PVBC/SBA-15 hybrid material.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42130513 and 41625014)the National Key Research and Development Program of China(Grant No.2019YFA0606801)。
文摘To understand the aerosol characteristics in a regional background environment,fine-particle(PM_(2.5),n=228)samples were collected over a one-year period at the Shangdianzi(SDZ)station,which is a Global Atmospheric Watch regional background station in North China.The chemical and optical characteristics of PM_(2.5)were analyzed,including organic carbon,elemental carbon,water-soluble organic carbon,water-soluble inorganic ions,and fluorescent components of watersoluble organic matter.The source factors of major aerosol components are apportioned,and the sources of the fluorescent chromophores are further analyzed.The major chemical components of PM_(2.5)at SDZ were NO_(3)^(-),organic matter,SO_(4)^(2-),and NH_(4)^(+).Annually,water-soluble organic carbon contributed 48%±15%to the total organic carbon.Secondary formation(52%)and fossil fuel combustion(63%)are the largest sources of water-soluble organic matter and water-insoluble organic matter,respectively.In addition,three humic-like and one protein-like matter were identified via parallel factor analysis for excitation–emission matrices.The fluorescence intensities of the components were highest in winter and lowest in summer,indicating the main impact of burning sources.This study contributes to understanding the chemical and optical characteristics of ambient aerosols in the background atmosphere.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 50271038）the Key Research Project Foundation of Shaanxi Normal University of China （No. 200403） Specialized Research Fund for the Doctoral Program of Higher Education of China （No. 20050698017）.
文摘A novel materials design procedure based on the co-doping of metal nanoparticle and azo dye compound （MNPADC） is developed to improve the properties of functional molecules. The synthesized materials were characterized by transmission electron micrograph （TEM）, ultraviolet-visible absorption spectra （UV-Vis） and fluorescence spectra （FS）. It was found that the fluorescence intensity of methyl orange （MO） was enhanced by 5 times in the aqueous composite system doped with silver nanoparticles whereas it was reduced by 15% and 20% in composite films with co-mixing and coating structures, respectively. The results indicate that the properties of functional molecules can be greatly improved in composite film with supra molecular structure and that the procedure presented here is effective.
文摘The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identified by elemental analyses. UV and IR of the complexeshave been investigated. The UV spectra indicated that the complexes' ultraviolet absorption weremainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are differentfrom those of free ligands. The fluorescence properties of them were investigated by usingluminescence spectroscopy, the results showed that only three complexes appear as betterluminescence, they were Eu-benzoic acid, Eu-m-phthalic acid and Eu-phthalic acid, while the othersexhibited the ligands' wideband emission.
文摘The enhancement effects of Y ( Ⅲ) ions on the fluorescence of Ce ( Ⅲ) in Ce ( Ⅲ)-Y ( Ⅲ)-PMMA (polymethylmethacrylate ) or Ce ( Ⅲ)-Y ( Ⅲ)-PVC (polyvinyl chloride ) complex systems were observed. The influence of Y ( Ⅲ) ions on the emission spectra of PMMA ligands in PMMA-Y ( Ⅲ) and the fluorescent enhance- ment of Y( Ⅲ) on Ce( Ⅲ) emission in PMMA-Ce-Y by Y( Ⅲ) ion were studied. It was also of interest to note that when Y ( Ⅲ) ions were added into PMMA and into bpy(bipyridine ) , respectively , the emission spectrum of PMMA ligands was split into fine structure bands by Y ( Ⅲ) , and the fluorescence intensities of bpy ligands in bpy-Y ( Ⅲ) complexes were considerably increased.
基金Supported by the National Natural Science Foundation of China (20761002)the Natural Science Foundation of Guangxi Province (0832080)the Innovation Project of Guangxi Graduate Education (2008106080817M366)
文摘A novel compound 4,8,10-trimethyl-2-（3,5-dimethylpyrazol）-pyrido-[2＇,3＇：3,4]-py-razol-[1,5-5-a]-pyrimidine（C17H18N6） has been synthesized from 2,6-dichloro-4-methylnico-tino-nitrile,hydrazine and acetylacetone by substitution and cyclolization.The structure was charac-terized by elemental analysis,1H NMR and IR,and single-crystal structure was determined by X-ray diffraction analysis.The compound crystallizes in the monoclinic system,space group P21/c with a = 8.0338（9）,b = 28.618（3）,c = 7.2688（8）,β = 111.051（2）o,V = 1559.6（3） 3,Z = 4,Dc = 1.305 g/cm3,μ = 0.083 mm-1,Mr = 306.37,F（000） = 648,S = 0.971,the final R = 0.0795 and wR = 0.1746 for 1457 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The results demonstrate that the pyridine,pyrazole and pyrimidine rings are nearly coplanar,which is evident from the dihedral angles among the four rings in the range of 0.13～4.15o.The face-to-face π-π stacking interactions among pyridine,pyrazol and pyrimidine rings result in a supramolecular crystal,in which they seem to be effective in stabilizing the structure.Meanwhile,the fluorescence properties of the title compound were discussed,which showed very strong fluorescence.The calculated results（selected bond lengths,bond angles and torsion angles） are all typical and agree well with the experimental results,which demonstrates that B3LYP/6-31＋G＊ is suitable for the title compound.
基金Supported by the National Natural Science Foundation of China for Young Scholars(No.21201087)Natural Science Foundation of Jiangsu Province(No.BK20131244)+1 种基金Jiangsu Overseas Research & Training Program for University Prominent Young & Middle-aged Teachers and Presidents,a start-up grant from Jiangsu University of Science and Technology,and Jiangsu Innovation Program for Graduate Student(No.KYZZ15-0300)Innovation Program for Graduate Student from Jiangsu University of Science and Technology,China
文摘Two metal-organic coordination complexes, [Zn（2,6-ndc）（1,2-bix）]n（1） and [Zn（2,6-ndc）（1,3-bix）]n（2）（2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis（imidazole-1-ylmethyl）-benzene and 1,3-bix = 1,3-bis（imidazole-1-ylmethyl）-benzene） have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions（π-π packing interactions） only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365（λ（ex） = 329 nm） and 367 nm（λex = 344 nm）, respectively.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11404048,61205154 and 11375034the Fundamental Research Funds for the Central Universities under Grant Nos 3132015233,3132013104,3132014337,3132015144 and3132015152+1 种基金the State Key Laboratory of Fine Chemicals(KF1409)the Program for Liaoning Excellent Talents in University under Grant No LJQ2014051
文摘The two-photon fluorescence properties and ultrafast responses of a hyperbranched polyyne （hb-DPP-J2） with triphenylamine as the central core, Diketo-Pyrrolo-Pyrrole as the connecting unit and electron acceptor are studied. The polymer has a D-π-A-π-D conjugated structure along the extended polyyne w-bridge systems, and the effective condugated unit repeats itself in the whole hyperbranehed polymer chain. The polymer exhibits a large two-photon absorption cross section and high fluorescence quantum yields. The ultrafast dynamic results give a deep understanding of the excited energy transfer processes under excitation, and reveal a long relaxation lifetime of the intramolecular charge transfer （ICT） state.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51025210,51102156 and 51272131the Young and Middle-Aged Scientists Research Awards Fund of Shandong Province under Grant No BS2011CL024
文摘We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluorescence lifetime and polarized emission cross sections in the visible range are measured and calculated in a temperature range from 77K to 300 K, and the variations of the fluorescence lifetime and spectra are discovered. The reasons for these changes are explained accordingly. The output wavelength of the 720nm laser is first reported on the laser performance by using a fiber-coupled laser diode at the wavelength of 442nm as the pump source, and the maximum cw output power is about 303roW.
基金supported by China Postdoctoral Science Foundation (20080431027)the Postdoctoral Science Foundation of Central South University (50573019)
文摘A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aPhen with 1,10-Phenanthroline （Phen） were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ^1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis （TG-DTA）. The investigation of fluorescence properties of the complexes Eu（MEP）3·2H2O and Eu（MEP）3Phen showed that the Eu（III） ion could be sensitized efficiently by the ligand to some extent, in partitular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the n-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.
基金Project supported by the National Natural Science Foundation of China and the China Energy Conservation Investment Corporation (50173004 and 50503002)the Beijing New Star Project (2003A11)+1 种基金the National High-Tech Research Developing Foundation ("863", 2003AA324030) Beijing Municipal Commission of Education (JD100100403)
文摘A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA )2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare earth complexes in the SiR matrix were investigated. As for the cured rubber, it is found that its fluorescent intensity is relatively low compared with that of uncured rubber. Low temperature is beneficial to dispersion of Eu(TTA )2(phen)(MA) homogeneously. When the amount of rare earth complexes is low, the fluorescent intensity of composites prepared by mechanical blending method above melting point of Eu(TTA )2(phen)(MA) is much higher than that of composites prepared below melting point.
基金Project supported by the National Natural Science Foundation of China and the China Energy Conservation Investment Corporation (50173004 and 50503002)the Beijing New Star Project (2003A11)+1 种基金the National High-Tech Research Developing Foundation (863. 2003AA324030) Beijing Municipal Commission of Education (JD100100403)
文摘Series of doped rare earth compiexes-EuxGd(1-x) (CA)3·nH2O (CA = citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x) (CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.
基金We gratefully acknowledge the support of the National Natural Science Foundation of China (29671004).
文摘Aniline oligomer composite materials using heteropolyacid H4SiW12O40 as dopant was synthesized, and the effect of the doping concentration on the photoluminescence and surface photovoltaic properties were investigated.
基金Project(20761002) supported by the National Natural Science Foundation of China
文摘Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.
基金NNSFC (Grants 21171129 and 21173157)Tianjin Educational Committee (2006ZD07)
文摘Two new 1-naphthoate-based Pb（Ⅱ） complexes, [Pb（phen）（NA）2]n 1 and [Pb（bpp）（NA）2]n 2 （NA = 1-naphthoate, phen = 1,10-phenanthroline, and bpp = 1,3-bi（4-pyri- dyl）propane）, were hydrothermally synthesized and structurally characterized. 1 is of monoclinic system, space group C2/c with a = 28.114（3）, b = 10.9601（10）, c = 8.6843（8） , β = 93.3760（10）°, V = 2671.3（4） 3, Dc = 1.814 g/cm3, Mr = 729.73, Z = 4, F（000） = 1416, μ = 6.360 mm-1, the final R = 0.0346 and wR = 0.0948 for 2184 observed reflections with I 〉 2σ（I）. Complex 2 crystallizes in monoclinic, space group C2/c with a = 26.491（2）, b = 8.7773（6）, c = 27.893（2） , β = 113.3020（10）°, V = 5956.8（8）3, Dc = 1.668 g/cm3, Mr = 747.78, Z = 8, F（000） = 2928, μ = 5.706 mm-1, the final R = 0.0211 and wR = 0.0493 for 3677 observed reflections with I 〉 2σ（I）. Both complexes present one-dimensional （1-D） zigzag chains extended by anionic NA linkers for 1 and bridged by neutral bpp connectors for 2, which are further aggregated into 2-D supramolecular networks by interchain π···π stacking interactions. In addition, the two solid-state complexes exhibit different strong emissions at room temperature, suggesting their potential applications as fluorescence materials.
基金Supported by the National Natural Science Foundation of China(No. 20071014).
文摘A preliminary study on a novel free base porphyrin dimer and a zinc prophyrin dimer by comparing their fluorescence properties with those of the corresponding monomers is presented. The fluorescence intensity of the free base dimer is five times higher than that of the monomer, but the fluorescence intensity of the zinc porphyrin dimer is nearly similar to that of the zinc porphyrin monomer. The emission spectra show that energy transfer occurs between the two units.
基金Supported from the Guangdong Provincial Laboratory of Green Chemical Technology (20040012)
文摘Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis（1,2,4-triazol-1-ylmethyl）biphenylene 1 and 4,4-bis（3,5-dimethyl-1,2,4-triazol-1-ylmethyl）biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26（6）° in 1·H2O·HCl, while co-planar （0.00（7）°） in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H…O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H…Cl, C-H…Cl, C-H…O and π-π supramolecular interactions. The hydrogen bonds of O-H…Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H…O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.
文摘Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.
基金Project supported by the Fundamental Research Funds for the Central Universities (CUG090108)
文摘Red phosphors Y2O3:Eu were synthesized via molten salt synthesis method with the eutectic mixtures of KNO3-NaNO3 or KCl-NaCl as the fluxes. The as-prepared samples were investigated by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The results showed that as-synthesized phosphors had good cubic crystallinity and the effect of annealing temperature on crystallinity was significant. Furthermore, different special morphologies of products were ob...
基金supported by Department of Atomic Energy-Board of Research in Nuclear Sciences(DAE-BRNS)government of India(2009/34/36/BRNS/3174)
文摘Optical absorption and fluorescence spectra of Sm3＋-doped zincfluorophosphate glasses with molar composition of 44P2O5＋17K20＋9Al2O3＋（30-χ）ZnF2＋χSm2O3 （χ=0.01 mol.%, 0.05 mol.%, 0.1 mol.%, 0.5 mol.%, 1.0 mol.%, 2.0 and 3.0 mol.%） referred as PKAZFSm were prepared by melt quenching technique and were characterized through Raman, absorption, emission and decay curve analysis. From the absorption spectra, Judd-Ofelt intensity parameters were determined and were used to predict radiative properties such as transition probabilities （AR, radiative lifetimes （τR）, branching ratios （βR）, effective bandwidths （△λeff） and stimulated emission cross-section （σ（λp）） for the excited 4G5/2 luminescent level. The decay curve for the 4G5/2 level was single exponential for lower concentration and became non-exponential for higher concentrations. The non-exponential nature of the decay curves of the 4G5/2 level increased with increase in Sm3＋ ions concentration accompanied by decrease in lifetime due to energy transfer processes among the Sm3＋ ions. The non-exponential decay curves was well fitted to the generalized Inokuti-Hirayama model for S=6, indicating that the energy transfer among optically active ions was of dipole-dipole interaction. The cross-relaxation mechanism responsible for the quenching of lifetimes and the effect of variation of concentration on the spectroscopic properties were also discussed.
基金supported by the National Natural Science Foundation of China(No.21203085)Promotive Research Fund for Young and Middle-aged Scientists of Shandong Province in China(doctor fund,Nos.BS2011CL011,BS2011CL012 and BS2012CL009)
文摘A novel copolymer with fluorescence properties in mesoporous silica SBA-15 was prepared via a combination of surface-initiated reversible addition-fragmentation chain transfer（RAFT） polymerization and ＂click＂ chemistry.A sufficient amount of peroxide groups were introduced into mesoporous silica SBA-15 channel pores and were further used to initiate the RAFT polymerization of styrene and 4-vinylbenzyl azide,resulting in SBA-15 supported polystyrene-co-poly（4-vinylbenzyl azide） copolymer（PS-co-PVBA/SBA-15） hybrid material.The samples were characterized by Fourier transform infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM）,thermogravimetry analysis（TGA）,N_2 adsorption-desorption isotherms and X-ray diffraction（XRD）,respectively.The results show that the styrene and 4-vinylbenzyl azide had copolymerized inside mesoporous silica SBA-15.Subsequently,Npropargyl-carbazole（PC） was connected to PS-co-PVBA/SBA-15 hybrid material via ＂click＂ reaction,resulting in PS-co-PVBC/SBA-15 with carbazole side groups hybrid material.The fluorescence spectrum is dominated by a broad band from 350 nm to 400 nm in narrow region and the maximum peak is 362 nm,indicating the characteristic absorption of the carbazole group of PS-co-PVBC/SBA-15 hybrid material.
