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.     

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.     

Dynamic Study of Gemini Surfactant and Single-chain Surfactant at Air／Water Interface

Molecular dynamics (MD) simulation are used to study the properties of gemini surfactant of ethyl-α,ω-bis(dodecyldimethylammonium bromide) (C12C2C12) and dodecyl-trimethylammonium bromide (DTAB) at the air/water interface, respectively. In the two systems,t he surfactant concentrations are both 28 wt.%, and other conditions are also the same. After reaching the thermodynamic equilibrium, the concentration profiles, the radial distributions functions (RDF) and the mean squared displacement (MSD) are investigated. The results reveal that the surface activity of C12C2C12 surfactant is higher than DTAB surfactant.     

气液色谱法研究一些五员杂环和Ni[CF_3COCHC(C_4H_4S)=NCH_2]_2加合反应的热力学性质

用气液色谱法研究过一系列作为Lewis碱(B)的有机配体和作为Lewis酸(A)的配合物之间的加合作用.研究较多的碱已有脂肪醇、醚、酮、醛、脂及胶等.对生物体系中广为存在的杂环配体碱的工作还很少.本文着重研究噻吩,呋喃和吡咯这类小分子杂环配体和Ni[CF_3COCHC(C_4H_4S)=NCH_2]_2(以下简称A)配合物的加合反应. Ni[CF_3COCHC(C_4H_4S)=NCH_2]_2的合成参考文献.固定液角鲨烷系英国进口,     

4′-乙酰基苯并-15-冠-5缩氨基硫脲的微波合成及晶体结构

硫脲衍生物主要通过氢键与阴离子相互作用达到识别的目的，冠醚和硫脲两个主体分子亚单元之间的协同作用往往使冠醚和硫脲表现出对某些客体更加优越的络合识别能力，我们在以前工作的基础上，微波辐射下合成了标题化合物并用红外光谱、核磁共振氢谱、元素分析、X射线单晶衍射对其结构进行了表征，欲进一步研究其对阳离子和阴离子识别的双重功效。     

A New Asterosaponin from the Starfish Culcita novaeguineae

A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence.     

一种合成4β-甲基-5α胆甾烷的新路线

本文报道以胆甾醇为原料经四步反应立体控制合成4β-甲基-5α-胆甾烷(6)的新路线。4-甲基胆甾-4-烯-3-酮(3)经Clemmensen还原,得4-甲基胆甾-4-烯(4)(65％)及4-甲基胆甾-3-烯(5)(15％)。用10％Pd-C在无水乙醇中室温催化氢化4,得6(70％)与4α-甲基-5α- 胆甾烷(7)(30％)的混合物;而选用Brown催化剂在同样条件下氢化4,得到产物6与7的比例为95:5。     

金汞齐富集冷原子荧光测汞法的研究

本文介绍了一种用于测定汞的金汞齐富集热解系统。研究了该系统与冷原子荧光测汞仪联用的工作条件和干扰,在最佳条件下的检出下限为4×10~(-13)克汞,分析周期3分钟,相对标准偏差2.5%(1.5×10~(-9)克汞)。     

磁疗手术胆结石的红外光谱观测

本文报道用Nicolet 170 SXFT-IR红外光谱仪观测磁疗手术胆结石、磁疗破碎排出胆结石及服中草药破碎胆结石的红外光谱,分析并比较了它们的光谱特征。     

2-芳基硫杂脯氨酸结构特征的研究

对12种2-芳基硫杂脯氨酸进行了红外光谱和核磁共振谱测定,对其中两个化合物作了质谱测定。结果表明,这类化合物固态时主要以两性离子形式存在;有较强的分子离子峰,是一类较稳定的化合物。它们还存在一对非对映异构体,芳环上的取代基对芳环电子云密度的影响较大,而对四氢噻唑环的影响较小。