Triphenanthro‐anellierte [18]Annulene mit Alkoxy‐Seitenketten — Eine neue Klasse discotischer Flüssigkristalle

Triphenanthro‐Anellated [18]Annulenes with Alkoxy Side Chains ‐ A Novel Class of Discotic Liquid Crystals Two different types 6 and 16 of [18]annulenes condensed with phenanthrene systems were prepared by cyclocondensation reactions (Schemes 2 and 3). The central 18‐membered rings do not show a macrocyclic diamagnetic ring current. Conformational analyses and X‐ray analyses in the solid state reveal non‐planar structures in which aromatic “islands” are connected by ( E )‐configurated olefinic bridges. The introduction of long alkoxy side chains yields a new class of discotic liquid crystals; either N D or hexagonal columnar phases are generated, which were characterized by DSC, microscopy with polarized light, and small‐angle scanning X‐ray.