《化学化工专业英语.ppt》由会员分享，可在线阅读，更多相关《化学化工专业英语.ppt（12页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、09级化学类演讲人：贾会友制作者：刘月宇Theme：Application of Tin and Nanometer Tin in Allylation of Carbonyl Compounds in Tap Water As we all know chemical pollution is global problem，How to reducing chemical pollution？Introduction With the development of industrialization,organic chemists have been confronted with a n
2、ew challenge of finding novel methods in organic synthesis that can reduce and finally eliminate the impact of volatile organic solvents and hazardous toxic chemicals on the environment.So,using aqueous media to perform organic reactions has attracted considerable interest recently because water is
3、considered to be a safe and environmentally benign solventThe first of experiment step Firstly,to initiate the experiment,a mixture of benzaldehyde,allyl bromide,and the metal powder in 3 mL of distilled or tap water without any coreagent or cosolvent was stirred at room temperature.The second of ex
4、periment stepAfter about 24 h,the reaction was monitored by TLC,and the reaction mixture was extracted with ether;subsequently,the ether extract was washed with water and dried with magnesium sulfateThe third of experiment stepAfter removal of the solvent,the crude product was obtained.The yield of
5、the allylation product was measured by 1H NMRThe metals used varied from Fe to Sn,and the reaction results are listed in Table 1.This study demonstrated that the unusual phenomenon of nanometer tin-mediated allylation was caused by properties of nanometer tin particles.The smaller the radius of tin
6、nanometer particles,the greater the ratio of surface to volume,which leads to a large increase of atoms on the surface and an abundance of suspended and unsaturated bonds and so on,affected by the unsaturated coordination.All these make the surface of the tin nanometer particle more active and enhan
7、ce the reaction selectivity.What is more,replacing the distilled water with tap water had no influence on the allylations.Our work showed us that substantial progress could be made in organic reactions in water,which have great potential in reducing chemical pollution.What is more,replacing the dist
8、illed water with tap water had no influence on the allylations,it supply a way to do the organic experiment in the waterConclusionIn conclusion,the result demonstrated that an efficient and clean synthesis for allylation in distilled or tap water with high product yields can be developed.Nano-tin particles were applied in the allylations of aldehyde and ketone,and satisfactory results were obtained.