Polyhaloalkyl ether derivatives as well as liquid crystal compositions and liquid crystal display elements containing them

摘要

A compound expressed by the general formula (1): wherein R1 denotes an alkyl group having 1 to 20 carbon atoms in which one or more methylene groups in said group may be replaced by oxygen atoms or -CH=CH- and one or more hydrogen atoms in said group may be replaced by fluorine or chlorine atoms, with the proviso that two or more methylene groups may not be continuously replaced by oxygen atoms; Y1 denotes a halogen atom, CN, CF3, CHF2 or an alkoxy group having 1 to 5 carbon atoms, in which at least one hydrogen atom is replaced by a fluorine atom and one or more hydrogen atoms may be further replaced by chlorine atoms; Z1, Z2 and Z3 each independently denote a covalent bond, -CH2CH2-, -CH=CH- or CF2O-, with the proviso that at least one of Z1, Z2, and Z3 is -CF2O-; rings A1, A2 and A3 each independently denote trans-1,4-cyclohexylene, 3-cyclohexene-1,4-ylene, 3-fluoro-3-cyclohexene-1,4-ylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, trans-1-sila-1,4-cyclohexylene, trans-4-sila-1,4-cyclohexylene or 1,4-phenylene in which one or more hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, with the proviso that ring A1, A2 or A3 bonded with the carbon atom of -CF2O- is a member selected from the group consisting of trans-1,4-cyclohexylene, 3-cyclohexene-1,4-ylene, and 3-fluoro-3-cyclohexene-1,4-ylene; ring A4 denotes 1,4-phenylene in which one or more hydrogen atoms may be replaced by fluorine atoms or chlorine atoms; and m and n each independently denote 0 or 1.