New chiral ethers with the 2-arylidene-p-menthan-3-one skeleton have been investigated as components of the induced cholesteric (N*) systems based on 4-pentyl-4'-cyanobiphenyl. A rather high helical twisting power in combination with the weak temperature dependence of the induced helical pitch has been demonstrated for these compounds. The chiral compounds studied containing the terminal oxyalkyl group have been found to increase the thermal stability of N* mesophase. The experimental results obtained have been interpreted basing on the conformational analysis by semi-empirical AM1 and PM3 methods. The significant predominance of gauche-conformers of bent shape for benzyloxy fragment has been found to be the major factor causing the distinctions in the behavior of these chiral dopants in LC host system with respect to their linear analogs containing no ether linking group. The shift of the conformational equilibrium of the chiral ethers towards more anisometric conformers provoked by the orienting effect of the liquid crysalline environment has been assumed.

Date Published: 27 June 2002
PDF: 5 pages
Proc. SPIE 4759, XIV Conference on Liquid Crystals: Chemistry, Physics, and Applications, (27 June 2002); doi: 10.1117/12.472141

Published in SPIE Proceedings Vol. 4759:
XIV Conference on Liquid Crystals: Chemistry, Physics, and Applications
Jolanta Rutkowska; Stanislaw J. Klosowicz; Jerzy Zielinski, Editor(s)