Air-Stable Benzo[ c]thiophene Diimide n-Type π-Electron Core.

In this paper, the molecular design of the first deep-lowest unoccupied molecular orbital (LUMO) level diimide π-electron core, benzo[ c]thiophene diimide (BTDI), as a novel n-type organic semiconductor was determined. An original synthetic sequence was devised to obtain the target cyclohexyl-BTDI (Cy6-BTDI) derivative. Cy6-BTDI demonstrated completely reversible reduction waves and a stable radical anionic state. Favorable brickwork molecular assembly and two-dimensional charge transport properties of Cy6-BTDI were exhibited in the solid state. As a result, air-stable electron mobilities were obtained from the BTDI organic field-effect transistors under ambient conditions.