Login / Signup

Azacalixquinarenes: From Canonical to (Poly-)Zwitterionic Macrocycles.

Simon PascalLucien LavaudCloé AzariasAlexandre VarlotGabriel CanardMichel GiorgiDenis JacqueminOlivier Siri
Published in: The Journal of organic chemistry (2019)
Azacalixquinarenes, a new family of macrocycles composed of diaminobenzoquinone diimine units linked by dinitrobenzene rings, are synthesized by selective oxidation of the parent azacalixarenes. Crystallographic analyses of two compounds demonstrated the presence of canonical (uncharged) and zwitterionic quinones within a single structure. The electron-withdrawing nature of the dinitrobenzene moieties can trigger the intramolecular H-transfer that generates zwitterionic ground-state quinones. The nature of the N-substituents and the polarity of the solvent have a crucial impact on the equilibrium between the canonical and zwitterionic forms that present distinct optical and electrochemical properties. Thus, within [4]- and [6]-membered macrocycles, poly-zwitterionic structures can be reached, as demonstrated experimentally and theoretically using first-principle approaches.
Keyphrases
  • high resolution
  • ionic liquid
  • gold nanoparticles
  • molecular dynamics
  • nitric oxide
  • high speed
  • solar cells
  • label free
  • energy transfer