Synthesis and liquid crystal properties of chiral compounds containing the core structure of 6-hydroxynicotinic acid or 4-hydroxyphenylacetic acid

The carboxylic acid 4-hydroxybenzoic acid, bonded directly with (R)-2-octanol, is the core molecule of chiral liquid crystal (R)-MHPOBC. This acid was substituted either by 6-hydroxynicotinic or by 4-hydroxyphenylacetic acid. Such a structural variation induced a remarkable influence on the liquid crystal properties of (R)-MHPOBC. The series of compounds 1 similar to 4 containing 6-hydroxynicotinic acid moiety tend to exhibit a chiral smectic C (SmC*) phase, while the series of compounds 5 similar to 8 containing 4-hydroxyphenylacetic acid moiety tend to possess a chiral nematic (N*) phase.