| 摘要 |
NEW MATERIAL:trans-4-(4-Substituted phenyl)cyclohexanecarboxylic acid 4- chlorophenyl thioester of formula I (R is 1-10C alkyl or alkoxy). EXAMPLE:S-4-Chlorophenyl trans-4-(4-propylphenyl)cyclohexanecarbthiate. USE:It shows nematic liquid crystal phase and, when it is mixed with a liquid crystal such as biphenyl, phenylcyclohexane, ester and Schiff-base, the nematic- clear point can be raised without increase in threshold voltage and saturation voltage. It gives a liquid crystal substance with broadened nematic temperature range and increased stability to moisture, light and heat. PREPARATION:The reaction between a compound of formula II and another compound of formula III is followed by the reaction of the product of formula IVwith the third compound of formula V in pyridine to give the compound of formula I .
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