W. Weissflog, E. Dietzmann, C. Stützer
1996
Citations
0
Influential Citations
4
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Journal
Molecular Crystals and Liquid Crystals
Abstract
Abstract New benzoyloxybenzoic acids bearing both terminal and lateral groups have been synthesized. Substituted aryl rings are laterally attached to the basic mesogens by means of an odd-numbered spacer. Therefore, liquid crystalline behaviour can be observed at high temperatures. The crystal and molecular structure of 3-(4-cyano-benzyloxycarbonyl)-4-(4-n-octyloxybenzoyloxy)benzoic acid 3b has been determined by X-ray analysis. 3b crystallizes in space group P21/n with four molecules in a unit cell of the following dimensions: a = 15.682(2), b = 7.701(1), c = 23.107(3)A β = 97.69(1)°. The structure was solved by direct methods and refined to an R value of 0.057 for 3684 observed reflections. The molecules of 3b are associated to dimers with a shape unusual for mesogens exhibiting nematic and smectic phases. In the crystal the dimers are closely packed to ribbons which on their part are connected to lamellar sheets. The nitro-substituted homologue 3c was proved to be isostructural with 3b.