2,7‐Dioctylbenzofuro[3,2‐ b ]benzofuran: An Organic Semiconductor with Two‐dimensional Transport Channels

We report herein a synthesis of benzofuro[3,2‐ b ]benzofuran (BFBF) by an intramolecular Ullmann C−O coupling reaction. To tune the film forming ability and self‐assembling behaviour, the derivative possessing two alkyl chains, 2,7‐dioctylbenzofuro[3,2‐ b ]benzofuran (C 8 ‐BFBF), was further prepared. The packing structures of these two compounds were studied by XRD analysis, showing a two‐dimensional (2D) stacking structure in the solid state. DFT calculations indicated that C 8 ‐BFBF exhibited large transfer integrals along the two stacking directions. The OFET devices based on C 8 ‐BFBF showed typical hole transport properties with mobility up to 0.076 cm 2  V −1  s −1 .