π‐Extended Pyrrole‐Fused Heteropine: Synthesis, Properties, and Application in Organic Field‐Effect Transistors

Sulfur‐embedded polycyclic aromatic compounds have been used as building blocks for numerous organic semiconductors over the past few decades. While the success is based on thiophene‐containing compounds, aromatic compounds that contain thiepine, a sulfur‐containing seven‐membered‐ring arene, has been less well investigated. Here we report the synthesis and properties of π‐extended pyrrole‐fused heteropine compounds such as thiepine and oxepine. A π‐extended pyrrole‐fused thiepine exhibited a “pitched π‐stacking” structure in the crystal, and exhibited a high charge carrier mobility of up to 1.0 cm2 V−1 s−1 in single‐crystal field‐effect transistors. Here we report an efficient method for the synthesis of π‐extended pyrrole‐fused heteropine compounds and investigated their optical and electronic properties. A π‐extended pyrrole‐fused thiepine exhibited a “pitched π‐stacking” structure in the crystal, and exhibited a high charge carrier mobility of up to 1.0 cm2 V−1 s−1 in single‐crystal field‐effect transistors.