Steric Effects and Liquid Crystal Behaviour. Properties of the Liquid Crystals Formed by Certain 2'-Fluoro-and 2'-Chloro-4-Biphenylyl 4″-n-Alkoxybenzoates: A Comparison with Analogous 4-(2'-Pyridyl) Phenyl 4”-n-Alkoxybenzoates

Abstract

Eight 2'-fluoro- and six 2'-chloro-4-biphenylyl 4″-n-alkoxybenzoates have been prepared and their liquid crystal phases have been investigated. The properties of esters, in which the halogeno-substituent exerts a steric effect which influences liquid crystal behaviour, are compared with those of the analogous 4-(2'-pyridyl)phenyl 4”-n-alkoxcybenzoates in an attempt to evaluate the steric effect of the hetero-nitrogen atom.