一维链状4-羧基苯氧乙酸桥联钴配位聚合物[Co(p-CPOA)(2，2′-bipy)(H2O)]n的合成与晶体结构

A novel coordination polymer of [Co(p-CPOA)(2，2′-bipy)(H₂O)]_n (p-CPOA^2-=4-carboxylphenoxyacetate dianion, 2,2′-bipy=2,2′-bipyridine) was synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. The title complex crystallizes in monoclinic space group C2/c, with a=1.424 4(3) nm, b=1.316 6(3) nm, c=1.947 7(4) nm, β=104.56(3)°. V=3.535 3(14) nm³, Z=8, R=0.028 5, wR=0.089 1. The cobalt(Ⅱ) ion displays a distorted octahedral coordination geometry, defined by three carboxyl oxygen atoms from different p-CPOA^2- groups, two nitrogen atoms from 2,2′-bipyridine ligand and one water molecule. The cobalt atoms are bridged by p-CPOA^2- groups, forming a one-dimensional chain structure along a axis. The adjacent Co…Co atoms distance is 0.996 8 nm. A layer supramolecular network is contrsucted by the hydrogen bonds and π-π stacking interactions. CCDC: 220039.     

Impetus for solvothermal synthesis technique: synthesis and structure of a novel 1-D borophosphate using ionic liquid as medium

A novel borophosphate compound has been synthesized under solvothermal conditions using ionic liquid as a medium and structurally characterized by single-crystal X-ray diffractions. The compound crystallizes in the monoclinic, space group P2(1)/n, a=8.089(8) Å, b=13.977(12) Å, c=8.441(8) Å, β=112.517(11)°, Z=2, V=881.7(14) Å³, R₁=0.03, wR₂=0.079 and S=1.01. Its structure consists of a 1-D straight chain that is built of the alternative linkage of mutually perpendicular four-member rings. Other characterizations by IR and thermal and elemental analyses are also described.     

镝的钼硅杂多配合物的合成,结构和振动光谱

合成了镝的钼硅杂多配合物K_(10)H_3[Dy(SiMo_(11)O_(39))_2]·20H_2O,用X射线单晶结构分析,确定其空间群为P2_1/n,晶胞参数.结果表明:SiMo_(11)O_(39)~(8-)作为四齿配体与Dy配位,Dy与8个氧原子配位,形成四方反棱柱.K离子的配位数有6、7、8、和94种.讨论了该配合物的振动光谱.     

X-ray photoelectron spectroscopic study of the mechanism of palladium matrix modification in the electrothermal atomic absorption spectrometric determination of lead and bismuth

The mechanism of palladium matrix modification is studied for the determination of lead and bismuth by graphite-furnace atomic absorption spectrometry. The binding energies of the charring products for lead and bismuth in the presence or absence of palladium obtained at the initial stage of atomization were measured. The binding energies indicated the formation of PbPd and BiPd bonds, thus explaining the increase in appearance temperatures of lead and bismuth in the presence of palladium.     

反相高效液相色谱中复杂体系二元多台阶梯度分离条件快速优化方法

提出了一种反相高效液相色谱中二元多台阶梯度分离条件快速优化方法。通过数次线性梯度初始实验，求得溶质的保留方程。在此基础上，利用重叠分离区域图（OSRM）方法，快速求得复杂样品的最佳多台阶梯度分离条件。该方法只需要几个小时就可以完成对复杂样品分离条件的优化，并通过对中药川芎提取物的分离加以验证，获得了较好的预测精度和分离效果。     

Improvement of Pulse Amperometric Detection Integrated Automated Flow Injection Analysis of Ethylenethiourea Determination

Improvement of pulse amperometric detection (PAD) method is demonstrated in determination of ethylenethiourea (imidazolidine‐2‐thione, ETU). The anodic detection of ETU will produce polymeric film on an electrode leading to an inactive electrode surface. Here, the PAD method was used to remove the polymeric film formed on the electrode surface between ETU detection. Further, the scheme was integrated with automated flow injection analysis (AFIA) for determining ETU. The operational parameters of PAD in the AFIA system were discussed thoroughly. The analytical characteristics of the system were evaluated at optimum conditions. The linear range of calibration plot was between 20 to 300 μM (the correlative coefficient, r = 0.999) and the detection limit was 0.9 μM (S/N = 3). The relative standard deviations of detection of 50 μM ETU were 0.82% with and 9.07% without PAD scheme. The results indicate the system is a very promising tool for ETU determination. Finally, the matrix effects of two water samples that were collected from a campus and a farm show good recoveries of 92% and 96%.     

A preliminary study of isopropyl alcohol matrix effect and correction in ICP-MS

Isopropyl alcohol matrix effect was found to be element specific by using the defined matrix effect factor in ICP-MS,which could not be corrected by using the conventional internal reference method.Unlike the conventional internal reference method,the presented method allows for the analyte to behave differently from the internal reference under the influence of the matrix.     

Al-MSU-S-Y介孔分子筛的合成及其催化合成缩醛(酮)的研究

以离子液体1-十六烷基-3-甲基溴代咪唑为模板剂合成了Al-MSU-S-Y介孔分子筛,利用XRD、N2吸附-脱附对其进行结构表征,结果表明该方法合成的样品具有较大的孔径、孔容以及比表面积,而且孔径分布较窄.研究了Al-MSU-S-Y对乙二醇与环己酮、丁酮、丙酮、丙醛、丁醛、异丁醛、戊醛、异戊醛、正己醛、正辛醛、苯甲醛等十余种醛(酮)的缩合反应的催化性能,结果表明Al-MSU-S-Y介孔分子筛对醛(酮)与醇的缩合反应有较好的催化性能.     

The Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water

The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione,bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.     

介稳态氧化钨超微粉体的水热合成与光致变色性质研究

Under hydrothermal conditions, the superfine powders of cubic pyrochlore-type of tungsten oxide and hexagonal tungsten bronze were obtained by using Na₂WO₄·2H₂O as the starting material. The products were characterized by XRD, TG, IR, UV and EPMA, respectively. The effects of the pH value, the acid concentration, reaction temperature and time on the structure and particle size of products were investigated in detail. The conditions for the preparation of superfine powders of tungsten oxide were optimized. The pH 2.5～4.5 of the reaction system led to the formation of a pyrochlore phase and pH 0.5～2.0 gave the hexagonal tungsten bronze structure. The photochromism property of the hexagonal tungsten bronze was studied. The results show that pyrochlore and bronze phases are decomposed at 300 ℃ and 450 ℃, respectively. With the increasing of temperature, the structure of the two oxides changes. The pyrochlore-type powder changes completely into triclinic Na₂W₄O₁₃ around 500 ℃, while the bronze phase into a mixture of Na₂W₆O₁₉ and triclinic WO₃ at 550 ℃. The powder of the hexagonal tungsten bronze showed better photochromism property.