306988-01-2Relevant articles and documents
Liquid crystal compounds having bis(trifluoromethyl) phenyl rings, liquid crystal compositions and liquid crystal display devices
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, (2008/06/13)
The compound (1) having 2,3-bis(trifluoromethyl)-1,4-phenylene is stable chemically and has excellent miscibility with other liquid crystal compounds, large and negative dielectric anisotropy and proper optical anisotropy. A liquid crystal composition comprising the compound has large specific resistance and a large voltage holding ratio, and that the composition is useful for a liquid crystal display element. The compound (1) is represented by formula (1): Ra[!Parenopenst!]A1—Z1[!Parenclosest!]m[!Parenopenst!]A2—Z2[!Parenclosest!]n—A3—Z3—A4—Rb??(1) wherein Ra and Rb independently are alkyl having 1 to 20 carbons, any —CH2— in the alkyl may be replaced by —O—, —S—, —CH═CH—, or —C≡C—, and any hydrogen may be replaced by halogen; A1, A2, A3, and A4 independently are 1,4-cyclohexylene, 1,4-cyclohexenyleene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyridazine-3,6-diyl, or 2,3-bis(trifluoromethyl)-1,4-phenylene, any hydrogen in these rings may be replaced by halogen, and at least one of A1, A2, A3, and A4 is 2,3-bis(trifluoromethyl)-1,4-phenylene; Z1, Z2 and Z3 independently are a single bond, —(CH2)2—, —(CF2)2—, —COO—, —OCO—, —CH2O—, —OCH2—, —CF2O—, —OCF2—, —CH═CH—, —CF═CF—, —C≡C—, —(CH2)4—, —(CH2)3O—, or —Q(CH2)3—; m and n independently are 0 or 1.
