J. Phys. II France
Volume 6, Numéro 2, February 1996
Page(s) 271 - 279
DOI: 10.1051/jp2:1996181
J. Phys. II France 6 (1996) 271-279

Structural Characterization of New Ferroelectric Liquid-Crystalline Siloxanes

Mohammed Ibn-Elhaj1, Antoine Skoulios1, Daniel Guillon1, Joanna Newton2, Philip Hodge2 and Harry J. Coles2

1  Institut de Physique et Chimie des Matériaux de Strasbourg CNRS: UMR 380046, Groupe des Matériaux Organiques, 23 rue du Loess, 67037 Strasbourg Cedex, France
2  Liquid Crystal Group, Physics Department, The University, Manchester, M13 9PL, UK

(Received 6 June 1995, received in final form 16 October 1995, accepted 23 October 1995)

In a previous paper [1] we reported the structural study of new smectogenic molecules containing three distinct parts, an aromatic core, a central paraffin chain and a siloxane endgroup. In the present paper we report the structural characterization of new ferroelectric liquid crystalline siloxanes containing, in addition to these three parts, a branched aliphatic tail. These low molar mass chiral organosiloxane mesognes and their racemic analogs have been characterized using X-ray diffraction both on powder and oriented samples. The chiral (and achiral) compounds exhibit enantiotropic ferroelectric smectic C * (or smectic C) mesophases with high tilt angles at low temperatures and over a broad temperatrue range.

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