Thieno[3,4-f]isothianaphthene and itsN-substitutes: a theoretical insight

Geometries and Electronic Structures of Co‐Oligomers and Co‐Polymers Based on Tricyclic Nonclassical Thiophene: A Theoretical Study

“…Some researchers have suggested strong donor/acceptor interactions exist among such systems and the lone-pair electrons on S11 are strongly delocalized. [8] The The order of the HOMO/LUMO energy separation is opposite to that of the intramolecular charge transfer on the p orbital. The results show that the HOMO/ LUMO energy separation is tightly related to the p-electron delocalization in these systems.…”

“…[14][15][16] In addition, other non-classical thiophenes such as thieno [3,4-f]isothia-naphthene (TIT) and its N-substitutes have also attracted more and more attention in recent decades, both experimentally and theoretically. [8,12] In this study, four new co-polymers based on four different tricyclic non-classical thiophenes involving dithieno- [3,4-b:3 0 ,4 0 -e]pyrazine (DTP), thieno [5,6-c]benzo[c] [1,2,5]thiadiazole (TBT), TIT and TTP were designed, denoted (EDTP) n , (ETBT) n , (ETIT) n and (ETTP) n , respectively, as shown in Scheme 1. Theoretical analysis of the geometries and electronic properties of these new copolymers, as well as of their monomers and oligomers, is reported.…”

“…[6] So, to design a low-band-gap polymer, one needs to have a complete understanding of the relationship between the energy gap of a polymer and the electronic structures of its monomer units, as well as the relationship between the chemical structure of a polymer and its electronic properties. Non-classical thiophenes have been regarded as promising candidates for the design of intrinsically-conductive polymers, due to their unusual electronic structures, since the first non-classical thiophene -thieno [3,4-c]thiophene [7][8][9] -was synthesized in 1967. [10][11][12][13] In 1997, Tanaka…”

“…Non‐classical thiophenes have been regarded as promising candidates for the design of intrinsically‐conductive polymers, due to their unusual electronic structures, since the first non‐classical thiophene – thieno[3,4‐c]thiophene7–9 – was synthesized in 1967 10–13. In 1997, Tanaka and Yamashita synthesized [1,2,5]thiadiazolo[3,4‐b]thieno[3,4‐e]pyrazine (TTP) 12.…”

Near infrared absorbing benzobis(thiadiazole) derivatives: computational studies point to biradical nature of the ground states

“…In general molecules containing the sulfur diimide group (NSN) have attracted a lot of attention due to their non‐Kekule structures and interesting properties 38–54. The description of this bond in the earlier literature has been in favor of the hypervalent sulfur (NSN) 51.…”