Octasubstituted dibenzochrysenes: discotic liquid crystals with a twisted core

Octafunctionalised dibenzochrysenes are prepared in order to study the liquid crystalline properties that have chiral and achiral peripheral aliphatic chains. The syntheses of dibenzochrysene derivatives are achieved by a conventional method that has been developed recently. The achiral derivatives that have long peripheral aliphatic chains exhibit hexagonal and rectangular columnar mesophases over a wide thermal range, whereas those with short chains exhibit only hexagonal or more ordered (not identified) columnar phases, such as the columnar plastic. The chiral derivates exhibit only the hexagonal columnar mesophase. The nature of these mesophases is investigated by polarising optical microscopy and X-ray diffraction studies.