Improving the property-function tuning range of thiophene materials via facile synthesis of oligo/polythiophene-s-oxides and mixed voligo/polythiophene-s-oxides/oligo/polythiophene-s,s-dioxides

A platform is described for the first time for the facile synthesis of oligo- and polythiophene-S-oxides and the corresponding -S,S-dioxides in short times, mild conditions, high yields. Employing ultrasound assistance, brominated thiophenes are selectively mono- or dioxygenated at room temperature. These building blocks are then combined with metalated thiophenes via microwave-assisted cross-coupling reactions through a "Lego-like" strategy to afford unprecedented oligo/polythiophene-S-oxides and mixed -S-oxides/-S,S-dioxides. It is demonstrated that depending on the number, type, and sequence alternation of nonoxygenated, monooxygenated, and dioxygenated thiophene units a very wide property-function tuning can be achieved spanning from frontier orbital energies and energy gaps, to charge transport characteristics and supramolecular H-bonding interactions with specific proteins inside live cells.