Effects of Lateral Substitutents on N-I Transition Temperature Reexamined

Abstract

Depressions in the N-I transition temperature of 4-(4-alkoxybenzylidene-amino)phenyl benzoate and N-[4-(4-alkoxybenzoyloxy)benzylidene]aniline by the introduction of a lateral methyl or chloro group into the benzoate moiety of the former compound or the aniline moiety of the latter have been examined. In contrast to the view expressed by Gray et al., our results strongly suggest that the nature of the terminal substituent is as important as the size of the lateral substituents and/or the steric hindrance determining the transition temperature.