二甲苯异构体双电荷离子和单电荷离子的动能谱研究

利用质量分析离子动能谱和碰撞诱导解离技采研究了邻、间、对二甲苯分子在电子轰击质谱中产生的双电荷离子[C8H10]2+、[C8H9]2+和单电荷离子[C8H10]+。根据测定的电荷分离反应的释放动能T和由此估算的双电荷离子电荷分离反应过渡态两电荷间距R,推测出过渡态的结构,利用单电荷离子[C8H10]+的MIKES/CID谱可区分邻二甲苯与间、对二甲苯异构体.     

Kinetic Modeling of Ethylene Glycol Monoesterification

The monoesterification of ethylene glycol under isothermal conditions was conducted using benzoic acid in methane‐sulfonic acid/Al₂O₃ as a catalyst. Using this reagent, glycol was selectively monoesterified with high yield. The reactions were performed within an automated batch reactor under equimolar conditions, constant rotational frequency of the stirrer, and within the temperature range from 65 to 85°C. The rate constant related to this reaction and to the corresponding reverse reaction, activation energy, and preexponential factor was derived from experimental data. It has been concluded that under these conditions the formation of dibenzoate was successfully prevented.     

甲酰胺在乙二醇-水混合溶剂中的稀释焓

酰胺是肽的基本结构单元, 而且在蛋白质的二级结构中与酰胺联系的氢键对蛋白质的稳定起着十分重要的作用. 作为蛋白质模型化合物热力学性质研究的一部分, 报道了甲酰胺在乙二醇水溶液中的稀释焓.      

蒽醌在乙二醇/Triton X胶束与乙二醇/三乙胺溶液中光还原的时间分辨电子自旋共振研究

用时间分辨电子自旋共振研究了乙二醇/Triton X 胶束与乙二醇/三乙胺溶液中蒽醌(AQ)的光还原. 在蒽醌/乙二醇/Triton X/H₂O胶束中, 获得蒽半醌自由基AQH^•的很强的TR-ESR信号, 并检测到一定强度的负离子基AQ^•－ TR-ESR信号. 在蒽醌/乙二醇/三乙胺/H₂O体系中同时有较强的AQH^•与AQ^•－的TR-ESR信号. 分析并讨论了蒽醌在两种体系中的还原过程. 根据CIDEP的强度与Triton X及三乙胺浓度的关系, 推求了三线态³AQ^*对自由基AQH^•的反应速率常数. 根据化学诱导动态电子极化(CIDEP)信号随时间的变化, 计算了AQH^•的CIDEP弛豫时间.     

Foam Separation of Nickel and Copper Ions from Dilute Aqueous Solutions

The minimal expenditure of anionic surfactant, sodium dodecyl sulfate, required for decreasing concentrations of nickel and copper ions to the maximum permissible concentration was determined experimentally. A possibility of selective recovery of nickel ions by foam separation with sodium dodecyl sulfate under conditions of complex formation of copper cations with thiosulfate anions was studied.     

Effect of the B Vitamins on the Radiolysis of Aqueous Ethanol and Ethylene Glycol Solutions

The effects of vitamins B₁, B₂, and B₆ and pyridoxal phosphate on the formation of the final radiolysis products of aqueous ethanol and ethylene glycol solutions were studied. It was found that vitamin B₂ and pyridoxal phosphate effectively oxidize R^·CHOH species to suppress their recombination and fragmentation reactions, thereby increasing the yields of corresponding oxidation products. Vitamins B₁ and B₆ are capable of reducing alcohol radicals to the parent molecules and, hence, decreasing the yields of the main radiolysis products.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 5, 2005, pp. 325–329.Original Russian Text Copyright © 2005 by Lagutin, Shadyro.     

Effect of Anodic Polarization on the Hydrogen Diffusion through a Steel Membrane in Ethylene Glycol Solutions

Diffusion of hydrogen through a steel membrane from ethylene glycol solutions of HCl containing 0.1–10 wt % H₂O is studied. The effect of the nature of discharging proton, hydrogen ion concentration, and anodic polarization on the process is considered. Kinetic parameters of cathodic reduction of proton donors on the Armco iron under similar experimental conditions are obtained.     

Kinetic Parameters of Gold Dissolution in Cyanide Solutions: The Effect of Complex Cyanide Ions of Mercury

The kinetics of the gold dissolution in cyanide solutions is studied at constant values of the coverage () of the gold surface by mercury atoms. The constancy of is ensured by maintaining an identical value of the duration (t) of contact of electrode with solution (after renewing its surface by cutting off a thin surface layer of metal) at a potential of –1.3 V, at which the discharge of mercury ions is limited by their diffusion to the electrode. At t = const kinetic dependences of the gold dissolution process correspond to the Tafel equation. Effective values of exchange current i ₀, transfer coefficient , and reaction order by cyanide ions P are determined. With increasing value of their magnitude increases from values 10^–5 A cm^–2, 0.1, and 0.17 that are characteristic of purely cyanide solutions (composition 0.1 M KCN, 0.1 M KOH, and 0.01 M KAu(CN)₂) to i ₀ 2 × 10^–4 A cm^–2, = 0.46, and P 1 at t = 270 s. These results are compared with the data obtained earlier during similar investigations in solutions containing thallium, lead, and bismuth. Common and individual features in the behavior of mercury-containing electrolytes are revealed. It is shown that the possible mechanism of the acceleration of the gold dissolution process in the presence of catalytically active atoms, which had been proposed in these works, may be used also for explaining the action of mercury atoms on this process.     

Erratum to: “Aqueous Phenol and Ethylene Glycol Solutions in Electrohydrodynamic Liquid Bridging”

The original version of the article was published in Cent. Eur. J. Chem. 9(3) (2011), pp 391–403. Unfortunately, the original version of this article contains mistakes in the caption of the y-axis of Figs. 5,6 and 10 due to a font conversion problem. The actual units on the y-axis of these figures should be μS cm⁻¹, not mS cm⁻¹.     

Recovery of Nickel Ions from Dilute Solutions by Electrodialysis Combined with Ion Exchange

The possibility of using inorganic ion exchangers based on zirconium hydrophosphate and a weakly cross-linked cation-exchange resin for continuous purification of dilute nickel-containing solution by a combined method of electrodialysis and ion exchange was studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 418–424.Original Russian Text Copyright © 2005 by Dzyaz’ko, Rozhdestvenskaya, Pal’chik.     

气相二茂铁双电荷离子的动能谱研究

The unimolecular charge separation reactions of the doubly charged ions FeC_(10)H_(10)~(2+)、FeC_(10)H_9~(2+)、FeC_(10)H_8~(2+) produced in the ion source by electron impact from ferrocene have been studied using Mass analyzed Ion Kinetic Energy Spectrometry (MIKES) technique. From the values of the kinetic energy releases (T), the intercharge distances (R) of the exploding doubly charged ions in their transition structures have been estimated and some structural informations about the transition states can be obtained. The collision induced reactions of the FeC_(10)H_(10)~(2+) ion with Ar have been studied using MIKES, we postulate a new type of continuing reaction which may be "collisional charge separation induced dissociation".     

Effect of Fluoride or Chloride Ions on the Morphology of ZrO2 Thin Film Grown in Ethylene Glycol Electrolyte by Anodization

0.3 wt % ammonium fluoride (NH₄F) or ammonium chloride (NH₄Cl) was added to ethylene glycol (EG) as an active ingredient for the formation of anodic oxide comprising of ZrO₂ nanotubes (ZNTs) by anodic oxidation of zirconium (Zr) at 20 V for 10 min. It was observed that nanotubes were successfully grown in EG/NH₄F/H₂O with aspect ratio of 144.3. Shorter tubes were formed in EG/NH₄F/H₂O₂. This could be due to higher excessive chemical etching at the tip of the tubes. When fluoride was replaced by chloride in both electrolytes, multilayered oxide resembling pyramids was observed. The pyramids have width at the bottom of 3-4 μm and the top is 1-2 μm with 10.7 μm height. Oxidation of Zr in EG/NH₄Cl/H₂O₂ was rater rapid. The multilayered structure is thought to have formed due to the re-deposition of ZrO₂ or hydrated ZrO₂ on the foil inside pores formed within the oxide layer. XRD result revealed an amorphous structure for as-anodized samples regardless of the electrolytes used for this work.     

熔化提取-毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇的残留量

提出了毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇残留量的方法。样品在50℃熔化,经甲醇超声浸提,以丙二醇为内标,采用HP-5毛细管色谱柱分离,用火焰离子化检测器测定。乙二醇的质量浓度在102.6~1 026.0 mg.L-1范围内呈线性,方法的检出限(3S/N)为30 mg.L-1。应用此方法分析乙二醇硬脂酸酯,回收率在93.7%~103.2%之间。     

Solutions,in Particular Dilute Solutions of Nonelectrolytes: A Review

Journal of Solution Chemistry - The liquid state is one of the three principal states of matter and arguably the most important one; and liquid mixtures represent a large research field of profound...     

Effect of Ethylene Glycol and Its Oligomers on the Copper(II) Electroreduction Kinetics in Halide-Containing Acid Sulfate Solutions

The kinetics of the copper electroreduction in acid sulfate solutions containing ethylene glycol derivatives (EG) with the common formula HO-(CH₂-CH₂-O)_m-H is studied by means of voltammetry and impedance spectroscopy. All the EG (m≤6) display weak surface activity and barely effect the cathodic kinetics in the absence of halides. Halides can initiate inhibiting adsorption of EG only when the number of ether oxygen atoms in them is 3 (m ≤ 4), by inhibiting the first-electron transfer onto ions Cu²⁺. These effects are discussed invoking notions on the formation of pseudocrown structures in the adsorption layer.     

Crossover Equation of State and Microstructural Properties of Infinitely Dilute Solutions Near the Critical Point of a Pure Solvent

Microstructural (correlation integrals, cluster size) and related thermodynamic (partial molar volume, Krichevskii parameter) properties of infinitely dilute solutions near the critical point of a pure solvent are studied in terms of nonclassical (crossover) equations of state. The Krichevskii parameter was evaluated for a number of binary solutions by analyzing the initial slopes of the critical lines and the properties of a pure solvent. Qualitative explanation is offered for the physicochemical mechanism of the anomalously high solubility of slightly volatile substances in a supercritical solvent based on microstructural and thermodynamic characteristics of a supercritical fluid mixture.     

紫外分光光度法测定乙二醇中的钛含量

乙二醇中的钛加入浓硫酸后,在酸性介质中与过氧化氢(H2O2)发生配合显色反应,配合物的最大吸收峰位于410 nm处.对影响配合显色光度法测定钛含量的因素进行了考察,建立了乙二醇中的钛含量的测定方法,获得了满意的结果.该方法是一种简便、迅速、可靠的钛含量分析方法.