| 摘要 |
Anisotropic compounds having a nematic phase have the formula <IMAGE> (1) wherein A is a cyclic radical selected from the group consisting of <IMAGE> (10) <IMAGE> (11) <IMAGE> (12) Z is selected from the group consisting of a single bond, a -CH2CH2- group, a methyleneoxy group and an oxymethylene group, n is 1 or 2, p is 0, 1, or 2, r is 0 or 1, X is selected from the group consisting of fluorine, chlorine, bromine, iodine, nitrile and methyl, R1 and R2 are selected from the group consisting of hydrogen, C1-C12-alkyl, C1-C12-alkoxy, C1-C12-alkanoyloxy and C1-C12-alkylamino and cyclic groups of the formulas <IMAGE> (13) <IMAGE> (14) <IMAGE> (15) <IMAGE> (16) wherein R3 through R6 are selected from the group consisting of hydrogen, C1-C12-alkyl, C1-C12-alkoxy, C1-C12-alkanoyloxy, and C1-C12-alkylamino, and Z2 through Z6 represent a Z group, with the provisos that: (A) none of the above aromatic radicals (10), (11), (13), (14) or (15) is directly bonded to the C-atom of a methyleneoxy or oxymethylene group; and (B) at least one X group is methyl when only one or none of the groups R1 and R2 is a cyclic radical of formulas (13) or (16), A has the formula (12), Z is a single bond, and any of Z3 or Z6, if present, is a single bond. Compounds having the defined lateral substituents on the rings have a reduced tendency to form smectic phases as compared with the compounds not having such lateral substituents.
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