Thiahelicenes

Thiahelicene-based inherently chiral films for enantioselective electroanalysis

“…Among the different helicene families, a most convenient one for application as active materials in advanced devices is the thiahelicene series,32,33 alternating condensed thiophene T and benzene B rings, and ending with two thiophene terminals. Angular benzodithiophene TBT is its smaller term, followed by five-membered TBTBT ( 5-TH ), seven-membered TBTBTBT ( 7-TH , tetrathiahelicene), nine-membered TBTBTBTBT ( 9-TH , pentathiahelicene) and so on (Fig.…”

Radical Cation and Neutral Radical of Aza-thia[7]helicene with SOMO–HOMO Energy Level Inversion

“…Recent resurgence of interest in [ n ]­helicenes, ortho -annelated polycyclic aromatic molecules with nonplanar helical conjugation of the π-electron system, has revitalized the efforts to develop more efficient synthetic methods and expansive applications . [ n ]­Helicenes have become more accessible and modern synthetic methodologies have provided a variety of new [ n ]­heterohelicenes, in which the embedded heteroatom(s) could provide additional functionalities. ,− While these developments greatly facilitate the design and synthesis of open-shell [ n ]­helicene molecules, the detrimental reactivity of open-shell species remains the biggest impediment. The common, effective strategy for stabilizing open-shell species is to shield the radical site using bulky substituents, but it may be difficult to implement, as well as unappealing, in the design and synthesis of [ n ]­helicenes.…”

Helical nanostructures for organic electronics: the role of topological sulfur in ad hoc synthesized dithia[7]helicenes studied in the solid state and on a gold surface

“…9 Indeed, to date, a large number of thiahelicenes including di, 10 tri, tetra, and hexathia [7]helicenes have been synthesized in this manner, always bearing S atoms in exo position. 11 To the best of our knowledge, there is however only one example of an endo thiahelicene, namely 1-thia [7]helicene, synthesized only recently from 1-helicenethiol by construction of a new fused thiophene ring attached to the sulfur predetermined position. 12 With this background in mind, we carried out rst the synthesis of the fragments 3 and 4, bearing the desired naphtho[2,1-b]thiophene and naphtho [1,2-b] thiophene ring fusion, as precursors of exo-and endo-dithia [7] helicene-1 and 2, respectively (Scheme 1, see the ESI † for an efficient synthesis of 3 and 4).…”