Schiff base helicenes - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2019

Schiff base helicenes

Nicolas Zigon
Mariia Savchuk
  • Fonction : Auteur
Steven Vertueux
  • Fonction : Auteur
  • PersonId : 1068782
N. Avarvari

Résumé

Circularly polarized light emitters or complexes displaying magnetochiral dichroism (linking magnetism and chirality) are actively researched species. 1 Helicenes form a class of chiral molecules renowned for their intriguing physical properties, particularly their typical helicoidal structure and exceptional chiroptical properties (intense optical activity and circular dichroism). On the other hand, salen ligands are chelating tetradentate Schiff bases whose complexes with metals possess excellent properties in catalysis, luminescence or magnetism, for example. 2 The controlled synthesis of chiral magnets as complexes containing both helicene and salen moieties is therefore an important challenge. 3 A consistent and systematic study for the synthesis of helicen/salen based derivatives was therefore designed in our group, in order to access compounds displaying magnetochiral dichroism. X-Ray structure Structure of the Zn-complex crystallized in P2 1 /c space group Synthetic methods and characterizations A synthetic pathway based on a Wittig reaction between a phosphonium ylide and a functionalized aldehyde, followed by a photocyclisation in diluted conditions yields a brominated [4]helicene, whose substitution by cyanide and subsequent reduction to the aldehyde afford the Schiff base precursor. Reaction with 0.5 equivalent of diamine in MeOH in the presence of a metal provides the desired complexes in good yields (80-90%) for the last step. Perspectives A robust synthetic pathway was designed for the synthesis of Schiff base helicenes. Nevertheless, the inherent flexibility of [4]helicene denies it any chirality at room temperature. The synthesis of Schiff base [6]helicene coupled to chiral resolution will provide chiral and conformationnally stable complexes. CD and CPL spectra will be recorded for the complexes, and magnetic optical properties will be measured. Thanks to the versatility of the organic platform, the extension of this strategy to other metals with magnetic (e.g. Cu II) or catalytic properties (e.g. Mn III) will be straightforward.
Fichier principal
Vignette du fichier
nz0912 Schiff base helicenes-ISCOM2019 - Copie.pdf (1.36 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-02889192 , version 1 (03-07-2020)

Identifiants

  • HAL Id : hal-02889192 , version 1

Citer

Nicolas Zigon, Mariia Savchuk, Steven Vertueux, N. Avarvari. Schiff base helicenes. ISCOM2019, Sep 2019, Tomar, Portugal. 2019. ⟨hal-02889192⟩
33 Consultations
34 Téléchargements

Partager

Gmail Facebook X LinkedIn More