Stabilization of an Enantiopure Sub‐monolayer of Helicene Radical Cations on a Au(111) Surface through Noncovalent Interactions

Abstract

In the past few years, the chirality and magnetism of molecules have received notable interest for the development of novel molecular devices. Chiral helicenes combine both these properties, and thus their nanostructuration is the first step toward developing new multifunctional devices. Here, we present a novel strategy to deposit a sub‐monolayer of enantiopure thia[4]helicene radical cations on a pre‐functionalized Au(111) substrate. This approach results in both the paramagnetic character and the chemical structure of these molecules being maintained at the nanoscale, as demonstrated by in‐house characterizations. Furthermore, synchrotron‐based X‐ray natural circular dichroism confirmed that the handedness of the thia[4]helicene is preserved on the surface.

SET and HAT/PCET acid‐mediated oxidation processes in helical shaped fused bis‐phenothiazines

“…Quantitative knowledge of medium effects on the redox behaviour of helicenes allows its rational manipulation and better design of applications, e. g. for their use as chiral spin filters, which is currently under development in our group. [16] We believe that the distinctive properties of these molecules will attract many researchers, in the light of the synthetic accessibility in continuing improvement in our laboratories.…”

“…Helical shaped bis-phenothiazines, like derivatives 1-9 prepared for this study, have found interesting opportunities in material science [11,16] and a detailed quantitative investigation of their red-ox one-electron properties appeared a mandatory step to underpin their peculiar characteristics.…”

“…Thus, the possibility of tailoring the spin filtering exploiting the chiral induced spin selectivity (CISS) effect of the exceptionally stable radical cations obtained from compounds possessing skeleton C, is under development. [16] This wide spectrum of applications required to study in detail the one-electron oxidation behaviour of compounds possessing skeleton C, also by preparing hydroxy substituted derivatives capable to participate in proton-coupled electron transfer (PCET) processes. In this contribution we report a detailed study of SET and HAT/PCET mediated oxidations of differently substituted thia [4]helicenes.…”

Bridging Performance Gaps: Exploring New Classes of Materials for Future Spintronics Technological Challenges

“…[ 29 ] Additionally, Sessoli's employment of chirality‐induced spin selectivity has demonstrated its efficiency in spin‐specific electron transport. [ 30 ] Overall, the use of open‐shell macroradicals in spintronics has shown great promise in recent years. Their unique electronic properties make them a promising candidate for numerous spin‐based electronic devices.…”

Resolution of a Configurationally Stable Hetero[4]helicene

“…The availability of differently functionalized enantiomerically pure helicenes, avoiding the limitation associated with chiral HPLC resolution [17,23] is mandatory for the development of the appealing applications of these peculiar systems [21,22,24]. Therefore, in recent years we tried to set off regio-, stereo-and enantioselective synthetic approaches for the preparations of 1.…”