Revisiting zethrene: synthesis, reactivity and semiconductor properties

Zethrene, a unique polycyclic aromatic hydrocarbon with formally fixed C–C double bonds, is predicted to have interesting properties and potential applications as an optical and electronic material. Here we report a novel synthesis of zethrene with improved yield, which presumably involves dinaphtho[10]-annulene as an unstable intermediate. With this convenient access to zethrene, we used zethrene as a p-type semiconductor in thin film transistors for the first time. It is found that Diels–Alder addition to the bay region of zethrene leads to new derivatives of benzo[pqr]naphtho[8,1,2-bcd]perylene, which behave as n-type organic semiconductors.