title: Extension of N-Heteroacenes through a Four-Membered Ring.
abstract: The synthesis of novel π-extended N-heteroacenes, which have a large tetraazaacene subunit and a quinoxaline subunit connected through a four-membered ring, is reported. They were studied with experimental and computational methods in comparison to the corresponding tetraazaacenes. As found from the DFT calculation, the four-membered ring is a better linker than a five-membered ring or a C-C single bond to extend N-heteroacenes for a new design of n-type semiconductors in terms of the spatial delocalization and energy level of LUMO as well as the reorganization energy. In solution-processed thin film transistors, the π-extended N-heteroacenes are found to function as n-type semiconductors with field effect mobility of up to 0.02 cm(2)  V(-1)  s(-1) under ambient conditions.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P. R. China.
authors.forename: Shuaijun
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P. R. China.
authors.forename: Bowen
authors.initials: B
authors.lastname: Shan
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P. R. China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P. R. China. miaoqian@cuhk.edu.hk.|Institute of Molecular Functional Materials, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China. miaoqian@cuhk.edu.hk.
authors.forename: Qian
authors.initials: Q
authors.lastname: Miao
keywords: arenes; conjugation; organic thin film transistors; polycycles; semiconductors