手性高效液相色谱法测定1—（6‘—甲氧基萘）乙醇不对称氢酯基化反应

在自制的硅基纤维素－三（３，５－二甲基苯基氨基甲酸酯）高效液相色谱手性固定相上（ＨＰＬＣ－ＣＳＰ），优化了１－（６＇－甲氧基萘）乙醇氢酯基化反应产物－萘普生甲酯手性分离的条件，测定了相应的一系列不对称氢酯基化反应产物的对映体过剩值（ｅ．ｅ．值）。结果表明，在ＣＤＭＰＣ－ＣＳＰ手性柱上用ＨＰＬＣ测定此类不对称催化反应的光学产率，评价催化剂体系的手性选择是一种非常理想的方法。     

Bimetallic Alkoxides of Barium and Zirconium: Preparation of BaZrO3 Powder

Complex formation in solutions of barium and zirconium alkoxides in ROH (R=i-Pr, Et) was studied. A number of bimetallic complexes were isolated, and their structure and properties were studied. The sol-gel method yields a single-phase BaZrO₃ powder only wheni-PrOH solutions of the alkoxides are used. In this case, the oxocomplex, BaZrO(OPr-i)₄.(1–2)i-PrOH, is the precursor of the mixed oxide.     

Zustandsbarogramme — Zustandsdiagramme durch Gesamtdruckmessungen

From phasebarograms it is possible to construct phase diagrams. We show on example of the system Bi/Se/O how follow ternary sections from the total pressure measurements in equilibrium and how we can attribute the barogram of the ternary region Bi₂Se₃/Bi₂O₂Se/Se to the binary system Bi₂Se₃/Se. The knowledge of the ternary system Bi/Se/I and its coexistent pressure courses allow to followT-p-x conditions for the chemical transport of phases from this system.

     

双核铁原子簇体系的CI计算

用ＩＮＤＯ／ＣＩ方法研究了含有Ｆｅ－Ｆｅ键的原子簇体系［Ｆｅ２Ｓ２Ｘ４］＾２－（Ｘ＝Ｃｌ，Ｂｒ，Ｉ）的电子光谱及电子结构，对于这些多谱带体系，谱带波数计算值与实验值符合，在谱带的指认分析中，发现了πｄ＾１→πｄ等新的跃迁方式，对跃迁方式作了解释和分类，并讨论了谱带的电荷转移性质，此外，还对体系的化学键等性质进行了分析。     

Study on the Phase Diagram of CsCl-CeCl3-HCl(11%)-H2O System and the Properties of the Compounds

The equilibrium solubility of CsCl-CeCl3-HCl(11%)-H2O qua-ternary system at 25℃ has been determined by the physicchemical analysis method ,and the phase diagram was plotted, Two new double salts 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O obtained from the complicated system were identified and characterized by XRD,TG-DTA ,DSC,UV and fluorescence spectroscopy, Studies on the fluorescence excitation and emission show that 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O have upconversion luminescence of infrared-visible range,and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl.     

GIAO/DFT evaluation of 13C NMR chemical shifts of selected acetals based on DFT optimized geometries

DFT/B3LYP calculations of the ground-state conformation of eight cyclic and acyclic acetals are presented and compared with experimental data. Results of single-point GIAO/DFT calculations at five different levels of theory show that isotropic shieldings need to be empirically scaled to achieve agreement with experimental chemical shifts. Statistical evaluation of data indicates that the most accurate prediction of 13C chemical shifts is achieved at the MPW1PW91/6-311G** level of theory. An empirical equation describing the relationship between delta values and shielding constants is postulated. This equation has been applied to the non-chair ground-state conformation of the six-membered acetonide and to the conformationally flexible benzodioxonine derivative. The agreement observed between the experimental and predicted chemical shifts shows that calculations at the MPW1PW91/6-311G** level of theory are adequate for addressing questions of conformation.     

A practical synthesis of carbamates using an ‘in-situ’ generated polymer-supported chloroformate

A versatile method for the synthesis of carbamates from an ‘in-situ’ generated polymer-supported chloroformate resin is presented. BTC (bis-trichloromethyl carbonate) is used as phosgene equivalent to afford a supported chloroformate, which, by sequential ‘one-pot’ reaction with a variety of alcohols and amines, furnishes the corresponding carbamates in high yields and purities.     

Fabrication of high performance thin films from metal fluorocomplex aqueous solution by the liquid phase deposition

The hetro-structured oxide thin films from metal fluorocomplex solution have been prepared by the liquid phase deposition (LPD) method. The Pt/Nb₂O₅ and Au/Nb₂O₅ composite films can be prepared from a mixed solution of niobium source, H₃BO₃, Pt(NH₃)₄Cl₂ and HAuCl₄ aqueous solutions under the ambient temperature and atmosphere. In the case of Au/SiO₂ composite film, (NH₄)₂SiF₆ solution is used as a mother solution. The Pt and Au ionic species are deposited in Nb₂O₅ and SiO₂ matrices. They are reduced to their metallic state after treatment above 200 °C. The size of dispersed particles can be controlled by heat treatment temperature. It is also clear that, gold nanoparticles are also found to interact with SiO₂, although the interaction is smaller than that with Nb₂O₅ showing the size of Au nanoparticles remain smaller in Nb₂O₅ that in SiO₂.     

BEHAVIOR OF SUPPORTED NANO-COPPER CATALYST IN CO OXIDATION

IntroductionNanomaterialisanewkindofmaterialwithparticlesizebetWeenIurnand100urn.Becauseofthesmallparticlesizeandthelargespecificsufficearea,nanomaterialpossessesmanyparticularproperties,suchashighersufficeenergyandhighersurfaceactivity.t.[l]Thehigheracti…     

配位-沉淀法制备Ni(OH)2和NiO超微粉

本工作采用配位 -沉淀法成功的制备了薄片形氢氧化镍和氧化镍超微粉末 ,通过 XRD、TG-DTA、IR及 TEM等实验手段对超微粉的组成结构进行分析表征。