Abstract

A rational synthesis for dibenzo[fg,op]naphthacene derivatives (also named as dibenzopyrene) is described. The methodology involves the preparation of a quaterphenyl using a palladium-catalysed cross-coupling of arylboronic acids followed by chemical or photochemical cyclization. The versatility of the process is shown by the formation of various dibenzo[fg,op]naphthacene derivatives having identical or non-identical peripheral chains. All the new compounds exhibit a single mesophase, which has been identified by X-ray diffractometry and optical microscopy as hexagonal columnar (Col_h). X-Ray results confirm that hexasubstituted dibenzonaphthacenes are more ordered than octasubstituted derivatives.