催化动力学光度法测定痕量铜

在醋酸 -醋酸钠缓冲介质中 ,过氧化氢可缓慢地氧化灿烂甲酚蓝 ,痕量铜离子可强烈地催化此褪色反应。从而建立了动力学光度测定痕量铜的新方法。方法的检出限为 6 .7× 10 -9g/ m L,测定铜的线性范围为0 .0 5— 1.0 μg/ m L。用于茶叶和自来水中痕量铜的分析 ,结果令人满意。     

Synthesis and Crystal Structure of a New Lanthanum（Ⅲ） 4-Cyanobenzoate Complex

A new dinuclear La（Ⅲ） complex [La2（4-cba）4[H（4-cba）2]2（phen）2（H2O）4] （4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline） 1 has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by singlecrystal X-ray diffraction. Crystallographic data： C88H58La2N12O20, Mr = 1881.28, triclinic P1, a = 7.518（3）, b = 17.033（6）, c = 17.551（6）A, α = 115.333（4）, β = 92.9910（10）, γ = 99.366（5）°, V = 1985.3（12）A^3, Z = 1, Dc = 1.574 g/cm^3, F（000） = 944 μ = 1.145 mm^–1, the final R = 0.0281 and wR = 0.0686 for 6708 reflections with Ⅰ 〉 2σ（I）. In 1, two nine-coordinated La（Ⅲ） ions are connected by two 4-cba ligands in a syn-syn bidentate coordination mode, and the other six 4-cba ligands terminate the La（Ⅲ） ions, resulting in an isolated dinuclear structure. Two different types of intramolecular hydrogen bonds, asymmetrical O-H…O and symmetrical O…H…O, exist in the crystal. The title complex molecules are connected through hydrogen bonds and weak π-π stacking interactions to generate a 2-D layered network. The thermogravimetric analysis of 1 has also been discussed.     

水热-溶胶-凝胶法制备高比表面积MgAl2O4尖晶石

以金属硝酸盐为原料,聚乙烯醇为稳定剂,在200℃水热反应温度下制备了氧化铝和氧化镁凝胶经700℃焙烧4h后获得高纯度、结晶完整的镁铝尖晶石(MgAl2O4).用XRD、TG-DTA、SEM和BET等表征结果表明,加入PVA-124可以对胶体粒子起到保护作用,阻止胶粒因热运动碰撞而聚集,并使铝、镁氧化物胶粒均匀混合,在较...     

Synthesis and Crystal Structure of 4-Nitro-2- [（2-diethylaminoethylimino）methyl]phenol

1 INTRODUCTION Schiff base ligands have played an important role in the development of coordination chemistry as they readily form stable complexes with most metal ions[1～4]. These complexes are very interesting in many fields, such as catalysis and enzymatic reac- tions[5, 6], magnetism and molecular architectures[7～9]. The complexes derived from the similar tridentate Schiff base ligand 2-[(2-dimethylaminoethylimino)- methyl]phenol[10, 11] and its derivatives[12～14] have been widely …     

Synthesis and Crystal Structure of Bis[2-[2-(diethylamino)ethyliminomethyl]-4-nitrophenolato]dimethanolcobalt(Ⅱ) Dinitrate

The title mononuclear cobalt(Ⅱ) complex [Co(DENP)2(MeOH)2]·2NO3 (DENP =2-[2-(diethylamino)ethyliminomethyl]-4-nitrophenolate) was prepared and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pī with a = 8.297(1), b = 11.075(2), c = 11.134(2) (A), α = 69.69(1),β = 70.97(2), γ =84.02(2)°, Z = 1, V = 907.0(4) (A)3, Dc = 1.424 g/cm3, Mr = 777.66, λ(MoKα) = 0.71073 (A), μ = 0.548mm-1, F(000) = 409, R = 0.0628 and wR = 0.1734. The complex consists of a [Co(DENP)2-(MeOH)2]2+ cation and two disordered nitrate anions. The Co atom, lying at the inversion centre, is six-coordinated by two DENP ligands and two MeOH molecules in an octahedral geometry. The molecules in the crystal are linked through intermolecular O-H…O, O-H…N and N-H…O hydrogen bonds, forming chains parallel to the b axis.     

Mild-temperature Synthesis of Covellite Copper Sulfide Hexagonal Nanoplatelets via the Hydrothermal Route

Covellite CuS hexagonal nanoplatelets were prepared by a simple hydrothermal process at mild temperature, using sodium dodecyl benzene sulfonate （SDBS） as an assisting reagent. The products were characterized by X-ray powder diffraction （XRD）, transmission electron microscopy （TEM） and UV-vis absorption spectroscopy. An energy-dispersive X-ray spectrometer （EDS） was used to analyze the elementary compositions of the intermediate products. A possible formation mechanism of hexagonal nanoplatelets is discussed, using TEM observations.     

Synthesis,crystal structures,and antimicrobial activity of a pair of isostructural dinuclear copper(II) complexes derived from 4-nitro-2-[(2-diethylaminoethylimino)methyl]phenol

A pair of isostructural azido- or thiocyanato-bridged centrosymmetric dinuclear copper(II) complexes, [Cu₂L₂(μ_1,3-N₃)₂] (1) and [Cu₂L₂(μ_1,3-NCS)₂] (2), derived from the Schiff base ligand 4-nitro-2-[(2-diethylaminoethylimino)methyl]phenol (HL), have been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. Each Cu atom in the complexes is five-coordinate in a square pyramidal geometry by one O and two N atoms of one Schiff base ligand, and by two terminal donor atoms from two bridging azide or thiocyanate ligands. Both the azide and thiocyanate ligands adopt end-to-end bridging mode in the complexes. The distance between the two copper atoms is 5.205(2) Å for (1) and 5.515(2) Å for (2). The antimicrobial activity of the complexes has been tested.     

由镁、铝醇盐配合物合成纳米粒子MgAl2O4尖晶石

Mg and Al alkoxide complex was synthesized in a cell without battery separator by electrochemical dissolution of aluminum for 6 h and magnesium for 1.8 h at 45 ℃ in ethanol solution of 0.04 mol·dm^-3 (Bu₄N)Br with a current density of 100 mA·cm^-2. IR and Raman spectroscopy were used to characterize the structure of the precursor of MgAl₂O₄. The results show that the current efficiency attains 98.4% and the precursor is MgAl₂(OCH₂CH₃)₅(acac)₃. The acac^- group-containing precursor could prevent it from agglomeration. The xerogel was obtained by drying in vacuum for 24 h and hydrolysis under pH≈8.5 of the precursor, which was heated at 350 ℃ for 2 h to obtain the nano-MgAl₂O₄ powder. XRD and TEM were used to investigate the structure of nano-MgAl₂O₄. The result suggests that the xerogel with an average particle size of 10 nm and the Nano-sized Spinel MgAl₂O₄ Particle of 12 nm thus obtained are with high purity.     

Synthesis and Crystal Structure of Bis{2-bromo- 4-chloro-6-[（2-isopropylammonioethylimino）- methyl]phenolato}bisthiocyanatozinc（Ⅱ）

A Schiff base zinc(Ⅱ) complex [Zn(C12H16BrClN2O)2(NCS)2] was prepared and characterized by elemental analysis,IR and single-crystal X-ray diffraction. The crystal belongs to the triclinic system,space group P1 with a=8.414(1),b=9.124(1),c=22.212(3),α=79.177(2),β=86.296(2),γ=89.899(2)o,V=1671.3(4)3,Z=2,Dc=1.631 g/cm3,Mr=820.79,λ(MoKα)= 0.71073,μ=3.444 mm-1,F(000)=824,R=0.0646 and wR=0.1179. A total of 7371 unique reflections were collected,of which 3904 with I > 2σ(I) were observed. The complex crystallizes with two half-molecules per asymmetric unit and each mononuclear molecule is centrosymmetric. The Zn atom lying at the inversion centre is six-coordinated in a slightly distorted octahedral geometry by two phenolate O atoms and two imine N atoms from two Schiff base ligands,as well as two N atoms from two thiocyanate anions. In the crystal structure,the combination of π-π stacking interactions and intermolecular hydrogen bonds (N–H…Br,N–H…O,N–H…N,C–H…O,C–H…S and C–H…Cl) leads to a three-dimensional network.