Nucleophilic aromatic substitution reaction of nitroarenes with alkyl- or arylthio groups in dimethyl sulfoxide by means of cesium carbonate

Treatment of nitroarenes having electron-withdrawing groups at the ortho or para position with alkanethiol in the presence of cesium carbonate in dimethyl sulfoxide at 25 °C leads to nucleophilic displacement of the nitro group with the alkylthio group. Cesium carbonate is superior to other bases such as potassium carbonate, sodium carbonate, and triethylamine. The cesium-mediated nucleophilic aromatic substitution reaction provides a mild yet powerful and user-friendly protocol for the synthesis of aryl sulfides.     

The homologous conjugate addition of thiols to electron-deficient cyclopropanes catalyzed by a calcium(II) complex

The synthesis of γ-sulfanyl malonates was achieved through the addition of thiols to electron deficient cyclopropanes. These reactions are catalyzed by calcium acetylacetonate, Ca(acac)₂. A variety of electron rich and electron deficient thiols were added without the need for prior activation or exogenous base. The thiol additions to donor–acceptor cyclopropanes bearing electron-rich and electron-deficient aromatic and heteroaromatic groups proceeded in good to excellent yields.     

Effect of thiol-containing monomer on the preparation of temperature-sensitive hydrogel microspheres

The main objective of this study is to prepare, thermally, sensitive microgel particles bearing thiol groups via precipitation polymerization of N-isopropylacrylamide (NIPAM), methylenebisacrylamide (MBA) and vinylbenzylisothiouronium chloride (VBIC) using 2-2′-azobis(2-amidinopropane)-dihydrochloride (V50) as initiator. The influence of various parameters has been investigated as a systematic study to point out the role of each reactant on polymerization conversion, and consequently, on particles and water-soluble polymer formation. The final microgel particles were characterized with respect to particle size and swelling ability. The aim of this paper is to complete our first short communication; Macromolecular symposia, 2000. 150: p. 283–290.     

Passive Q-switch and mode-locking modulators for Nd:hosted lasers

Four kinds of currently available Nd:hosted laser passive Q-switch and mode-locking modulators: plastic dye sheet, LiF:F₂⁻ color center crystal, Cr⁺⁴ :YAG crystal and RG1000 colored glass filter were investigated in detail and summarized for comparison for the first time. The LiF:F₂⁻ crystal with outstanding annealability, long lifetime, low cost and operability at high repetition rates is highly recommended.     

A simple acylation of thiols with anhydrides

Different thiols were efficiently acylated at room temperature with different anhydrides in the presence of potassium carbonate. Chemoselective protection of thiol in the presence of hydroxy group was achieved using di-tert-butyl dicarbonate and isatoic anhydride.     

基于S1000D标准的技术插图制作过程规范研究

为了规范交互式电子技术手册中技术插图制作过程,解决因不同制作者完成图形的差异性及格式多样化等问题,通过将S1000D、GJB6600等标准与本单位实际工作情况相结合,从技术插图的制作过程进行了全方位的分析研究,对插图标注、图层分配、布局等作了规范性要求,形成了切合实际满足IETM标准的技术插图制作过程规范,该规范能有效指导IETM实施过程中的技术插图制作,提高IETM手册的编制效率和过程质量。本研究使技术插图的制作过程真正实现了规范化。     

S1000D标准下数据模块发布样式的研究

【】：为了促进S1000D标准在以信息化为中心的综合保障技术中的应用,满足后勤保障信息的有效管理与使用,本文在研究了S1000D标准的基础上,重点研究了数据模块样式发布的方法。并以某一民用航空发动机的描述性信息数据模块为研究对象,研究了利用XSL-FO将XML文档到PDF文档格式的转换方法并实现了最终的展示效果。该方法对于相关标准和技术在实际工作中的应用具有重要的指导性意义。     

Electrode Modified with Cobalt Cyclohexylbutyrate for the Determination of Low Molecular Weight Thiol Group Bearing Compounds Using Catalytic Stripping Voltammetry

Glassy carbon electrode, modified with cobalt(II) cyclohexylbutyrate monohydrate immobilized in polystyrene matrix is usable for determination of thiol group bearing compounds both in oxidized and reduced forms using catalytic stripping voltammetry. The measurements are carried out in acetate buffer (pH 4.3) containing Tween 40. After the accumulation step at −850 mV vs. Ag/AgCl a peak at −170 mV is observed on linear sweep voltammogram, the height of which is proportional to the concentration of added thiol. Addition of carbon nanotubes into polystyrene film enhances the sensitivity of the modified electrode. The detection limit is 1×10⁻⁶ mol dm⁻³ for all studied thiols. The electrode can be regenerated by exposing it to the potential between 300–600 mV.     

Sensitivity of Positive Ion Mode Electrospray Ionization Mass Spectrometry in the Analysis of Thiol Metabolites

High signal intensities of glutathione (GSH), [GSH+H]⁺ (m/z 308), cysteine (CySH), [CySH+H]⁺ (m/z 122), and homocysteine (hCySH), [hCySH+H]⁺ (m/z 136), are observed in ESI MS with on‐line electrochemistry (EC). Dimers formed by H‐bonding, which are not electrochemical products, are detected as [2GSH+H]⁺ (m/z 615), [2CySH+H]⁺ (m/z 243) and [2hCySH+H]⁺ (m/z 271) together with disulfide dimers GSSG, CySSCy and hCySSCyh, [GSSG+H]⁺ (m/z 613), [CySSCy+H]⁺ (m/z 241) and [hCySSCyh+H]⁺ (m/z 269). When dopamine is present a thiol/dopamine quinone (DAQ) adduct is observed. Formation of this adduct is proposed to occur by an electrochemical mechanism during ESI. Catalysis of thiol oxidation and analysis of thiol mixtures is addressed.