New building block designed for polythiophene

3,4-Ethylenedioxythiophene, known as EDOT, is the monomer of choice to make polythiophene conducting films used in applications as varied as antistatic coatings, light-emitting diodes, and solar cells. Now, meet VDOT, or 3,4-vinylenedioxythiophene (shown), a next-generation compound that could potentially supplant EDOT for making organic electronic devices (Chem. Commun. 2006, 275). Philippe Leriche, Philippe Blanchard, Jean Roncali, and their colleagues at the University of Angers, in France, synthesized VDOT from 3,4-dimethoxythiophene in a multistep process that includes transetherification of the methoxy groups to form vinyl ether groups and a subsequent ring-closing metathesis reaction. VDOT differs from EDOT only by having a double bond in the diether ring. But introducing sp²-hybridized carbons creates changes in the electronic structure of the monomer that are expected to impart stronger -intermolecular interactions along the conjugated polythiophene chain and make VDOT-based materials more stable than their EDOT analogs.