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?

被引:118
作者
Abdallah, DJ
Robertson, A
Hsu, HF
Weiss, RG [1 ]
机构
[1] Georgetown Univ, Dept Chem, Washington, DC 20057 USA
[2] Cytec Ind Inc, Niagara Falls, ON L2E 6T4, Canada
[3] MIT, Dept Chem & Biochem, Cambridge, MA 02139 USA
关键词
D O I
10.1021/ja994055g
中图分类号
O6 [化学];
学科分类号
0703 ;
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 Az (SmA(2)) 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-allcyl chains (and the remainder as methyl groups) in their neat crystalline and liquid-crystalline phases.
引用
收藏
页码:3053 / 3062
页数:10
相关论文
共 55 条
  • [1] Crystal structures of symmetrical tetra-n-alkyl ammonium and phosphonium halides.: Dissection of competing interactions leading to "biradial" and "tetraradial" shapes
    Abdallah, DJ
    Bachman, RE
    Perlstein, J
    Weiss, RG
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 1999, 103 (43): : 9269 - 9278
  • [2] ABDALLAH DJ, IN PRESS LIQ CRYST
  • [3] A NEW SMECTIC MESOPHASE WITH 2-DIMENSIONAL TETRAGONAL SYMMETRY FROM DIALKYLDIMETHYLAMMONIUM BROMIDES-ST
    ALAMI, E
    LEVY, H
    ZANA, R
    WEBER, P
    SKOULIOS, A
    [J]. LIQUID CRYSTALS, 1993, 13 (02) : 201 - 212
  • [4] TABLES OF BOND LENGTHS DETERMINED BY X-RAY AND NEUTRON-DIFFRACTION .1. BOND LENGTHS IN ORGANIC-COMPOUNDS
    ALLEN, FH
    KENNARD, O
    WATSON, DG
    BRAMMER, L
    ORPEN, AG
    TAYLOR, R
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2, 1987, (12): : S1 - S19
  • [5] VAN DER WAALS VOLUMES + RADII
    BONDI, A
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1964, 68 (03) : 441 - +
  • [6] AN ANALYSIS OF SOLID PHASE BEHAVIOR OF NORMAL PARAFFINS
    BROADHURST, MG
    [J]. JOURNAL OF RESEARCH OF THE NATIONAL BUREAU OF STANDARDS SECTION A-PHYSICS AND CHEMISTRY, 1962, 66 (03): : 241 - +
  • [7] POLYMORPHISM IN ANHYDROUS AMPHIPHILIC SYSTEMS - LONG-CHAIN PRIMARY NORMAL-ALKYLAMMONIUM CHLORIDES
    BUSICO, V
    CERNICCHLARO, P
    CORRADINI, P
    VACATELLO, M
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1983, 87 (09) : 1631 - 1635
  • [8] THERMAL-BEHAVIOR AND OBSERVATION OF A SMECTIC PHASE IN N-PENTADECYLAMMONIUM CHLORIDE
    BUSICO, V
    CORRADINI, P
    VACATELLO, M
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1982, 86 (06) : 1033 - 1034
  • [9] HEXADECYLTRIMETHYLAMMONIUM BROMIDE
    CAMPANELLI, AR
    SCARAMUZZA, L
    [J]. ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS, 1986, 42 : 1380 - 1383
  • [10] DEMUS D, 1978, TEXTURES LIQUID CRYS, P61