Preparation and Fluorescence Properties of Co-doped Nanocomposite Film Based on Supra Molecular Structure

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.

Crystal structure and fluorescence property of antofloxacin

Antofloxacin free base is prepared from antofloxacin hydrochloride by removing hydrogen chloride. Its crystal is obtained by slow evaporation of an acetonitrile-methanol mixed solution. Single-crystal X-ray diffraction reveals that the crystallography belongs to a triclinic PI space group with cell parameters： a = 0. 663 07（13） nm, b = 0. 898 39（18） nm, c = 1. 569 0（3） nm, α = 75.12（3）°,β = 87.92（3）°, γ = 77.57 （3）°. Antofloxacin shows no fluorescence in solution, but the crystalline state emits strong green light at 510 nm under the excitation of 360 nm, indicating a fluorescence enhancement induced by aggregation. It demonstrates that intermolecular packing and interaction in the crystal lead to the improved fluorescence quantum yield. These results provide important intbrmation for the further exploration of the structure-activity relationship of antofloxacin and the development of new drugs.

Effects of Y(Ⅲ) Ions on the Fluorescence Properties of Ce(Ⅲ) Ion and the Organic Ligands in the Complex

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.

Synthesis,fluorescence properties of Eu(Ⅲ) complexes with novel carbazole functionalized β-diketone ligand

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.

Syntheses, characteristics, and fluorescence properties of complexes of europium with benzoic acid and its derivatives

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.

Influence of Blending Temperature on Fluorescence Properties of Silicone Rubber Matrix Eu(TTA)_2(phen)(MA) Composites

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.

Synthesis,Fluorescence and Magnetic Properties of a New Europium(Ⅲ)Complex Eu(C14H9O3)2(C12H8N2)2(NO3)

A new europium(III)complex Eu(CHO)(CHN)(NO)has been synthesized with 2-benzoylbenzoic acid and 1,10-phenanthroline as ligands.Crystal data for the complex are as follows:monoclinic,space group P2/c,a=9.6733(6),b=22.9521(14),c=19.7701(12)?,β=94.9800(10)o,V=4372.8(5)?~3,D=1.557 g/cm~3,Z=4,μ(Mo Kα)=1.501 mm,F(000)=2064,the final R=0.0214 and w R=0.0510.The Eu(III)ion is coordinated by ten atoms to give a bicapped square antiprism coordination geometry.The complex shows two intense fluorescence emission bands arising from the transitions of Eu:~5D→~7F(594 nm)and ~5D→~7F(618 nm).In addition,its XT decreases from 1.29767 cm~3?mol?K at 300 K to 0.01531 cm~3?mol?K at 2 K.

Electrochemical properties of spinel LiMn_2O_4 and LiAl_(0.1)Mn_(1.9)O_(3.9)F_(0.1) synthesized by solid-state reaction

Two types of spinel cathode powders, LiMn2O4 and LiAl0.1Mn1.9O3.9F0.1, were synthesized by solid-state reaction, X-ray diffraction （XRD） patterns of the prepared samples were identified as the spinel structure with a space group of Fd 3^- m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. The LiAl0.1Mn1.9O3.9F0.1 sample showed a little lower initial capacity, but better cycling performance than the LiMn2O4 sample at both room temperature and an elevated temperature. The Vanderbilt method was used to test the electrochemical conductivity of the LiMn2O4 samples. The electrochemical impedance spectroscopy （EIS） method was employed to investigate the electrochemical properties of these spinel LiMn2O4 samples.

Fluorescence Quenching of a Novel Eu(Ⅲ) Coordination Compound for the Detection of Trace Amounts of Water： Synthesis, Structure and Photoluminescent Property

A novel luminescent coordination compound Eu（TTA）3（DEDAF）（1, TTA = 1,1,1-trifluoro-3-（2-thenoyl）acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren） has been synthesized and fully characterized by infrared spectrum, elemental analysis, UV-vis spectrum, etc. X-ray single-crystal diffraction analysis reveals that compound 1 shows a mononuclear structure with the europium atom in coordinating to one DAF and three TTA ligands. The mononuclear structure units are assembled into a 3-D polymer by hydrogen bonds and π-π interactions. Photoluminescent property of 1 was investigated in detail at room temperature. Complex 1 emits strong red luminescence. However, it could be quenched even by small amount of water. The fluorescence intensity at 614 nm decreases linearly with the water content increasing（vol% in acetonitrile） in the range of 0.025~0.2% under 278 nm excitation. Thermogravimetric analysis has also been studied, which demonstrates good thermal stability of 1.

Fluorescent Double Network Hydrogels with Ionic Responsiveness and High Mechanical Properties for Visual Detection

We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,while the ionic cross-linked hydrogel of terbium ions and sodium alginate serves as the second network.The double-network structure,the introduction of nanoparticles and the reversible ionic crosslinked interactions confer high mechanical properties to the hydrogel.Terbium ions are not only used as the ionic cross-linked points,but also used as green emitters to endow hydrogels with fluorescent properties.On the basis of the “antenna effect” of terbium ions and the ion exchange interaction,the fluorescence of the hydrogels can make selective responses to various ions(such as organic acid radical ions,transition metal ions) in aqueous solutions,which enables a convenient strategy for visual detection toward ions.Consequently,the fluorescent double network hydrogel fabricated in this study is promising for use in the field of visual sensor detection.

Synthesis, Crystal Structure, Fluorescence, Thermal Stability and Magnetic Properties of the Dinuclear Manganese(Ⅱ) Complex [Mn_2(L)_2(2,2'-bipy)_2(H_2O)_5]_2·3H_2O

A new dinuclear manganese complex [Mn2（L）2（2,2＇-bipy）2（H2O）512·3H2O has been synthesized with MnSO4·H2O, 2,2＇-bibenzoic acid （H2L） and 2,2＇-bipyridine（2,2＇-bipy） in the mixed solvent ethanol and water. It crystallizes in monoclinic, space group Pi with a = 9.9944（10）, b = 21.939（2）, c = 25.628（3） A, a = 108.429（3）, β = 100.613（4）, 7 = 102.821（3）°, V = 4997.9（9） A3, Dc= 1.355 g/cm^3, Z = 2, F（000） = 2108, GOOF = 1.074, the R= 0.0626 and wR= 0.1531. The structure of the complex contains two [Mn2（L）2（2,2＇-bipy）2] units, ten coordinated H2O molecules and three uncoordinated H2O molecules. The fluorescence, thermal stability and magnetic properties of the complex were investigated.

Crystal Structure,Fluorescence and Thermal Stability Properties of a Dinuclear Copper(Ⅱ) Complex[Cu_2(L)_2(phen)_2]-5H_2O(H_2L = Bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid)

A new dinuclear copper（II） complex [Cu2（L）2（phen）2]·5H2O （1） with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid （H2L） and 1,10-phenanthroline （phen） as ligands has been synthesized in the mixed solvents of ethanol and water. It crystallizes in the monoclinic space group P21/c, with a = 17.925（4）, b = 19.908（4）, c = 11.235（2） A, β = 97.65（3）°, V= 3973.4（14） A3, Dc = 1.552 g/cm^3, Z = 8, F（000） = 1910, the final GOOF = 1.056, R= 0.0519 and wR= 0.1293. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two copper ions are bridged by twoμ2-η1 ：η0-3-carboxylate groups of L^2- anions. The fluorescence and thermal stability properties of 1 were studied. The results show that 1 has an intense fluorescent emission at around 381 rim. The TG analysis shows that I is stable below 143 ℃.

Fluorescence Properties of Eu^(3+)/Gd^(3+)/Citric Acid Mixed Complexes Doping in Silicon Rubber Matrix

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.

Study on the Surface Photovoltage and Fluorescence Properties of N, N-Bis(4-aminopheny)-1, 4 quinonenediimine Doped with H_4SiW_(12)O_(40)

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.

Fluorescence Properties of Porphyrin Dimers Incorporating an Anhydride Linker

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.

Syntheses, Crystal Structures and Fluorescence Properties of Two Pb(Ⅱ) 1-Naphthoate Complexes

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.

VUV luminescence properties of Y_(0.95)Eu_(0.05)PO_4 phosphor derived by a modified solid-state route

A modified solid-state route was attempted to prepare Y0.95 Eu0.05PO4 PDP phosphor, involving milling a powdered mixture of YCl3, EuCl3, and （NH4）2HPO4 and calcining the milling-derived precursor. The thermal decomposition behavior of the milling-derived precursor was investigated by thermogravimetric analysis （TGA）. Phase compositions, morphologies, and luminescence properties of the prepared phosphor powder were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, and vacuum ultraviolet （VUV） emission spectra, respectively. The results indicated that the Y0.95Eu0.05PO4 phosphor powder obtained at a calcination temperature of 900℃ was xenotime-structured. The phosphor powder particles were uniform and spherical-shaped with a primary particle size of-200 um. In comparison with that derived by the conventional solid-state route, the phosphor powder prepared by the modified solid-state route exhibited a higher color purity, presenting a predominant emission peak at 619 nm under 147 um VUV excitation.

Solid-state synthesis and electrochemical properties of SmVO_4 cathode materials for low temperature SOFCs

A new cathode material fabricated by solid state reaction method was reported. The SmVO4 powder was obtained by firing the mixture of Sm2O3 and V2O5 powders in the temperature range of 700-1200 ℃. Its structure was identified by X-ray diffraction method and the electrochemical properties of SmVO4 as cathodes for solid oxide fuel cells (SOFCs) were investigated in single unit cell at the temperature ranged from 450-550 ℃. The results of the single fuel cell unit show that the maximum current densities are 641, 797, 688 mA·cm-2 and the maximum power output are 165, 268, 303 mW·cm-2 and the open circuit voltage are 1.04, 0.96, 0.92 V at 450, 500 and 550 ℃, respectively.

Synthesis,Crystal Structure,Fluorescence Properties and Geometrical Calculation of 4,8,10-Trimethyl-2-(3,5-dimethylpyrazol)-pyrido-[2',3':3,4]-pyrazol[1,5-a]-pyrimidin

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.

Effect of lithium content on the electrochemical properties of solid-state-synthesized spinel Li_xMn_2O_4

Lithium-substituted LixMn2O4 （x = 0.98, 1.03, 1.08） spinel samples were synthesized by solid-state reaction. X-ray diffraction （XRD） patterns show that the prepared samples have a spinel structure with a space group of Fd 3 m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. Li1.03Mn2O4 shows high capacity at both low and high current densities, while Lil.08Mn2O4shows good cycling performance but relatively low capacity when cycled at both room and elevated temperatures. A variety of electrochemical methods were employed to investigate the electrochemical properties of these series of spinel LixMn2O4.