Oxidation of thiol compounds by molecular oxygen in aqueous solutions

Side self-oxidation of thiols was studied. It was found that these reactions in neutral and alkaline solutions are induced by impurities of variable-valence metals. The ability of transition metals to catalyze oxidation of thiols changes in the order Cu > Mn > Fe > Ni Co. The plot of the self-oxidation rate vs. pH passes through a maximum whose position on the pH scale depends on both the nature of metal and the structure of the thiol oxidized. For thiols having different structures, the kinetic orders in reactions catalyzed by copper ions differently vary with pH, which is apparently associated with the formation of complexes possessing different catalytic activity.     

环境和生物样品中铂族金属的分析研究进展

评述了近年来环境和生物样品中痕量铂族金属的分析研究进展，重点介绍了样品的预处理和分离富集技术以及检测手段等。     

Hydrothermal synthesis, crystal structures and luminescent properties of two new Ln(III)–succinate (Ln=Eu, Tb) complexes exhibiting three dimensional networks

Two new coordination polymers, [Eu₂(L)₃(H₂O)₂]_n 1 and {[Tb₂(L)₃(H₂O)₂]·H₂O}_n 2, (H₂L=succinic acid) have been synthesized by the reaction of H₂L with nitrate salts of Eu(III) or Tb(III) under hydrothermal conditions. The X-ray diffraction analysis reveals that the two complexes are constructed by L bridging the chains of edge-sharing EuO₈(H₂O) or TbO₈(H₂O) polyhedra to form 3D network structure. 1 and 2 possess different topological structures due to the difference in the conformations of L. The solid photoluminescence of 1 and 2 was also investigated in room temperature.     

利用天然斜发沸石从高离子强度的强碱性溶液中吸附和洗脱K+和Rb+的研究

在80℃下，用间歇法研究了NH4^ 型天然斜发沸石对某厂高离子 强碱性循环液中的K^ 和Rb^ 的吸附，得到不同粒度天然斜发沸石对K^ 和Rb^ 的交换吸附量，用不同浓度的NH4HCO3溶液对沸石进行洗脱再生，是到洗脱速率随着洗脱液浓度增大而增大。本文对沸石与钾含量很高的高离子强度强碱性溶液中碱金属的交换吸附和洗脱过程进行了初步探讨。     

Synthesis and Crystal Structure of [{Cd(hmbdc)(H2O)3}·2H2O]n

A novel coordination polymer [{Cd(hmbdc)(H2O)3}·2H2O]n (hmbdc=5-hydroxy- isophthalic acid) has been synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a=9.599(3), b=18.699(5), c=7.557(2) (A), β= 108.198(4)°, V=1288.6(6) (A)3, Z=4, Mr=382.60, Dc=1.972 g/cm3, F(000)=760, μ=1.740, the final R=0.0555 and wR=0.0995 for 1732 observed reflections with Ⅰ ＞ 2σ(Ⅰ). The structural analysis shows that the intermolecular hydrogen bonds and π-π interactions result in a three-dimensional supramolecular framework.     

Optimization of the process variables for the synthesis of cardanol-based novolac-type phenolic resin using response surface methodology

Models capable of predicting the maximum extent of conversion (p) of cardanol-based novolac-type phenolic resin, have been developed using response surface methodology to determine the optimum reaction conditions. Three-dimensional response surface and their contour plot were drawn. The maximum extent of conversion (98.93%) was predicted when the cardanol was condensed with formaldehyde (molar ratio 1:0.652) at 119.84 °C for a time period of 3 h with the catalyst (e.g., citric acid) concentration of 1.988% of total volume of cardanol and formaldehyde. The pH of the reaction mixture was maintained at 3.0. These predicted values for optimum process conditions were in good agreement with experimental data.     

Dynamic stereochemistry of hypervalent silicon, germanium and tin compounds containing amidomethyl C, O-chelating ligands

The results of NMR-spectroscopy studies of the structure, dynamic stereochemistry, and intermolecular interactions in solutions of organic derivatives of penta-and hexacoordinated silicon, germanium, and tin containing amidomethyl, lactamomethyl, and related bidentate ligands are surveyed. For the series of works “Dynamic stereochemistry of hypervalent compounds of silicon, germanium, and tin,” the author was awarded the Academia Europea Prize for young scientists from CIS in 1996. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1912–1934. November, 1997.     

中性配合物Cr(acac)_3、mer-和fac-[Cr(bza)_3]的光学拆分

本文用新方法合成了Cr(bza)_3,改进了其mer-、fac-异构体的分离方法;增大了Cr(acac)_3的化学拆分量(1.5g)。试制了DBT(二苯甲酰-d-酒石酸)吸附型手性固定相(CSP),并成功地用于色谱拆分标题配合物的对映体,mer-[Cr(bza)_3]的部分拆分是首次发现的,其他配合物的拆分结果均优于文献方法。根据mer-[Cr(bza)_3)拆分流出液前、后组分的CD光谱,指定了其对映体绝对构型。还讨论了DBT吸附型CSP的拆分效能和色谱特性。     

Synthesis of the first stable carborane containing simple enol

A carborane-containing stable simple enol — 1-2-isopropyl-o-carboran-I-yl)-1-phenyl2-mesityl-2-lrydroxyctlrylcne — has been synthesized. This enol does not isomerize to the starting ketone or keto-enol mixture even after prolonged heating in benzene in the presence of CF₃COOH.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1561–1563, June, 1996.     

过硫酸盐和N,N,N′,N′-四甲基乙二胺体系引发烯类聚合机理的研究

<正> 过硫酸盐和N,N,N′,N′-四甲基乙二胺(TMEDA)体系用作烯类聚合的引发剂已有报道。本文报道该引发体系的反应机理。1.实验方法