淡江大學機構典藏:Item 987654321/25215
English  |  正體中文  |  简体中文  |  全文笔数/总笔数 : 55956/90025 (62%)
造访人次 : 11521228      在线人数 : 85
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/987654321/25215


    题名: Smectic Liquid-Crystalline Phases of Quaternary Group VA (Especially Phosphonium) Salts with Three Equivalent Long n-Alkyl Chains. How Do Layered Assemblies Form in Liquid-Crystalline and Crystalline Phases?
    作者: Abdallah, David J.;Robertson,Allan;徐秀福;Hsu, Hsiu-Fu;Weiss, Richard G.
    贡献者: 淡江大學化學學系
    日期: 2000-04-05
    上传时间: 2009-12-01
    出版者: American Chemical Society (ACS)
    摘要: The neat phase behavior of 28 phosphonium salts (nPmA), each with three equivalent long n-alkyl chains containing m carbon atoms and one shorter chain containing n carbon atoms or a benzyl group, have been examined. Eighteen form a liquid-crystalline smectic A2 (SmA2) phase, where the lipophilic chains assemble in bilayers that sandwich an “ionic plane” consisting of an array of anions and positively charged phosphorus atoms. Several analogous ammonium salts are examined as well. These are the first structures reported for liquid-crystalline amphiphiles containing three equivalent long n-alkyl chains and a single atom headgroup. In addition, the nPmA demonstrate how the steric interactions of lipophilic chains and electrostatic interactions among the ionic parts must be balanced in layered assemblies when the cross-sectional area of the chains is much larger than that of the headgroups. A model is proposed to explain the dependence of layer thicknesses in the liquid-crystalline phases of the nPmA on m, n, and the size of the anion. A comparison is made of the packing modes among analogous Group VA salts (N.B., N or P) with 1−4 long n-alkyl chains (and the remainder as methyl groups) in their neat crystalline and liquid-crystalline phases.
    關聯: Journal of the American Chemical Society 122(13), pp.3053-3062
    DOI: 10.1021/ja994055g
    显示于类别:[化學學系暨研究所] 期刊論文

    文件中的档案:

    档案 大小格式浏览次数
    0KbUnknown224检视/开启

    在機構典藏中所有的数据项都受到原著作权保护.

    TAIR相关文章

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