Thienoacenes

This chapter focuses on representative thienoacenes frequently utilized in the studies of organic electronics. It highlights variety of methods for the synthesis, tunability of molecular electronic structures of thienoacenes by controlling the molecular structures, which can make thienoacene-based molecular and polymer semiconductors useful in the application of organic electronic devices. There are several key ones significantly contribute to the recent development of new thienoacenes, including short-step syntheses of 4,8-disubstituted benzo [1,2-b:4,5-b']dithiophene (BDT) and 5,11-disubstituted anthra [2,3-b:6,7(7,6)-b']dithiophenes (ADT) from commercially available thiophene derivatives, thiophene-annulation reactions ("thienannulation") to construct terminal thiophene ring(s) in acenedithiophene substructures, and thienannulations to construct internal thiophene ring(s). One of the major motivations behind the recent development of thienoacene-based molecules has been to realize high performance organic field-effect transistors (OFETs) devices with high mobility and good stability. The chapter discusses correlation between the packing structure and electronic structure in the solid state of some representative parent thienoacene systems.