Synthese und fluessigkristalline Eigenschaften 2,6-disubstituierter Naphtaline

Article abstract of DOI:10.1002/hlca.19850680533

The syntheses and the mesomorphic properties of a series of novel 2,6-disubstituted naphthalenes are described. 4-<6-(n-Alkyl)-2-naphthyl>benzonitriles 5 and 4-<6-(n-Alkoxy)-2-naphthyl>benzonitriles 8 exhibit wide-range nematic mesophases. 6,6'-Di(n-Alkyl)-2,2'-binaphthyls 6 have been isolated as by-products from the reaction mixtures of 5.Some of these novel compounds have polymorphic properties.The esters 13 and 15 of 4-(6-hydroxy-2-naphthyl)benzonitrile show enhanced mesophase stabilities which reach maximum values in the series of α,β-unsaturated esters 15.The 4-(n-pentyl)benzoate 14 of the same (hydroxynaphthyl)benzonitrile has a melting point of 125 deg and a clearing point of > 310 deg.This particular derivative belongs to those liquid-crystalline compounds having the broadest purely nematic-phase range.In addition, (RS)-4-(2-pentyl-6-chromanyl)benzonitrile (20) and three compounds with two and four laterally arranged CN groups at the bicyclo<2,2,2>octene, bicyclo<2,2,2>octadiene, and phenyl-ring systems 31-33 were synthesized.Only 20 shows mesomorphic properties.