Synthesis and field-effect properties of alfa,omega-disubstituted sexithiophenes bearing polar groups

The synthesis of sexithiophenes bearing amide or ester groups in the Ą,č-terminal positions is described, along with their characterization in the solid state. The influence of the functional group on mobilities and on/off ratios of the org. FET devices was investigated. The oligomer bearing the ester functional group sepd. from the sexithiophene core by an ethylene spacer showed a hole field-effect mobility as high as 0.012 cm2 V-1 s-1, which is among the highest reported so far for org. FETs using sexithiophenes modified with polar groups.