Sulfur containing stable unsubstituted heptacene analogs.

Heptacene and higher polyacenes have been sought for their high degree of charge carrier mobility in thin film transistors. Such acenes are, however, extremely unstable in ambient conditions. Approaches to obtain stable heptacenes include introduction of suitable substituents, of heteroatoms, or both. Methods to synthesize stable linear and a nonlinear unsubstituted heptacene analogs are discussed. No changes in the UV-visible absorption spectra in solution over time for these materials indicate higher oxidative stability compared to analogous polyacenes.