分子内桥连有机钴配合物的合成及热稳定性研究

The intramolecularly bridged alkyl cobaltic complexes are one of important coenzyme B₁₂ model coplexes. In this paper, study on the thermolytic reaction of aqua(3-bromopropyl)cobaloximes in solution revealed that a new intramolecularly bridged alkyl cobaloximes complex was formed and the reaction is influenced by tempertature and solvent. Adding cyclodxtrin has no obvious effect to the rate of the reaction, but various products with different axial bases were obtained. The intramolecularly bridged alkyl cobaloxime complex (bromo(O-trimethylene-dimethy- lglyoxime)(dimethylglyoximate)cobalt(Ⅲ)) was characterized by EA and ESI-MS. Thermogravimetric analysis of this complex found that a carbon radical that from homolysis of the Co-C bond is retained in the proximity of Co^Ⅱ- complex, which is very similar to the behavior of coenzyme B₁₂.     

新型配合物Mn2Hg4(SCN)12的合成与晶体结构分析

A new inorganic coordination compound Mn₂Hg₄(SCN)₁₂ was synthesized. The grown crystals were characterized by elemental analysis, infrared spectroscopic analysis and powder crystal X-ray diffraction in detail. The crystal structure of Mn₂Hg₄(SCN)₁₂ was determined by single-crystal X-ray diffraction. It belongs to monoclinic system, P2₁/c space group. The cell dimensions are: a=1.171 6 nm, b=1.431 05 nm, c=2.105 1 nm, β=100.738°, and Z=4. In the structure of it, half of Mn²⁺ cations have five-coordinate number, and other half of Mn²⁺ cations have six-coordinate number; 3/4 of Hg²⁺ cations are coordinated by four SCN^-, 1/4 of Hg²⁺ cations are coordinated by three SCN^- and one NCS^-, all the coordination geometry of Hg²⁺ show slightly distorted tetrahedrons. CCDC: 244939.     

Eu3+掺杂SiO2-B2O3-NaF玻璃的制备及发光性质

The Eu-doped SiO₂-B₂O₃-NaF glass was prepared by sol-gel process, using tetraethoxy Silicane, boric acid and sodium fluoride as starting materials, 0.10 mol·L^-1 EuCl₃ solution as the dopant. The luminescent properties of Eu³⁺ doped SiO₂-B₂O₃-NaF phosphors were investigated. The phosphors showed prominent luminescence in pink, the strong emission of Eu³⁺ comes from electronic transition of ⁵D₀- ⁷F₁（591 nm）and ⁵D₀- ⁷F₂（615 nm）,which derived from two transition modes of magnetic-dipole and electric-dipole .The peak intensity of 591nm in SiO₂-B₂O₃-NaF matrix is much stronger than it in the other matrixes, it means that SiO₂-B₂O₃-NaF has sensitization on the transition of ⁵D₀- ⁷F₁ (Eu³⁺). If there are broad bonds in the range of 275～380 nm in the excitation spectrum of Eu³⁺ -doped SiO₂-B₂O₃-NaF glass, the emission peak intensity should be intensified. It is because the electron migration CT band of O^2--Eu³⁺. For all Eu³⁺ concentrations used, the investigation found that when the mass of fraction got to 29.19×10^-3, the luminescence intensity reached the summit. And there is a phenomenon of concentration quenching. Investigation with the same concentration of Eu³⁺ at different annealed temperature, we found that the sample annealed at 400 ℃, the luminescence intensity achieved its maximum value, and Eu³⁺ in this matrix had a phenomenon of temperature quenching. The structural characterization of these luminescent materials was carried by used XRD and TEM. The result showed that the phosphor was in amorphous phase.     

掺镍型层状LixNiyMn1-yO2正极材料的合成与电性能研究

A kind of cathode material of layered Li_xNi_yMn_1-yO₂ characterized with the O2 type has been synthesized by a simple method. Its precursor Na_xNi_yMn_1-yO₂ has been prepared from manganese dioxide， nickel hydroxide and sodium carbonate at high temperature in air and quickly cooled in cold water， then it has been exchanged by the melted LiNO₃ at 300～400℃ in air. The effects of calcine-temperature for the precursors and its compositions (the content of Na and Ni) on the electrochemical properties of the material Li_xNi_yMn_1-yO₂ have been investingated by XRD and electrochemical tests. The results show that the sample Li_0.7Ni_0.3Mn_0.7O₂， has the best electrochemical properties which shows only one charge-discharge potential stage of 2.8～3.0V and has a high specific capacity over 180mAh·g^-1 cycled between 2.0～4.20V. A significant structure transformation to the spinal-type phase has not been found in the charge-discharge cycling and the discharge specific capacity around 165mAh·g^-1 has re-mained after the 20th cyclings for the material.     

CexPr1-xO2-δ复合氧化物的XRD和Raman表征

A series of Ce_xPr_1-xO_2-δ mixed oxides were synthesized by sol-gel method and characterized by Raman and XRD techniques. When x value was changed from 1.0 to 0.5, only a cubic phase CeO₂ was observed. The samples were very well crystallized on decreasing x from 0.50 to 0.99. For Ce_xPr_1-xO_2-δ samples 465 cm^-1 and 1 150 cm^-1 Raman peaks are attributed to the Raman active F_2g mode of CeO₂. The broad peak at about 570 cm^-1 in the region of 0.3 ≤x≤ 0.99 can be linked to lattice defects resulting in oxygen vacancies. The new band at about 195 cm^-1 may be attributed to the asymmetric vibration caused by the formation of oxygen vacancies. Calcination temperatures had great effect on the peak intensity for CeO₂ but less effect on Ce_0.8Pr_0.2O_2-δ in Raman spectra. It might be due to the transformation of the colors for the mixed oxides, the insertion of Pr atom into the ceria lattice could enhance the sintering resistance and thermal stability of the mixed oxides.     

BaO-Al2O3-B2O3系密封玻璃的结构与性质

The BaO-Al₂O₃-B₂O₃ glasses manufactured for solid oxide fuel cell(SOFC) sealing were studied. The effect of different n_BaO/n_B2O3 on crystal, thermal properties, density and infrared spectra of this system has been discussed. The results show that the trends of crystallization, glass transformation temperature, dilatometric softening temperature and density increase with n_BaO/n_B2O3 values. But a typical property deviation occurs when n_BaO/n_B2O3 is 0.875, and its coefficient of thermal expansion has the maximum at this point. The changes of properties can attribute to the conversion of boron from tetrahedral coordination to trigonal, breakage of the local glass network and interaction between the network modifiers. These can be proved by infrared spectra of glasses. Thermal properties of some studied samples are suitable for the sealing of SOFC using Sm doped ceria electrolyte and operating at 400～600 ℃.     

球形La2O3∶Eu纳米晶的制备及其发光特性

The spheric La₂O₃∶Eu nanocrystals were prepared using NH₃·H₂O-NH₄HCO₃ mixture as precipitant. The material was characterized by FTIR, XRD and TEM techniques. The luminescence properties of Eu³⁺ in spheric La₂O₃ were measured by three dimension spectra, emission and excitation spectra. The results indicate that the La₂O₃∶Eu nanocrystals are in hexagonal phase by annealing at 800 ℃, the crystal size is about 30 nm. The maximum emission and excitation wavelength were determined by three dimensional spectroscopy to be at 591 nm and 394 nm, respectively. In emission spectrum the band at 591 nm and 612 nm are corresponding to ⁵D₀-⁷F₁ and ⁵D₀-⁷F₂ transition of Eu³⁺ ions. With increasing in annealing temperature the differences of intensity of the two transitions are increased. This phenomenon shows that the luminescence intensity of La₂O₃∶Eu nanocrystals can be tuned by changing annealing temperature.     

不同温度下VUV光激发的Pr3+离子的发光性质

The luminescent properties of Pr³⁺-doped LaB₃O₆, SrAl₁₂O₁₉, SrB₄O₇ and NaYF₄ in the vaccum ultraviol-et (VUV) range at different temperatures were investigated under the excitation of high-energetic synchrotron radiation. For Pr³⁺ ions in LaB₃O₆, SrAl₁₂O₁₉ and SrB₄O₇, only the parity-forbidden ¹S₀→4f² transitions were observ-ed in the emission spectra at relatively low temperature; but the parity-allowed 4f5d→4f² transitions appeared simultaneously when the temperature was high enough. And the intensity of broad 4f5d→4f² emission increased relative to the intensity of ¹S₀→4f² emissions with increasing temperature. Then the thermal equilibrium model of energy levels was employed to the lowest 4f5d state and ¹S₀ state of Pr³⁺ in the three hosts. The calculated curves were in good agreement with the experimental values, indicating the occurrence of the thermal excitation from ¹S₀ state to 4f5d states at high temperatures when the lowest 4f5d state lies higher than ¹S₀ state and the photon energy is high enough.     

LiNi1-xMxVO4的红外光谱和拉曼光谱研究

The vanadates of LiNi_1-xM_xVO₄(M=Fe,Co,Ni) containing VO₄ tetrahedrons were synthesized by soft chemical method through a new mild liquid route. The samples sintered at 450℃ for 3h and at 650℃ for 3h are named for LT-LiNiVO₄ and for MT-LiNi_1-xM_xVO₄ respectively. All of the products were measured by X-ray diffraction, IR and Raman spectra respectively. In comparison with IR spectra of V₂O₅ and NiO, the LT-LiNiVO₄ has a strong and broad IR absorption band of VO₄ tetrahedrons located at 600～850cm^-1 with three small splitting peaks corresponding to the asymmetry stretching vibrations of V-O bonds. The results of IR and Raman spectra for MT-LiNi_1-xM_xVO₄ show that the cations of Ni²⁺, Co²⁺, Fe²⁺ have the influences on the frequency shifts of the V-O vibrations.     

CrOx/ SBA-15介孔催化剂上丙烷在二氧化碳气氛中脱氢反应的研究

The structure and catalytic properties based on Chromium Oxide supported on mesoporous SBA-15 for oxidative dehydrogenation of propane by CO₂ have been studied by using X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and propane pulsing experiments in the absence of gas-phase O₂. It has been shown that propane conversion and propene yield increase with Cr loadings. The propane conversion and propene yield on CrO_x(Cr: 10wt%)/SBA-15 catalyst for oxidative dehydrogenation of propane by CO₂ at 550 ℃ reach 24.8% and 21.8%, respectively .The results of ESR, UV-Vis DRS and propane pulsing experiments indicate that Cr^Ⅲ in the CrO_x/ SBA-15 catalyst is the main active species in oxidative dehydrogenation of propane by CO₂ and Cr^Ⅵ, Cr^Ⅴ is inactive in dehydrogenation.     

纳米三氧化二钴低温热容和热力学性质的研究

The isobaric molar heat capacities of nano Co₂O₃ were determined by an adiabatic calorimeter in the temper-ature range from 78 to 350K. No phase transition takes place in this temperature range. The relationship of C_p，m with respect to thermodynamic temperature T was established as C_p，m=-11.998X³-9.6431X²+63.478X+81.291(J·K^-1·mol^-1) ， where X=(T-201.903)/121.535， the correlation coefficient R₂=0.9996. Ac-cording to this relationship and the relationships between thermodynamic functions， the thermodynamic functions of nano Co₂O₃ relative to the standard temperature of 298.15K were derived based on the measured heat capacity data. The average grain size of the studied nano Co₂O₃ sample was determined to be 12nm by TEM.     

ZrWO4F2的前驱物法合成和表征

Zirconium tungsten oxyfluoride, ZrWO₄F₂, was firstly synthesized with the precursor route. The composition of the compound was determined by combining the results of ICP and XPS. The indexed powder X-ray diffraction pattern of this compound indicates that it is a pure phase, orthorhombic crystal system, space group D₂²=P2₁22 and a=15.32(2)?,b=13.877(7)?,c=8.42(2)?.Combining the results of the DTA-TGA curves from room temperature to 700℃ and XRD patterns in different temperatures the mechanism was revealed during the solid precursor (1) been heated to 700℃. The zirconium tungsten oxyfluoride was considered to be a metastable com-pound. The ascertaining of annealing time and temperature is the key of handling.     

锌(Ⅱ)-氨基酸水杨醛席夫碱-α-氨基酸三元配合物的稳定性

The stability constants of binary complexes of Zn(Ⅱ)-α-amino acid and ternary complexes of Zn(Ⅱ)-N-Salicylideneaminio acid (ligand A)-α-amino acid(ligand B) at (25±0.1)℃ and in the presence of 0.1 mol·L^-1 KNO₃ have been determined by pH method. The α-amino acid(Aa) used were Glycine(Gly), L-Serine(Ser), L-Leucine(Leu), L-Proline(Pro) and L-Phenylalanine(Phe). It was found that the linear free energy relationship (LFER) exists nicely between the following parameter pairs logβ₁₀₂ and pK^B₂, logβ₁₁₁ and pK^B₂, and logβ₁₁₁ and pK^A₂. The ΔlgK was used to characterize the stability of ternary complexes related to the stability of parent binary complexes. The hydrophobic interaction between ligands in the ternary complexes was studied.     

合成大比表面γ-Mo2N的新方法

The production of high specific surface area γ-Mo₂N (up to 165 m²·g^-1, passivated) by temperature programmed reaction of MoO₃ with mixtures of N₂ and H₂ was reported. The synthetic condition of high surface area γ-Mo₂N (usually, S_BET>100 m²·g^-1) were quite difficult and the amount of starting material MoO₃ in each batch was much less than 0.5 gram. However, some synthetic conditions had been greatly improved in our experiments. The crystalline phase and specific surface area had been characterized by XRD and BET. The XRD gave some information for reaction mechanism.     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

RE(Et2dtc)3(phen)(RE=La，Pr，Nd，Sm)的恒容燃烧能测定(英)

Four ternary solid complexes were synthesized with sodium diethyldithiocarbamate (NaEt₂dtc)(b), 1,10-phenanthroline (o-phen) (c) and hydrated lanthanide chlorides in absolute ethanol by an improved reported method. The complexes were identified as the general formula of RE(Et₂dtc)₃(phen) (RE=La, Pr, Nd, Sm) by chemical and elemental analyses. IR spectra of the complexes showed that the RE³⁺ was coordinated with sulfur atoms of NaEt₂dtc and nitrogen atoms of o-phen. The constant-volume combustion energies of complexes, Δ_cU, were determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion, Δ_cH_m^?, and standard enthalpies of formation, Δ_fH_m^?, were calculated for these complexes, respectively.     

离子层气相反应法(ILGAR)制备CuInS2薄膜的研究

CuInS₂ thin films have been prepared by ion layer gas reaction (ILGAR) using C₂H₅OH as solvent, CuCl and InCl₃ as reagents and H₂S gas as sulfuration source. The effects of cationic concentrations and numbers of cycle on the properties of CuInS₂ film were investigated. The chemical composition, crystalline structure, surface topography, deposited rate, optical and electronic properties of the films were characterized by X-ray diffractrometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible spectrometry (UV-Vis) and Hall System. The results show that the crystalline of CuInS₂ thin films and the deposition rate have been improved with the increase of cationic concentration, while CuxS segregation phases appear with further increasing cationic concentration. The deposition rate is close to constant as cationic concentration is fixed. CuInS₂ thin film derived form lower cationic concentration is uniform, compact and good in adhesion to the substrates. The absorption coefficient of CuInS₂ thin films is larger than 10⁴ cm^-1, and the band gap E_g is in the range of 1.30～1.40 eV. The dark resisitivity of the thin film decreases from 50 to 10 Ω·cm and the carrier concentration ranges are over 10¹⁶ cm^-3.     

助熔剂法制备的LaMgAl11O19∶Eun+(n=2，3)的发光特性

LaMgAl₁₁O₁₉∶Euⁿ⁺(n=2,3) was synthesized by solid state reaction using H₃BO₃ as a flux at 1 400 ℃ for 4 hours. And their luminescent properties was investigated under UV and VUV excitation. Strong pure blue emission due to d-f transition of Eu²⁺ was observed in LaMgAl₁₁O₁₉∶Eu²⁺ both in 254 nm and 147 nm excitation. At the same time, red emission due to ⁵D₀ → ⁷F_J (J=0, 1, 2, 3, 4) transition of Eu³⁺ also observed in LaMgAl₁₁O₁₉∶Eu³⁺. The dependence of emission intensity of blue/red emission on Eu²⁺ / Eu³⁺-content was evaluated. The result indicated that the blue emission intensity was arrived optimum when Eu²⁺-content was 0.10 mol·mol^-1under both UV and VUV excitation while red emission intensity reached optimum when Eu³⁺-content was 0.125 mol·mol^-1 under UV excitation. This suggests that LaMgAl₁₁O₁₉∶Eu²⁺ phosphors could be potential blue phosphor for the application in PDP.     

纳米尖晶石LixMn2O4的制备与电化学性能表征

Nano-spinel Li_xMn₂O₄(0.6 ≤x≤ 1.0) was synthesized by two steps of coprecipitation and calcination. The influences of calcination temperature, time and Li/Mn ratio on the crystal structure and the particle size of Li_xMn₂O₄ were investigated. It was shown that the higher the calcination temperature, the more complete the crystal structure, and the larger the particle size. Moreover, the influence of calcination time on the crystal structure was insignificant when it was more than 3h at 700℃. With the increase of x in Li_xMn₂O₄ in the range of 0.6～1.0, the d111 and lattice parameter a increased first and then decreased. The electrochemical properties of nano-spinel LiMn₂O₄ using as cathode material of lithium-ion battery were studied. The low discharge capacity might be due to the irreversible capacity loss brought by the large surface area and lattice vacancies of the nano-spinel.     

一个新的双核锌配合物Zn2(dhaash)2(py)4的合成及晶体结构

The crystal of binuclear zinc complex Zn₂(dhaash)₂(py)₄ was obtained in DMF and pyridine, where H₂dhaash is 2,4-dihydroxy-5-acetylacetophenone-N-salicylhydrazone. It has been characterized by IR, UV, element analysis and X-ray single crystal diffraction. The crystallographic data were as follows: monoclinic system, space group P2₁/c, a=1.108 98(11) nm, b=1.640 84(16) nm, c=1.445 14(14) nm, β=108.617(2)°, Z=2, V=2.492 1(4) nm³, D_c=1.466 g·cm^-3, M_r=1 099.74, μ=1.031 mm^-1, F(000)=1 136 and the final R=0.044 8 and wR=0.105 8 for 4 143 observed reflections with I≥2σ(I), respectively. The X-ray crystal structure analysis revealed that, in the centrosymmetric binuclear complex molecule, two zinc(Ⅱ) centers are linked by two oxygen atoms (O(3) and O(3A)), respectively. Zn(1)…Zn(1A) distance is 0.314 81(6) nm, O(3)…O(3A) distance is 0.270 4(2) nm. Every zinc(Ⅱ) ion has an elongated octahedral coordination. For example, the two pyridine nitrogen atoms, one oxygen atom and one nitrogen atom from salicylhydrazone, one oxygen atom from 2,4-dihydroxy-5-acetylacetophenone in one dhaash^2- ligand and one oxygen atom from 2,4-dihydroxy-5-acetylacetophenone in another dhaash^2- ligand coordinated to zinc(Ⅱ) ion, respectively. Two zinc(Ⅱ) ions and all the 72 non-hydrogen atoms in the two dhaash^2- ligands are in the same plane. CCDC: 261929.