Crystal and molecular structure of isomorphous choiesteryl chloride and cholesteryl bromide

Vani, GV and Vijayan, Kalyani (1979) Crystal and molecular structure of isomorphous choiesteryl chloride and cholesteryl bromide. Molecular Crystal and Liquid Crystal, 51 . pp. 253-264.

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    Abstract

    Cholesteryl chloride and the isomorphous cholesteryl bromide crystallize in the monoclinic space group P2, with two molecules in the unit cell. The cell dimensions are a= 10.82, b=7.61, t = 21.46 xB1; 0.02 A, beta = 131.8 xB1; 1xB0; for the chloride and a = 11.10, b = 7.56, c = 21.83 xB1; 0.02 A, beta = 133.9 xB1; Iquot; for the bromide. The crystal structure has been solved by the heavy atom method and refined by least squares procedure using visually estimated photographic data. The terminal group of atoms C(25), C(26) and C(27) are disordered. The rings A and C in the molecule assume slightly distorted chair conformations. Ring B has a 8beta, 9x half-chair conformation and ring D has a 13beta, I4x half-chair conformation. The ring junctions B-C and C-D are trans whereas the junction A-B is quasi irons. The chain at C(17) is in a fully extended13; configuration.13; 13; The crystal packing is smectic-like with the molecules arranged in distinct layers. The neighboring molecules in a layer are oriented antiparallel to each other. The unit cells of the cholesteryl halides are two molecules thick, one molecule wide and one molecule long. The direction of thickness makes an angle of 35degree with the a-axis. The width is at 8xB0; to the b-axis and the length is at 5degree to the c-axis. The modified Hodgkin notation is 13; Ma(35degree)b(8degree)c(5degree)211.

    Item Type: Journal Article
    Additional Information: Copyright for this article belongs to Gordon and Breach Science Publishers Ltd.
    Uncontrolled Keywords: Cholesteryl bromide;Crystal and molecular structure;Isomorphous
    Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
    Division/Department: Other, Materials Science Division
    Depositing User: Mr. Ravikumar R
    Date Deposited: 18 Oct 2006
    Last Modified: 24 May 2010 09:52
    URI: http://nal-ir.nal.res.in/id/eprint/3108

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