The Synthesis and 31P NMR Spectral Studies of Cyclophosphazenes

A modified method for preparing large-scale quantities of pure hexachlorocyclophosphazene (N₃P₃Cl₆) and octachlorocyclotetraphosphazene (N₄P₄Cl₈), phosphorus pentachloride with ammonium chloride, in the presence of zinc chloride, has been developed. The time of the reaction and the quantities of the catalyst are also studied. It is found that the optimum reaction time is 1.5 h and by-products are remarkably reduced by addition of 10% zinc chloride. As indicated by the ³¹ P NMR spectra, the synthesis and separation of cyclophosphazenes can be accomplished in moderate yield of tetramer (39%) and good yield of trimer (83%).     

Highly improved crystallization behavior of poly(L‐lactide) induced by a novel nucleating agent: substituted‐aryl phosphate salts

In this work, a novel nucleating agent (NA) based on substituted‐aryl phosphate salts was introduced into poly(L‐Lactide) (PLLA). The nonisothermal and isothermal crystallization behaviors of nucleated PLLA samples were investigated through differential scanning calorimetry (DSC), wide angle X‐ray diffraction, and polarized optical microscope (POM). Furthermore, the effect of annealing treatment on the cold crystallization behaviors of nucleated samples was also investigated. The results show that the crystallization of PLLA, whether for the melt crystallization (including nonisothermal and isothermal crystallization process) or for the cold crystallization (including the cold crystallization occurring during the DSC heating process and during the annealing process), is greatly dependent upon the content of NA. At relatively lower NA content (≤0.1 wt%), the nucleation effect of NA is inconspicuous, however, at higher NA content (≥0.2 wt%), it exhibits great nucleation effect for the crystallization of PLLA. Further results show that the double endothermic peak of PLLA depends on the temperature applied for the crystallization. Copyright © 2012 John Wiley & Sons, Ltd.     

Detection of Chemical Warfare Nerve Agents via a Beckmann Fragmentation of Aldoxime

Abstract

A new (E)-pyrene-1-carbaldehyde O-tert-butyldimethylsilyl oxime 3 was synthesized for the detection of chemical warfare nerve agents, O-isopropyl methylphosphonofluoridate (GB) and O-pinacolyl methylphosphonofluoridate (GD). ¹H NMR spectrum showed that the tert-butyldimethylsilyl (TBDMS) group was deprotected using TBAF and the oximate supernucleophile was made. Upon addition of chemical warfare agents (GB and GD) (50 mol%), the reaction was completely finished within 5 min and also the color change of reaction mixture was observed under a hand-held UV lamp with the naked eye.     

The Special Issue Dedicated to the Memory of Professor Wei-Shan Zhou(周维善)

This special issue is dedicated to the memory of thelate Professor Wei-Shan Zhou at Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences.     

Quantitative microfluidic biomolecular analysis for systems biology and medicine

In the postgenome era, biology and medicine are rapidly evolving towards quantitative and systems studies of complex biological systems. Emerging breakthroughs in microfluidic technologies and innovative applications are transforming systems biology by offering new capabilities to address the challenges in many areas, such as single-cell genomics, gene regulation networks, and pathology. In this review, we focus on recent progress in microfluidic technology from the perspective of its applications to promoting quantitative and systems biomolecular analysis in biology and medicine.     

Synthesis of monodisperse oligocarbazoles-functionalized anthracenes with intense blue-emitting

New well-defined monodisperse oligocarbazoles-functionalized anthracenes An-OCZn (n = 1, 2, 3) have been synthesized through Suzuki cross-coupling reaction of the brominated oligocarbazoles and 9,10-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anthracene. They show good solubility in organic solvents, including dichloromethane, chloroform, toluene, ethyl acetate, and tetrahydrofuran. It should be noted that, in the case of An-OCZn, the formation of the excimer based on anthracene unit is suppressed completely due to the introduction of oligocarbazoles in 9,10-position of anthracene so that an intense blue-emitting has been afforded. In addition, the obtained An-OCZn exhibit good electrochemical and thermal stabilities. Thus, the oligocarbazoles-functionalized anthracenes can be a class of promising candidates for novel blue-emitting materials employed in OLEDs or related devices.     

体积排阻色谱-电感耦合等离子体质谱分析富硒大米含硒蛋白组成

建立体积排阻色谱-电感耦合等离子体质谱(SEC-HPLC-ICP-MS)联用技术分析富硒大米含硒蛋白组成方法。通过水提、盐提、碱提和醇提方法提取,并用丙酮沉淀蛋白,硒的回收率分别为9.6%,16.8%,48.2%和14.9%,纯化后的蛋白结合硒的量由大到小依次为碱溶谷蛋白>球蛋白>醇溶蛋白>清蛋白。蛋白液经SEC-HPLC-ICP-MS检测,通过蛋白色谱峰(λ=280 nm)和ICP-MS硒峰(78Se)对比分析,利用分子量标准曲线测定出4类蛋白中含硒蛋白的分子量。结果表明,富硒大米中清蛋白和醇溶蛋白并不是硒的主要存在蛋白。硒主要存在于>7 kDa的碱溶谷蛋白和球蛋白,其中碱溶含硒蛋白主要组分F1分子量为199.8 kDa。