Pyrrolo[3,2‑<i>b</i>]pyrrole-Based Quinoidal Compounds For High Performance n‑Channel Organic Field-Effect Transistor

It is a very important and challenging topic to design high performance n-channel organic semiconductors with a new type conjugated skeleton. Herein, a new class of n-channel organic semiconductors, pyrrolo­[3,2-b]­pyrrole-based quinoidal molecules QBPBP and QFBPBP, was designed and synthesized. Both compounds have low-lying lowest unoccupied molecular orbital energy level and high thermal stability. Single crystal structures reveal they adopt unusual two-dimensional layer-type packing structures in single crystals. Multiple π–π and CN···H interactions are observed in the layer, and alkyl–alkyl chain interactions exist between layers. Transistors based on single ribbons displayed gate voltage-dependent electron mobility with an average of 4.0 cm2 V–1 s–1 and a peak over 6.0 cm2 V–1 s–1 under N2. These results demonstrate pyrrolo­[3,2-b]­pyrrole-based quinoidal molecules are a new prototype for high performance n-channel organic semiconductors.