Design and synthesis of two conjugated semiconductors containing quinoidal cyclopentadithiophene core

Abstract We report the design and synthesis of two conjugated semiconductors (QT and QP) with a quinoidal cyclopentadithiophene core through a simple method. X-ray single-crystal analysis provides detailed structure information such as molecular geometry, bond length alternation and solid packing motifs. The quinoidal character enables QT and QP with narrow bandgaps and strong absorption coefficients (>105 M−1 cm−1) in UV–Vis region. The charge transport properties of quinoidal semiconductor single crystals are investigated by organic field-effect transistors. QT achieves a hole mobility of 2.4 × 10−3 cm2/Vs while QP obtains a hole mobility of 6.9 × 10−4 cm2/Vs. The report of such type of quinoidal skeleton may provide useful guidance for constructing promising conjugated semiconductors for organic electronics.