Carboxylate compounds, liquid crystal compositions and liquid crystal elements containing said compounds and method of optical modulation using said elements.

摘要

The invention provides carboxylate compounds of the following formula (A): <CHEM> wherein R is a group selected from C3-C20 alkyl, C3-C20 alkoxy and halogenated C3-C20 alkyl, X and Y are each, independently, a group selected from: -COO-,-OCO-, -CH2CH2-. CH2O-, OCH2-, -S-S-, <CHEM> and <CHEM> or a single bond, A and B are each, independently, a group selected from <CHEM> <CHEM> and <CHEM> and R<*> is an optically active group of 4 to 20 carbon atoms, the group containing at least one asymmetric carbon atom and being optionally substituted by one or more halogen atoms, and m and n are each an integer of 0 to 2; with the proviso that both m and n are not 0 at the same time. The compounds are employed in liquid crystal compositions. A liquid crystal element containing such a composition, a process for the preparation of the element and a method of light modulation involving use of the element are also disclosed.