To find a new simple method of synthesizing liquid crystals, the trans- and cis-4-(4′-pentylphenyl) cyclohexanecarboxylic acids were synthesized by selective reduction of 4′-pentylbiphenyl-4-carboxylic acid. The isomerization of 4′-alkylphenyl-4-cis-cyclohexanecarboxylic acid to its trans isomer was realized. Their structure assignments were confirmed by 13C NMR. Five compounds of general structure R-X-Y-COO-Z-R′, where X, Y, Z are either phenyl or trans cyclohexyl rings, were synthesized. Their structures were determined by IR, NMR, and MS. The phase transition temperatures were measured by DSC. Mesomorphic textures were recognized by polarized microscopy. All compounds exhibited liquid crystal phases, the influences of terminal groups on the phase transition temperatures were discussed.
|Original language||English (US)|
|Number of pages||4|
|Journal||Qinghua Daxue Xuebao/Journal of Tsinghua University|
|State||Published - Dec 1 1998|
ASJC Scopus subject areas
- Computer Science Applications
- Applied Mathematics