Thiepin-Fused Heteroacenes: Simple Synthesis, Unusual Structure, and Semiconductors with Less Anisotropic Behavior
Article first published online: 17 SEP 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chemistry - A European Journal
Volume 19, Issue 43, pages 14573–14580, October 18, 2013
How to Cite
Cai, Z., Zhang, H., Geng, H., Liu, Z., Yang, S., Luo, H., Jiang, L., Peng, Q., Zhang, G., Chen, J., Yi, Y., Hu, W. and Zhang, D. (2013), Thiepin-Fused Heteroacenes: Simple Synthesis, Unusual Structure, and Semiconductors with Less Anisotropic Behavior. Chem. Eur. J., 19: 14573–14580. doi: 10.1002/chem.201302114
- Issue published online: 14 OCT 2013
- Article first published online: 17 SEP 2013
- Manuscript Received: 3 JUN 2013
- State Basic Program
- Chinese Academy of Sciences.
- density functional calculations;
- electronic structure;
- fused ring systems;
The simple one-pot syntheses of sulfur-rich thiepin-fused heteroacences with an alkylidene–fluorene framework, THA1 and THA6 (thiepin-fused heteroacene 1 or 6, in which the thiepin is conjugated at both ortho positions with SCH3 or SC6H13, respectively), is reported. Based on electrochemical studies and theoretical calculations, their LUMO energies are relatively low (−3.26 eV), and their HOMO and HOMO−1 orbitals are nearly degenerate. The thiepin ring contributes mainly to HOMO−1 and LUMO orbitals, however, HOMO orbitals dominantly reside on thienoacence rings. Within the crystal of THA1, the molecules adopt a herringbone arrangement and multiple intermolecular interactions lead to the formation of a 2D network. Interestingly, THA6 shows totally different intermolecular arrangements. Organic field-effect transistor (OFET) devices show both compounds exhibiting p-type semiconducting behavior. Thin films or microcrystals of THA1 possess relatively high hole mobility. Moreover, the mobilities of the microcrystal of THA1 along three directions are in the same order, thus the hole-carrier transporting within the hexagonal-plane of microcrystal of THA1 exhibits less anisotropic behavior. In comparison, both thin films and microrods of THA6 show low hole mobilities. This agrees well with the intermolecular arrangements and interactions within crystal of THA6. Further theoretical calculations reveal that significant intermolecular electronic coupling among HOMO−1 orbitals and sulfur atoms play an important role in intermolecular electronic coupling for THA1.