Patent DE-19748818-A1 (DE)
Title: Optically active, smectic liquid crystal mixture, containing a temperature stable polyfluorinated cyclohexane derivative useful of the fabrication of switching and display devices
Inventor: WINGEN RAINER DR
IPC: C09K19/42
Filed: 1997-11-05
Abstract: A polyfluorinated cyclohexane derivative contains 2-4 ring systems of at least 5 members, and exhibits a stable smectic liquid crystalline phase, and is optically active.  A polyfluorinated cyclohexne derivative (I) is of formula (1) and contains 2-4 ring systems of at least 5 members: R<1>(-A<1>-M<1>)a(-A<2>-M<2>)b(-A<3>)c-M<3>-B(1) where: B = perfluorocyclohexyl (C6F11); R<1> = a) H, -OCF3, -CF3, -CN, -F, -Cl, -OCH2F, -OCHF2, -CHF2 or -CH2F; b) 1-20C alkyl whereby one or more non-neighbouring and non-terminal CH2 groups are optionally replaced by -O-, -S-, -CO-O-, -O-CO-, -O-CO-O- or -Si(CH3)2- and/or one or more CH2 groups are optionally replaced by -CH=CH-, -C equivalent to C-, cyclopropane-1,2-dinyl; 1,4-phenylene; 1,4-cyclohexylene or 1,3-cyclopentylene and/or one or more H atoms are optionally replaced by F and/or Cl and/or the terminal CH3 groups are optionally replaced by the following chiral groups (optically active or racemic):          R<3> - R<7> = H, 1-16C alkyl whereby one or more non-neighboring and non-terminal CH2 groups are optionally replaced by -O- and/or one or two CH2 groups are replaced by -CH=CH-. R<4> and R<5> together may be -(CH2)4- or -(CH2)5- if bonded to an oxirane, dioxolane, tetrahydrofuran, tetrahydropyran, butyrolactone or valerolactone system; M<1>, M<2> = -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CS-O-, -CS-S-, -O-CS-, -S-CS-, -CH2-O- M<3> = -O-CO-, -O-CH2-, -CH=CH-, -CH2-CH2-, -CH2CH2-O-CH2-, -CH2-CH2-O-C(=O)-, -CH2-CH2-CH=CH-, -(CH2)4- or a single bond; A<1>, A<2>, A<3> = 1,4-phenylene or pyridine-2,5-diyl, optionally having one or more H atoms substituted by F, Cl and/or CN; pyrazine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl, or thiophene-2,5-diyl, optionally having one or two H atoms substituted by F, Cl and/or CN; 1,4-cyclohexylene optionally having one or two H atoms replaced by CN, CH3 and/or F; napthalene-2,6-diyl, napthalene-1,4-diyl or napthalene-1,5-diyl optionally having one or more H atoms replaced by F, Cl and/or CN and/or one or two CH groups replaced by N; 1,3,4-thiadiazol-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,3-dithian-2,5-diyl , 1,3-thiazol-2,4-diyl, thiophene-2,4-diyl or 1,3-thiazol-2,5-diyl, optionally having one H atom replaced by F, Cl and/or CN; napthalene-2,6-diyl, napthalene-1,4-diyl or napthalene-1,5-diyl whereby one or more H atoms are replaced by F, Cl and/or CN and/or one or two CH groups are replaced by N; phenanthrene-2,7-diyl or 9,10-dihydrophenanthrene-2,7-diyl having one or more H atoms replaced by F and/or one or two CH groups replaced by N; indan-2,5-diyl, indan-1-one-2,5-diyl, benzothiazol-2,6-diyl, benzothiazol-2,5-diyl, benzoxazol-2,6-diyl, benzoxazol-2,5-diyl, benzofuran-2,5-diyl, benzofuran-2,6-diyl, 2,3-dihydrobenzofuran-2,5-diyl, piperazine-1,4-diyl, piperazine-2,5-diyl or 1,3-dioxaborinane-2,5-diyl; a, b, c = 0 or 1. Independent claims are included for (i) a liquid crystal mixture (II) containing one or more polyfluorinated cyclohexane derivatives (I) and (ii) a switch and/or display device containing an optically active, smectic liquid crystal mixture (II).