Facile synthesis of flake-like dihydrate zinc oxalate particles

Monodispersed dihydrated zinc oxalate(ZnC_2O_4·2H_2O) particles with characteristic morphology were synthesized by aging a mixed solution of zinc nitrate(Zn(NO_3)_2) and sodium oxalate(Na_2C_2O_4) in the presence of a citrate ligand, with an average flat size of approximately 10–15 μm. The important parameters, including the solution pH values and the concentration of the zinc ions and citrate ligand, were investigated using a series of experiments. It is verified that the citrate ligand significantly affects the morphology of zinc oxalate particles, probably via its multiple roles of chelating, dispersing, and selective absorption. Thermodynamic equilibrium of the distribution of zinc species in an aqueous solution of Zn(Ⅱ)-citrate-oxalate-H_2O was estimated to explain the experimental results and to clarify the size and morphological evolution mechanism of the precipitated particles.     

The constitutes and isomer distribution of di-（potassium sulfonate）-di-phthalimidomethyl phthalocyanine zinc

Sulfonate and/or phthalimidomethyl phthalocyanine zincs are obtained by the condensation reaction of anhydrous zinc acetate and two precursors, i.e. 4-phthalimidomethyl phthalonitrile and 4-（potassium sulfonated） phthalonitrile. The ZnPCSnPm mixture was separated into 5 components according to the number of substituted sulfonate groups and each component which has the same chemical constituent consists of different regioisomers. An HPLC method in isocratic conditions was developed to exercise quality control and make quantitative analysis of the photosensitizer, di-（potassium sulfonate）-diphthalimidomethyl phthalocyanine zinc （abbreviated as ZnPcS2P2, here, S represents sulfonate group, P the phthalimidomethyl group and ZnPc the phthalocyanine zinc）. Furthermore, by comparing the retention behavior of ZnPcS2P2 with that of ZnPcS2, positional structure of isomers of ZnPcS2P2 was speculated. Reversed-phase HPLC method with TEA-phosphate buffer and DMF as eluents in gradient conditions has been proved to be a powerful tool for the separation of such complex system.     

Raman spectroscopy study of zinc finger ZNF191（243-368）

The structure of ZNF191(243-368), the zinc finger region protein of zinc finger protein ZNF191, and its structural change upon thermal and EDTA-induced denaturation were investigated by the Raman spectroscopy. It was demonstrated that the coordination between Zn^2 and His/Cys in ZNF191(243-368) is the essential factor to the stability of zinc finger, which plays an important role in maintaining the hydrophobic core and the secondary structure in zinc finger, and the Raman spectroscopy is a powerful tool for investigating the structure of ZNF191(243-368).     

Thermodynamics and phase transformations in the recovery of zinc from willemite

Willemite is a common component of zinc and lead metallurgical slags that, in the absence of effective utilization methods, cause serious environmental problems. To solve this problem and increase zinc recovery, we proposed a novel extraction method of zinc from willemite by calcified roasting followed by leaching in NH₄Cl-NH₃·H₂O solution. The thermodynamics and phase conversion of Zn₂SiO₄ to zinc oxide (ZnO) during calcified roasting with CaO were investigated. The mechanism of mineralogical phase conversion and the effects of the CaO-to-Zn₂SiO₄ mole ratio (n(CaO)/n(Zn₂SiO₄)), roasting temperature, and the roasting time on zinc-bearing phase conversion were experimentally investigated. The results show that Zn₂SiO₄ was first converted to Ca₂ZnSi₂O₇ and then to ZnO. The critical step in extracting zinc from willemite is the conversion of Zn₂SiO₄ to ZnO. The zinc percent leached in the ammonia leaching system rapidly increased because of the gradual complete phase conversion from willemite to ZnO via the calcified roasting process.     

A novel hydrothermal method for zinc extraction and separation from zinc ferrite and electric arc furnace dust

A novel hydrothermal process was developed to extract zinc from pure zinc ferrite (ZnFe₂O₄) nanopowder and zinc-containing electric arc furnace (EAF) dust using hexahydrated ferric chloride (FeCl₃·6H₂O) as a decomposing agent. The effects of solid FeCl₃·6H₂O to ZnFe₂O₄ ratio by mass (R_F/Z), hydrothermal reaction temperature, and time on zinc extraction were systematically investigated. In the results, when the hydrothermal reaction is conducted at 150℃ for 2 h with R_F/Z of 15:20, the efficiency of zinc extraction from ZnFe₂O₄ reaches 97.2%, and the concentration of ferric ions (Fe3+) in the leaching solution is nearly zero, indicating a high selectivity for zinc. In addition, the zinc extraction efficiency from the EAF dust reaches 94.5% in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl₃·6H₂O to EAF dust ratio by mass (R_{F/EAF dust}) of 15:10. Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.     

Synthesis, structure, optoelectronic properties of novel zinc Schiff-base complexes

Two novel zinc Schiff-base complexes, bis-(N-(2-hydroxybenzidene)-p-aminodimethylaniline)zinc(II) (2) and bis-(N-(2-hydroxy-1-naphthidene)-p-aminodimethylaniline)zinc(II) (4) were designed and synthesized. Both the complexes exhibit good solubility in organic solvents and excellent thermal stabilities. A single crystal of 2 was grown and its crystalline structure was determined from X-ray diffraction data. Analysis of the electronic structures of both the zinc complexes calculated by density functional theory reveals a localization of orbital. The UV-Vis absorption and photoluminescence profiles of 4 in thin film are similar to those of 2, but the emission for 4 is red-shifted compared to 2. Three-layered devices with a configuration of ITO/NPB/2/Alq 3 /LiF/Al and ITO/NPB/4/Alq 3 /LiF/Al show a yellow and red emission, respectively.     

Investigation on composite Au/TiO_2 nanoparticles (Ⅰ)——Synthesis and characterization

Nanometer sized Au/TiO\-2 particles were synthesized by irradiation of a HAuCl\-4 solution containing colloidal TiO\-2 with light of wavelength (λ)>330 nm. The absorption maximum attributed to the surface plasmon band of gold was observed at 540 nm, a red shift of about 20 nm from the position in aqueous solution. The Au clusters are situated on the surface of TiO\-2 in terms of microcrystallite, which was confirmed by HRTEM, EDS and XRD. The electronic interfaction between the metal and the suport was discussed.     

Three-dimensional observation of the phase structure of high density polyethylene （HDPE）/poly（ethyleneco-butene） （PEB） blend by laser scanning confocal microscopy

In this paper,high density polyethylene (HDPE)/poly(ethylene-co-butene) (PEB) blend (50/50 wt%) was prepared through solution blending and then compression molding,and subsequently examined by laser scanning confocal microscopy (LSCM). The PEB used in this experiment was labeled with a small quantity of a fluorescein derivative to render fluorescence. The initial films showed uniform dye dis-tribution and no indication of phase separation within the resolution of optical microscopy. Sample films annealing at 140℃ followed by rapid cooling to room temperature showed obvious phase sepa-ration and bicontinuous structure. The present work indicates that by labeling one component with fluorescein derivative,LSCM can efficiently perform in situ depth profiling of polymer blends.     

HPLC Determination of Ascorbic Acid Using Luminol-Cu(Ⅱ) Chemiluminescence-Application to the Analysis of Juice Beverage

The chemiluminescence (CL) of luminol-Cu(Ⅱ) was applied to HPLC determination of ascorbic acid, which was separated by a C18 reverse-phase column with a mobile phase of 0.25 mol/L HAc. The eluted ascorbic acid was mixed with 0.3 mmol/L luminol and 0.05 mol/L CuSO4. The light emission from the reaction of Cu(Ⅱ) oxidized ascorbic acid and luminol was detected by a modified luminometer. The detection limit was 3.6×10-6 mol/L for ascorbic acid at a S/N ratio of 3, and the linear calibration range was 2×10-4- 2×10-3 mol/L. The relative standard deviation for 5 replicate injections of 1×10-3 mol/L ascorbic acid was calculated as 4.3 %. The method was successfully applied to determination of ascorbic acid in juice beverage.     

铁酸锌焙烧后的还原行为及氨浸特性

A novel method for recovering zinc from zinc ferrite by reduction roasting–ammonia leaching was studied in this paper. The reduction thermodynamic of zinc ferrite by CO was analyzed. The effects of roasting parameters on the phase transformation and conversion rate of zinc ferrite, and the leaching behavior of zinc from the reductive roasted samples by ammonia leaching, were experimentally investigated. The mineralogical phase compositions and chemical compositions of the samples were characterized by X-ray diffraction and chemical titration methods, respectively. The results showed that most of the zinc ferrite was transformed to zinc oxide and magnetite after weak reduction roasting. 86.43% of the zinc ferrite was transformed to zinc oxide under the optimum conditions: CO partial pressure of 25%, roasting temperature of 750°C, and roasting duration of 45 min. Finally, under the optimal leaching conditions, 78.12% of zinc was leached into the solution from the roasted zinc ferrite while all iron-bearing materials were kept in the leaching residue. The leaching conditions are listed as follows: leaching duration of 90 min, ammonia solution with 6 mol/L concentration, leaching temperature of 50°C, solid-to-liquid ratio of 40 g/L, and stirring speed of 200 r/min.     

铜(Ⅰ)、银(Ⅰ)氮氧自由基配合物磁构效应的理论研究

采用密度泛函结合对称性破损(DFT-BS)方法,研究了铜(Ⅰ)、银(Ⅰ)氮氧自由基配合物磁构效应。计算结果表明,在考察改变两个氮氧自由基二面角(θ)而引起磁交换偶合常数(J)的变化时发现,将AgⅠ和CuⅠ配合物中氮氧自由基的正交排列逐渐转为平行排列,最终都实现由铁磁性偶合转变为反铁磁性偶合,但转变的过程并不完全相同。分子轨道和自旋集居数分析都很好解释了计算结果。分析还表明,AgⅠ和CuⅠ两个结构相似的配合物,磁构效应之所以不同,实际上是由它们的磁偶合机理不同所导致。     

Ethylene polymerization by novel highly active iron/acetyl（imino）pyridyl complex

In recent years, significant developments have oc- curred in olefin polymerization with late-transition- metal catalyst systems, in particular, the discovery of exceptionally active catalysts based on penta- coordi- nate iron and cobalt bearing bis(imino)pyridyl triden- tate ligands with substituted aryl groups, reported in- dependently by the groups of Brookhart[1] and Gibson[2]. Following this discovery, a considerable amount of efforts have been dedicated to investigate the nature of the ac…     

硫酸介质中3,5-二(2-吡啶基)-1,2,4-三唑对铜的缓蚀作用的电化学研究

利用动电位扫描、循环极化、循环伏安等电化学方法研究了3,5-二(2-吡啶基)-1,2,4-三唑(HBPT)在0.5 mol/L H2SO4介质中对铜的缓蚀性能.极化曲线研究表明3,5-二(2-吡啶基)-1,2,4-三唑在0.5 mol/L硫酸溶液中对铜的阳极反应起抑制作用,对铜的阴极反应起促进作用,属于阳极型缓蚀剂.循环伏安研究显示3,5-二(2-吡啶基)-1,2,4-三唑可能在电极表面产生吸附或与一价铜发生作用,从而在0.5 mol/L硫酸溶液中对铜起到缓蚀作用.     

1-(4-氯苯甲酰基)-3-[5-(4-吡啶基)-1,3,4 -噻二唑-2-基]脲的合成及杀菌活性

通过2-氨基-5-(4-吡啶基)-1,3,4-噻二唑与4-氯苯甲酰基异氰酸酯反应,合成了目标化合物1-(4-氯苯甲酰基)-3-[5-(4-吡啶基)-1,3,4-噻二唑-2-基]脲,通过IR1、H NMR、MS和元素分析等方法对它的结构进行了表征.并测定了其杀菌活性,结果发现:目标化合物在50 mg/L浓度下对黄瓜灰霉病菌和苹果轮纹病菌的抑制率达到80%以上.     

3,5-二溴水杨醛缩邻苯二胺及其配合物的合成与谱学性质

合成了3,5-二溴水杨醛缩邻苯二胺配体H2L(L=C20H10N2O2Br4)及其铜(II)、镍(II)的配合物ML.Py(M为Cu和Ni;Py为吡啶)和锌的配合物[ZnL.Py].DMF,并用元素分析、红外光谱、紫外-可见光谱对它们进行了表征,同时用质谱、核磁共振谱对配体进行了表征。研究结果表明配合物为五配位,吡啶分子参与了配位。     

Synthesis of novel polymer-bonded water-soluble metal porphyrins

The reaction of 5, 10, 15, 20-tetra-(4-pyridyl) porphyrin 1 with triruthenium dodecacarbonyl [Ru₃(CO)₁₂], zinc(II) acetate, copper(II) acetate, cobalt(II) acetate afforded complexes 2a−2d respectively. Treatment of 2a−2d with Merrifield’s peptide resin obtained 3a−3d. The compounds 3a−3d reacted with methyl iodide respectively gave 4a−4d. New complexes 4a−4d have been identified by IR, UV-visible spectra, and AES. Foundation item: Supported by the Natural Science Foundation of Hubei Province Biography: LI Zao-ying (1949-), female, Associate professor.     

2-(4-吡啶基)咪唑二羧酸锌配位聚合物的自发拆分

非手性配体2-(4-吡啶基)-4,5-咪唑二羧酸（H2L）与硝酸锌进行水热反应得到组成为[ZnL]n?2nH2O的自发拆分的2种三维金属-有机框架手性晶体，空间群分别为P41212和P43212，其中配位多面体分别为和型Zn(NO)2N三角双锥结构. 两种晶体分别存在着约0. 2 nm宽的不同手性的超微四方孔道，容纳的结晶水分子通过氢键分别形成右手和左手螺旋. 320 ℃以下主体框架保持稳定. 晶体在440 nm左右的荧光发射相比配体增强2倍以上. 该研究对于由非手性原料合成手性多空材料的进一步研究具有积极意义.     

N,N-二(4-(6-2,2′-联吡啶)-苯甲基)-2-(氨甲基)吡啶的合成、结构和光谱性质

合成了一种多齿配体N,N-二(4-(6-2,2′-联吡啶)-苯甲基)-2-(氨甲基)吡啶(C40H32N6),并用MS,EA,1HNMR进行结构表征,测试了吸收光谱(UV)和荧光光谱(FL).随HBF4,乙酸锌的加入,荧光光谱明显红移;随Cu2+浓度增加吸收峰强度逐渐增加,但发射峰逐渐消失,成为激发态荧光体的猝灭剂.测量并计算了摩尔消光系数和量子产率,并用密度泛函理论计算预测了其稳定的空间构型.     

[（mtan）Zn（μ—0H）Zn（mtan）]（C1O4）3的晶体结构分析

标题化合物[(mtan)Zn(OH2)](ClO4)2 (1) (mtan = 5-甲基-1,5,9-三氮杂壬烷) 是在pH < 7 的乙腈水溶液中制取的,而在11 > pH 7的条件下,配合物1中的水分子配体很容易电离出质子,形成二聚体[(mtan)Zn(m-OH)Zn(mtan)](ClO4)3 (2)的产率很高。在13.5 > pH 11的范围内,溶液中就会产生 [(mtan)Zn(m-O)Zn(mtan)](ClO4)2 (3),X-射线单晶结构分析表明,化合物(2)由[(mtan)Zn(m-OH)Zn(mtan)]3+和三个ClO4-组成,晶体参数:单斜晶系空间群P2(1)/m,a轴 7.802(2), b轴 12.121(3),c轴 15.662(3) 牛琤 104.29(2)o,V 1435.3(6) 3。Zn(II)呈现稍微扭曲的四面体配位环境。     

TAN螯合物高效液相色谱分离和测定铜（Ⅱ）,镍（Ⅱ）,钴（Ⅱ）

以1-(2-噻唑偶氮)-2-萘酚(TAN)螯合物,于Shim-pack CLC-CN柱上,用含甲醇-四氢呋喃-醋酸-醋酸钠缓冲液(pH=3.5)-乙醇(60:19.8:19.8:0.4 V/V)溶液作流动相,并用分光光度检测器于570nm处进行检测,发展了一种高效液相色谱分离测定铜(Ⅱ),镍(Ⅱ),钴(Ⅱ)的方法.此法具有高的灵敏度,其绝对检测限分别为:铜(Ⅱ)1.8ng,镍(Ⅱ)1.8ng和钴(Ⅱ)0.6ng.在测定条件下,大多数金属离子不干扰.