二氧化硅负载胂钯(0)配合物催化酰氯和芳基碘与四苯硼化钠的苯基化反应

氯丙基三乙氧基硅烷依次与气相法二氧化硅、二苯胂钾、氯化钯作用, 再用水合肼还原, 合成了二氧化硅负载的胂钯(0)配合物. 该配合物是酰氯及芳基碘化物与四苯硼化钠苯基化反应的有效催化剂, 为苯基酮及不对称联苯的合成提供了简便且实用的新方法.     

Surface Tension, Heat Capacity, and Volume of Amphiphilic Compounds in Formamide Solutions

Density measurements of sodium dodecyl sulfate (SDS), sodium decyl sulfate (SDeS), sodium octyl sulfate(SOS), and sodium hexyl sulfate(SHS) in formamide (FA) as functions of the surfactant concentrations were carried out at 25°C. For SDS in FA, additional density measurements at 35 and 60°C and surface tension and specific heat capacity measurements at 25°C were also performed. From density and specific heat capacity data, the apparent molar volume and heat capacity of the surfactants as functions of concentration were calculated. The surface excess of SDS at the solution–air interface was also determined from the surface tension measurements using the Gibbs adsorption equation. Under our experimental conditions, none of the experimental results evidence micelle formation. In addition, volumetric studies of the hexanol–SDS–FA ternary system at 25°C evidence only interactions between the dispersed surfactant and alcohol.     

微量热法研究亚砷酸钠对鲫鱼肝脏线粒体的影响

Metabolic thermogenic curves of mitochondria isolated from liver tissue of Carassius auratus and the effect of different concentration of NaAsO2 on it were investigated by TAM air isothermal microcalorimeter, ampoule method, at 28.00 ℃. From the thermogenic curves, activity recovery rate constants k, the maximum heat production rate （Pmax） and the total heat produced （Q） were obtained. The values of k and Pmax decline gradually with the increase of the concentration of NaAsO2, and both of the values of Pmax and k are highly correlated to the concentration of NaAsO2. When concentration of NaAsO2 reached 16.0 μg/mL, the maximum heat production rate dropped to 70.8% of the control group, and the corresponding percentage of k was 71.4% of the control group. This experimental result indicates that the addition of NaAsO2 has restrained the metabolic activities of mitochondria in vitro.     

New reaction of the sodium salt of 2-nitroethanol. X-ray analysis of the sodium salt of 2-oxo-3-hydroxypropionic acid oxime, 2-bromo-2-nitropropane-1,3-diol,and the model 2,2-dinitropropane-1,3-diol

A novel reaction of the sodium salt of 2-nitroethanol in aqueous ammonia resulted in the sodium salt of 2-oxo-3-hydroxypropionic acid oxime (1) has been found. Bromination of1 affords 2-bromo-2-nitropropane-1,3-diol (2) with a previously unknown molecular conformation. The formation mechanisms of compounds1 and2 were suggested. X-ray analysis of products1,2 and that of the model compound, 2,2-dinitropropane-1,3-diol, was performed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1217–1221, May, 1996.     

Studies of an inclusion complex of a redox-active barbiturate with β-cyclodextrin

The effects of β-cyclodextrin (β-CD) on the spectral properties and electrochemical behaviour of barbitone sodium were studied using electrochemical and optical techniques. The apparent changes in the UV-visible absorption spectrum and fluorescence quenching of the barbiturate upon addition of β-CD afford clear evidence of the inclusion complex formation of β-CD in aqueous solutions. The redox acitivity of barbitone sodium in both the absence and presence of β-CD was assessed by an electrochemical method in 0.05 M potassium nitrate-nitric acid (pH 1.8) solution. While the complexation reaction remains is equilibrium, the apparent formation constant of the inclusion complex could be obtained by either spectral or electrochemical methods. Quantitative evaluation of the data gave 326 l mol⁻¹ under equilibrium conditions at 20°C. Possible conclusions are discussed on the basis of environmental changes around the barbiturate molecules on inclusion.     

Apparent molar volumes and heat capacities of aqueous solutions of sodium benzenesulfonate at 25°C

Apparent molar volumes and heat capacities of sodium benzenesulfonate have been measured at 25°C and at molalities up to 1.1 molal using a Picker flow densimeter and a Picker flow heat capacity calorimeter. Data for both properties have been modeled with Pitzer equations for the respective functions, and the standard state values evaluated. The apparent molar volume of sodium benzenesulfonate appears to be relatively insensitive to sample preparation. Possible reasons for the difference in the apparent molar volume reported here and the literature value are discussed.     

Spectrofluorimetric determination of thiabendazole in a micellar medium

A sensitive, selective Spectrofluorimetric method has been developed for the determination of thiabendazole in a sodium dodecylsulphate micellar medium. The method features a linear determination range of 0.020-15 g and a detection limit of 0.2 ng/ml, with a relative standard deviation of less than 3%. By using a straightforward extraction procedure with ethyl acetate and hydrochloric acid, the method provided average thiabendazole recoveries above 96% from apple, pear and potato samples.     

在线电生锰(Ⅲ)流动注射化学发光法测定地塞米松磷酸钠

采用在线恒电流电解产生Mn(Ⅲ)与流动注射化学发光法相结合,基于地塞米松磷酸钠可使Mn*#-Na2SO3新体系化学发光大大加强的现象,建立了测定地塞米松磷酸钠的新分析方法.其线性范围为1×10-4～1×10-2 g/L;检出限为7×10-5 g/L;RSD为1.2%.该法成功地应用于针剂中地塞米松磷酸钠的测定.     

Über die quasi-binären Systeme NaNO2/Na2O und NaCN/Na2O. Phasendiagramme und Natrium-Ionenleitung in Na3O(NO2) und Na3O(CN)

On the Quasi-Binary Systems NaNO₂/Na₂O and NaCN/Na₂O. Phase Diagrams and Sodium Ion Conductivity of Na₃O(NO₂) and Na₃O(CN) Measurements of the electrical conductivities of Na₃O(NO₂) and Na₃O(CN) show sharp increases in conductivity at temperatures between 200° and 250°C, According to the phase diagrams of the quasi-binary systems NaNO₂/Na₂O and NaCN/Na₂O this is not an effect established by fusion. It seems to be a consequence of a “melting” of the sodium sublattice or the rotational disorder of complex anions.