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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
U.S. Patent Number: 5384070
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.
Inventors: Hemmerling; Wolfgang (Sulzbach, DE), Dubal; Hans-Rolf (Konigstein, DE), Escher; Claus (Muhltal, DE), Illian; Gerhard (Frankfurt am Main, DE), Inoguchi; Yoshio (Tokyo, DE), Muller; Ingrid (Hofheim, DE), Murakami; Mikio (Konigstein, DE), Ohlendorf; Dieter (Liederbach, DE), Wingen; Rainer (Hattersheim am Main, DE)
Assignee: Hoechst Aktiengesellschaft (Frankfurt am Main, DE)
Application Number: 08/065,080
Issued: 1995-01-24
Expired: 2007-01-24
Classes: 252/299.61 ; 349/182; 544/298; 544/318; 544/335; 546/268.7; 546/282.4; 546/284.7; 546/290; 546/296; 546/301; 546/339; 546/342; 548/128; 548/129; 549/357; 549/473; 549/499; 549/502
Field of search: 252/299.01,299.6,299.61,299.63 544/318,298,335 546/268,275,276,277,290,296,301,339,342 548/128,129 549/357,473,499,502
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