金催化化学发光新体系——苯并吡喃化学发光分析法测定金矿中的痕量金

本文提出了一种测定矿样中痕量金的化学发光分析法,氯化6,7-二羟基-2,4-二甲基苯并吡喃-H_2O_2化学发光体系,方法的检出限为7ppb。工作曲线线性范围是10～1000ppbAu,测定的相对标准偏差小于7％。应用本法测定矿样中的金,结果良好。     

Palladium catalyzed mild reduction of α,β-unsaturated compounds by triethylsilane

The palladium(II) chloride/triethylsilane system has been successfully applied for the selective hydrogenation of the carbon-carbon double bond of α,β-unsaturated ketones to yield the corresponding saturated carbonyl compounds. The reaction takes place under mild conditions and affords high yields.     

Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.     

Elastic and Thermophysical Properties of Poly(Vinyl Chloride) and Chlorinated Polyethylene Blends

The results of experimental and theoretical investigations of elastic and thermophysical properties of poly(vinyl chloride) (PVC) and chlorinated polyethylene (CPE) blends are presented. Eight types of specimens with different ratios of weight contents of PVC and CPE (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) were tested. The effect of blend composition on the elastic constants (tensile and shear modulus) is discussed. The data on the thermal conductivity, thermal diffusivity, and heat capacity of the blends investigated are also presented.     

Solubility of carbon dioxide in aqueous solutions of sodium chloride: Experimental results and correlation

The solubility of carbon dioxide in aqueous solutions of sodium chloride was measured in the temperature range from 40 to 160°C, up to 6 mol-kg salt solutions and total pressures up to 10 MPa. Pitzer's⁽¹⁾ equations as well as the Chen and Evans⁽²⁾ model were used to correlate the new data. Results are reported and compared to literature data and correlations.     

Thermal decomposition of hexamminecobalt(III) chloride

The results of comparative thermal analysis (TG-DTG-DTA-DSC) of the thermal decomposition of hexamminecobalt(III) chloride in air atmosphere are reported. The kinetics and mechanism of the thermal decomposition, the process enthalpy and the variation in specific thermal capacity of the solid product reaction with temperature were determined.     

N—烃氧丙酰基四氢噻唑—2—硫酮的合成

在三聚氯氰存在下由烃氧丙酸与四氢噻唑-2-硫酮反应得到N-烃氧丙酰四氢噻哇-2-硫酮(2a-i),由2a,c-h与格氏试剂反应得到烃氧乙基苯基酮(3a,c-h).产物2a-i未见报道.     

Matrix-Untersuchungen zu monomerem Kupfer(I)-chlorid und seinen Komplexen mit N2 und PN IR-spektroskopische Nachweise und ab-initio Rechnungen

Matrix-Investigations on Monomeric Copper(I) Chloride and its Complexes with N₂ and PN Ligands. IR Spectroscopic Results and ab-initio Calculation In solid argon the reaction of monomeric CuCl with N₂ yields ClCuN₂. On the basis of two absorptions in the ir-spectrum and their corresponding isotopic shifts (_14/15N) and with the help of a normal coordinate analysis, linearity of the molecule has been deduced. These results are confirmed by large scale ab-initio Calculations (CPF, MP2). Reaction of monomeric CuCl with molecular PN under matrix condition is shown to give rise to new absorptions in the IR spectrum which arev assigned to a linear molecule ClCuNP.     

A polymer onium acting as phase-transfer catalyst in halogen-exchange fluorination promoted by microwave

A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource.     

Highly stereoselective synthesis of peracylated α-aldopyranosyl chlorides from aldopyranose peracetates and thionyl chloride catalyzed by BiCl3 generated in situ from the procatalyst BiOCl

Aldopyranose peracetates react with thionyl chloride and BiCl₃, generated in situ from a substoichiometric amount of the procatalyst BiOCl, producing the corresponding peracylated aldopyranosyl chlorides in very good to excellent yields (82–97%) with exclusive α-anomeric selectivity.