Helicene-based chiroptical switches

Helicenes are molecules with ortho-fused aromatic rings that adopt an inherently chiral helical shape. This helical topology combined with the extended pi-conjugated system provides them with excellent chiroptical and photophysical properties. These properties and peculiarities make helicenes important candidates for the conception of new chiroptical switches. Several examples of light-, redox- and pH-triggered helicene-based switches have recently appeared in the literature including examples from our group. Some of them are multi-input and/or multi-output systems in which the changes can be triggered by different stimuli and/or read-out by different techniques, an attractive advantage for functional materials. (C) 2015 Academie des sciences. Published by Elsevier Masson SAS.