Fused π-extended discotic triangular porphyrinoids

Abstract

A novel fused two-dimensionally π-expanded triangular porphyrinoid has been designed. The synthesis is based on facile hexaazatrinaphthalene chemistry in combination with well-established condensation procedures to simultaneously close three porphyrinic cavities. A series of different functionalized π-expanded triangular derivatives were synthesized and their optical and electrochemical properties, as well as their supramolecular organization investigated. Low lying HOMO‒LUMO energy gaps between 1.11–1.32 eV were found for the highly π-conjugated planar triangular hexaazatrinaphthalene derivatives which organize into discotic liquid crystalline columnar stacks. Thereby, derivatives with alkoxy substituents reveal significantly higher order due to their improved flexibility in comparison to their alkyl counterparts.