ABSTRACT
The importance of aromatic molecules with extended p-conjugation has increased owing to their fundamental chemical and physical natures as well as their potential applications in various functional materials such as organic field-effect transistors, organic light-emitting diodes, and organic photovoltaics. This chapter describes phenacene-based material chemistry, including physical properties, synthesis, and semiconductor applications by comparing with those of acenes. Phenacenes are quite stable and robust in an atmosphere of ultraviolet illumination in the presence of oxygen under which acenes are never durable. Higher phenacenes, such as picene and fulminene, were identified as stable aromatic compounds in the oil industry more than hundred years ago. Although the Mallory photocyclization is a powerful phenacene-synthesis method, the reaction efficiency is not always very high. The double Mallory photocyclization was also applied to a substrate having three chrysene moieties, which were connected with maleic acid ester bridges.
