Odd-Even Effects in Bent-Core Compounds Containing Terminal N-Alkyl Carboxylate Groups
banana-shaped molecules, smectic liquid-crystals, 2 homologous series, achiral molecules, b-7 mesophase, helical superstructures, polar order, phase, mesogens, behavior
A homologous series of eleven five-ring symmetrical bent-core compounds containing terminal n-alkyl carboxylate groups were synthesized, characterized and their dielectric and electro-optical properties have been investigated. The lower homologues (n = 6-11) of the series show B-2 structures with an interesting odd-even effect concerning their local director tilt and polar arrangements. This odd-even effect probably is due to steric (entropic) reasons, which are not suppressed by the relatively low polar interaction. Three of the middle homologues display a B-7' phase, which is bistable and shows linear electro-optical switching with a transition to the chiral antiferroelectric smectic phase at a lower temperature. The higher homologues (n = 16, 18) exhibit only a B-7' phase.
Umadevi, S.; Jakli, Antal; and Sadashiva, B. K. (2006). Odd-Even Effects in Bent-Core Compounds Containing Terminal N-Alkyl Carboxylate Groups. Soft Matter 2(10), 875-885. doi: 10.1039/b605061a Retrieved from http://digitalcommons.kent.edu/cpippubs/337