Hexadecadehydrodibenzo[20]‑, Tetracosadehydrotribenzo[30]‑, and Dotriacontadehydrotetrabenzo[40]annulenes: Syntheses, Characterizations, Electronic Properties, and Self-Associations

Hexadecadehydrodibenzo­[20]-, tetracosadehydrotribenzo[30]-, and dotriacontadehydrotetrabenzo[40]­annulene derivatives ([20]-, [30]-, and [40]­DBAs) possessing tetrayne linkages were synthesized. X-ray diffraction analysis demonstrated that the molecules of [30]­DBA and p-xylene form a 2D sheetlike structure. Planar [20]- and [30]­DBAs show significantly weak or almost no tropicity. The extension of the acetylenic linkages from a diyne to a tetrayne unit narrows HOMO–LUMO gaps. The self-association behavior of [30]­DBA in solution resulting from effective π–π stacking interactions was observed.