Hydrothermal synthesis and crystal structure of a layered vanadium oxide with an interlayer metal coordination complex: [Co(phen)3][V10O26]·H2O

A novel compound, [Co(phen)₃][V₁₀O₂₆]·H₂O, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group Ccca with a=13.447(3), b=29.936(6), c=23.252(5) Å, V=9360(3) Å³, Z=8 and R=0.0285. Data were collected on a Rigaku R-AXIS RAPID IP diffractometer at 293 K in the range of 1.36<θ<24.99°. The structure of the compound consists of vanadium oxide layers, which are built up from the infinite VO₄ chains by corners and edges sharing. The [Co(phen)₃]²⁺ complexes occupy the interlayer space and contact each other via π−π stacking interactions of the phen groups to form infinite one-dimensional chains.     

Methotrexate-loaded biodegradable polymeric micelles: preparation, physicochemical properties and in vitro drug release

Polymeric micelles based on amphiphilic diblock copolymers methoxy poly(ethylene glycol)-polylactide with various hydrophobic lengths were designed as carriers of poorly water-soluble anticancer drug methotrexate (MTX). Relationship between physicochemical characteristics of micelles and release behavior was explored. The critical micelle concentration was determined by fluorescence spectroscopy using 9-chloromethyl anthracene as fluorescence probe. Core-shell type polymeric micelles were prepared by free-surfactant dialysis technique. The mean size of micelles loaded with MTX was 50-200 nm with narrow polydispersity. Physicochemical properties of drug-loaded micelles were evaluated. In vitro release behavior of MTX was also investigated. MTX was continuously released from micelles and less than 50% MTX was released in 5 days. Release rate was dependent on chemical structures of micelles and enhanced by decreasing polylactide lengths.     

Knoevenagel缩合反应研究的新进展

综述了近年来Knoevenagel缩合反应研究的新进展, 包括微波、超声波、固相合成、离子液体等新技术新试剂在该反应中的应用.     

聚乙酸乙烯酯的溶液性质及长链支化度

用粘度法,GPC和LALLS测定了线型及不同转化率的PVAc分级级份的粘度与分子量。提出了以线型和支化聚合物的K,α计算临界分子量的方法。讨论了表征PVAc长链支化的各种参数与分子量和转化率之间的关系以及不同条件下迭代法计算的支化频率λ的差异。实验结果表明,特性粘数和数均分子量乘积所表示的流体力学体积更适合GPC的普适标定概念。     

Rapid—In—situ Determination of Chromium （VI） in Water Using Modified Diphenylcarbazine with Citrate

In recent years, the determination of Cr (VI) has attracted great attention because of its toxicity to human, plants and animals1-5. Usually, in the industrial waste water, the concentration of Cr (VI) is relatively high and should be determined frequently. So, an accurate, quick, and convenient method for the measurement of Cr (VI) in environmental water, as well as in river, lake, sea and tap water, is of great importance. The method for determination of Cr (VI) by diphenylcarbazine …     

Determination of Enantiomeric Excess of Glutamic Acids by Lab-made Capillary Array Electrophoresis

The techniques of combinatorial chemistry have recently been applied to the discovery of new asymmetric catalyst for a variety of organic transformations1-3. Using combina- torial methods, it is straightforward to generate thousands of potential asymmetri…     

CO吸附在过渡金属铂表面的微观动力学研究

建立了处理双原子分子-表面相互作用的推广的LEPS势.借助推广的LEPS势,系统研究了一氧化碳分子在铂低指数表面吸附的动力学特性,重现了低指数表面的分子吸附热、吸附几何及本征振动等实验数据；鉴定了某些不合理的文献信息,预测了实验尚未探测到的重要信息:预测到Pt(100)表面四重洞位的C－O伸缩振动频率为1 962.60 cm－1;预测到Pt(110)表面吸附态的C－O及C－Pt键长分别为115.1、147 pm.     

蜜蜂外激素9－ODA和9－HDA的合成

６－溴－２－己酮在Ｌｉ２ｃｕＣｌ４催化下与γ－溴代巴豆酸甲酯进行格氏偶联，合成了蜂王物质９－羰基－（Ｅ）－２－癸烯酸（９－ＯＤＡ），将其还原得到另一蜂王物质９－羟基－（Ｅ）－２－癸烯酸（９－ＨＤＡ）。该法是合成９－ＯＤＡ和９－ＨＤＡ的新路线。     

Tuning cell adhesion on gradient poly(2-hydroxyethyl methacrylate)-grafted surfaces

A simple yet versatile method was developed to prepare a low-density polymerization initiator gradient, which was combined with surface-initiated atom transfer radical polymerization (ATRP) to produce a well-defined poly(2-hydroxyethyl methacrylate) (HEMA) gradient substrate. A smooth variation in film thickness was measured across the gradient, ranging from 20 A to over 80 A, but we observed a nonmonotonic variation in water contact angle. Fits of X-ray reflectivity profiles suggested that at the low graft density end, the polymer chain structure was in a "mushroom" regime, while the polymer chains at high graft density were in a "brush" regime. It was found that the "mushroom" region of the gradient could be made adhesive to cells by adsorbing adhesion proteins, and cell adhesion could be tuned by controlling the density of the polymer grafts. Fibroblasts were seeded on gradients precoated with fibronectin to test cellular responses to this novel substrate, but it was found that cell adhesion did not follow the expected trend; instead, saturated cell adhesion and spreading was found at the low grafting density region.