Highly soluble acenes as semiconductors for thin film transistors

Acene derivatives 3, 5, 7 and 9 bearing two trimethoxyphenylethynyl substituents have been synthesized. The optical properties of these acenes have been investigated by UV/Vis and fluorescence spectroscopy and their eletrochemical properties have been elucidated by cyclic voltammetry (CV). X-Ray analysis of the anthracene and tetracene derivatives 3 and 5 has revealed a 1-D pi-stacking in crystals of 3 and 5. In contrast to their parent hydrocarbons, the present disubstituted acenes are highly soluble in different solvents. Spin-coating has afforded amorphous thin films that exhibit field effect mobility. Best performance has been achieved for the OTFTs prepared from the pentacene derivative 7 with a field effect mobility of 1.9 x 10(-5) cm(2) V-1 s(-1) and an on/off ratio of 10(3).