芳香烃氯甲基化反应的综述

芳香烃氯甲基化是有机合成中的重要反应。本文综述了芳香烃氯甲基化的反应，并按不同类型的氯甲基化试剂、不同活性的反应催化剂、不同极性的反应介质，及采用相转移催化技术等四方面分别予以讨论     

氯铝酸室温离子液体介质中Blanc氯甲基化反应的研究

在卤化1－烷基吡啶，1－甲基－3－烷基咪唑季胺盐和盐酸三甲胺与无水 AlCl3构成的氯铝酸室温离子液体反应介质中，尝试了苯及其衍生物和氯甲醚的 Blanc氯甲基化反应。结果表明底物的不同对反应有较大影响，苯与氯甲醚反应主 要生成氯甲基化产物，而烷基苯与氯甲醚反应则主要生成二苯基甲烷衍生物。反应 具有适中至高的转化率和选择性，依据底物的不同，反应结束后可以和离子液体系 分层，便于产物分离。氯铝酸离子液体具有一定的重复使用性。     

Geographical origin of Sauvignon Blanc wines predicted by mass spectrometry and metal oxide based electronic nose

Analysis of 34 Sauvignon Blanc wine samples from three different countries and six regions was performed by gas chromatography-mass spectrometry (GC-MS). Linear discriminant analysis (LDA) showed that there were three distinct clusters or classes of wines with different aroma profiles. Wines from the Loire region in France and Australian wines from Tasmania and Western Australia were found to have similar aroma patterns. New Zealand wines from the Marlborough region as well as the Australian ones from Victoria were grouped together based on the volatile composition. Wines from South Australia region formed one discrete class. Seven analytes, most of them esters, were found to be the relevant chemical compounds that characterized the classes. The grouping information obtained by GC-MS, was used to train metal oxide based electronic (MOS-Enose) and mass spectrometry based electronic (MS-Enose) noses. The combined use of solid phase microextraction (SPME) and ethanol removal prior to MOS-Enose analysis, allowed an average error of prediction of the regional origins of Sauvignon Blanc wines of 6.5% compared to 24% when static headspace (SHS) was employed. For MS-Enose, the misclassification rate was higher probably due to the requirement to delimit the m/z range considered.     

Re-interpretation of the Old Masters' practices through optical and rheological investigation: The presence of calcite

Lead white, composed of a mixture of cerussite and hydrocerussite (respectively PbCO₃ and Pb₃(CO₃)₂(OH)₂), is often associated in paintings with other white pigments, especially calcite. By combining in-situ analyses with paint reconstructions, we attempt to get a better understanding of the role of this addition of calcite and to investigate how artists may have used it to modify the properties of their paints. Lead-based white pigments of a Dutch 17th-century nuancier have been analysed as well as historical paintings. Two examples are given: one from a painting by Roger van der Weyden, in the 15th century, and one by Nicolas Poussin, in the 17th century, from specific zones that indicate the addition of calcite. The presence of calcite and pigments enhances both the optical and the rheological properties. Visible reflectance spectroscopy was carried out on pure paints as well as mixtures and indicated an increase in the transparency of the paint mixture in comparison to pure lead white. Rheological measurements also indicated an increase in the elastic and viscous moduli, as well as of the yield stress again in comparison to pure lead white. Calcite could thus have been used to assist in the creation of impasto effects in lead white paints.