Linearly Fused Azaacenes: Novel Approaches and New Applications beyond Field-Effect Transistors (FETs)

Replacing the CH groups in the backbones of acenes with heteroatoms offers scientists greater opportunities to tune their properties, as the type, position, number, and the valence of the introduced heteroatoms have strong effects on the frontier orbital energy levels. When the heteroatoms are nitrogen atoms, all of the resulting materials are called azaacenes. Recently, the synthesis, structure, physical properties, and applications of azaacene derivatives have been intensively investigated. This review focuses on recent synthetic efforts (since 2013) toward making novel azaacenes as well as their potential applications beyond field-effect transistors (FETs) including organic light-emitting diodes (OLEDs), memory devices, phototransistors, solar cells, photoelectrical chemical cells, sensors, and conductors.