Synthesis of oxygenated fused oligothiophenes with HOF·CH ₃CN

(Chemical Equation Presented) For the first time a range of fused oligothiophenes was oxidized with use of the HOF·CH₃CN complex by transferring one or more sulfur atoms to sulfonyl groups under very mild conditions. These materials exhibit considerable red-shift absorptions in the UV/visible relative to the parent compounds. Their highly interesting photoluminescence properties and molecular packing in the solid state are also reported.