Synthesis and characterization of new 2,3-disubstituted thieno[3,4-b]pyrazines: tunable building blocks for low band gap conjugated materials.

Synthetic methods have been developed for the preparation of new 2,3-dihalothieno[3,4-b]pyrazines, from which a variety of new 2,3-difunctionalized thieno[3,4-b]pyrazines have been produced as precursors to conjugated materials. Structural, electronic, and optical characterization of these new analogues illustrate the extent to which the electronic nature of the functional groups can be used to tune the electronic properties of the thieno[3,4-b]pyrazine unit.