Cu（I）/Diamine-catalyzed Aryl-alkyne Coupling Reactions

Arylalkynes are important building blocks for the synthesis of natural products,pharmaceuticals,and artificial molecular devices1.They are often synthesized via the Pd-catalyzed Sonogashira coupling reactions between aryl halides and terminal alkynes2,3.Unfortunately,it remains difficult to apply the Sonogashira reaction to industrial scale and/or pharmaceutical synthesis,due to the high cost of Pd and the difficulty in removing the toxic Pd residues from the reaction products.Thus it is wor…     

Fluorous Synthesis of Biaryl-Substituted Proline Analogs by 1,3-Dipolar Cycloaddition and Suzuki Coupling Reactions

A solution-phase synthesis of bicyclic prolines containing four points of diversity has been developed by a two-step synthesis involving 1,3-dipolar cycloaddition of perfluoroalkylsulfonyl-protected hydroxybenzaldehydes followed by Pd-catalyzed Suzuki coupling reaction of fluorous sulfonates with boronic acids. Both reactions are conducted under microwave irradiation and reaction mixtures are purified by solid-phase extractions without performing chromatography.     

Determination of mercury in human urine by neutron activation analysis,with lead diethyldithiocarbamate as a preconcentration agent

Lead diethyldithiocarbamate is an effective reagent for preconcentration of mercury in urine for neutron activation analysis. Sodium and bromine are removed from the sample by this procedure. As lead diethyldithiocarbamate is insensitive to neutron activation, radiochemical separation is not needed after neutron irradiation. Results from the analysis of urine collected from workers in caustic soda manufacturing plants are discussed.     

催化动力学光度法间接测定水中痕量硫离子

在氨水介质中,硫离子可阻抑Fe(Ⅲ)催化过氧化氢氧化二甲酚橙褪色,并且催化体系和阻抑体系在570 nm处吸光度的差值与硫离子浓度呈线性关系,据此建立了阻抑动力学光度法间接测定痕量硫离子的新方法。方法的线性范围为0.0020~0.044mg/L,检出限为1.6×10-9g/mL,对0.040 mg/L硫离子进行10次平行测定的相对标准偏差为2.1%。方法用于废水中硫离子的测定,结果满意。     

Thermus thermophilus 木糖异构酶与木糖醇的分子对接及模型分析

在1BXB结构基础上, 通过分子对接方法构建木糖异构酶与抑制剂木糖醇的复合物模型, 为合理设计解除木糖醇对木糖异构酶的抑制及进一步揭示木糖醇对该酶抑制机理提供参考.     

固体电解质La2-xCaxMo1.7W0.3O9-δ(0≤x≤0.2)的合成、表征及电性能

在氧离子导体La₂Mo_1.7W_0.3O₉的基础上，采用固相法合成了La位掺杂的Ca系列新型氧化物La_2-xCa_xMo_1.7W_0.3O_9-δ(0≤x≤0.2)。通过XRD、Raman和XPS等手段对化合物结构进行表征，交流阻抗谱测试其电性能。结果表明：掺杂离子Ca²⁺的半径小于基质离子La³⁺的半径导致晶格收缩；Ca的掺杂在La₂Mo_1.7W_0.3O₉自身内置氧空位的基础上增加了额外的氧空位，提高了氧离子导体的电导率，550 ℃电导率由0.79 × 10^-4 S·cm^-1 (x=0.0)增加到1.5 × 10^-4 S·cm^-1 (x=0.16，0.2)，电导率增加89.9%。     

不同形貌氧化镍纳米材料的合成及其电化学性能

以水-乙二醇为溶剂,以聚乙烯吡咯烷酮(PVP)为表面活性剂,采用溶剂热法合成了NiO纳米片,NiO纳米薄片通过自组装形成花状结构。 改变反应温度和溶剂,制备了NiO纳米立方体颗粒和NiO纳米球形颗粒。 用合成的NiO纳米材料制备工作电极,在6 mol/L的KOH溶液中利用三电极体系进行了电化学性能测试。 在电化学性能测试中进行了循环伏安测试、恒电流充放电测试和电化学阻抗谱(EIS)测试。 结果表明,NiO纳米片的比电容最高(在电流密度为0.5 A/g时比电容值为402 F/g),倍率性能最佳(0.5 A/g增加至4 A/g时有80.1%的电容保持率)。 在电流密度为4 A/g时对NiO纳米片进行1000次恒流充放电循环测试,比电容损失了9.7%。     

Lithium dioxobis[trioxoiodato(V)]vanadate,Li[VO2(IO3)2]

The title compound represents a new structure type, in which distorted VO₆ octa­hedra are bridged by iodate groups to form infinite two‐dimensional [VO₂(IO₃)₂]⁻ layers that are separated by octa­hedrally coordinated Li⁺ cations.     

Monoterpene Glycosides from the Roots of Paeonia lactiflora

The roots of Paeonia lactiflora Pall. is one of the most important traditional Chinese medicines, which has been used for the treatment of dizziness, spasm, menstrual disorder, spontaneous and night sweating, and as a general analgesic1. Chemical constitu…     

在吡啶溶剂中氯化镍催化的溴代芳烃自身偶联反应

Pyridine was used as a solvent for homocoupling of aryl bromides catalyzed by nickel chloride/triarylphosphinein the presence of zinc and recycled easily.Triphenylphosphine was the best ligand for nickel in this coupling reac-tion.