Conformational effect of a lateral alkoxy group on mesomorphic properties

The mesomorphic properties of some homologs of 4-(4-alkoxyphenoxycarbonyl)p henyl 3-alkoxybenzoate (1), 3-alkoxy-4-methylbenzoate (2), and 3-alkoxy-2-m ethylbenzoate (3) were examined. Except the methoxy homolog, 1 are nonmesog enic, but 2 and 3 tend to exhibit a nematic phase. The nematic-isotropic tr ansition temperature decreases in the order of 3 > 2 > 1. The unusual mesom orphic properties are discussed in terms of the conformational effect of th e alkoxy group.