Electronic modulation of fused oliglothiophenes by chemical oxidation

The reaction of pentathienoacene (f-5T) with mCPBA produced a series of oxidized derivatives containing one or two thiophene-S,S-dioxide rings. The regioselectivity of the oxidation reflects the aromaticity of each thiophene ring in the f-5T skeleton, and the extent of the oxidation significantly affects the fluorescence and redox properties.