| 摘要 |
Achiral fluorine-containing liquid crystal compounds are provided. These compounds are of the general formula I <IMG> where M, N and P are each independently <IMG> a, b, and c are independently zero or an integer of from 1 to 3 with the proviso that the sum of a + b + c be at least 2; each A and B are non-directionally and each independently nil, <IMG> <IMG>, -CH2CH2-, -CH=CH-, -C~C-, CH=N-, -CH2-O-, -CO-or -O-; each X, Y and Z are independently -H, -Cl, -F, -Br, -I, -OH, 2/3 -OCH3, -CH3, -CN or -NO2; each l, m and n are independently zero or an integer of 1 to 4, D is <IMG>, -O-(CH2)r-, -(CH2)r-, -OSO2-, -SO2-, -SO2-(CH2)r-, -O(CH2)r-O-(CH2)r, <IMG> where r and r' are independently 1 to 20, and p is 0 to 4; R is -O-C4H2q-O-C q'H2q'+l' -C q H2q-O-C q'H2q'+l' -C q H2q-R', -O-c q H2q-R', <IMG> where R' is -Cl, -F, -CF3, -NO2, -CN, -H, <IMG> and q and q' are independently 1 to 20, and R can be straight chain or branched, and R f is C q F2q+1 where q and q' are independently 1 to 20. The compounds comprise a fluorocarbon terminal portion and a hydrocarbon or another fluorocarbon terminal portion, the terminal 3/3 portions being connected by a central core, the compounds having smectic mesophases or having latent smectic mesophases. The compounds are useful in smectic liquid crystal display devices bath alone and in mixtures with other materials. Also provided is a process for preparing these compounds.
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