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Synthese und flüssigkristalline Eigenschaften 2,6‐disubstituierter Naphthaline
Author(s) -
Lauk Urs H.,
Skrabal Peter,
Zollinger Heinrich
Publication year - 1985
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19850680533
Subject(s) - chemistry , benzonitrile , mesophase , liquid crystal , alkyl , bicyclic molecule , melting point , alkoxy group , stereochemistry , organic chemistry , medicinal chemistry , phase (matter) , physics , optics
Synthesis and Liquid‐Crystal Properties of 2,6‐Disubstituted Naphthalene Derivatives 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 widerange 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° and a clearing point of > 310°. 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 the phenyl‐ring systems 31 – 33 were synthesized. Only 20 shows mesomorphic properties.