Use of optically active tetrahydrofuran-2-carboxylic acid esters as dopants in liquid-crystal mixtures, liquid-crystal mixtures containing same and novel optically active tetrahydrofuran-2-carboxylic acid esters

US5384070A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Wolfgang Hemmerling · Pocking, DE
• Hans-Rolf Dubal · Königstein, DE
• Claus Escher · Mühltal, DE
• Gerhard Illian · Frankfurt am Main, DE
• Yoshio Inoguchi · Tokyo, JP
• Ingrid Muller · Niedernhausen, DE
• Mikio Murakami · Kakegawa, JP
• Dieter Ohlendorf · Liederbach, DE
• Rainer Wingen · Hattersheim, DE

Key dates

• Filing date: May 20, 1993
• Grant date: Jan 24, 1995
• Expiry date: May 20, 2013

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K19/588
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The use of optically active tetrahydrofuran-2-carboxylic acid esters as dopants in liquid-crystal mixtures, liquid-crystal mixtures containing same and novel optically active tetrahydrofuran-2-carboxylic acid esters. Optically active tetrahydrofuran-2-carboxylic acid esters containing a mesogenic molecular building unit are suitable as dopants in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases having short switching times and in electroclinic phases having large electroclinic coefficients. A further advantage is that they induce a helix having a very small pitch so that they are also suitable for helix compensation in LC mixtures. The compounds are symbolized by the general formula: ##STR1## in which the symbols and indices essentially denote: R.sup.1 =alkyl/alkenyl or tetrahydrofurancarbonyloxy or -thio; j, l, n=zero, 1 or 2; k, m=zero or 1; --A.sup.1, --A.sup.2, --A.sup.3 =phenylene, cycloalkylene or corresponding heterocyclates containing nitrogen, oxygen or sulfur; --M.sup.1, --M.sup.2 =bridges such as --CO--O, --OCH.sub.2 or --CH.dbd.CH; X=oxygen or sulfur.