title: Synthesis, structures, and properties of disubstituted heteroacenes on one side containing both pyrrole and thiophene rings.
abstract: A new series of ladder-type heteroacenes containing both pyrrole and furan rings, 5,6-disubstituted diindolo[3,2-b:4,5-b']thiophenes (DITs), were effectively synthesized from N-functionalized 3,3'-dibromo-2,2'-biindoles undergoing intramolecular cyclization with bis(phenylsulfonyl) sulfide and organolithium. Single-crystal X-ray results demonstrate that 5,6-dipropyldiindolo[3,2-b:4,5-b']thiophene (4b) forms a herringbone-type of packing motif and 5,6-di(p-tolyl)diindolo[3,2-b:4,5-b']thiophene (4d) forms a parallel packing motif. Both of them have S-S contacts, enhancing the electronic transport between molecules. Their photophysical properties suggest that the skeleton of diindolo[3,2- b:4,5-b']thiophene is more favorable to aggregate in solid than that of indolo[3,2-b]carbazole. The large band gaps and low-lying HOMO energy levels could result in much better stability.
authors.affiliation: Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Qi
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Qiu
authors.forename: Yunqi
authors.initials: Y
authors.lastname: Liu
authors.forename: Hengjun
authors.initials: H
authors.lastname: Zhang
authors.forename: Xike
authors.initials: X
authors.lastname: Gao
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Kun
authors.initials: K
authors.lastname: Lu
authors.forename: Chunyan
authors.initials: C
authors.lastname: Du
authors.forename: Gui
authors.initials: G
authors.lastname: Yu
authors.forename: Daoben
authors.initials: D
authors.lastname: Zhu