USE OF OPTICALLY ACTIVE TETRAHYDROFURAN-2-CARBONIC ACID ESTERS AS DOPING AGENTS IN LIQUID CRYSTAL MIXTURES, THESE CONTAINING LIQUID CRYSTAL MIXTURES AND NEW OPTICALLY ACTIVE TETRAHYDROFURANESE-2-CARBONSAE.

摘要

Optically active tetrahydrofuran-2-carboxylic acid esters containing a mesogenic molecular building block are suitable as dopes in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases having short switching times and in electroclinic phases having high electroclinic coefficients. A further advantage is that they induce a helix of very low pitch, so they are also suitable for helix compensation in LC mixtures. The compounds are symbolised by the general formula IMAGE in which the symbols and indices essentially have the following meanings: R1 = alkyl/alkenyl or tetrahydrofurancarbonyloxy or -thio; j, l and n = zero, 1 or 2; k and m = zero or 1; -A1, -A2 and -A3 = phenylene, cycloalkylene or corresponding N-, O- or S-containing heterocycles; -M1 and -M2 = bridges, such as -CO-O-, -OCH2- or -CH=CH-; and X = O or S.