An Alternative Method for Anomeric Deacetylation of Per-acetylated Carbohydrates

An alternative method for anomeric deacetylation of fully acetylated carbohydrates has been developed using imidazole in methanol.     

Structure of Tetra[β-(1,2,4-triazole-1-yl)propiophenone] Dichloro Nickel(II) Solvate Hexahydrate Complex: [NiCl_2(C_2H_2N_3CH_2CH_2COPh)_4]·6H_2O

IntroductionRecently ,thecompoundscontaining 1H 1,2 ,4 tria zolegrouphaveattractedmuchinterestbecausetheyex hibitsomefungicidalactivity ,plantgrowthregulatingac tivity ,1antibacterialactivityagainstPucciniareconditeandrootsgrowthregulationforcucumber .2 Also ,suchcom poundsareincreasinglybeingstudiedbecauseofthecoor dinationchemistryoftriazolesactingasligandsintransi tionmetalcompounds .Asamatteroffact ,thetriazolederivativeshavebeenextensivelyusedasterminalandbridgingligands ,andtheyleadto…     

Ce(H_2O)_7Al(OH)_6Mo_6O_(18)·4H_2O: A New One-dimensional Zigzag Chainlike Structure of Anderson Cluster Linked by Cerium Ions

IntroductionPolyoxometalates(POMs),as an important familyof metal oxides,have been receiving considerable at-tention in solid-state materials chemistry due to their di-verse topological properties and potential applications incatalysis,photochemistry,electrochemistry,medicineand magnetism[1,2].Recently,one of the intriguingfields in the polyoxometalate chemistry is to find somenovel subunits and then connect them into one-,two-,even three-dimensional(1-,2-,even3-D)extendednetworks,either thro…     

酚醛型吸附树脂对水体系中吡啶和N,N-二甲基苯胺的吸附性能研究

研究了酚醛型吸附树脂在水体系中对吡啶和N，N-二甲基苯胺的静态和动态吸附行为．结果表明，在水中树脂对吡啶和N，N-二甲基苯胺的吸附主要以疏水吸附机理进行；吸附吡啶和N．N-二甲基苯胺的初始阶段，即达到38．3～48．9％平衡吸附时，吸附速率数据和半经验速率方程很吻合：酚醛型吸附树脂等温吸附吡啶和N，N-二甲基苯胺的平衡吸附数据符合Langmuir方程，相关系数在0．99以上，酚醛型吸附树脂吸附吡啶和N，N-二甲基苯胺属单分子层吸附：用80％的乙醇溶液作洗脱剂来洗脱吸附吡啶已达饱和的JDW-2树脂，效果是很理想的．在3．6个床体积内洗脱率达91．52％，4．8个床体积内洗脱率达到94．85％。表明酚醛型吸附树脂具有优良的洗脱性能．     

Studies of a new series of ion-pair complexes [Mo(dtc)_4][Ln(dtc)_4] (Ln=La-Er,exp.Pm)

A new series of ion-pair complexes [Mo(dtc)4][Ln(dtc)4] (Ln=La-Er, exp. Pm) were synthesized from MoCl5, LnCl3 and Nadtc in anhydrous methanol. The crystal structures of the four complexes, [Mo(dtc)4][Ln(dtc)4] (Ln=Nd, Sm, Ho and Er) have been determined by X-ray diffraction. Spectroscopic properties of all these complexes are also discussed here.     

透射电镜薄样品倾转过程中的附加旋转及其计算

模拟透射电镜双倾台进行样品位向调整过程,推导出反映样品倾转前后其合成倾转轴(即共有菊池线对的法线)方向变化规律的计算公式,称为附加旋转角计算公式。指出,实现样品位向调整的双倾操作,等效于样品绕其合成倾转轴的倾转及该倾转轴绕Z轴(平行入射束方向)的旋转之和。利用双倾台对薄膜样品进行的系列倾转实验表明,由附加旋转角公式计算的附加旋转角和实测值相一致。还根据双倾操作过程导出了合成倾转角的计算公式,它可用于判断样品位向调整的准确度。     

Comparison of(η~6-Fluoroarene)tricarbonylchromium Complexes with Their Chloro-analogs in Radical Aromatic Substitutions

Reactions of fluoroarene-Cr(CO)_3 complexes with SmI_2 andcarbonyl compounds in THF/HMPA at-40— -60℃ affordedthe corresponding radical aromatic substitution products in highyield. Compared to the corresponding chloroarene-Cr.(CO)_3complexes, fluoroarene-Cr(CO)_3 complexes showed a higher ef-ficiency and slightly lower regioselectivity.     

制备参数对β-Mo2N0.78催化剂加氢脱硫活性影响的研究

以N2与H2的混合气为反应气，和三氧化钼进行多段程序升温反应，制得一种β晶型的氮化钼。以噻吩为模型化合物的常压加氢脱硫反应表明，β-Mo2N0.78具有较强的加氢脱硫活性和强的抗硫化性能。同时考察了预还原、反应温度以及氮化末温、升温速率、反应气中N2-H2比及氮化时间等制备参数对β-Mo2N0.78加氢脱硫活性的影响。研究发现，β-Mo2N0.78的加氢脱硫活性在320 ℃～400 ℃随反应温度的升高增强，而还原预处理会降低催化剂的活性。氮化末温、氮化时间、反应气组成和升温速率等制备参数对催化剂的活性有明显的影响：随着氮化末温的升高，所制备的催化剂催化加氢脱硫活性降低；在氮化末温恒温较长时间，可以引起制备催化剂的加氢脱硫活性下降；存在最佳的反应气组成和各段升温速率。小晶粒的β-Mo2N0.78具有强的加氢脱硫活性。     

Synthesis of Polyacrylaminothiourea Chelating Fiber and Properties of Concentration and Separation of Trace Noble Metal Ions from Samples

A novel polyacrylaminothiourea chelating fiber was synthesized simply and rapidly from nitrilon (an acrylonitrile-based synthetic fiber), which was applied to preconcentrate and separate of trace amount of Au(Ⅲ）,Pt(Ⅳ）,Pd(Ⅳ） and Ir (Ⅳ） ions from solution of samples.The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 20.0mL/min at pH2, and can also be desorbed with 15 mL of 4mol/L HCl 3% thiourea from the fiber column with recoveries of 96.5%-100%.The chelating fiber can be reused for ten times,the recoveries of these ions are still over 92%,and hundred to thousand times of excess of Fe(Ⅲ）,Al（Ⅲ）,Ca(Ⅱ），Mg（Ⅱ）,Ni(Ⅱ）,Mn（Ⅱ),Cu(Ⅱ），Zn(Ⅱ），and Cd(Ⅱ） cause no interference on the determination of the analyzed ions by inductively-coupled plasma atomic emission spectrometry (ICP-AES).The static saturation adsorption capacities of the fiber for the analytes are in the range of 1.15-2.80mmol/g.The relative standard deviations for the determination of 20.0ng/mL each of Au(Ⅲ）,Pt(Ⅳ）,Pd(Ⅳ）and Ir(Ⅳ） are in the range of 0.7%-3.0%.The recoveries for test from standard additions to real solution samples are between 96% and 100%.The concentration of each ion in powder sample detected by the method is in good agreement with the certified value.     

新型分子筛Ti-MMM-1的合成及其催化性能的研究

通过控制TEOS的水解，在不同时间添加与MCM-41和MFI相应的有机模板剂合成出了一种新型分子筛，Ti-MMM-1，采用XRD、FT-IR和低温N2吸附对其进行表征，并用H2O2氧化环己烷和环己醇对其催化活性进行评价．结果表明，Ti-MMM-1是一种具有MCM-41和MFI结构的两相混合的微孔／介孔材料，IR分析表明钛原子已进入分子筛骨架，并在环己烷和环己醇的氧化中表现出较好的催化活性和较高的选择性．