Willgerodt-Kindler reaction at room temperature: Synthesis of thioamides from aromatic aldehydes and cyclic secondary amines

A simple method for the synthesis of thioamide derivatives in DMSO at room temperature and at 120 °C has been developed. Total 27 compounds were prepared under both conditions via a one-pot, three component reaction between substituted aromatic aldehydes, elemental sulfur powder, and cyclic secondary amines. By optimizing the mole ratio of sulfur powder and amines, we have successfully carried out Willgerodt-Kindler reaction of aromatic aldehydes at room temperature. At 120 °C, it is catalyst free reaction with lower reaction time whereas at room temperature, due to the additional amine molecule, Willgerodt-Kindler reaction of aromatic aldehydes is successfully carried out at room temperature. On gram-scale, the reaction is successfully attempted under both conditions with good yields.     

Titrimetric determination of gold by precipitation with hydroquinone

A rapid method for the volumetric determination of gold is described. Gold(III) is reduced to metal with excess of hydroquinone at room temperature and the excess is titrated with ceric sulphate. The effect of chloride ion on the reducibility of gold(III) to the metal is discussed. This method can be successfully employed for the determination of gold in presence of certain base and noble metals. The method was successfully adopted for the determination of gold in a commercial sample.     

Sorbents for Analytical Determination of Cesium-137 and Strontium-90 in Natural Objects

The problem of determination of small activities of cesium and strontium in natural waters can be successfully solved by as design of highly sensitive lowbackground devices as development of new efficient techniques of concentrating radionuclides from large volumes of natural waters. While the problem of cesium concentrating may be solved quite successfully by a number of sorbents,the strontium concentrating is rather complicated.     

Synthesis of 2-aminothiazoles from styrene derivatives mediated by 1,3-dibromo-5,5-dimethylhydrantoin (DBH)

An efficient procedure for the synthesis of 2-aminothiazoles via DBH-mediated oxidative cyclization of styrenes and thioureas is reported. Various alkenes were successfully transformed to the corresponding 2-aminothiazoles in yields of 10–81% via a two-step one-pot manner using DBH as both the bromine source and oxidant. The method can be readily carried out in gram-scale and successfully applied to the synthesis of anti-inflammatory drug fanetizole using styrene as starting material.     

Single-step in situ synthesis of double bond-grafted yttrium-hydroxide nanotube core-shell structures

Novel MMA-Y(OH)(3) nanotube core-shell structures have been successfully prepared with double bonds successfully grafted on the surface through a single-step in-situ hydrothermal method.     

氧化石墨的制备及其有机化处理

Graphite oxide(GO) was successfully prepared by using expandable graphite， which is a new starting material instead of the normally adopted natural graphite. XRD and XPS data indicated that， in the same reaction condition due to the application of expandable graphite， the extent of oxidation for the product， GO， was considerably en-hanced and the period required for oxidation was greatly shortened. In addition， the prepared GO was modified by surfactant， that is the new sample， S-GO， was obtained. As a consequence the extended interlayer space has proved itself to be successfully intercalated by the surfactant.     

Deconvolution of optical stimulated luminescence decay curves

The Thermoluminescence (TL)-like presentation method introduced to describe the isothermal decay of a thermoluminescence glow-peak, is extended in the present work for the case of the Optical Stimulated Luminescence (OSL) decay curves. The Glow-Curve Deconvolution analysis extensively used to analyse TL glow-curves is successfully applied to find the individual components of the Optical stimulated decay curves. The method is successfully applied to both synthetic and experimental OSL decay curves of quartz, feldspar and mixed quartz plus feldspar aliquots. The potential use of the Peak Shaped (PS) TL-like presentation to extract qualitative and quantitative information from an OSL decay curves is also discussed.     

一种双光束红外光谱及其在气固相多相催化反应实时原位表征中的应用

单光束红外光谱技术(原位傅立叶透射变换红外、原位漫反射红外和衰减全反射红外光谱技术)虽然已经用于气固相多相催化反应的原位表征中,但这些光谱在真实反应条件下会受到气体分子振动光谱和加热条件下产生的发射光谱的严重影响,不能实时获得催化剂表面的真实信息.另外,由于在真实的气固相多相催化反应过程中,催化剂本底的信息会随着反应时间的延长而发生变化,因此单光束红外光谱技术在扣除本底信息方面存在误差.为了实现在反应条件下,实时、原位表征催化剂表面的状态,我们报道了一种双光束红外光谱表征技术.该技术包括双光束红外光谱系统及双光束红外反应池.其特征在于:实时双光束原位红外光谱系统由两台完全相同的红外光谱仪和双光束红外反应池组成.双光束红外反应池由完全相同的样品池和参考池连接而成,样品池和参考池处于同一水平线上分别对应于样品光谱仪和参考光谱仪,由计算机同步控制两台红外光谱仪,排除实时状态下的气体分子振动光谱干扰和加热条件下产生的发射光谱干扰.该技术可以对真实反应条件下的气固相多相催化反应进行实时原位表征.通过应用程序的关联可以实时、同步采集样品光束和背景光束谱图来得到催化剂表面物种随反应时间变化的真实信息.该技术克服了单光束红外光谱在原位多相催化反应表征方面的缺陷,使表征结果变得更加精确可靠.该技术还可以在变化的气相组分条件下,获得不同温度下、实时的催化剂表面活性中心、活性相和中间物种的信息.采用上述双光束红外光谱仪对丁烯在纳米HZSM-5催化剂上芳构化反应过程进行了实时、原位观测,首次在实际反应条件下,观察到了异丁烯在纳米HZSM-5沸石的表面Br?nsted酸中心上经历吸附、活化、聚合、环化等反应步骤生成芳烃的过程.     

Sonoelectrochemical synthesis of CdSe nanotubes

CdSe nanotubes were successfully synthesized by a sonoelectrochemical technique for the first time; the formation process of the CdSe nanotubes was carefully studied and a sonication-induced roll-up mechanism is proposed.     

Synthesis of modified DNA by PCR with alkyne-bearing purines followed by a click reaction

Alkyne-bearing deazapurine triphosphates were prepared and successfully incorporated into DNA using the polymerase chain reaction (PCR). The obtained alkyne-labeled DNA was successfully used in a click reaction with galactose azide.     

Development and validation of a solid-phase microextraction method for the analysis of volatile organic compounds in groundwater samples

Summary Solid-phase microextraction is a relatively recent extraction technique for sample preparation. It has been used successfully to analyse environmental pollutants in a variety of matrices such as soils, water and air. In this work, a simple and rapid method for the analysis of volatile organic and polar compounds from polluted groundwater samples by SPME coupled with gas chromatography (GC) is described. Different types of fibres were studied and the extraction process was optimised. The fibre that proved to be the best to analyse this kind of samples was CAR-PDMS. The method was validated by analysis of synthetic samples and comparison with headspace—GC. The optimised method was successfully applied to the analysis of ground-water samples.     

Electroreduction of triphenylphosphine dichloride and the efficient one-pot reductive conversion of phosphine oxide to triphenylphosphine

Electroreduction of triphenylphosphine dichloride in acetonitrile was performed successfully in an undivided cell fitted with an aluminium sacrificial anode and a platinum cathode. Further, the one-pot transformation of triphenylphosphine oxide to triphenylphosphine was achieved successfully by the treatment of triphenylphosphine oxide in acetonitrile with oxalyl chloride and subsequent electrochemical reduction.     

2D NMR Studies on the Structure of Urushiol of Chinese Lacquer

The urushiol diacetate was successfully separated by centrifugal rotation TLC on the silica gel coated with silver nitrate.The structure and configuration of key component of.urushiol (64.6%) were determined successfully by using 1H and 13C conventional method,DEPT technique,homo- and heteronuclear chemical shift correlation 2D-NMR,2D-J NMR,hftteronuclear relayed coherencetransfer 2D-NMR,and relaxation time T1 investigation.The as-signment of resonances for 1H and C were confirmed.There is plentyof evidence which shows that the key component of urushiol is3-(8'Z,11'E,13'Z-pentadecatrienyl)catechol.The results show that RELAY 2D-NMR new technique can be successfully applied to determining the structure of complicated unknown compounds.     

A polar glass capillary column for residue work

Polydiethylene glycol adipate (DEGA) has been successfully used as stationary phase for residue analysis by glass capillary gas chromatography. A specially stabilized version of the phase yields a good polar column which is stable up to 250°C when used in temperature programmed cycles. The paper lists 90 pesticides that have been successfully chromatographed in ng quantities on a DEGA column.     

Synthesis of optically pure 2,3,4-trisubstituted tetrahydrofurans via a two-step sequential Michael-Evans aldol cyclization strategy: total synthesis of (+)-magnolone

Synthesis of optically pure 2,3,4-trisubstituted tetrahydrofurans is described employing a two-step Michael-Evans aldol cyclization strategy. The approach is successfully applied for the total synthesis of furano lignan natural product (+)-magnolone.     

全色光致聚合物的全息记录 特性及应用研究

优选亚甲基蓝、曙红Y、吖啶橙分别作为红敏、绿敏、蓝敏光敏剂,制作出全色光致聚合物全息记录材料.全息记录特性测量表明,该材料在红、绿、蓝三基色激光记录下均具有大于90%的衍射效率和较高的感光灵敏度(70 mJ/cm²).开展了该材料的角度复用、波长复用全息存储实验,在材料的同一位置处分别以不同参物光夹角及不同记录波长成功存储了多幅全息图,且再现图像清晰明亮,相互之间无明显串扰,表明该材料具有良好的全息记录性能及应用价值.     

Efficient synthesis of the key intermediate triptophenolide methyl ether for the synthesis of (−)-triptolide

An efficient synthesis of triptophenolide methyl ether 4 from the readily available abietic acid 3 in nine steps is described and successfully applied to the synthesis of (−)-triptolide 1. The route is of characteristic of low cost, high yield and easy operation. In addition, every reaction in this route has been successfully scaled-up to a 100 g substrate level without loss of yield.     

Cell-permeable small molecule probes for site-specific labeling of proteins

We have successfully synthesized a number of small molecule probes designed for site-specific labeling of N-terminal cysteine-containing proteins expressed in live cells. Their utility for site-specific, covalent modifications of proteins was successfully demonstrated with purified proteins in vitro, and with live bacterial cells in vivo.     

Nickel-catalyzed intermolecular codimerization of acrylates and alkynes

The linear codimerization of acrylates and alkynes to produce 1,3-dienes is successfully demonstrated using a nickel catalyst in association with 2-aminopyridine as an additive.     

Intercalation of multiply solvated hexafluorophospate anion into graphite electrode from mixtures of methyl acetate,ethyl methyl and ethylene carbonates

Graphite is a universal host material for ion intercalation.Li+-graphite intercalation compounds (GICs) have been successfully utilized as the anode material in...