碲氢化钠还原亚胺的方法

本文报道一种还原亚胺的新方法。取代的芳基和脂肪基亚胺可以在较温和的条件下被碲氢化钠顺利地还原为相应的仲胺。     

Spectral and photochemical characteristics of CdSe nanoparticles stabilized in polymer-containing media

The optical characteristics of CdSe nanoparticles, produced in aqueous solutions and polymer films in the reaction of cadmium chloride and sodium selenosulfate, were studied. The main parameters that make it possible to vary the forbidden band width were identified. The absorption, photoluminescence, Raman, and nonstationary decolorization spectra of CdSe nanoparticles of various sizes were analyzed. It was demonstrated that under the conditions of pulsed irradiation the CdSe nanoparticles are capable of accumulating excess electrons and inducing redox transformations in components of the solution (oxygen, methylviologen, and sulfite ions). __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 3, pp. 150–155, May–June, 2006.     

耐盐性聚丙烯酸盐类高吸水树脂的制备

耐盐性聚丙烯酸盐类高吸水树脂的制备宋彦凤，崔占臣，陈欣芳（吉林大学材料科学系长春１３００２３）关键词丙烯酸钠，丙烯酰胺，丙烯酸羟乙酯，共聚物，吸水树脂，耐酸性高吸水树脂是一种应用比较广的功能性高分子材料［１～５］．它的吸水率可高达几百倍乃至几千倍。但...     

Freezing temperatures and densities of solutions of some hydrocarbons and sodium oleate inN-methylacetamide. Evidence for a solvophobic interaction

The freezing temperatures and densities (at 31°C) of solutions of octane, nonane, decane, 3,3-diethylpentane, and sodium oleate inN-methylacetamide (NMA) have been measured. The molality of the freezing solution was calculated from the density. The solubilities of octane, nonane, and decane inN-methylacetamide are also reported. Apparent molal volumes calculated from the densities are close to the values in the pure hydrocarbons and are not strong functions of the concentration. This indicates the absence of any unusual packing effect. The calculated free energies of transfer of the hydrocarbons from pure hydrocarbon to NMA solution are much less negative than the corresponding values for water, showing that the bulk solvophobic interaction inN-methylacetamide is smaller than in water. This is consistent with the freezing temperatures of sodium oleate which show that micelles do not form below 0.1 mole-kg^–1. The osmotic coefficients of the hydrocarbons calculated from the freezing temperatures showed negative deviations from ideality that were larger for the hydrocarbons with the higher molecular weights. Two estimates of the pairwise solvophobic interaction inN-methylacetamide indicate that it is also smaller than in water. The solvophobic effect in this solvent does not include the large entropy and enthalpy effects found in aqueous solutions.     

微波辐射下苯亚磺酸钠的S-烃基化

在微波辐射下，不用任何有机溶剂和无机载体，苯亚磺酸钠和卤代烃能迅速发生反应生成相应的S-烃基化产物。     

The thermal decomposition of NaHCO3 powders and single crystals

The thermal decomposition of four commercial powders and of differently stored single crystals of sodium hydrogen carbonate is studied by power compensation DSC and by optical and FT-IR microscopy. Independently of manufacturer, specified purity and price, the thermal curves of all the commercial powders show a more or less pronounced low temperature peak preceding the one due to the main decomposition. Such small peak is not observed when samples of laboratory recrystallized material are used. However the thermal behaviour of the latter preparation differs remarkably depending on storage conditions: the material kept in closed glass containers decomposes at temperatures higher than those of the material stored in a dessiccator in the presence of concentrated H₂SO₄. The observation by optical microscopy of the behaviour of the surfaces of single crystals coming from different storage conditions when the temperature is raised in a Kofler heater helps the interpretation of the data collected. The mechanism of the decomposition is discussed and the relevant kinetic parameters reported.     

Synthesis of carbamoylformhydroxymoyl chlorides and study of their reactivities

Carbamoylformhydroxymoyl chlorides were synthesized by the reactions of carbamoylformamide oximes with sodium nitrite in the presence of hydrochloric acid, and their reactivities were examined.     

Growth Mechanism of Large Monodispersed Silica Particles Prepared from Tetraethoxysilane in the Presence of Sodium Dodecyl Sulfate

Monodispersed silica particles up to ca. 1.2 μm in diameter were prepared by hydrolysis of tetraethoxysilane in the presence of sodium dodecyl sulfate (SDS). The particle size was increased with an increase of SDS added. The geometrical standard deviation of the particles was decreased with an increase of SDS. In the earlier reaction stage, double spherical particles by the coalescence of the particles were frequently observed when large amounts of SDS were added. Particle size was gradually increased after the coalescence occurred and spherical particles were finally obtained. The results of Nielsen’s chronomal analysis suggest that the polynuclear layer growth took place after the coalescence of the particles in the presence of larger amount of SDS.     

氯化钠在球形纳米氧化铈形成过程中的作用

以水合碳酸铈为原料, 以氯化钠作为助磨剂和阻聚剂, 采用机械活化法制备了球形纳米氧化铈, 用XRD法研究了水合碳酸铈与氯化钠质量比、球磨时间、煅烧温度对CeO2粉体晶粒度的影响, 用TEM对最终产物粒子进行形貌观察. 结果表明: 在碳酸铈的球磨过程及其随后的煅烧过程中, 氯化钠的存在起到了很好的助磨和阻聚作用, 所得CeO2为类球形粒子, 分散性较好, 晶粒度约为30～50 nm.