English  |  正體中文  |  简体中文  |  全文笔数/总笔数 : 56738/90513 (63%)
造访人次 : 12089274      在线人数 : 158
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
搜寻范围 查询小技巧:
  • 您可在西文检索词汇前后加上"双引号",以获取较精准的检索结果
  • 若欲以作者姓名搜寻,建议至进阶搜寻限定作者字段,可获得较完整数据
  • 进阶搜寻

    jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/61533

    题名: Comparison of the orders of gas-phase basicities and ammonium ion affinities of polyethers by the kinetic method and ligand exchange technique
    作者: Wu, H. F.;吳慧芬;Brodbelt, J. S.
    贡献者: 淡江大學化學學系
    日期: 1993-09-01
    上传时间: 2011-10-15 23:14:19 (UTC+8)
    摘要: The orders of relative gas-phase basicities and ammonium ion affinities of a series of polyethers obtained by application of the kinetics method and ligand exchange technique are compared to evaluate the discrepancies of results between the two techniques. The order of gas-phase basicities determined by the ligand exchange technique in a quadrupole ion trap agrees with the order established previously by Kebarle using equilibrium methods in a high-pressure mass spectrometer. The order obtained by the kinetic method in a triple quadrupole mass spectrometer varies for the ranking of one polyether (12-crown-4), and this discrepancy is attributed to a difference in the rates of the competing dissociation pathways from the triethylene glycol dimethyl ether/12-crown-4 proton-bound adduct, owing to a substantial variation in the flexibilities of these two ethers. For the order of gas-phase ammonium ion affinities, the kinetic method results agree overall with the ligand exchange results; however, the order of ammonium ion affinities for tetraethylene glycol dimethyl ether and 15-crown-5 could not be differentiated by the ligand exchange method because of the rapidity of ammonium ion transfer between the two polyethers in both directions.
    關聯: Journal of the American society for mass spectrometry4, pp.718-722
    DOI: 10.1016/1044-0305(93)80050-9
    显示于类别:[化學學系暨研究所] 期刊論文


    档案 大小格式浏览次数



    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - 回馈