Synthesis and crystal structure of cyclopentylindene rare earth complex (C5H9C9H6)(3)SMCl-Li+ (THF)(4)

Rare earth complex (C5H9C9H6)(3)SmCl-Li+ (THF)(4)( I ) was synthesized by reacting anhydrous SmCl3 with two equivalents of C5H9C9H6Li. From mix-solvent of THF and hexane, red color single crystals were obtained. The crystal belongs to a cubic system, space group P2(1)3 with unit cell parameters a= b=c= 1. 754 0(2) nm, alpha=beta=gamma=90degrees, V=5. 396 4(11) nm(3), Z = 4. The ten-coordinated samarium atom is bonded to three cyclopentylindenyl rings and a chlorine atom to form the anionic part of the title complex, ring centroids and the chlorine atom form a tortured tetrahedron around samarium. In the cationic part, lithium atom coordinates to four oxygen atoms of THF molecules to form a normal tetrahedron. The Sm-C(within the same ring) distance varies from 0. 268 to 0. 299 nm.

Catalytic behavior of concentrated heteropolyacid solution in acylation of anisole with acetic anhydride

The catalytic behavior of concentrated heteropolyacid solution in acylation. of anisole with acetic anhydride has been investigated under the reaction conditions such as molar ratio of anisole to acetic anhydride, reaction temperature and mass ratio of reactant to catalyst. When the molar ratio of anisole to acetic anhydride is changed from 2:1 to 1:1, the yield of methoxyacetophenone (MOAP) increases a little, but when it is changed from 1: 1 to 1: 2, the yield has a greater increase from 15% to 30%. The yield of MOAP at the reaction temperature of 363 K doubles that at 333 K. The highest yield is obtained when the mass ratio of reactant to catalyst is 12.8. The conclusion is therefore that the heteropolyacid in acetic acid can effectively catalyze the acylation of anisole with acetic anhydride, and its activity and selectivity are comparable to those of acid clay and molecular sieve.

Chemiluminescent determination of glucose with a modified carbon paste electrode

A flow injection analysis detection method for glucose is presented which is based on the oxidation of glucose by glucose oxidase followed by chemiluminescent detection of hydrogen peroxide. Both glucose oxidase and hematin, a chemiluminescent reaction catalyst, were bulk-immobilized conveniently by direct mixing with carbon paste, which allows renewal of the electrode surface by simply polishing or cutting to expose a new and fully active surface in the case of fouling. Luminol in reagent solution passed through the flow cell and reacted with hydrogen peroxide produced by the enzyme reactor in the presence of the catalyst to yield light. An applied potential of -0.4 V avoided the electrode fouling effectively. The log-log plot of the emitted light intensity vs glucose concentration was linear over the range of 1-100 mmol L-1 with a correlation coefficient of 0.992. Application of this method to other chemiluminescent and bioluminescent systems is suggested. (C) 1999 Academic Press.

Synthesis and characterization of sandwiched heteropolycompound

New complex K5O4Na4H5 [Sn-3(PW9O34)(2)]. 16N(2)O was prepared and its structure was determined by elemental analysis, IR, P-31, W-183 NMR, polarography, XPS and X-ray crystallography. The anion has A-alpha-Keggin structure. The new complex crystallize is the monoclinic, P2(1)/n with a = 1.3625 (3) nm, b = 2.3625 (5) nm, c = 2.9306 (6) nm, alpha = 90 degrees, beta = 99.67 (3)degrees, gamma = 90 degrees, V = 9.299 nm(3), Z = 4.

The application of matrix-assisted laser desorption jonization mass spectrometry in enzymes of Agkistrodon blomhoffii Ussurensis venom analysis

The matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS) spectra of four enzymes (PLA, AEase, Fibrolase, L-a.a. oxidase) in Agkistrodon blomhoffii Ussurensis venom, were given and interpreted. The experiment data showed that MALDI-TOF-MS can be used directly in enzyme analysis with high sensitivity and rapidity. In addition, the results were better than those from sodium dodecyl sulfate-polyacrylamide.

长白山白眉蝮蛇蛇毒酶的基质辅助激光解吸质谱分析

用基质辅助激光解吸飞行时间质谱(MALDI-TOF-MS)法对长白山眉蝮蛇蛇毒所含4种主要酶:磷脂酶A_2、精氨酸酯酶、纤溶酶及L-氨基酸氧化酶进行了纯度鉴定和分子量测定,结果表明WALDI-TO-FMS具有灵敏度高、分辨能力强、分析时间短及样品用量少等优点.用MALDI-TOFMS法分析蛇毒酶的纯度和分子量简捷、快速且重现性好,是SDS聚丙烯酰胺凝胶电泳所无法比拟的.

Phase transition temperature of HPT(2,3,6,7,10,11-hexa-n-pentyloxytriphenylene) from molecule dynamic simulation

Molecule dynamics simulation was used on HPT(2,3,6,7,10,11-hexa-n-pentyloxytriphenylene), which is a discotic Liquid crystal. From analyzing the energy and displacement varying with the temperature, the phase transition temperature of PM6MPP can be predicted. The deviations of T-g, T-m and T-i due to the MD time scale are small enough that it should be possibly used to predict the material properties especially when more powerful computers are available.

Isothermal and nonisothermal melt crystallization kinetic behavior of poly(aryl ether biphenyl ether ketone ketone): PEDEKK

Isothermal and nonisothermal melt crystallization kinetics of a novel poly(aryl ether ketone), PEDEKK, were investigated by differential scanning calorimetry. Several kinetic analyses were used to describe the crystallization behavior. The activation energies were determined as 425 and 176 KJ/mol for isothermal and nonisothermal crystallization, respectively. The equilibrium melting point T-m(o) was estimated to be 444 degrees C by using the Hoffman-Weeks approach. The observed crystallization characteristics of PEDEKK were compared with those of the other members of the poly(arpl ether ketone) family.

杂多酸的固载化─关于制备负载型酸催化剂的一般原理

杂多酸同时具有酸和氧化－还原的催化特性，有着很广泛的应用前景．这类化合物在一系列精细合成中取代硫酸作为催化剂以满足环保的要求，显示出了很大的潜力．杂多酸固载化后，不仅能在液相氧化和酸催化反应中把催化剂从反应介质中很方便地分离出来，而且还为这类均相催化反应的多相化，甚至利用催化蒸馏新工艺等创造了应有的条件，可以使生产工艺大大简化，获得更广泛的应用．本文以很好表征过的多种孔性材料，包括氧化物，如Ａｌ_２Ｏ_３、ＳｉＯ_２、ＴｉＯ_２、硅藻土、膨润土和来源不同的活性炭为载体，考察了负载杂多酸催化剂的催化活性．在大量前期工作的基础上，通过总结载体对固载杂多酸催化活性的影响等，探讨载体的内在性质在杂多酸固载、吸附和催化反应中的作用本质，为由吸附法制备各种负载型固体酸催化剂在液相中的应用提供可资参考的模型.

固体杂多酸盐的催化性能Ⅲ．钼磷、钼硅杂多酸碱金属盐的合成、表征和催化酯化反应

合成了Ｈ３ＰＭｏ１２、Ｈ４ＳｉＭｏ１２杂多酸的一系列铯盐：ＣｓｘＨ３－ｘＰＭｏ１２Ｏ４０·ｍＨ２Ｏ（ｘ＝０～３，ｍ＝４～７），ＣｓｘＨ４－ｘＳｉＭｏ１２Ｏ４０·ｍＨ２Ｏ（ｘ＝０～４，ｍ＝４～７）。测定了它们的酸强度、ｐＨ滴定曲线、ＮＨ３－ＴＰＤ、ＩＲ光谱和比表面积。以乙酸和正丁醇的酯化为探针反应，考察了催化剂的酸催化活性。实验结果表明，杂多酸铯盐对乙酸和正丁醇的催化酯化活性只与总酸量有关，与表面积无关，属假液相反应

梳状高分子固体电解质的离子导电性研究

深入研究了交替马来酸酐共聚物多缩乙二醇酯（ＣＰ３５０）两种锂盐络合物ＣＰ３５０／ＬｉＡｓＦ＿６和ＣＰ３５０／ＬｉＰＦ＿６的离子传导性能，给出了与复阻抗谱相对应的等效电路．离子电导率随［Ｌｉ］／［ＥＯ］的变化而出现一极大值，室温下，两体系电导率极大值分别为１．３８×１０（－４），８．３２×１０（－５）Ｓ／ｃｍ．电导率随温度升高而增加．导电行为呈非－Ａｒｒｈｅｎｉｕｓ特征．阴阳离子半径之和（ｒ＿ｃ＋ｒ＿ａ）愈大，离子电导率愈高．

DETERMINATION OF HYDRAZINES BY CAPILLARY ZONE ELECTROPHORESIS WITH AMPEROMETRIC DETECTION AT A PLATINUM PARTICLE-MODIFIED CARBON-FIBER MICROELECTRODE

A novel modified electrode dispersed with ultrafine platinum particles on the surface of a 30-mu m carbon fibre microelectrode was investigated as an amperometric detector in capillary zone electrophoresis (CEEC) for determining hydrazines. The unique cha

电导法测定稀土冠醚配合物的稳定常数

用电导法研究了无水乙腈溶液中稀土高氯酸盐与DB·18-C-6、3,3-二甲基16-C-5(Me_2·16-C-5)、16-C-5的配位反应,以及1:9(V/V)H_2O-CH_3CN体系中稀土高氯酸盐与Me_2·16-C-6的配位行为,计算了1:1配合物的稳定常数。在无水乙腈中稀土与16-C-5的稳定常数大于稀土与Me_2·16-C-5的。加入少量水后,对轻稀土lgK值减小;重稀土则lgK值增大。

磷酸二丁酯稀土络合物的合成与红外光谱研究

本文用稀土氯化物与磷酸三丁酯反应制备了标题络合物Ln(DBP)3(Ln=La,Eu,Yb),研究了络合物的热分解机理。由残渣的红外光谱确认其热分解最终产物为稀土偏磷酸盐。测定了络合物的红外光谱,对其1300cm~(-1)以下的主要吸收谱带进行了归属。红外光谱表明,标题络合物与Sm(DMP)_3等磷酸二甲酯稀土络合物具有相同的配位形式和结构类型。每个稀土离子通过双“O—P—O”桥与邻近的三个稀土离子相连接,形成“双桥二十四元环”的多聚网络结构。Ln—O键基本上是离子键。