Morphology-controllable synthesis and characterization of single-crystal molybdenum trioxide

Molybdenum trioxide nanobelts and prism-like particles with good crystallinity and high surface areas have been prepared by a facile hydrothermal method, and the morphology could be controlled by using different inorganic salts, such as KNO3, Ca(NO3)(2), La(NO3)(3), etc. The possible growth mechanism of molybdenum trioxide prism-like particles is discussed on the basis of the presence of HI and the modification of metal cations. The as-prepared nanomaterials are characterized by means of powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transformation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and ultraviolet and visible spectroscopy (UV-vis). TEM and HRTEM micrographs show that the molybdenum trioxide nanobelts and prism-like particles have a relatively high degree of crystallinity and uniformity. BET specific surface areas of the as-prepared molybdenum trioxide nanocrystals are 67-79 m(2)g(-1). XPS analysis indicates that the hexavalent molybdenum is predominant in the nanocrystals. UV-vis spectra reveal that the direct band gap energy of the annealed molybdenum trioxide prism-like particles shows a pronounced blue shift compared to that of bulk MoO3 powder.

Observation of a water-anion layer constructed from water tetramers and nitrate anions in the crystal host of a cobalt complex

A novel self-assembled layer consisting of water tetramers and nitrate anions has been observed in the [Co(1,10-phenanthroline)(2)(NO3)]center dot(NO)(3)center dot 4H(2)O complex. X-ray crystallography and FT-IR spectroscopy indicate that although the water tetramers exist in an energetically less stable uudd configuration, the anionic host environments may play an important role in the formation and stabilization of the water clusters.

Kinetics of cerium(IV) extraction with DEHEHP from HNO3-HF medium using a constant interfacial cell with laminar flow

Studies of the extraction kinetics of cerium(IV) into n-heptane solutions of di(2-ethylhexyl)-2-ethylhexyl phosphonate DEHEHP from HNO3-HF solutions have been carried out using a constant interfacial cell with laminar flow. The experimental hydrodynamic conditions were chosen so that the contribution of diffusion to the measured rate of reaction was minimized. The data were analyzed in terms of pseudo-first order constants. The effects of the stirring rate, specific interfacial area, and temperature on the extraction rate showed that the most probable reaction zone is in the aqueous homogeneous phase. The results were compared with those of the system without HF. It was concluded that the presence of HF decreases the extraction rate of cerium. The addition of HF increases the activation energy for the forward reaction from 21.2 to 55.3 kJ/mol and for the reverse process from 57.9 to 79.0 kJ/mol. According to the experimental data correlated as a function of the concentration of the relevant species involved in the extraction reaction, the corresponding rate equation was deduced as follows:-d[Ce]/dt = k[Ce] center dot B-0.62 center dot HF-0.58 center dot [NO3-](0.57)

Extraction of rare earths(III) from nitrate medium with di-(2-ethylhexyl) 2-ethylhexyl phosphonate and synergistic extraction combined with 1-phenyl-3-methyl-4-benzoy l-pyrazolone-5

The extraction of trivalent rare earths ( RE) from nitrate solutions with di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP, B) and synergistic extraction combined with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP, HA) were investigated. The extraction distribution ratios demonstrate a distinct "tetra effect," and Y lies between Tb and Dy when DEHEHP is used as a single extractant for RE. According to the corresponding separation factors (SF12) for adjacent pairs of rare earths, it could be concluded that DEHEHP could be employed for the separation of La from the other rare earths, and Y from light rare earths. The present work has also found that mixtures of HPMBP and DEHEHP have an evident synergistic effect for RE(III). Taking Y( III) as an example, a possible synergistic extraction mechanism is proposed. The enhancement of extraction in the binary system can be explained due to the species Y(NO3) (.) A(2) (.) HA (.) B formed. The synergistic enhancement coefficients ( R), extraction constants, formation constants and thermodynamic functions of the reaction were calculated.

轻稀土镧、铈急性生物效应的血清~1HNMR谱代谢组学研究

采用现代核磁共振和模式识别技术,通过分析腹腔注射给药La(NO3)3(2,10和50mg/kg体重)和Ce(NO3)3(2,10和50mg/kg体重)48h后大鼠血清的核磁共振氢谱,由内源性代谢物浓度的变化研究了两种稀土化合物在大鼠体内的急性生物效应,利用主成分分析法对两者进行了分类比较.在低剂量(2mg/kg体重)组La(NO3)3和Ce(NO3)3血清中,乳酸和肌酸酐等内源性代谢物浓度发生了微小变化;在高剂量组(10和50mg/kg体重)中,含量变化较大的重要内源性代谢物包括3羟丁酸、丙氨酸、肌酸酐、丙酮、乙酸、琥珀酸和葡萄糖等,其中3羟丁酸和丙氨酸等在La的剂量组中变化较大,Ce的剂量组血清中丙酮、琥珀酸和葡萄糖含量变化明显.实验结果表明,低剂量La和Ce的毒性较低,并对机体影响较小,高剂量则对大鼠肝脏造成损伤,且Ce的毒性大于La.

魔角旋转核磁共振代谢组学方法对镧、铈急性生物效应的比较研究

利用高分辨魔角旋转核磁共振(MAS1H NMR)技术对腹腔注射不同剂量[2,10,50 mg/kg(体重)]的硝酸镧[La(NO3)3]和硝酸铈[Ce(NO3)3]的雄性W istar大鼠肝、肾组织的MAS1H NMR谱进行比较分析,研究了La(NO3)3和Ce(NO3)3的急性生物效应,并结合模式识别技术对不同剂量La(NO3)3和Ce(NO3)3的急性生物效应进行了分类.研究结果表明,La(NO3)3对大鼠的急性毒性主要表现为肝毒,Ce(NO3)3对大鼠肝、肾同时造成损伤.该方法可用于其它稀土及金属化合物的毒性预测和毒理学研究.

Synthesis and fluorescence properties of Eu2+-doped KMgF3 nanoparticles

The phase diagram of a cetyltrimethyl ammonium bromide( CTAB)/n-butanol/n-octane/KNO3-Mg( NO3)(2) system was drawn. Nanoparticles of Eu2+-doped KMgF3 were prepared from the quaternary microemulsions of cetyltrimethyl ammonium bromide(CTAB), n-butanol, n-octane and water. The X-ray diffraction(XRD) patterns were indexed to a pure KMgF3 cubic phase. The environmental scanning electron microscopic (ESEM) images show the presence of spherical Eu2+-doped KMgF3 nanoparticles with a diameter of ca. 20 nm. The emission of KMgF3: Eu2+ nanoparticles peaks at 360 mn. The excitation band was observed at 250 nm with a blue shift of ca. 70 nm compared with that of KMgF3: Eu2+ single crystal. The preparation method of nano-KMgF3: Eu2+/PMMA composite films was inquired into.

Studies of electron-transfer and charge-transfer coupling processes at a liquid/liquid interface by double-barrel micropipet technique

Investigation of a heterogeneous electron-transfer (ET) reaction at the water/1,2-dichloroethane interface employing a double-barrel micropipet technique is reported. The chosen system was the reaction between Fe(CN)(6)(3-) in the aqueous phase (W) and ferrocene in 1,2-dichloroethane (DCE). According to the generation and the collection currents as well as collection efficiency, the ET-ion-transfer (IT) coupling process at such an interface and competing reactions with the organic supporting electrolyte in the organic phase can be studied. In addition, this technique has been found to be an efficient method to distinguish and measure the charge-transfer coupling reaction between two ions (IT-IT) processes occurring simultaneously at a liquid/liquid interface. On this basis, the formal Gibbs energies of transfer of some ions across the W/DCE interface, such as NO3-, NO2-, Cl-, COO-, TBA(+), IPAs+, Cs+, Rb+, K+, Na+, and Li+, for which their direct transfers are usually difficult to obtain because of the IT-IT coupling processes, were quantitatively evaluated.

Cyanex923萃取稀土(Ⅲ)的传质动力学

利用层流恒界面池 ,研究了在 (30 3± 0 .5 K)下纯化 Cyanex92 3-正庚烷 - Na NO3体系萃取 L a( )、Y( )和 Sm( )的传质动力学。考察了搅拌速度、温度及比界面积对萃取速率的影响。实验表明 ,在硝酸体系中 ,Cyanex92 3萃取 L a( )、Y( )和 Sm( )的正向表观活化能分别为 32 .0 k J· mol- 1、16 .4 k J· m ol- 1和 15 .1k J· m ol- 1 ,L a( )的萃取为混合控制过程 ,Y( )和 Sm( )萃取为扩散控制过程。实验还表明萃取过程的化学反应均发生在液 -液界面上。

Hydrothermal synthesis and X-ray single crystal structure of bimetallic cluster complex [{Co(phen)(2)}(2)V4O12]center dot H2O

A new bimetallic cluster complex with the formula [{Co(phen)(2)}(2)V4O12](H2O)-H-. was synthesized from the hydrothermal reaction of V2O5, H2C2O4, Co(NO3)(2), 1,10-phenanthroline (phen), (C4H9)(4)NOH and water. The compound crystallizes in an orthorhombic system with space group Pbcn and unit cell parameters a = 19.106(3) Angstrom, b = 15.250(3) Angstrom, c = 16.321(2) Angstrom, V = 4755.4(13) Angstrom(3), Z = 4 and R = 0.0318. The bimetallic cluster complex [{Co(phen)(2)}(2)V4O12](H2O)-H-. is composed of a discrete V4O124- cluster eovalently attached to two [Co(phen)(2)](2+) fragments and the discrete hexanuclear bimetallic clusters of [{Co(phen)(2)}(V4O12)-V-2](H2O)-H-. are further extended into interesting three-dimensional supermolecular arrays via pi-pi stacking interactions of phen groups. Other characterizations by elemental analysis, IR, and thermal analysis are also described.

Effect of rare earth element on the metabolism in rats by high resolution proton nuclear magnetic resonance spectroscopy

The high-field nuclear magnetic resonance (NMR) spectra can be used for the rapid multicomponent analysis in small amounts of biological fluids. In this paper, the effect of La (NO3)(3) on the rats' metabolism in urine was investigated by H-1 NMR analysis. The experimental groups of wistar rats were injected intraperitoneally with La(NO3)(3) at doses of 0.2, 2.0, 10 and 20mg/kg body weight. The remarkable variation of low molecular weight metabolites in urine has been identified by H-1 NMR spectra, in which dimethylamine, N, N-dimethylglycine, urea, alpha -ketoglutarate, trimethylamine N-oxide, succinate, citrate and amino acids have been suggested as NMR markers for renal damage and ethanol, lactate, taurine as the markers for liver damage. This work may assess its possible use in the early detection of biochemical changes associated with Rare Earth induced kidney and liver dysfunction.

Two new coordination polymers of Co(II) with 1,1 '-(1,4-butanediyl)bis(benzimidazole)

Two new compounds, [CoL2(H2O)(2)](NO3)(2). 8H(2)O (1) and [CoL(H2O)(2)(CH3CO2)(2)]. H2O (2), were obtained from self-assembly of the corresponding metal salts with 1,1'-(1,4-butanediyl)bis(benzimidazole) (L). In 1, each cobalt ion is coordinated to four nitrogen atoms from four molecules of L, and to two water molecules. Metal ions are bridged by L ligands to form infinite (4, 4) networks that contain 44-membered rings. The (4, 4) networks of 1 stack in a parallel fashion, resulting in the formation of large channels in the material. In 2, each cobalt ion is coordinated to two N atoms from two L molecules, two water molecules and two carboxylate O atoms from two acetate anions. Each L molecule is coordinated to two cobalt ions, acting as a bridging ligand as in 1. The bridged cobalt ions form an infinite zigzag chain structure.

Networks with hexagonal circuits in co-ordination polymers of metal ions (Zn-II, Cd-II) with 1,1 '-(1,4-butanediyl)bis(imidazole)

Three new compounds, [ZnL1.5(H2O)(SO4)]. 6H(2)O 1, [ZnL1.5(H2O)(2)][NO3](2). 2H(2)O 2 and [CdL1.5(H2O)(2)(SO4)]. 4H(2)O 3 were obtained from self-assembly of the corresponding metal salts with 1,1'-(1,4-butanediyl)bis(imidazole) (L). In both 1 and 2 zinc ion is five-co-ordinated, showing a less-common trigonal bipyramidal co-ordination polyhedron, while cadmium ion of 3 is six-co-ordinated with a common octahedral arrangement. The sulfate ions of 1 and 3 are co-ordinated, however the nitrate ions of 2 are not. Each of the three compounds is composed of a (6, 3) network with the hexagonal smallest circuit containing six metal ions and six L; each L is co-ordinated to two metal ions, acting as a bridging ligand. In 1 the 2-D sheet of (6, 3) networks is interpenetrated in an inclined mode by symmetry related, identical sheets to give an interlocked 3-D structure, while the (6, 3) networks of both 2 and 3 stack in a parallel fashion to construct frameworks having channels.

稀土长期毒性对大鼠体液的~1HNMR研究

采用现代核磁共振技术 ,通过分析灌胃给药 0 .2 ,2 .0 ,1 0 ,2 0mg/kg剂量的La(NO3) 36个月后大鼠血清中某些内源性化合物的变化研究了稀土化合物在动物体内的作用情况及长期毒性 ,同时对各剂量组三个月后大鼠尿液的1 HNMR谱图进行了分析 ,并通过血液中一些重要生化指标的测定对结果进行了验证 .体液中氨基酸、乳酸、N 氧三甲胺、3 羟丁酸、葡萄糖、尿素、柠檬酸等重要内源化合物的核磁共振谱峰发生了明显的变化 ,意味着动物体内的代谢出现异常 .结果表明高剂量稀土的引入可能使动物肾脏和肝脏均受到损害 ,且受损程度随稀土剂量的增高而渐趋严重

Nuclear magnetic resonance studies on the effects of Rare Earth in rats urine

Male Wistar rats were administrated orally with La(NO3)(3) at doses of 0. 05, 0. 2, 2. 0, 10 and 20 mg/kg body weight. Urine was collected over a 24 h period after dosing. Resonances for a large number of low molecular weight metabolites were assigned in a high resolution H-1 NMR spectra of rat urine. The variation of some low molecular weight metabolites in urine provided a sensitive measurement of Rare Earth induced renal and liver lesions, in which DMA, DMG, urea, Kg, TMAO, succinate, citrate and amino acids have been suggested as NMR markers for renal damage and ethanol, lactate, taurine as the markers for liver damage. The method could be applicable to study of the toxicological effects of other compounds and drugs.