Zwitterionic [4]helicene: a water-soluble and reversible pH-triggered ECD/CPL chiroptical switch in the UV and red spectral regions

Simon Pascal; Céline Besnard; Francesco Zinna; Lorenzo Di Bari; Boris Le Guennic; Denis Jacquemin; Jérôme Lacour

doi:10.1039/c6ob00752j

Zwitterionic [4]helicene: a water-soluble and reversible pH-triggered ECD/CPL chiroptical switch in the UV and red spectral regions

Org Biomol Chem. 2016 May 18;14(20):4590-4. doi: 10.1039/c6ob00752j.

Authors

Simon Pascal¹, Céline Besnard², Francesco Zinna³, Lorenzo Di Bari³, Boris Le Guennic⁴, Denis Jacquemin⁵, Jérôme Lacour¹

Affiliations

¹ University of Geneva, Department of Organic Chemistry, quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland. Jerome.lacour@unige.ch.
² Laboratory of Crystallography, University of Geneva, quai Ernest Ansermet 24, CH-1211 Geneva 4, Switzerland.
³ Università di Pisa, Dipartimento di Chimica e Chimica Industriale, Via G. Moruzzi 13, 56124 Pisa, Italy.
⁴ Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, 263 avenue du Général Leclerc, 35042 Rennes Cedex, France.
⁵ Laboratoire CEISAM, UMR 6230 CNRS, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France and Institut Universitaire de France, 1, rue Descartes, F-75005 Paris Cedex 05, France.

PMID: 27139039
DOI: 10.1039/c6ob00752j

Abstract

The chiroptical switching properties of a readily accessible and water-soluble diaza [4]helicene are disclosed. This zwitterionic dye displays pH-dependent absorption and emission properties and this enables a reversible turn on/off of electronic circular dichroism at 300 nm and of circularly polarized luminescence in the red region upon protonation/deprotonation.