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Proceedings Paper

Synthesis and mesophase studies of crown ether derivatives
Author(s): Olga Akopova; Anatoly Alexandrov; Tamara Pashkova; Lubov Kotovicz; Alexandr Kurnosov; Adam Krowczynski
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Paper Abstract

Novel mesogenic para-substituted dibenzo-18-crown-6 (I a-c) and dibenzo-24-crown-8 (II d, e) are studied. Synthesis and the structural investigations of 4,4'(5')-bis(4''- alkoxybenzylidenamino)-dibenzo-18-crown-6 (I-a), 4,5'-bis (3''-(4''-alkoxyphenyl-)-3''-oxo-1''-propenyl-amino)- dibenzo-18-crown-6(I-c), 4,5'-bis(4''-(4'''- alkoxybenzoyloxy)-benzylidenamino)-(II-e) are presented. The high temperature nematic phase is observed for the trans- isomers of materials I-b,c and II-d,e. The aroylvinylamine- derivatives (I-c, II-e) have higher phase transition temperatures than relevant azomethine derivatives (I-b, II- d). Among studied compounds the material II-d is the most stable. Materials I and II have also rather complex solid state polymorphism. The structure of Cr-8 (II-d and II-e) was investigated by the x-ray scattering method. In crystal phases of II-d and II-e the monoclinic lattices have been found with a equals 5.48 angstrom, b equals 8.34 angstrom, c equals 47.3 angstrom (beta) equals 124 degrees and a equals 45.0 angstrom, b equals 8.8 angstrom, c equals 13.8 angstrom, (gamma) equals 111 degrees parameters, respectively. The conformation of a central crown-ether fragment in the crystal as well as in nematic phase is suggested.

Paper Details

Date Published: 1 January 1998
PDF: 4 pages
Proc. SPIE 3319, Liquid Crystals: Chemistry and Structure, (1 January 1998); doi: 10.1117/12.301252
Show Author Affiliations
Olga Akopova, Ivanovo State Univ. (Russia)
Anatoly Alexandrov, Ivanovo State Univ. (Russia)
Tamara Pashkova, Ivanovo State Univ. (Russia)
Lubov Kotovicz, Ivanovo State Univ. (Russia)
Alexandr Kurnosov, Ivanovo State Univ. (Russia)
Adam Krowczynski, Univ. of Warsaw (Poland)

Published in SPIE Proceedings Vol. 3319:
Liquid Crystals: Chemistry and Structure
Marzena Tykarska; Roman S. Dabrowski; Jerzy Zielinski, Editor(s)

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