3,4,5-trifluorobenzenes, and their use in liquid-crystal mixtures

US5716543A · kind A · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Hubert Schlosser · Hofheim, DE
• Dietmar Jungbauer · Weiterstadt, DE

Key dates

• Filing date: Apr 4, 1996
• Grant date: Feb 10, 1998
• Expiry date: Apr 4, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C2601/14
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A 3,4,5-trifluorobenzene derivatives of formula (I): ##STR1## in which R.sup.1 is a straight-chain or branched alkyl having 1 to 15 carbon atoms in which one or two nonadjacent --CH.sub.2 --groups are optionally replaced by --O--, --CH.dbd.CH--, --C.tbd.C--, cyclopropane-1,2-diyl or --Si(CH.sub.3).sub.2 --, and in which one or more H atoms in the alkyl radical may be substituted by F; A.sup.1, A.sup.2 and A.sup.3 are identical or different 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl in which one or two H atoms are, optionally, replaced by F, trans-1,4-cyclohexylene, 1,3-dioxane-2,5-diyl or naphthalene-2,6-diyl, PA1 M.sup.1 and M.sup.2 are identical or different --CH.sub.2 CH.sub.2 --,--CH.dbd.CH--,--C.tbd.C--,--CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 --O--,--O--CH.sub.2 --,--CO--O-- or--O--CO; X is --CH.sub.2 --O--,--OCH.sub.2 -- or --O--CO--; and k, l, m, n, o and p are zero or one provided that the sum k+m+o is greater than zero. The substances of the invention are characterized by a good temperature behavior of the nematic phase and good solubility.